Digestive Endoscopy, EarlyView.
https://ift.tt/2k0SaGF
Δευτέρα 14 Μαΐου 2018
Efficacy and safety of cold versus hot snare polypectomy for resecting small colorectal polyps: Systematic review and meta‐analysis
The Effectiveness of Trimetazidine Treatment in Patients with Stable Angina Pectoris of Various Durations: Results from the CHOICE-2 Study
Abstract
Introduction
Trimetazidine (TMZ) has been shown to reduce angina symptoms and to increase exercise capacity in randomized clinical trials, but more extensive data would be useful to assess its effects in real-world clinical practice and in patients with different durations of disease.
Methods
CHOICE-2 was a Russian, multicenter, 6-month, open-label, prospective observational study that assessed the effect of adding TMZ modified release 35 mg bid to antianginal treatment in a real-world setting. The present analysis of CHOICE-2 results explored the effects of adding TMZ to background antianginal therapies with regard to the duration of stable angina.
Results
A total of 741 patients with known durations of disease were divided into four groups according to stable angina pectoris (AP) duration, ranging from less than 1 year to more than 9 years. Addition of TMZ led to a significant decrease in the frequency of angina attacks and in the use of short-acting nitrates in all groups. In patients with recently diagnosed angina (AP duration < 1 year), the average number of angina attacks per week decreased significantly from 3.75 ± 4.63 to 0.67 ± 1.51 and in those with advanced disease (AP duration > 9 years) from 5.63 ± 5.24 to 1.32 ± 2.07. Angina-free walking distance also improved significantly. Addition of TMZ also improved patient well-being. Results were achieved rapidly (within 2 weeks), were maintained over 6 months, and were obtained in all patient groups regardless of angina duration.
Conclusion
TMZ added to other antianginal therapies proved to be effective for reducing angina attacks and short-acting nitrate use, increasing angina-free walking distance, and improving patient well-being in a real-life setting, irrespective of angina duration, including patients with recently diagnosed angina. This provides an opportunity for intensification of treatment early on in the disease process, with the aim of decreasing angina burden and improving patient quality of life.
Funding
Servier.
Trial Registration
ISRCTN identifier ISRCTN65209863.
https://ift.tt/2IGIT4E
Safety and dose modification for patients receiving niraparib
Abstract
Background
Niraparib is a poly(ADP-ribose) polymerase (PARP) inhibitor approved in the United States and Europe for maintenance treatment of adult patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in complete or partial response to platinum-based chemotherapy. In the pivotal ENGOT-OV16/NOVA trial, the dose reduction rate due to TEAE was 68.9%, and the discontinuation rate due to TEAE was 14.7%, including 3.3% due to thrombocytopenia. A retrospective analysis was performed to identify clinical parameters that predict dose reductions. Patients and methods
All analyses were performed on the safety population, comprising all patients who received at least one dose of study drug. Patients were analyzed according to the study drug consumed (ie, as treated). A predictive modeling method (decision trees) was used to identify important variables for predicting the likelihood of developing grade ≥3 thrombocytopenia within 30 days after the first dose of niraparib and determine cutoff points for chosen variables. Results
Following dose modification, 200 mg was the most commonly administered dose in the ENGOT-OV16/NOVA trial. Baseline platelet count and baseline body weight were identified as risk factors for increased incidence of grade ≥3 thrombocytopenia. Patients with a baseline body weight <77 kg or a baseline platelet count <150,000/μL in effect received an average daily dose approximating 200 mg (median = 207 mg) due to dose interruption and reduction. Progression-free survival in patients who were dose reduced to either 200 mg or 100 mg was consistent with that of patients who remained at the 300 mg starting dose. Conclusions
The analysis presented suggests that patients with baseline body weight of < 77 kg or baseline platelets of < 150,000/μL may benefit from a starting dose of 200 mg per day.(ClinicalTrials.gov ID: NCT01847274)https://ift.tt/2rKiRmw
Randomized phase 3 study of docetaxel plus bavituximab in previously treated advanced non-squamous non-small-cell lung cancer
Abstract
Background
Bavituximab is a monoclonal antibody that targets phosphatidylserine in the presence of β2 glycoprotein 1 (β2GP1) to exert an anti-tumor immune response. This phase 3 trial determined the efficacy of bavituximab combined with docetaxel in patients with previously treated advanced non-small cell lung cancer (NSCLC). Patients and Methods
Key eligibility criteria included advanced non-squamous NSCLC with disease progression after treatment with platinum-based doublet chemotherapy, evidence of disease control after at least two cycles of first-line therapy, presence of measurable disease, ECOG performance status 0 or 1, adequate bone marrow and organ function, and no recent history of clinically significant bleeding. Eligible patients were randomized 1:1 to receive up to six 21-day cycles of docetaxel plus either weekly bavituximab 3 mg/kg or placebo until progression or toxicity. The primary endpoint was overall survival (OS). Results
A total of 597 patients were enrolled. Median OS was 10.5 months in the docetaxel + bavituximab arm and was 10.9 months in the docetaxel + placebo arm (HR 1.06; 95% CI, 0.88-1.29; P=0.533). There was no difference in PFS (HR 1.00; 95% CI, 0.82-1.22; P=0.990). Toxicities were manageable and similar between arms. In subset analysis, among patients with high baseline serum β2GP1 levels ≥200 µg/mL, a non-significant OS trend favored the bavituximab arm (HR 0.82; 95% CI 0.63-1.06; P=0.134). Among patients who received post-study immune checkpoint inhibitor therapy, OS favored the bavituximab arm (HR 0.46; 95% CI 0.26-0.81; P=0.006). Conclusions
The combination of bavituximab plus docetaxel is not superior to docetaxel in patients with previously treated advanced NSCLC. The addition of bavituximab to docetaxel does not meaningfully increase toxicity. The potential benefit of bavituximab observed in patients with high β2GP1 levels and in patients subsequently treated with immune checkpoint inhibitors requires further investigation.NCT01999673https://ift.tt/2IjCcpW
Long‐term longitudinal changes in baseline PSA distribution and estimated prevalence of prostate cancer in male Japanese participants of population‐based PSA screening
International Journal of Cancer, EarlyView.
https://ift.tt/2IFDBGE
Cortical alterations in phobic postural vertigo – a multimodal imaging approach
Annals of Clinical and Translational Neurology, EarlyView.
https://ift.tt/2IjdVQC
YAP1-Mediated Suppression of USP31 Enhances NF{kappa}B Activity to Promote Sarcomagenesis
To date, no consistent oncogenic driver mutations have been identified in most adult soft tissue sarcomas; these tumors are thus generally insensitive to existing targeted therapies. Here we investigated alternate mechanisms underlying sarcomagenesis to identify potential therapeutic interventions. Undifferentiated pleomorphic sarcoma (UPS) is an aggressive tumor frequently found in skeletal muscle where deregulation of the Hippo pathway and aberrant stabilization of its transcriptional effector yes-associated protein 1 (YAP1) increases proliferation and tumorigenesis. However, the downstream mechanisms driving this deregulation are incompletely understood. Using autochthonous mouse models and whole genome analyses, we found that YAP1 was constitutively active in some sarcomas due to epigenetic silencing of its inhibitor angiomotin (AMOT). Epigenetic modulators vorinostat and JQ1 restored AMOT expression and wild-type Hippo pathway signaling, which induced a muscle differentiation program and inhibited sarcomagenesis. YAP1 promoted sarcomagenesis by inhibiting expression of ubiquitin-specific peptidase 31 (USP31), a newly identified upstream negative regulator of NFκB signaling. Combined treatment with epigenetic modulators effectively restored USP31 expression, resulting in decreased NFκB activity. Our findings highlight a key underlying molecular mechanism in UPS and demonstrate the potential impact of an epigenetic approach to sarcoma treatment.Significance: A new link between Hippo pathway signaling, NFκB, and epigenetic reprogramming is highlighted and has the potential for therapeutic intervention in soft tissue sarcomas. Cancer Res; 78(10); 2705–20. ©2018 AACR.
https://ift.tt/2Imk9eG
From MGUS to Multiple Myeloma, a Paradigm for Clonal Evolution of Premalignant Cells
Multiple myeloma (MM) is a treatable, but incurable, malignancy of plasma cells (PC) in the bone marrow (BM). It represents the final stage in a continuum of PC dyscrasias and is consistently preceded by a premalignant phase termed monoclonal gammopathy of undetermined significance (MGUS). The existence of this well-defined premalignant phase provides the opportunity to study clonal evolution of a premalignant condition into overt cancer. Unraveling the mechanisms of malignant transformation of PC could enable early identification of MGUS patients at high risk of progression and may point to novel therapeutic targets, thereby possibly delaying or preventing malignant transformation. The MGUS-to-MM progression requires multiple genomic events and the establishment of a permissive BM microenvironment, although it is generally not clear if the various microenvironmental events are causes or consequences of disease progression. Advances in gene-sequencing techniques and the use of serial paired analyses have allowed for a more specific identification of driver lesions. The challenge in cancer biology is to identify and target those lesions that confer selective advantage and thereby drive evolution of a premalignant clone. Here, we review recent advances in the understanding of malignant transformation of MGUS to MM. Cancer Res; 78(10); 2449–56. ©2018 AACR.
https://ift.tt/2jVyiot
Interleukin-30/IL27p28 Shapes Prostate Cancer Stem-like Cell Behavior and Is Critical for Tumor Onset and Metastasization
Prostate cancer stem-like cells (PCSLC) are believed to be responsible for prostate cancer onset and metastasis. Autocrine and microenvironmental signals dictate PCSLC behavior and patient outcome. In prostate cancer patients, IL30/IL27p28 has been linked with tumor progression, but the mechanisms underlying this link remain mostly elusive. Here, we asked whether IL30 may favor prostate cancer progression by conditioning PCSLCs and assessed the value of blocking IL30 to suppress tumor growth. IL30 was produced by PCSLCs in human and murine prostatic intraepithelial neoplasia and displayed significant autocrine and paracrine effects. PCSLC-derived IL30 supported PCSLC viability, self-renewal and tumorigenicity, expression of inflammatory mediators and growth factors, tumor immune evasion, and regulated chemokine and chemokine receptor genes, primarily via STAT1/STAT3 signaling. IL30 overproduction by PCSLCs promoted tumor onset and development associated with increased proliferation, vascularization, and myeloid cell recruitment. Furthermore, it promoted PCSLC dissemination to lymph nodes and bone marrow by upregulating the CXCR5/CXCL13 axis, and drove metastasis to lungs through the CXCR4/CXCL12 axis. These mechanisms were drastically hindered by IL30 knockdown or knockout in PCSLCs. Collectively, these results mark IL30 as a key driver of PCSLC behavior. Targeting IL30 signaling may be a potential therapeutic strategy against prostate cancer progression and recurrence.Significance: IL30 plays an important role in regulating prostate cancer stem-like cell behavior and metastatic potential, therefore targeting this cytokine could hamper prostate cancer progression or recurrence. Cancer Res; 78(10); 2654–68. ©2018 AACR.
https://ift.tt/2IjlaUB
MYD88 L265P Mutation in Lymphoid Malignancies
Next-generation sequencing has revealed cancer genomic landscapes, in which over 100 driver genes that, when altered by intragenic mutations, can promote oncogenesis. MYD88 is a driver gene found in hematologic B-cell malignancies. A missense mutation (L265P) changing leucine at position 265 to proline in MYD88 is found in ∼90% of Waldenström macroglobulinemia (WM) cases and in significant portions of activated B-cell diffuse large B-cell lymphomas and IgM monoclonal gammopathy of undetermined significance. Few cancers such as WM have a single amino acid substitution in one gene like MYD88 L265P that occurs in ∼90% of cases, making WM paradigmatic for study of a single causative mutation in oncogenesis. In this review, we summarize the frequency and cancer spectrum of MYD88 L265P and its downstream effects in lymphoid cancers. Malignant B cells with MYD88 L265P are likely transformed from IgM-producing B cells either in response to T-cell–independent antigens or in response to protein antigens before class switching. We also discuss therapeutic strategies that include targeting Bruton tyrosine kinase and other kinases, interfering with the assembly of MYD88 and its interacting partners, and MYD88 L265P-specific peptide-based immunotherapy. Cancer Res; 78(10); 2457–62. ©2018 AACR.
https://ift.tt/2IlJCF8
MPO Promoter Polymorphism rs2333227 Enhances Malignant Phenotypes of Colorectal Cancer by Altering the Binding Affinity of AP-2{alpha}
Myeloperoxidase (MPO) promoter SNPs rs2243828 (−764T>C) and rs2333227 (G-463A) program malignant phenotypes by regulating MPO transcriptional activity. In this study, we enrolled a total of 1,175 controls and 1,078 patients with colorectal cancer with comprehensive clinical and survival information to assess whether these SNPs could affect the susceptibility and development of colorectal cancer. The MPO rs2333227 TT genotype significantly increased the risk of colorectal cancer and decreased the overall survival time of patients. Colorectal cancer cells with the rs2333227 TT genotype exhibited enhanced proliferation, migration, and invasion capacity in vitro and in vivo. Mechanistically, we found that MPO SNP rs2333227 C to T mutation altered the binding affinity of the transcription factors AP-2α to the rs2333227 mutation region, sequentially enhancing expression levels of MPO and activating further IL23A–MMP9 axis–mediated oncogenic signaling. Taken together, our findings indicate that MPO SNP rs2333227 serves as a marker of enhanced risk for development of colorectal cancer.Significance: MPO polymorphisms are a guide for high risk and poor prognosis in patients colorectal cancer. Cancer Res; 78(10); 2760–9. ©2018 AACR.
https://ift.tt/2IlUWB9
Bivalent Chromatin Domains in Glioblastoma Reveal a Subtype-Specific Signature of Glioma Stem Cells
Glioblastoma multiforme (GBM) can be clustered by gene expression into four main subtypes associated with prognosis and survival, but enhancers and other gene-regulatory elements have not yet been identified in primary tumors. Here, we profiled six histone modifications and CTCF binding as well as gene expression in primary gliomas and identified chromatin states that define distinct regulatory elements across the tumor genome. Enhancers in mesenchymal and classical tumor subtypes drove gene expression associated with cell migration and invasion, whereas enhancers in proneural tumors controlled genes associated with a less aggressive phenotype in GBM. We identified bivalent domains marked by activating and repressive chromatin modifications. Interestingly, the gene interaction network from common (subtype-independent) bivalent domains was highly enriched for homeobox genes and transcription factors and dominated by SHH and Wnt signaling pathways. This subtype-independent signature of early neural development may be indicative of poised dedifferentiation capacity in glioblastoma and could provide potential targets for therapy.Significance: Enhancers and bivalent domains in glioblastoma are regulated in a subtype-specific manner that resembles gene regulation in glioma stem cells. Cancer Res; 78(10); 2463–74. ©2018 AACR.
https://ift.tt/2jZLAQW
Zeb1 in Stromal Myofibroblasts Promotes Kras-Driven Development of Pancreatic Cancer
The transcription factor Zeb1 has been identified as a crucial player in Kras-dependent oncogenesis. In pancreatic ductal adenocarcinoma (PDAC), Zeb1 is highly expressed in myofibroblasts and correlates with poor prognosis. As Kras mutations are key drivers in PDAC, we aimed here to assess the necessity of Zeb1 for Kras-driven PDAC and to define the role of Zeb1-expressing myofibroblasts in PDAC development. Genetically engineered mice with conditional pancreatic KrasG12D and Trp53 mutations (KPC) were crossed with Zeb1 haploinsufficient mice (Z+/−). Extensive PDAC was prominent in all 20-week-old KPC;Z+/+ mice, whereas only low-grade precursor lesions were detected in age-matched KPC;Z+/− littermates, with PDAC developing eventually in KPC;Z+/− aged animals. Zeb1 expression in myofibroblasts occurred early in tumorigenesis and Zeb1 haploinsufficiency retarded native expansion of stromal myofibroblasts during precursor-to-cancer progression. Zeb1 downregulation in mPSC repressed their activated gene profile, impaired their migratory and proliferative activity, and attenuated their tumor-supporting features. Conditioned media from Z+/+ mouse-activated (myofibroblast-like) pancreatic stellate cells (mPSC) boosted Ras activity in pancreatic cancer cells carrying mutant Kras; this effect was not observed when using conditioned media from Z+/− mPSC, revealing a paracrinal cooperative axis between Zeb1-expressing PSC and oncogenic Kras-bearing tumor cells. We conclude that Zeb1-expressing stromal myofibroblasts enable a heterotypic collaboration with the Kras-fated epithelial compartment, thus supporting pancreatic malignancy.Significance: Zeb1 expression in stromal myofibroblasts supports PDAC development via collaboration with the epithelial compartment bearing oncogenic Kras mutations. Cancer Res; 78(10); 2624–37. ©2018 AACR.
https://ift.tt/2Imxy6k
PML Recruits TET2 to Regulate DNA Modification and Cell Proliferation in Response to Chemotherapeutic Agent
Aberrant DNA methylation plays a critical role in the development and progression of cancer. Failure to demethylate and to consequently reactivate methylation-silenced genes in cancer contributes to chemotherapeutic resistance, yet the regulatory mechanisms of DNA demethylation in response to chemotherapeutic agents remain unclear. Here, we show that promyelocytic leukemia (PML) recruits ten–eleven translocation dioxygenase 2 (TET2) to regulate DNA modification and cell proliferation in response to chemotherapeutic agents. TET2 was required by multiple chemotherapeutic agents (such as doxorubicin) to prmote 5-hydroxymethylcytosine (5hmC) formation. Stable isotope labeling with amino acids in cell culture, followed by immunoprecipitation–mass spectrometry, identified potential binding partners of TET2, of which PML mostly enhanced 5hmC formation. PML physically bound to TET2 via the PML C-terminal domain and recruited TET2 to PML-positive nuclear bodies. This interaction was disrupted by the PML-RARA t(15;17) mutation, which stems from chromosomal translocation between DNA encoding the C-terminal domain of PML and the retinoic acid receptor alpha (RARA) gene. In response to chemotherapeutic drugs, PML recruited TET2, regulated DNA modification, reactivated methylation-silenced genes, and impaired cell proliferation. Knockout of PML abolished doxorubicin-promoted DNA modification. In addition, PML and TET2 levels positively correlated with improved overall survival in patients with head and neck cancer. These findings shed insight into the regulatory mechanisms of DNA modification in response to chemotherapeutic agents.Significance: Promyeloctic leukemia protein recruits TET2, regulating DNA modification and cell proliferation in response to chemotherapeutic agents. Cancer Res; 78(10); 2475–89. ©2018 AACR.
https://ift.tt/2Ioyesc
TRPM2 Mediates Neutrophil Killing of Disseminated Tumor Cells
Neutrophils play a critical role in cancer, with both protumor and antitumor neutrophil subpopulations reported. The antitumor neutrophil subpopulation has the capacity to kill tumor cells and limit metastatic spread, yet not all tumor cells are equally susceptible to neutrophil cytotoxicity. Because cells that evade neutrophils have greater chances of forming metastases, we explored the mechanism neutrophils use to kill tumor cells. Neutrophil cytotoxicity was previously shown to be mediated by secretion of H2O2. We report here that neutrophil cytotoxicity is Ca2+ dependent and is mediated by TRPM2, a ubiquitously expressed H2O2-dependent Ca2+ channel. Perturbing TRPM2 expression limited tumor cell proliferation, leading to attenuated tumor growth. Concomitantly, cells expressing reduced levels of TRPM2 were protected from neutrophil cytotoxicity and seeded more efficiently in the premetastatic lung.Significance: These findings identify the mechanism utilized by neutrophils to kill disseminated tumor cells and to limit metastatic spread. Cancer Res; 78(10); 2680–90. ©2018 AACR.
https://ift.tt/2Il1nnM
Organelle-Derived Acetyl-CoA Promotes Prostate Cancer Cell Survival, Migration, and Metastasis via Activation of Calmodulin Kinase II
Although emerging evidence suggests a potential role of calcium/calmodulin-dependent kinase II (CaMKII) in prostate cancer, its role in prostate cancer tumorigenesis is largely unknown. Here, we examine whether the acetyl CoA-CaMKII pathway, first described in frog oocytes, promotes prostate cancer tumorigenesis. In human prostate cancer specimens, metastatic prostate cancer expressed higher levels of active CaMKII compared with localized prostate cancer. Correspondingly, basal CaMKII activity was significantly higher in the more tumorigenic PC3 and PC3-mm2 cells relative to the less tumorigenic LNCaP and C4-2B4 cells. Deletion of CaMKII by CRISPR/Cas9 in PC3-mm2 cells abrogated cell survival under low-serum conditions, anchorage-independent growth and cell migration; overexpression of constitutively active CaMKII in C4-2B4 cells promoted these phenotypes. In an animal model of prostate cancer metastasis, genetic ablation of CaMKII reduced PC3-mm2 cell metastasis from the prostate to the lymph nodes. Knockdown of the acetyl-CoA transporter carnitine acetyltransferase abolished CaMKII activation, providing evidence that acetyl-CoA generated from organelles is a major activator of CaMKII. Genetic deletion of the β-oxidation rate-limiting enzyme ACOX family proteins decreased CaMKII activation, whereas overexpression of ACOXI increased CaMKII activation. Overall, our studies identify active CaMKII as a novel connection between organelle β-oxidation and acetyl-CoA transport with cell survival, migration, and prostate cancer metastasis.Significance: This study identifies a cell metabolic pathway that promotes prostate cancer metastasis and suggests prostate cancer may be susceptible to β-oxidation inhibitors. Cancer Res; 78(10); 2490–502. ©2018 AACR.
https://ift.tt/2IIqncf
Mass Spectrometry-Based Proteomics Reveals Potential Roles of NEK9 and MAP2K4 in Resistance to PI3K Inhibition in Triple-Negative Breast Cancers
Activation of PI3K signaling is frequently observed in triple-negative breast cancer (TNBC), yet PI3K inhibitors have shown limited clinical activity. To investigate intrinsic and adaptive mechanisms of resistance, we analyzed a panel of patient-derived xenograft models of TNBC with varying responsiveness to buparlisib, a pan-PI3K inhibitor. In a subset of patient-derived xenografts, resistance was associated with incomplete inhibition of PI3K signaling and upregulated MAPK/MEK signaling in response to buparlisib. Outlier phosphoproteome and kinome analyses identified novel candidates functionally important to buparlisib resistance, including NEK9 and MAP2K4. Knockdown of NEK9 or MAP2K4 reduced both baseline and feedback MAPK/MEK signaling and showed synthetic lethality with buparlisib in vitro. A complex in/del frameshift in PIK3CA decreased sensitivity to buparlisib via NEK9/MAP2K4–dependent mechanisms. In summary, our study supports a role for NEK9 and MAP2K4 in mediating buparlisib resistance and demonstrates the value of unbiased omic analyses in uncovering resistance mechanisms to targeted therapy.Significance: Integrative phosphoproteogenomic analysis is used to determine intrinsic resistance mechanisms of triple-negative breast tumors to PI3K inhibition. Cancer Res; 78(10); 2732–46. ©2018 AACR.
https://ift.tt/2ImxraU
Visualization of Breast Cancer Metabolism Using Multimodal Nonlinear Optical Microscopy of Cellular Lipids and Redox State
Label-free nonlinear optical microscopy (NLOM) based on two-photon excited fluorescence (TPEF) from cofactors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD+) is widely used for high-resolution cellular redox imaging. In this work, we combined three label-free NLOM imaging methods to quantitatively characterize breast cancer cells and their relative invasive potential: (i) TPEF optical redox ratio (ORR = FAD+/NADH + FAD+), (ii) coherent Raman scattering of cellular lipids, and (iii) second harmonic generation of extracellular matrix (ECM) collagen. 3D spheroid models of primary mammary epithelial (PME) cells and breast cancer cell lines (T47D and MDA-MB-231) were characterized based on their unique ORR and lipid volume fraction signatures. Treatment with 17β-estradiol (E2) increased glycolysis in both PME and T47D ER+ breast cancer acini. However, PME cells displayed increased lipid content with no effect on ECM, while T47D cells had decreased lipid storage (P < 0.001) and significant reorganization of collagen. By measuring deuterated lipids synthesized from exogenously administered deuterium-labeled glucose, treatment of T47D cells with E2 increased both lipid synthesis and consumption rates. These results confirm that glucose is a significant source for the cellular synthesis of lipid in glycolytic breast cancer cells, and that the combination of cellular redox and lipid fraction imaging endpoints is a powerful approach with new and complementary information content.Significance: These findings provide unique insight into metabolic processes, revealing correlations between cancer metastasis and cellular redox state, lipid metabolism, and extracellular matrix. Cancer Res; 78(10); 2503–12. ©2018 AACR.
https://ift.tt/2Il5fp7
Extracellular Citrate Affects Critical Elements of Cancer Cell Metabolism and Supports Cancer Development In Vivo
Glycolysis and fatty acid synthesis are highly active in cancer cells through cytosolic citrate metabolism, with intracellular citrate primarily derived from either glucose or glutamine via the tricarboxylic acid cycle. We show here that extracellular citrate is supplied to cancer cells through a plasma membrane-specific variant of the mitochondrial citrate transporter (pmCiC). Metabolomic analysis revealed that citrate uptake broadly affected cancer cell metabolism through citrate-dependent metabolic pathways. Treatment with gluconate specifically blocked pmCiC and decreased tumor growth in murine xenografts of human pancreatic cancer. This treatment altered metabolism within tumors, including fatty acid metabolism. High expression of pmCiC was associated with invasion and advanced tumor stage across many human cancers. These findings support the exploration of extracellular citrate transport as a novel potential target for cancer therapy.Significance: Uptake of extracellular citrate through pmCiC can be blocked with gluconate to reduce tumor growth and to alter metabolic characteristics of tumor tissue. Cancer Res; 78(10); 2513–23. ©2018 AACR.
https://ift.tt/2jYpwGe
RASSF1A Deficiency Enhances RAS-Driven Lung Tumorigenesis
Mutant K-RAS has been shown to have both tumor-promoting and -suppressing functions, and growing evidence suggests that the RASSF family of tumor suppressors can act as RAS apoptosis and senescence effectors. It has been hypothesized that inactivation of the RASSF1A tumor suppressor facilitates K-RAS–mediated transformation by uncoupling it from apoptotic pathways such as the Hippo pathway. In human lung tumors, combined activation of K-RAS and inactivation of RASSF1A is closely associated with the development of the most aggressive and worst prognosis tumors. Here, we describe the first transgenic mouse model for activation of K-RAS in the lung in a RASSF1A-defective background. RASSF1A deficiency profoundly enhanced the development of K-RAS–driven lung tumors in vivo. Analysis of these tumors showed loss of RASSF1A-uncoupled RAS from the proapoptotic Hippo pathway as expected. We also observed an upregulation of AKT and RALGEF signaling in the RASSF1A− tumors. Heterozygosity of RASSF1A alone mimicked many of the effects of RAS activation on mitogenic signaling in lung tissue, yet no tumors developed, indicating that nonstandard Ras signaling pathways may be playing a key role in tumor formation in vivo. In addition, we observed a marked increase in inflammation and IL6 production in RASSF1A-deficient tumors. Thus, RASSF1A loss profoundly affects RAS-driven lung tumorigenesis and mitogenic signaling in vivo. Deregulation of inflammatory pathways due to loss of RASSF1A may be essential for RAS-mediated tumorigenesis. These results may have considerable ramifications for future targeted therapy against RAS+/RASSF1A− tumors.Significance: A transgenic mouse model shows that suppression of RASSF1A dramatically enhances Ras-driven tumorigenesis and alters Ras signaling pathway activity.Graphical Abstract: https://ift.tt/2wGHrur. Cancer Res; 78(10); 2614–23. ©2018 AACR.
https://ift.tt/2IFyQgg
Loss of the Nuclear Pool of Ubiquitin Ligase CHIP/STUB1 in Breast Cancer Unleashes the MZF1-Cathepsin Pro-oncogenic Program
CHIP/STUB1 ubiquitin ligase is a negative co-chaperone for HSP90/HSC70, and its expression is reduced or lost in several cancers, including breast cancer. Using an extensive and well-annotated breast cancer tissue collection, we identified the loss of nuclear but not cytoplasmic CHIP to predict more aggressive tumorigenesis and shorter patient survival, with loss of CHIP in two thirds of ErbB2+ and triple-negative breast cancers (TNBC) and in one third of ER+ breast cancers. Reduced CHIP expression was seen in breast cancer patient-derived xenograft tumors and in ErbB2+ and TNBC cell lines. Ectopic CHIP expression in ErbB2+ lines suppressed in vitro oncogenic traits and in vivo xenograft tumor growth. An unbiased screen for CHIP-regulated nuclear transcription factors identified many candidates whose DNA-binding activity was up- or downregulated by CHIP. We characterized myeloid zinc finger 1 (MZF1) as a CHIP target, given its recently identified role as a positive regulator of cathepsin B/L (CTSB/L)-mediated tumor cell invasion downstream of ErbB2. We show that CHIP negatively regulates CTSB/L expression in ErbB2+ and other breast cancer cell lines. CTSB inhibition abrogates invasion and matrix degradation in vitro and halts ErbB2+ breast cancer cell line xenograft growth. We conclude that loss of CHIP remodels the cellular transcriptome to unleash critical pro-oncogenic pathways, such as the matrix-degrading enzymes of the cathepsin family, whose components can provide new therapeutic opportunities in breast and other cancers with loss of CHIP expression.Significance: These findings reveal a novel targetable pathway of breast oncogenesis unleashed by the loss of tumor suppressor ubiquitin ligase CHIP/STUB1. Cancer Res; 78(10); 2524–35. ©2018 AACR.
https://ift.tt/2ImxG5O
Targeting Cyclin D-CDK4/6 Sensitizes Immune-Refractory Cancer by Blocking the SCP3-NANOG Axis
Immunoediting caused by antitumor immunity drives tumor cells to acquire refractory phenotypes. We demonstrated previously that tumor antigen–specific T cells edit these cells such that they become resistant to CTL killing and enrich NANOGhigh cancer stem cell-like cells. In this study, we show that synaptonemal complex protein 3 (SCP3), a member of the Cor1 family, is overexpressed in immunoedited cells and upregulates NANOG by hyperactivating the cyclin D1–CDK4/6 axis. The SCP3–cyclin D1–CDK4/6 axis was preserved across various types of human cancer and correlated negatively with progression-free survival of cervical cancer patients. Targeting CDK4/6 with the inhibitor palbociclib reversed multiaggressive phenotypes of SCP3high immunoedited tumor cells and led to long-term control of the disease. Collectively, our findings establish a firm molecular link of multiaggressiveness among SCP3, NANOG, cyclin D1, and CDK4/6 and identify CDK4/6 inhibitors as actionable drugs for controlling SCP3high immune-refractory cancer.Significance: These findings reveal cyclin D1-CDK4/6 inhibition as an effective strategy for controlling SCP3high immune-refractroy cancer. Cancer Res; 78(10); 2638–53. ©2018 AACR.
https://ift.tt/2IGA5f6
hPCL3s Promotes Hepatocellular Carcinoma Metastasis by Activating {beta}-Catenin Signaling
Two isoforms of human Polycomb-like protein 3 (hPCL3) have been reported as components of the nuclear Polycomb repressive complex 2 (PRC2), with the short isoform (hPCL3s) showing a dominant cytoplasmic localization. The function of cytoplasmic hPCL3s has, however, not been addressed. In this study, we report that hPCL3s is upregulated in clinical hepatocellular carcinoma (HCC) samples and its expression correlated with HCC clinical features. hPCL3s positively regulated the migration, invasion, and metastasis of HCC cells. hPCL3s interacted with components of the cytoplasmic β-catenin destruction complex, inhibited β-catenin degradation, and activated β-catenin/T-cell factor signaling. Downstream of the β-catenin cascade, IL6 mediated the motility-promoting functions of hPCL3s. Forced expression of hPCL3s in the liver of a HCC mouse model promoted tumorigenesis and metastasis. Taken together, these data show that hPCL3s promotes the metastasis of HCC by activating the β-catenin/IL6 pathway.Significance: hPCL3s has an oncogenic role in hepatocellular carcinoma by activating the β-catenin/IL6 signaling axis to promote metastasis. Cancer Res; 78(10); 2536–49. ©2018 AACR.
https://ift.tt/2jVRi6j
Loss of Pax5 Exploits Sca1-BCR-ABLp190 Susceptibility to Confer the Metabolic Shift Essential for pB-ALL
Preleukemic clones carrying BCR-ABLp190 oncogenic lesions are found in neonatal cord blood, where the majority of preleukemic carriers do not convert into precursor B-cell acute lymphoblastic leukemia (pB-ALL). However, the critical question of how these preleukemic cells transform into pB-ALL remains undefined. Here, we model a BCR-ABLp190 preleukemic state and show that limiting BCR-ABLp190 expression to hematopoietic stem/progenitor cells (HS/PC) in mice (Sca1-BCR-ABLp190) causes pB-ALL at low penetrance, which resembles the human disease. pB-ALL blast cells were BCR-ABL–negative and transcriptionally similar to pro-B/pre-B cells, suggesting disease onset upon reduced Pax5 functionality. Consistent with this, double Sca1-BCR-ABLp190+Pax5+/− mice developed pB-ALL with shorter latencies, 90% incidence, and accumulation of genomic alterations in the remaining wild-type Pax5 allele. Mechanistically, the Pax5-deficient leukemic pro-B cells exhibited a metabolic switch toward increased glucose utilization and energy metabolism. Transcriptome analysis revealed that metabolic genes (IDH1, G6PC3, GAPDH, PGK1, MYC, ENO1, ACO1) were upregulated in Pax5-deficient leukemic cells, and a similar metabolic signature could be observed in human leukemia. Our studies unveil the first in vivo evidence that the combination between Sca1-BCR-ABLp190 and metabolic reprogramming imposed by reduced Pax5 expression is sufficient for pB-ALL development. These findings might help to prevent conversion of BCR-ABLp190 preleukemic cells.Significance: Loss of Pax5 drives metabolic reprogramming, which together with Sca1-restricted BCR-ABL expression enables leukemic transformation. Cancer Res; 78(10); 2669–79. ©2018 AACR.
https://ift.tt/2IM6nVY
Acquired Resistance of ER-Positive Breast Cancer to Endocrine Treatment Confers an Adaptive Sensitivity to TRAIL through Posttranslational Downregulation of c-FLIP
Purpose: One third of ER-positive breast cancer patients who initially respond to endocrine therapy become resistant to treatment. Such treatment failure is associated with poor prognosis and remains an area of unmet clinical need. Here, we identify a specific posttranslational modification that occurs during endocrine resistance and which results in tumor susceptibility to the apoptosis-inducer TRAIL. This potentially offers a novel stratified approach to targeting endocrine-resistant breast cancer.
Experimental Design: Cell line and primary-derived xenograft models of endocrine resistance were investigated for susceptibility to TRAIL. Tumor viability, cancer stem cell (CSC) viability (tumorspheres), tumor growth kinetics, and metastatic burden were assessed. Western blots for the TRAIL-pathway inhibitor, c-FLIP, and upstream regulators were performed. Results were confirmed in primary culture of 26 endocrine-resistant and endocrine-naïve breast tumors.
Results: Breast cancer cell lines with acquired resistance to tamoxifen (TAMR) or faslodex were more sensitive to TRAIL than their endocrine-sensitive controls. Moreover, TRAIL eliminated CSC-like activity in TAMR cells, resulting in prolonged remission of xenografts in vivo. In primary culture, TRAIL significantly depleted CSCs in 85% endocrine-resistant, compared with 8% endocrine-naïve, tumors, whereas systemic administration of TRAIL in endocrine-resistant patient-derived xenografts reduced tumor growth, CSC-like activity, and metastases. Acquired TRAIL sensitivity correlated with a reduction in intracellular levels of c-FLIP, and an increase in Jnk-mediated phosphorylation of E3-ligase, ITCH, which degrades c-FLIP.
Conclusions: These results identify a novel mechanism of acquired vulnerability to an extrinsic cell death stimulus, in endocrine-resistant breast cancers, which has both therapeutic and prognostic potential. Clin Cancer Res; 24(10); 2452–63. ©2018 AACR.
https://ift.tt/2IlT8In
Krüppel-like Factor 4 Suppresses Serine/Threonine Kinase 33 Activation and Metastasis of Gastric Cancer through Reversing Epithelial-Mesenchymal Transition
Background: Cancers with aberrant expression of Serine/threonine kinase 33 (STK33) has been reported to be particularly aggressive. However, its expression, clinical significance, and biological functions in gastric cancer remain largely unknown. In the present study, we determined the expression and function of STK33 in gastric cancer and delineated the clinical significance of the Krüppel-like factor 4 (KLF4)/STK33 signaling pathway.
Methods: STK33 expression and its association with multiple clinicopathologic characteristics were analyzed immunohistochemically in human gastric cancer specimens. STK33 knockdown and overexpression were used to dissect the underlying mechanism of its functions in gastric cancer cells. Regulation and underlying mechanisms of STK33 expression by KLF4 in gastric cancer cells were studied using cell and molecular biological methods.
Results: Drastically higher expression of STK33 was observed in gastric cancer and gastric intraepithelial neoplasia tissues compared with adjacent normal gastric tissues. Increased STK33 expression correlated directly with tumor size, lymph node, and distant metastasis; and patients with low STK33 expression gastric cancer were predicted to have a favorable prognosis. Enforced expression of STK33 promoted gastric cancer cell proliferation, migration, and invasion in vitro and in vivo, whereas reduced STK33 did the opposite. Moreover, STK33 promoted epithelial–mesenchymal transition (EMT) in vitro. Mechanistically, KLF4 transcriptionally inhibited STK33 expression in gastric cancer cells. KLF4-mediated inhibition of gastric cancer cell invasion was reversed by upregulation of STK33 expression.
Conclusions: STK33 has pro-tumor function and is a critical downstream mediator of KLF4 in gastric cancer. STK33 may serve as a potential prognostic marker and therapeutic target for gastric cancer. Clin Cancer Res; 24(10); 2440–51. ©2018 AACR.
https://ift.tt/2IIlNuz
Platelets Enhance Multiple Myeloma Progression via IL-1{beta} Upregulation
Purpose: Tumor cell–platelet interactions contribute to tumor progression and metastasis in solid tumors. However, the role of platelets in hematological malignancies is not clear. We investigated the association of platelet activation status with clinical stages in multiple myeloma (MM) patients and explored the role of platelets in MM progression.
Experimental Design: Platelets were obtained from healthy donors and MM patients. We examined platelet activation status in MM patients by flow cytometry and transmission electron microscopy. We also observed the enriched pathways that are involved with platelet activation in RNA sequencing of platelets. MM cell lines were used to assess the effect of platelets on MM cell proliferation in vitro and their engraftment in vivo. RNA sequencing of MM cell lines was performed to explore molecular mechanisms underlying MM cell–platelet interaction and a CRISPR/Cas9 knockout approach was used for validation.
Results: Platelets from MM patients were highly activated with disease progression. RNA sequencing of platelets revealed that genes involved in platelets were enriched in patients with smoldering MM (SMM) or MM. Platelets promoted MM cell proliferation in vitro and contributed to tumor engraftment in bone marrow in vivo. RNA sequencing revealed that IL-1β was upregulated in MM cell lines co-cultured with platelets, whereas IL-1β knockout in MM cell lines abrogated the effects of platelets on MM cell proliferation and engraftment in vivo.
Conclusions: Platelets from MM patients were highly activated with disease progression. IL-1β is critical to platelet-mediated MM progression and might be a potential target for MM treatment. Clin Cancer Res; 24(10); 2430–9. ©2018 AACR.
https://ift.tt/2InG2u9
Disruption of Wnt/{beta}-Catenin Exerts Antileukemia Activity and Synergizes with FLT3 Inhibition in FLT3-Mutant Acute Myeloid Leukemia
Purpose: Wnt/β-catenin signaling is required for leukemic stem cell function. FLT3 mutations are frequently observed in acute myeloid leukemia (AML). Anomalous FLT3 signaling increases β-catenin nuclear localization and transcriptional activity. FLT3 tyrosine kinase inhibitors (TKI) are used clinically to treat FLT3-mutated AML patients, but with limited efficacy. We investigated the antileukemia activity of combined Wnt/β-catenin and FLT3 inhibition in FLT3-mutant AML.
Experimental Design: Wnt/β-catenin signaling was inhibited by the β-catenin/CBP antagonist C-82/PRI-724 or siRNAs, and FLT3 signaling by sorafenib or quizartinib. Treatments on apoptosis, cell growth, and cell signaling were assessed in cell lines, patient samples, and in vivo in immunodeficient mice by flow cytometry, Western blot, RT-PCR, and CyTOF.
Results: We found significantly higher β-catenin expression in cytogenetically unfavorable and relapsed AML patient samples and in the bone marrow–resident leukemic cells compared with circulating blasts. Disrupting Wnt/β-catenin signaling suppressed AML cell growth, induced apoptosis, abrogated stromal protection, and synergized with TKIs in FLT3-mutated AML cells and stem/progenitor cells in vitro. The aforementioned combinatorial treatment improved survival of AML-xenografted mice in two in vivo models and impaired leukemia cell engraftment. Mechanistically, the combined inhibition of Wnt/β-catenin and FLT3 cooperatively decreased nuclear β-catenin and the levels of c-Myc and other Wnt/β-catenin and FLT3 signaling proteins. Importantly, β-catenin inhibition abrogated the microenvironmental protection afforded the leukemic stem/progenitor cells.
Conclusions: Disrupting Wnt/β-catenin signaling exerts potent activities against AML stem/progenitor cells and synergizes with FLT3 inhibition in FLT3-mutant AML. These findings provide a rationale for clinical development of this strategy for treating FLT3-mutated AML patients. Clin Cancer Res; 24(10); 2417–29. ©2018 AACR.
https://ift.tt/2jVP2fl
Androgen Deprivation Therapy Potentiates the Efficacy of Vascular Targeted Photodynamic Therapy of Prostate Cancer Xenografts
Purpose: WST11 vascular targeted photodynamic therapy (VTP) is a local ablation approach relying upon rapid, free radical-mediated destruction of tumor vasculature. A phase III trial showed that VTP significantly reduced disease progression when compared with active surveillance in patients with low-risk prostate cancer. The aim of this study was to identify a druggable pathway that could be combined with VTP to improve its efficacy and applicability to higher risk prostate cancer tumors.
Experimental Design: Transcriptome analysis of VTP-treated tumors (LNCaP-AR xenografts) was used to identify a candidate pathway for combination therapy. The efficacy of the combination therapy was assessed in mice bearing LNCaP-AR or VCaP tumors.
Results: Gene set enrichment analysis identifies the enrichment of androgen-responsive gene sets within hours after VTP treatment, suggesting that the androgen receptor (AR) may be a viable target in combination with VTP. We tested this hypothesis in mice bearing LNCaP-AR xenograft tumors by using androgen deprivation therapy (ADT), degarelix, in combination with VTP. Compared with either ADT or VTP alone, a single dose of degarelix in concert with VTP significantly inhibited tumor growth. A sharp decline in serum prostate-specific antigen (PSA) confirmed AR inhibition in this group. Tumors treated by VTP and degarelix displayed intense terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling staining 7 days after treatment, supporting an increased apoptotic frequency underlying the effect on tumor inhibition.
Conclusions: Improvement of local tumor control following androgen deprivation combined with VTP provides the rationale and preliminary protocol parameters for clinical trials in patients presented with locally advanced prostate cancer. Clin Cancer Res; 24(10); 2408–16. ©2018 AACR.
https://ift.tt/2IlSYkf
HSF1 Is Essential for Myeloma Cell Survival and A Promising Therapeutic Target
Purpose: Myeloma is a plasma cell malignancy characterized by the overproduction of immunoglobulin, and is therefore susceptible to therapies targeting protein homeostasis. We hypothesized that heat shock factor 1 (HSF1) was an attractive therapeutic target for myeloma due to its direct regulation of transcriptional programs implicated in both protein homeostasis and the oncogenic phenotype. Here, we interrogate HSF1 as a therapeutic target in myeloma using bioinformatic, genetic, and pharmacologic means.
Experimental Design: To assess the clinical relevance of HSF1, we analyzed publicly available patient myeloma gene expression datasets. Validation of this novel target was conducted in in vitro experiments using shRNA or inhibitors of the HSF1 pathway in human myeloma cell lines and primary cells as well as in in vivo human myeloma xenograft models.
Results: Expression of HSF1 and its target genes were associated with poorer myeloma patient survival. ShRNA-mediated knockdown or pharmacologic inhibition of the HSF1 pathway with a novel chemical probe, CCT251236, or with KRIBB11, led to caspase-mediated cell death that was associated with an increase in EIF2α phosphorylation, CHOP expression and a decrease in overall protein synthesis. Importantly, both CCT251236 and KRIBB11 induced cytotoxicity in human myeloma cell lines and patient-derived primary myeloma cells with a therapeutic window over normal cells. Pharmacologic inhibition induced tumor growth inhibition and was well-tolerated in a human myeloma xenograft murine model with evidence of pharmacodynamic biomarker modulation.
Conclusions: Taken together, our studies demonstrate the dependence of myeloma cells on HSF1 for survival and support the clinical evaluation of pharmacologic inhibitors of the HSF1 pathway in myeloma. Clin Cancer Res; 24(10); 2395–407. ©2018 AACR.
See related commentary by Parekh, p. 2237
https://ift.tt/2IM35C6
PD-1 Blockade and CD27 Stimulation Activate Distinct Transcriptional Programs That Synergize for CD8+ T-Cell-Driven Antitumor Immunity
Purpose: PD-1 checkpoint blockade has revolutionized the field of cancer immunotherapy, yet the frequency of responding patients is limited by inadequate T-cell priming secondary to a paucity of activatory dendritic cells (DC). DC signals can be bypassed by CD27 agonists, and we therefore investigated if the effectiveness of anti–PD-1/L1 could be improved by combining with agonist anti-CD27 monoclonal antibodies (mAb).
Experimental Design: The efficacy of PD-1/L1 blockade or agonist anti-CD27 mAb was compared with a dual-therapy approach in multiple tumor models. Global transcriptional profiling and flow cytometry analysis were used to delineate mechanisms underpinning the observed synergy.
Results: PD-1/PD-L1 blockade and agonist anti-CD27 mAb synergize for increased CD8+ T-cell expansion and effector function, exemplified by enhanced IFN, TNFα, granzyme B, and T-bet. Transcriptome analysis of CD8+ T cells revealed that combination therapy triggered a convergent program largely driven by IL2 and Myc. However, division of labor was also apparent such that anti–PD-1/L1 activates a cytotoxicity–gene expression program whereas anti-CD27 preferentially augments proliferation. In tumor models, either dependent on endogenous CD8+ T cells or adoptive transfer of transgenic T cells, anti-CD27 mAb synergized with PD-1/L1 blockade for antitumor immunity. Finally, we show that a clinically relevant anti-human CD27 mAb, varlilumab, similarly synergizes with PD-L1 blockade for protection against lymphoma in human–CD27 transgenic mice.
Conclusions: Our findings suggest that suboptimal T-cell invigoration in cancer patients undergoing treatment with PD-1 checkpoint blockers will be improved by dual PD-1 blockade and CD27 agonism and provide mechanistic insight into how these approaches cooperate for CD8+ T-cell activation. Clin Cancer Res; 24(10); 2383–94. ©2018 AACR.
https://ift.tt/2InFSTz
Chemotherapy Induces Breast Cancer Stemness in Association with Dysregulated Monocytosis
Purpose: Preoperative or neoadjuvant therapy (NT) is increasingly used in patients with locally advanced or inflammatory breast cancer to allow optimal surgery and aim for pathologic response. However, many breast cancers are resistant or relapse after treatment. Here, we investigated conjunctive chemotherapy-triggered events occurring systemically and locally, potentially promoting a cancer stem–like cell (CSC) phenotype and contributing to tumor relapse.
Experimental Design: We started by comparing the effect of paired pre- and post-NT patient sera on the CSC properties of breast cancer cells. Using cell lines, patient-derived xenograft models, and primary tumors, we investigated the regulation of CSCs and tumor progression by chemotherapy-induced factors.
Results: In human patients and mice, we detected a therapy-induced CSC-stimulatory activity in serum, which was attributed to therapy-associated monocytosis leading to systemic elevation of monocyte chemoattractant proteins (MCP). The post-NT hematopoietic regeneration in the bone marrow highlighted both altered monocyte–macrophage differentiation and biased commitment of stimulated hematopoietic stem cells toward monocytosis. Chemotherapeutic agents also induce monocyte expression of MCPs through a JNK-dependent mechanism. Genetic and pharmacologic inhibitions of the MCP-CCR2 pathway blocked chemotherapy's adverse effect on CSCs. Levels of nuclear Notch and ALDH1 were significantly elevated in primary breast cancers following NT, whereas higher levels of CCR2 in pre-NT tumors were associated with a poor response to NT.
Conclusions: Our data establish a mechanism of chemotherapy-induced cancer stemness by linking the cellular events in the bone marrow and tumors, and suggest pharmacologic inhibition of CCR2 as a potential cotreatment during conventional chemotherapy in neoadjuvant and adjuvant settings. Clin Cancer Res; 24(10); 2370–82. ©2018 AACR.
https://ift.tt/2jYMwoO
Foretinib Overcomes Entrectinib Resistance Associated with the NTRK1 G667C Mutation in NTRK1 Fusion-Positive Tumor Cells in a Brain Metastasis Model
Purpose: Rearrangement of the neurotrophic tropomyosin receptor kinase 1 (NTRK1) gene, which encodes tyrosine receptor kinase A (TRK-A), occurs in various cancers, including colon cancer. Although entrectinib is effective in the treatment of central nervous system (CNS) metastases that express NTRK1 fusion proteins, acquired resistance inevitably results in recurrence. The CNS is a sanctuary for targeted drugs; however, the mechanism by which CNS metastases become entrectinib-resistant remains elusive and must be clarified to develop better therapeutics.
Experimental Design: The entrectinib-resistant cell line KM12SM-ER was developed by continuous treatment with entrectinib in the brain metastasis–mimicking model inoculated with the entrectinib-sensitive human colon cancer cell line KM12SM, which harbors the TPM3-NTRK1 gene fusion. The mechanism of entrectinib resistance in KM12SM-ER cells was examined by next-generation sequencing. Compounds that overcame entrectinib resistance were screened from a library of 122 kinase inhibitors.
Results: KM12SM-ER cells, which showed moderate resistance to entrectinib in vitro, had acquired the G667C mutation in NTRK1. The kinase inhibitor foretinib inhibited TRK-A phosphorylation and the viability of KM12SM-ER cells bearing the NTRK1-G667C mutation in vitro. Moreover, foretinib markedly inhibited the progression of entrectinib-refractory KM12SM-ER–derived liver metastases and brain tumors in animal models, predominantly through inhibition of TRK-A phosphorylation.
Conclusions: These results suggest that foretinib may be effective in overcoming entrectinib resistance associated with the NTRK1-G667C mutation in NTRK1 fusion–positive tumors in various organs, including the brain, and provide a rationale for clinical trials of foretinib in cancer patients with entrectinib-resistant tumors harboring the NTRK1-G667C mutation, including patients with brain metastases. Clin Cancer Res; 24(10); 2357–69. ©2018 AACR.
https://ift.tt/2InFHYp
A Phase I Clinical Trial of Guadecitabine and Carboplatin in Platinum-Resistant, Recurrent Ovarian Cancer: Clinical, Pharmacokinetic, and Pharmacodynamic Analyses
Purpose: Epigenetic changes are implicated in acquired resistance to platinum. Guadecitabine is a next-generation hypomethylating agent (HMA). Here, we report the clinical results, along with pharmacokinetic (PK) and pharmacodynamic analyses of the phase I study of guadecitabine and carboplatin in patients with recurrent, platinum-resistant high-grade serous ovarian cancer, primary peritoneal carcinoma (PPC), or fallopian tube cancer (FTC).
Experimental Design: Guadecitabine was administered once daily on days 1 to 5 followed by carboplatin i.v. on day 8 of a 28-day cycle. Patients had either measurable or detectable disease. Safety assessments used CTCAE v4.
Results: Twenty patients were enrolled and treated. Median age was 56 years (38–72 years). The median number of prior regimens was 7 (1–14). In the first cohort (N = 6), the starting doses were guadecitabine 45 mg/m2 and carboplatin AUC5. Four patients experienced dose-limiting toxicity (DLT; neutropenia and thrombocytopenia), leading to dose deescalation of guadecitabine to 30 mg/m2 and of carboplatin to AUC4. No DLTs were observed in the subsequent 14 patients. Grade ≥3 adverse events ≥10% were neutropenia, leukopenia, anemia, nausea, vomiting, ascites, constipation, hypokalemia, pulmonary embolism, small-intestinal obstruction, and thrombocytopenia. Three patients had a partial response (PR), and 6 patients had stable disease (SD) >3 months, for an overall response rate (ORR) and clinical benefit rate of 15% and 45%, respectively. LINE-1 demethylation in PBMCs and promoter demethylation/gene reexpression in paired tumor biopsies/ascites were recorded.
Conclusions: Guadecitabine and carboplatin were tolerated and induced clinical responses in a heavily pretreated platinum-resistant ovarian cancer population, supporting a subsequent randomized phase II trial. Clin Cancer Res; 24(10); 2285–93. ©2018 AACR.
https://ift.tt/2jVP1Ij
Molecular Lymph Node Status for Prognostic Stratification of Prostate Cancer Patients Undergoing Radical Prostatectomy with Extended Pelvic Lymph Node Dissection
Purpose: Molecular lymph node (LN) analysis using quantitative polymerase chain reaction (qPCR) detects LN metastases with higher sensitivity than histopathology. However, the prognostic role of molecular LN status in prostate cancer patients treated with radical prostatectomy (RP) and extended pelvic LN dissection (ePLND) is unclear. To investigate the association of molecular compared with histopathologic LN status with biochemical recurrence.
Experimental Design: Patients with intermediate and high-risk prostate cancer were prospectively enrolled and underwent RP with ePLND, including the obturator, internal, external, and the common iliac region. LNs ≥3 mm were bisected and examined by standard histopathology and qPCR for Kallikrein3 (KLK3) expression. Biochemical recurrence was defined by confirmed postoperative PSA > 0.2 ng/mL.
Results: In 111 patients, 2,411 of 3,173 removed LNs were examined by both methods. Histopathology detected 68 LN metastases in 28 (25%) patients. Molecular analysis confirmed elevated KLK3 expression in 65 histopathologic LN metastases of all 28 pN1 patients (pN1/molN1) and additionally reclassified 224 histopathologic negative LNs and 32 (29%) pN0 patients as LN-positive (pN0/molN1).
At a median follow-up of 48 months, 52 (47%) patients developed biochemical recurrence. Median biochemical recurrence-free survival was 9 months [95% confidence interval (CI), 0.0–20.1] in pN1/molN1 patients, 24 months (95% CI, 1.7–46.3) in pN0/molN1 patients and was not reached in pN0/molN0 patients (P < 0.001). On multivariable Cox regression analysis, molecular LN status [HR 4.1 (95% CI, 1.9–8.8), P < 0.001] but not histopathologic LN status [HR 1.5 (95% CI, 0.8–3.0), P = 0.198] was confirmed as independent predictor of biochemical recurrence.
Conclusions: Molecular LN analysis identified pN0 patients with a high risk of biochemical recurrence and provided superior prognostic information in comparison with histopathology alone. Clin Cancer Res; 24(10); 2342–9. ©2018 AACR.
https://ift.tt/2IkVDdP
Phase Ib Study of Glasdegib, a Hedgehog Pathway Inhibitor, in Combination with Standard Chemotherapy in Patients with AML or High-Risk MDS
Purpose: This open-label, multicenter, dose-finding, phase Ib study (NCT01546038) evaluated the safety, pharmacokinetics, pharmacodynamics, and clinical activity of the novel Hedgehog pathway Smoothened inhibitor glasdegib (PF-04449913) in patients (N = 52) with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS).
Experimental Design: Glasdegib 100 or 200 mg was administered orally, once daily in 28-day cycles, in combination with low-dose cytarabine (arm A) or decitabine (arm B) to newly diagnosed patients considered not suitable for standard induction chemotherapy, and in combination with cytarabine/daunorubicin (arm C) to fit patients. The study followed a standard 3+3 dose-escalation design. The primary endpoint was dose-limiting toxicity (DLT). Ten additional patients were enrolled in expansion cohorts of arms A (n = 23) and C (n = 22) to confirm the recommended phase II dose (RP2D).
Results: No DLTs were observed in arms A and B; 1 DLT (grade 4 neuropathy) occurred in arm C. The most common treatment-related nonhematologic adverse events were mostly grades 1 and 2 in all arms. Muscle spasms, dysgeusia, and alopecia were generally mild. Overall, 16 patients (31%) achieved a complete remission (CR)/CR with incomplete blood count recovery. Note that 100 mg daily was selected as the RP2D for glasdegib in combination with standard chemotherapies in the absence of an estimated MTD in this setting.
Conclusions: Treatment with glasdegib in combination with standard chemotherapy was generally well-tolerated and consistent with prior findings, warranting further evaluation of glasdegib-based combinations in patients with AML or high-risk MDS. Clin Cancer Res; 24(10); 2294–303. ©2018 AACR.
https://ift.tt/2IElJfn
Updated Results of Rituximab Pre- and Post-BEAM with or without 90Yttrium Ibritumomab Tiuxetan during Autologous Transplant for Diffuse Large B-cell Lymphoma
Purpose: We evaluated the effect on long-term survival of adding rituximab (R) to BEAM (carmustine, etoposide, cytarabine, and melphalan) conditioning with or without yttrium-90 ibritumomab tiuxetan (90YIT) in patients with relapsed diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem cell transplant (ASCT).
Experimental design: Patients were enrolled on three consecutive phase II clinical trials. Patients received two doses of rituximab (375 and 1,000 mg/m2) during mobilization of stem cells, followed by 1,000 mg/m2 on days +1 and +8 after ASCT with R-BEAM or 90YIT-R-BEAM (90YIT dose of 0.4 mCi/kg) conditioning.
Results: One hundred thirteen patients were enrolled, with 73 receiving R-BEAM and 40 receiving 90YIT-R-BEAM. All patients had a prior exposure to rituximab. The median follow-up intervals for survivors were 11.8, 8.1, and 4.2 years in the three trials, respectively. The 5-year disease-free survival (DFS) rates were 62% for R-BEAM and 65% for 90YIT-R-BEAM (P = 0.82). The 5-year overall survival rates were 73% and 77%, respectively (P = 0.65). In patients with de novo DLBCL, survival outcomes of the germinal center/activated b-cell histologic subtypes were similar with 5-year OS rates (P = 0.52) and DFS rates (P = 0.64), irrespective of their time of relapse (<1 vs. >1 year) after initial induction chemotherapy (P = 0.97).
Conclusions: Administering ASCT with rituximab during stem cell collection and immediately after transplantation induces long-term disease remission and abolishes the negative prognostic impact of cell-of-origin in patients with relapsed DLBCL. The addition of 90YIT does not confer a further survival benefit. Clin Cancer Res; 24(10); 2304–11. ©2018 AACR.
https://ift.tt/2ImwsaQ
The Magnitude of Androgen Receptor Positivity in Breast Cancer Is Critical for Reliable Prediction of Disease Outcome
Purpose: Consensus is lacking regarding the androgen receptor (AR) as a prognostic marker in breast cancer. The objectives of this study were to comprehensively review the literature on AR prognostication and determine optimal criteria for AR as an independent predictor of breast cancer survival.
Experimental Design: AR positivity was assessed by immunostaining in two clinically validated primary breast cancer cohorts [training cohort, n = 219; validation cohort, n = 418; 77% and 79% estrogen receptor alpha (ERα) positive, respectively]. The optimal AR cut-point was determined by ROC analysis in the training cohort and applied to both cohorts.
Results: AR was an independent prognostic marker of breast cancer outcome in 22 of 46 (48%) previous studies that performed multivariate analyses. Most studies used cut-points of 1% or 10% nuclear positivity. Herein, neither 1% nor 10% cut-points were robustly prognostic. ROC analysis revealed that a higher AR cut-point (78% positivity) provided optimal sensitivity and specificity to predict breast cancer survival in the training (HR, 0.41; P = 0.015) and validation (HR, 0.50; P = 0.014) cohorts. Tenfold cross-validation confirmed the robustness of this AR cut-point. Patients with ERα-positive tumors and AR positivity ≥78% had the best survival in both cohorts (P < 0.0001). Among the combined ERα-positive cases, those with comparable or higher levels of AR (AR:ERα-positivity ratio >0.87) had the best outcomes (P < 0.0001).
Conclusions: This study defines an optimal AR cut-point to reliably predict breast cancer survival. Testing this cut-point in prospective cohorts is warranted for implementation of AR as a prognostic factor in the clinical management of breast cancer. Clin Cancer Res; 24(10); 2328–41. ©2018 AACR.
https://ift.tt/2ICdz78
Phase II Study of the Dual EGFR/HER3 Inhibitor Duligotuzumab (MEHD7945A) versus Cetuximab in Combination with FOLFIRI in Second-Line RAS Wild-Type Metastatic Colorectal Cancer
Purpose: Duligotuzumab is a dual-action antibody directed against EGFR and HER3.
Experimental Design: Metastatic colorectal cancer (mCRC) patients with KRAS ex2 wild-type received duligotuzumab or cetuximab and FOLFIRI until progression or intolerable toxicity. Mandatory tumor samples underwent mutation and biomarker analysis. Efficacy analysis was conducted in patients with RAS exon 2/3 wild-type tumors.
Results: Of 134 randomly assigned patients, 98 had RAS ex2/3 wild-type. Duligotuzumab provided no progression-free survival (PFS) or overall survival (OS) benefit compared with cetuximab, although there was a trend for a lower objective response rate (ORR) in the duligotuzumab arm. No relationship was seen between PFS or ORR and ERBB3, NRG1, or AREG expression. There were fewer skin rash events for duligotuzumab but more diarrhea. Although the incidence of grade ≥3 AEs was similar, the frequency of serious AEs was higher for duligotuzumab.
Conclusions: Duligotuzumab plus FOLFIRI did not appear to improve the outcomes in patients with RAS exon 2/3 wild-type mCRC compared with cetuximab + FOLFIRI. Clin Cancer Res; 24(10); 2276–84. ©2018 AACR.
https://ift.tt/2IkzmwI
A Genetic Polymorphism in CTLA-4 Is Associated with Overall Survival in Sunitinib-Treated Patients with Clear Cell Metastatic Renal Cell Carcinoma
Purpose: The survival of patients with clear cell metastatic renal cell carcinoma (cc-mRCC) has improved substantially since the introduction of tyrosine kinase inhibitors (TKI). With the fact that TKIs interact with immune responses, we investigated whether polymorphisms of genes involved in immune checkpoints are related to the clinical outcome of cc-mRCC patients treated with sunitinib as first TKI.
Experimental Design: Twenty-seven single-nucleotide polymorphisms (SNP) in CD274 (PD-L1), PDCD1 (PD-1), and CTLA-4 were tested for a possible association with progression-free survival (PFS) and overall survival (OS) in a discovery cohort of 550 sunitinib-treated cc-mRCC patients. SNPs with a significant association (P < 0.05) were tested in an independent validation cohort of 138 sunitinib-treated cc-mRCC patients. Finally, data of the discovery and validation cohort were pooled for meta-analysis.
Results: CTLA-4 rs231775 and CD274 rs7866740 showed significant associations with OS in the discovery cohort after correction for age, gender, and Heng prognostic risk group [HR, 0.84; 95% confidence interval (CI), 0.72–0.98; P = 0.028, and HR, 0.73; 95% CI, 0.54–0.99; P = 0.047, respectively]. In the validation cohort, the associations of both SNPs with OS did not meet the significance threshold of P < 0.05. After meta-analysis, CTLA-4 rs231775 showed a significant association with OS (HR, 0.83; 95% CI, 0.72–0.95; P = 0.008). Patients with the GG genotype had longer OS (35.1 months) compared with patients with an AG (30.3 months) or AA genotype (24.3 months). No significant associations with PFS were found.
Conclusions: The G-allele of rs231775 in the CTLA-4 gene is associated with an improved OS in sunitinib-treated cc-mRCC patients and could potentially be used as a prognostic biomarker. Clin Cancer Res; 24(10); 2350–6. ©2018 AACR.
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Evaluation of Overall Response Rate and Progression-Free Survival as Potential Surrogate Endpoints for Overall Survival in Immunotherapy Trials
Purpose: With the approval of immunotherapies for a variety of indications, methods to assess treatment benefit addressing the response patterns observed are important. We evaluated RECIST criteria–based overall response rate (ORR) and progression-free survival (PFS) as potential surrogate endpoints of overall survival (OS), and explored a modified definition of PFS by altering the threshold percentage determining disease progression to assess the association with survival benefit in immunotherapy trials.
Experimental Design: Thirteen randomized, multicenter, active-control trials containing immunotherapeutic agents submitted to the FDA were analyzed. Associations between treatment effects of ORR, PFS, modified PFS, and OS were evaluated at individual and trial levels. Patient-level responder analysis was performed for PFS and OS.
Results: The coefficient of determination (R²) measured the strength of associations, where values near 1 imply surrogacy and values close to 0 suggest no association. At the trial level, the association between hazard ratios (HR) of PFS and OS was R2 = 0.1303, and between the odds ratio (OR) of ORR and HR of OS was R2 = 0.1277. At the individual level, the Spearman rank correlation coefficient between PFS and OS was 0.61. Trial-level associations between modified PFS and OS ranged between 0.07 and 0.1, and individual-level correlations were approximately 0.6. HRs of PFS and OS for responders versus nonresponders were 0.129 [95% confidence interval (CI), 0.11–0.15] and 0.118 (95% CI, 0.11–0.13), respectively.
Conclusions: Although responders exhibited longer survival and PFS than nonresponders, the trial-level and individual-level associations were weak between PFS/ORR and OS. Modifications to PFS did not improve associations. Clin Cancer Res; 24(10); 2268–75. ©2018 AACR.
See related commentary by Korn and Freidlin, p. 2239
https://ift.tt/2IjjJpb
Exploration of a Novel Intermediate Response Endpoint in Immunotherapy Clinical Studies
Purpose: Both objective response rate (ORR) and progression-free survival as defined by RECIST are weakly associated with overall survival (OS) in trials evaluating immunotherapy drug products. We proposed a novel intermediate response endpoint (IME) for evaluating immunotherapies.
Experimental Design: We defined IME response as having no nontarget lesion progression, no new lesion appearance, and reaching a target lesion response determined by baseline tumor burden, tumor reduction depth, and tumor change dynamics within one year after randomization. Database used consisted of data from randomized active-controlled immunotherapy trials. Criterion for IME was developed on the basis of patient-level data from a training dataset, and further evaluated using an independent testing dataset. A patient-level responder analysis comparing OS between patients with and without an IME response was conducted using combined data. Association between trial-level OS hazard ratio (HR) and IME odds ratio (OR) was analyzed using a weighted linear regression model.
Results: A total of 5,806 patients from 9 randomized studies were included in the database. At patient level, patients with IME response had improved OS compared with nonresponders (HR = 0.09). At trial level, association between OS and IME was moderate (R2 = 0.68).
Conclusions: The IME was moderately associated with OS, and the association appeared to be stronger than the association observed between RECIST-defined ORR and OS. However, the analyses conducted in this research are exploratory and further evaluation is needed before using this endpoint in future studies. Clin Cancer Res; 24(10); 2262–7. ©2017 AACR.
https://ift.tt/2IGm15q
DICER1 and Associated Conditions: Identification of At-risk Individuals and Recommended Surveillance Strategies
Pathogenic germline DICER1 variants cause a hereditary cancer predisposition syndrome with a variety of manifestations. In addition to conferring increased cancer risks for pleuropulmonary blastoma (PPB) and ovarian sex cord–stromal tumors, particularly Sertoli–Leydig cell tumor, individuals with pathogenic germline DICER1 variants may also develop lung cysts, cystic nephroma, renal sarcoma and Wilms tumor, nodular hyperplasia of the thyroid, nasal chondromesenchymal hamartoma, ciliary body medulloepithelioma, genitourinary embryonal rhabdomyosarcoma, and brain tumors including pineoblastoma and pituitary blastoma. In May 2016, the International PPB Registry convened the inaugural International DICER1 Symposium to develop consensus testing and surveillance and treatment recommendations. Attendees from North America, Europe, and Russia provided expert representation from the disciplines of pediatric oncology, endocrinology, genetics, genetic counseling, radiology, pediatric surgery, pathology, and clinical research. Recommendations are provided for genetic testing; prenatal management; and surveillance for DICER1-associated pulmonary, renal, gynecologic, thyroid, ophthalmologic, otolaryngologic, and central nervous system tumors and gastrointestinal polyps. Risk for most DICER1-associated neoplasms is highest in early childhood and decreases in adulthood. Individual and caregiver education and judicious imaging-based surveillance are the primary recommended approaches. These testing and surveillance recommendations reflect a consensus of expert opinion and current literature. As DICER1 research expands, guidelines for screening and treatment will continue to be updated. Clin Cancer Res; 24(10); 2251–61. ©2018 AACR.
https://ift.tt/2Imj8U3
Biomarker-Based Therapy in Pancreatic Ductal Adenocarcinoma: An Emerging Reality?
Over the last decade, many of the major solid organ cancers have seen improvements in survival due to development of novel therapeutics and corresponding biomarkers that predict treatment efficacy or resistance. In contrast, favorable outcomes remain challenging in pancreatic ductal adenocarcinoma (PDAC), in part related to the lack of validated biomarkers for patient and treatment selection and thus optimal clinical decision-making. Increasingly, however, therapeutic development for PDAC is accompanied by bioassays to evaluate response and to study mechanism of actions with a corresponding increase in the number of trials in mid to late stage with integrated biomarkers. In addition, blood-based biomarkers that provide a measure of disease activity and allow for minimally invasive tumor analyses are emerging, including circulating tumor DNA, exosomes, and circulating tumor cells. In this article, we review potential biomarkers for currently approved therapies as well as emerging biomarkers for therapeutics under development. Clin Cancer Res; 24(10); 2241–50. ©2017 AACR.
https://ift.tt/2IM2Y9E
Dietary intake of total polyphenol and polyphenol classes and the risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort
Abstract
Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries. During a mean follow-up of 14 years, there were 5991 incident CRC cases, of which 3897 were in the colon and 2094 were in the rectum. Polyphenol intake was estimated using validated centre/country specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, a doubling in total dietary polyphenol intake was not associated with CRC risk in women (HRlog2 = 1.06, 95% CI 0.99–1.14) or in men (HRlog2 = 0.97, 95% CI 0.90–1.05), respectively. Phenolic acid intake, highly correlated with coffee consumption, was inversely associated with colon cancer in men (HRlog2 = 0.91, 95% CI 0.85–0.97) and positively associated with rectal cancer in women (HRlog2 = 1.10, 95% CI 1.02–1.19); although associations did not exceed the Bonferroni threshold for significance. Intake of other polyphenol classes was not related to colorectal, colon or rectal cancer risks. Our study suggests a possible inverse association between phenolic acid intake and colon cancer risk in men and positive with rectal cancer risk in women.
https://ift.tt/2IiGbz2
Functional interplay between E2F7 and ribosomal rRNA gene transcription regulates protein synthesis
Functional interplay between E2F7 and ribosomal rRNA gene transcription regulates protein synthesis
Functional interplay between E2F7 and ribosomal rRNA gene transcription regulates protein synthesis, Published online: 14 May 2018; doi:10.1038/s41419-018-0529-6
Functional interplay between E2F7 and ribosomal rRNA gene transcription regulates protein synthesishttps://ift.tt/2Kks90n
The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicity
The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicity
The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicity, Published online: 14 May 2018; doi:10.1038/s41419-018-0581-2
The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicityhttps://ift.tt/2jVCKUc
Autophagic degradation of caveolin-1 promotes liver sinusoidal endothelial cells defenestration
Autophagic degradation of caveolin-1 promotes liver sinusoidal endothelial cells defenestration
Autophagic degradation of caveolin-1 promotes liver sinusoidal endothelial cells defenestration, Published online: 14 May 2018; doi:10.1038/s41419-018-0567-0
Autophagic degradation of caveolin-1 promotes liver sinusoidal endothelial cells defenestrationhttps://ift.tt/2IIDrhQ
First‐in‐man–proof of concept study with molidustat: a novel selective oral HIF‐prolyl hydroxylase inhibitor for the treatment of renal anaemia
British Journal of Clinical Pharmacology, EarlyView.
https://ift.tt/2IiFEgw
Pharmacological treatments for alleviating agitation in dementia: a systematic review and network meta‐analysis
British Journal of Clinical Pharmacology, EarlyView.
https://ift.tt/2jWkXw5
Reducing potentially inappropriate drug prescribing in nursing home residents: effectiveness of a geriatric intervention
British Journal of Clinical Pharmacology, EarlyView.
https://ift.tt/2ImsqPK
Solitary femoral metastasis in a locoregionally controlled laryngeal carcinoma
ANZ Journal of Surgery, EarlyView.
https://ift.tt/2IF4N8t
Euthanasia and surgeons: an overview of the Victorian Voluntary Assisted Dying Act 2017 and its relevance to surgical practice in Australia
ANZ Journal of Surgery, EarlyView.
https://ift.tt/2IkY68h
A High-Resolution Genetic Map for the Laboratory Rat
An accurate and high-resolution genetic map is critical for mapping complex traits, yet the resolution of the current rat genetic map is far lower than human and mouse, and has not been updated since the original Jensen-Seaman map in 2004. For the first time, we have refined the rat genetic map to sub-centimorgan (cM) resolution (<0.02 cM) by using 95,769 genetic markers and 870 informative meiosis from a cohort of 528 heterogeneous stock (HS) rats. Global recombination rates in the revised sex-averaged map (0.66 cM/Mb) did not differ compared to the historical map (0.65 cM/Mb); however, substantial refinement was made to the localization of highly recombinant regions within the revised map. Also for the first time, sex-specific rat genetic maps were generated, which revealed both genomewide and fine-scale variation in recombination rates between male and female rats. Reanalysis of multiple quantitative trait loci (QTL) using the historical and refined rat genetic maps demonstrated marked changes to QTL localization, shape, and effect size. As a resource to the rat research community, we have provided revised centimorgan positions for all physical positions within the rat genome and commonly used genetic markers for trait mapping, including 44,828 SSLP markers and the RATDIV genotyping array. Collectively, this study provides a substantial improvement to the rat genetic map and an unprecedented resource for analysis of complex traits and recombination in the rat.
https://ift.tt/2KnYSC5
A Dense Linkage Map of Lake Victoria Cichlids Improved the Pundamilia Genome Assembly and Revealed a Major QTL for Sex-Determination
Genetic linkage maps are essential for comparative genomics, high quality genome sequence assembly and fine scale quantitative trait locus (QTL) mapping. In the present study we identified and genotyped markers via restriction-site associated DNA (RAD) sequencing and constructed a genetic linkage map based on 1,597 SNP markers of an interspecific F2 cross of two closely related Lake Victoria cichlids (Pundamilia pundamilia and P. sp. 'red head'). The SNP markers were distributed on 22 linkage groups and the total map size was 1,594 cM with an average marker distance of 1.01 cM. This high-resolution genetic linkage map was used to anchor the scaffolds of the Pundamilia genome and estimate recombination rates along the genome. Via QTL mapping we identified a major QTL for sex in a ~1.9 Mb region on Pun-LG10, which is homologous to Oreochromis niloticus LG 23 (Ore-LG23) and includes a well-known vertebrate sex-determination gene (amh).
https://ift.tt/2Igwd5b
Survey of Human Chromosome 21 Gene Expression Effects on Early Development in Danio rerio
Trisomy for human chromosome 21 (Hsa21) results in Down syndrome (DS), one of the most genetically complex conditions compatible with human survival. Assessment of the physiological consequences of dosage-driven overexpression of individual Hsa21 genes during early embryogenesis and the resulting contributions to DS pathology in mammals are not tractable in a systematic way. A recent study looked loss-of-function of C. elegans orthologues of Hsa21 genes and identified ten candidates with behavioral phenotypes, but the equivalent over-expression experiment has not been done. We turned to zebrafish as a developmental model and, using a number of surrogate phenotypes, we screened Hsa21 genes for dosage sensitive effects on early embyrogenesis. We prepared a library of 164 cDNAs of conserved protein coding genes, injected mRNA into early embryos and evaluated up to 5 days post-fertilization (dpf). Twenty-four genes produced a gross morphological phenotype, 11 of which could be reproduced reliably. Seven of these gave a phenotype consistent with down regulation of the sonic hedgehog (Shh) pathway; two showed defects indicative of defective neural crest migration; one resulted consistently in pericardial edema; and one was embryonic lethal. Combinatorial injections of multiple Hsa21 genes revealed both additive and compensatory effects, supporting the notion that complex genetic relationships underlie end phenotypes of trisomy that produce DS. Together, our data suggest that this system is useful in the genetic dissection of dosage-sensitive gene effects on early development and can inform the contribution of both individual loci and their combinatorial effects to phenotypes relevant to the etiopathology of DS.
https://ift.tt/2wGJxuc
The Protein Arginine Methyltransferase PRMT-5 Regulates SER-2 Tyramine Receptor-Mediated Behaviors in Caenorhabditis elegans
G protein-coupled receptors are 7-pass transmembrane receptors that couple to heterotrimeric G proteins to mediate cellular responses to a diverse array of stimuli. Understanding the mechanisms that regulate G protein-coupled receptors is crucial to manipulating their signaling for therapeutic benefit. One key regulatory mechanism that contributes to the functional diversity of many signaling proteins is post-translational modification. Whereas phosphorylation remains the best studied of such modifications, arginine methylation by protein arginine methyltransferases is emerging as a key regulator of protein function. We previously published the first functional evidence that arginine methylation of G protein-coupled receptors modulates their signaling. We report here a third receptor that is regulated by arginine methylation, the Caenorhabditis elegans SER-2 tyramine receptor. We show that arginines within a putative methylation motif in the third intracellular loop of SER-2 are methylated by PRMT5 in vitro. Our data also suggest that this modification enhances SER-2 signaling in vivo to modulate animal behavior. The identification of a third G protein-coupled receptor to be functionally regulated by arginine methylation suggests that this post-translational modification may be utilized to regulate signaling through a broad array of G protein-coupled receptors.
https://ift.tt/2Igw4yF
COPPER ACYL SALICYLATE HAS POTENTIAL AS AN ANTI-CRYPTOCOCCUS ANTI-FUNGAL AGENT [PublishAheadOfPrint]
The in vitro anti-fungal activity of aspirin against cryptococcal cells has been reported. However, its undesired effects may limit its clinical application. Conceivably, a derivative of aspirin could overcome this challenge. Toward this end, this paper considered the usage of an aspirinate-metal complex viz. copper acyl salicylate (CAS) as an anti-Cryptococcus anti-fungal agent. Additionally, the paper examined the influence of this compound on macrophage function. The in vitro susceptibility results revealed that cryptococcal cells were vulnerable (in a dose-dependent manner) to CAS, which may have effected growth inhibition by damaging cryptococcal cell membranes. Interestingly, when used in combined therapy with fluconazole or amphotericin B, synergism was observed. Furthermore, CAS did not negatively affect the growth as well as the metabolic activity of macrophages rather it sensitised these immune cells to produce INF-y and IL-6, which, in turn, may have aided in the phagocytosis of cryptococcal cells. When compared to our aspirin data, CAS was noted to be more effective in killing cryptococcal cells (based on susceptibility results) and less toxic towards macrophages (based on growth inhibition results). Taken together, it is reasonable to conclude that CAS may be a better anti-Cryptococcus drug that could deliver better therapeutic outcomes when compared to aspirin.
https://ift.tt/2IjteJa
Developmental sensitivity in Schistosoma mansoni to puromycin to establish drug selection of transgenic schistosomes [PublishAheadOfPrint]
Schistosomiasis is considered the most important disease caused by helminth parasites, in terms of morbidity and mortality. Tools to facilitate gain- and loss- of-function approaches can be expected to precipitate the discovery of novel interventions, and drug selection of transgenic schistosomes would facilitate the establishment of stable lines of engineered parasites. Sensitivity of developmental stages of schistosomes to the aminonucleoside antibiotic puromycin was investigated. For the schistosomulum and sporocyst stages, viability was quantified by fluorescence microscopy following dual staining with fluorescein diacetate and propidium iodine. By six days in culture, the 50% lethal concentration (LC50) for schistosomula was 19 μg/ml whereas the sporocysts were 45-fold more resilient. Puromycin potently inhibited the development of in vitro laid eggs (LC50 68 ng/ml) but was less effective against liver eggs (LC50 387 μg/ml). Toxicity for adult stages was evaluated using the xCELLigence-based, real-time motility assay (xWORM), which revealed LC50 values after 48 h of 4.9 and 17.3 μg/ml for male and female schistosomes, respectively. Also, schistosomula transduced with pseudotyped retrovirus encoding the puromycin resistance marker were partially rescued when cultured in the presence of the antibiotic. Together, these findings will facilitate selection on puromycin of transgenic schistosomes and the enrichment of cultures of transgenic eggs and sporocysts to facilitate the establishment of schistosome transgenic lines. Streamlining schistosome transgenesis with drug selection will open up new avenues to understand parasite biology and hopefully lead to new interventions for this neglected tropical disease.
https://ift.tt/2rIGA6C
Evolution of antibiotic resistance in biofilm and planktonic P. aeruginosa populations exposed to sub-inhibitory levels of ciprofloxacin [PublishAheadOfPrint]
The opportunistic Gram-negative pathogen Pseudomonas aeruginosa, known for its intrinsic and acquired antibiotic resistance, has a notorious ability to form biofilms, which often facilitate chronic infections. The evolutionary paths to antibiotic resistance have mainly been investigated in planktonic cultures and are less studied in biofilms. We experimentally evolved P. aeruginosa PAO1 colony-biofilms and stationary-phase planktonic cultures for seven passages in the presence of sub-inhibitory levels (0.1 mg/L) of ciprofloxacin (CIP) and performed a genotypic (whole bacterial population sequencing) and phenotypic assessment of the populations. We observed a higher proportion of CIP resistance in the CIP-evolved biofilm populations compared to planktonic populations exposed to the same drug concentrations. However, the minimal inhibitory concentrations (MICs) of ciprofloxacin were lower in CIP-resistant isolates selected from biofilm population compared to the MICs of CIP-resistant isolates from the planktonic cultures. We found common evolutionary trajectories between the different lineages, with mutations in known CIP resistance determinants as well as growth condition-dependent adaptations. A general trend towards a reduction in type IV-pili dependent motility (twitching) in CIP-evolved populations, and towards loss of virulence associated traits in the populations evolved in the absence of antibiotic, was observed. In conclusion, our data indicate that biofilms facilitate the development of low-level mutational resistance, probably due to the lower effective drug exposure compared to planktonic cultures. These results provide a framework for the selection process of resistant variants and the evolutionary mechanisms in the two different growth conditions.
https://ift.tt/2L1OSj4
Bacterial Silver Resistance Gained by Cooperative Interspecies Redox Behavior [PublishAheadOfPrint]
Silver has emerged as an important therapeutic option for wound infections in recent years due to its broad spectrum antimicrobial activity. The silver cation (Ag+), but not the bulk metal (Ag0), is highly toxic for most microorganisms although resistance due to genetic modification or horizontal gene transfer does occur. Pseudomonas aeruginosa, however, achieves silver resistance by producing the redox active metabolite pyocyanin that reduces Ag+ to non-toxic Ag0. Pyocyanin also possess broad spectrum antimicrobial activity. Many microbial species reduce pyocyanin, which reduces molecular oxygen to antimicrobial hydrogen peroxide. In this study it was hypothesized that both Ag+ and oxygen would act as competing terminal electron acceptors for pyocyanin thus acting as a universal microbial protectant from Ag+ while avoiding hydrogen peroxide formation. Escherichia coli and Staphylococcus aureus efficiently reduced pyocyanin and generated hydrogen peroxide while Ag+ markedly reduced the amount of hydrogen peroxide produced. Although unable to reduce directly Ag+ to Ag0 on their own, E. coli and S. aureus did so when pyocyanin was present resulting in increased survival when exposed to Ag+. Co-incubation experiments with either E. coli or S. aureus with P. aeruginosa demonstrated increased survival for those species to Ag+ but only if pyocyanin was present. These data demonstrate that microorganisms that display no intrinsic silver resistance may survive and proliferate under potentially toxic conditions provided their environment contains a suitable redox-active metabolite-producing bacterium. Chronic wounds are often polymicrobial in nature with pyocyanin producing P. aeruginosa frequently present therefore redox-based silver resistance may compromise treatment efforts.
https://ift.tt/2rIOsFk
Personalizing Polymyxin B Dosing Using an Adaptive Feedback Control Algorithm [PublishAheadOfPrint]
Polymyxin B is used as an antibiotic of last resort for patients with multidrug-resistant Gram-negative bacterial infections; however, it carries a significant risk of nephrotoxicity. Herein we present a polymyxin B therapeutic window based on target area under the concentration-time curve (AUC) values and an adaptive feedback control algorithm (algorithm) which allows for the personalization of polymyxin B dosing. The upper bound of this therapeutic window was determined through a pharmacometric meta-analysis of polymyxin B nephrotoxicity data, and the lower bound was derived from murine thigh-infection pharmacokinetic/pharmacodynamic studies. A previously developed polymyxin B population pharmacokinetic model was used as the backbone for the algorithm. Monte Carlo simulations (MCS) were performed to evaluate the performance of the algorithm using different sparse PK sampling strategies. The results of the nephrotoxicity meta-analysis showed that nephrotoxicity rate was significantly correlated with polymyxin B exposure. Based on this analysis and previously reported murine pharmacokinetic/pharmacodynamic studies, the target AUC0-24h window was determined to be 50-100 mg⋅h/L. MCS showed that with standard polymyxin B dosing without adaptive feedback control, only 71% of simulated subjects achieved AUC values within this window. Using a single pharmacokinetic sample collected at 24 hours and the algorithm, personalized dosing regimens could be computed, which resulted in over 95% of simulated subjects achieving AUC0-24h values within the target window. Target attainment further increased when more samples were used. Our algorithm increases the probability of target attainment using as few as one pharmacokinetic sample and enables precise, personalized dosing in a vulnerable patient population.
https://ift.tt/2L1wkz7
ClpA and HtpX Proteases Are Involved in Intrinsic Aminoglycoside Resistance of Stenotrophomonas maltophilia and Are Potential Aminoglycoside Adjuvant Targets [PublishAheadOfPrint]
The linkage of protease-chaperon system, SmeYZ pump, and aminoglycoside resistance was assessed in Stenotrophomonas maltophilia. The clpA, clpS, clpP, and htpX genes were upregulated in response to kanamycin exposure. Of them, clpA and htpX were the primary determinants responsible for intrinsic AG resistance. Inactivation of clpA and htpX compromised protease-mediated intrinsic aminoglycoside resistances and weakened SmeYZ pump-mediated aminoglycoside resistance, signifying HtpX and ClpA as potential AG adjuvant targets for treatment of S. maltophilia infections.
https://ift.tt/2rJuU3F
Co-location of the polymyxin resistance gene mcr-1 and variant of mcr-3 on a plasmid in Escherichia coli from chicken farm [PublishAheadOfPrint]
A colistin-resistant Escherichia coli from commercial poultry farm in China carried two colistin-resistance genes mcr-1 and variant of mcr-3 in an IncP plasmid. The variant of mcr-3 gene, named mcr-3.11, encoded two amino acid substitutions compared with the mcr-3. A novel genetic structure, ISKpn40-mcr-3-dgkA- ISKpn40, might be the key element mediating translocation of mcr-3 through the formation of circular form. The mcr-1 and mcr-3 genes co-located on a plasmid might pose huge threat to public health.
https://ift.tt/2KYf65I
Identification and characterization of conjugative plasmids that encode ciprofloxacin resistance in Salmonella [PublishAheadOfPrint]
This study aimed to characterize novel conjugative plasmids that encode transferrable ciprofloxacin resistance in Salmonella. In this study, 157 non-duplicated Salmonella isolates were recovered from food products, 55 out of which were found to be resistant to ciprofloxacin. Interestingly, 37 out of the 55 (67%) CipRSalmonella isolates did not harbor any mutations in the Quinolone resistance determine regions (QRDR). Interestingly, six Salmonella isolates were shown to carry two novel types of conjugative plasmids that could transfer ciprofloxacin resistance phenotype to E. coli J53 (AziR). The first type belonged to the ~110kb IncFIB type conjugative plasmid carrying qnrB-bearing and aac(6')-Ib-cr-bearing mobile elements. Transfer of the plasmid between E. coli or Salmonella could confer CIP MIC to 1 to 2μg/ml. The second type of conjugative plasmid belonged to ~240kb IncH1/IncF plasmids carrying a single PMQR gene, qnrS. Importantly, this type of conjugative ciprofloxacin resistance plasmids could be detected in clinical isolates of Salmonella. Dissemination of these conjugative plasmids that confer ciprofloxaicn resistance poses serious public health impact and Salmonella infection control.
https://ift.tt/2rEczoy
in vitro Activity of Imipenem-Relebactam and Ceftolozane-Tazobactam Against Resistant Gram-Negative Bacilli [PublishAheadOfPrint]
Understanding which antimicrobial agents are likely to be active against Gram-negative bacilli can guide selection of antimicrobials for empiric therapy as mechanistic-based (i.e., molecular) rapid diagnostics are adopted. Here, we determined the MICs of the novel β-lactam/β-lactamase inhibitor combination, imipenem-relebactam, along with ceftolozane-tazobactam, imipenem, ertapenem, meropenem, ceftriaxone, and cefepime, against 283 multidrug resistant isolates of Gram-negative bacilli. For isolates harboring blaKPC (n=111), the addition of relebactam to imipenem lowered the MIC50/MIC90 from 16/>128 μg/ml for imipenem alone to 0.25/1 μg/ml. For isolates harboring blaCTX-M (n=48), the MIC50/MIC90 of ceftolozane-tazobactam was 0.5/16 μg/ml (83% susceptible). For isolates harboring blaCMY-2 (n=17), the MIC50/MIC90 of ceftolozane-tazobactam was 4/8 μg/ml (47% susceptible). Imipenem-relebactam was active against most KPC-producing (but not NDM- or IMP-producing) Enterobacteriaceae, and is an encouraging addition to the present antibiotic repertoire.
https://ift.tt/2L3eRX9
Aztreonam-avibactam combination restores susceptibility of aztreonam in dual-carbapenemase-producing-Enterobacteriaceae [PublishAheadOfPrint]
Newly approved Food and Drug Administration (FDA) β-lactam-β-lactamase inhibitor (βL-βLI) inhibitor combinations such as ceftazidime-avibactam and meropenem-vaborbactam are potent inhibitors of class A carbapenemase (typified by KPC [Klebsiella pneumoniae carbapenemase]-like) (1, 2) but are ineffective against carbapenemase-producing Enterobacteriaceae (CPE) producing class B metallo-β-lactamases (MβLs) such as New Delhi metallo-β-lactamase (NDM) (1–4)....
https://ift.tt/2rIwvGN
OXA-72-mediated carbapenem resistance in sequence type 1 multidrug (colistin)-resistant Acinetobacter baumannii associated with urinary tract infection in a dog from Serbia [PublishAheadOfPrint]
Multidrug resistant Acinetobacter (A.) baumannii is primarily important as a causative agent of difficult to treat nosocomial infections in humans (1)....
https://ift.tt/2KZyC21
In vitro and in vivo activity of peptidomimetic compounds that target the periodontal pathogen Porphyromonas gingivalis [PublishAheadOfPrint]
The interaction of the periodontal pathogen Porphyromonas gingivalis with oral streptococci is important for initial colonization of the oral cavity by P. gingivalis and is mediated by a discrete motif of the streptococcal antigen I/II protein. A synthetic peptide encompassing this motif functions as a potent inhibitor of P. gingivalis adherence but the use of peptides as topically applied therapeutic agents in the oral cavity has limitations arising from the relatively high cost of peptide synthesis and their susceptibility to degradation by proteases expressed by oral organisms. In this study, we demonstrate the in vitro and in vivo activity of five small molecule mimetics of the streptococcal peptide. Using a three species biofilm model, all five compounds were shown to effectively inhibit the incorporation of P. gingivalis into in vitro biofilms and exhibited IC50 values of 10 to 20 μM. Four of the five compounds also significantly reduced maxillary alveolar bone resorption induced by P. gingivalis infection in a mouse model of periodontitis. All of the compounds were non-toxic towards a human telomerase immortalized gingival keratinocyte cell line. Three compounds exhibited slight toxicity against the murine macrophage J774A.1 cell line at the highest concentration tested. Compound PCP-III-201 was non-toxic to both cell lines and the most potent inhibitor of P. gingivalis virulence and thus may represent a novel potential therapeutic agent that targets P. gingivalis by preventing its colonization of the oral cavity.
https://ift.tt/2rIXodF
Rifabutin acts in synergy and is bactericidal with frontline Mycobacterium abscessus antibiotics clarithromycin and tigecycline, suggesting a potent treatment combination [PublishAheadOfPrint]
Mycobacterium abscessus (MAB) is a rapidly emerging mycobacterial pathogen causing dangerous pulmonary infections. Because these bacteria are intrinsically multidrug resistant, treatment options are limited and have questionable efficacy. The current treatment regimen relies on a combination of antibiotics including clarithromycin paired with amikacin and either imipenem or cefoxitin. Tigecycline may be added when triple therapy is ineffective. We initially screened a library containing the majority of clinically available antibiotics for anti-MAB activity. The screen identified rifabutin, which was then investigated for its interactions with MAB antibiotics used in drug regimens. Combination of rifabutin with either clarithromycin or tigecycline generated synergistic anti-MAB activity, dropping the rifabutin minimum inhibitory concentration below concentrations found in the lung. Importantly, these combinations generated bactericidal activity. The triple combination of clarithromycin, tigecycline, and rifabutin was also synergistic, and clinically relevant concentrations had a sterilizing effect on MAB cultures. We suggest that combinations including rifabutin should be further investigated for treatment of MAB pulmonary infections.
https://ift.tt/2L3bqzQ
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Αλέξανδρος Γ. Σφακιανάκης Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,0030693260717...
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heory of COVID-19 pathogenesis Publication date: November 2020Source: Medical Hypotheses, Volume 144Author(s): Yuichiro J. Suzuki ScienceD...
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