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Τετάρτη 5 Ιουλίου 2017

Looking beyond human papillomavirus (HPV) genotype 16 and 18: Defining HPV genotype distribution in cervical cancers in Australia prior to vaccination

Abstract

Australia has implemented a high coverage HPV vaccination program but has not to date established the distribution of HPV types that occur in cervical cancers in Australia. This information is important for determining the potential for cervical cancer prevention with both current and broader spectrum HPV vaccines. We analysed 847 cervical cancers diagnosed 2005-2015 in tertiary centres in the three most populous Australian states with resolution of specimens containing multiple HPV types using laser-capture microdissection. Archived FFPE tissue was reviewed by specialist pathologists, sandwich sectioned, and initially whole tissue sections genotyped for HPV. Samples were first genotyped using SPF10-LiPA25. Negative samples were screened with DNA ELISA kit HPV SPF10, followed by genotyping with SPF+ LiPA if ELISA positive. If still negative, samples were tested on a qPCR assay targeting the E6 region of HPV16,18, 45 and 33. Of the 847 cancers (65.1% squamous, 28.7% adenocarcinoma, 4.3% adenosquamous, 2.0% other), 92.9% had HPV detected. Of the HPV positive cancers, 607/787 (77.1%) contained HPV16 or 18, 125/787 (15.9%) contained HPV31/33/45/52 or 58, and 55 (7.0%) another HPV type. There was a strong correlation between HPV type and age, with younger women most likely to have HPV16/18 detected and least likely HPV negative. Our findings indicate that cervical cancers diagnosed in Australia more frequently contain HPV16/18 than in international series. This could be due to cervical screening in Australia increasing the proportion of adenocarcinomas, in which types 18 and 16 more strongly predominate, due to prevention of squamous cancers. This article is protected by copyright. All rights reserved.



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The Clinical Impact of Tumour-infiltrating Lymphocytes in Colorectal Cancer Differs by Anatomical Subsite: A Cohort Study

Abstract

Accumulating evidence demonstrates an association between dense infiltration of lymphocytes and prognosis in colorectal cancer (CRC), but whether this prognostic impact differs by tumour location remains unknown. This study investigated the prognostic impact of cytotoxic and regulatory T cells in CRC, with particular reference to the anatomical subsite of the primary tumour. The density of CD3+, CD8+, and FoxP3+ tumour-infiltrating T cells was calculated in tissue microarrays with tumours from 557 incident CRC cases from a prospective population-based cohort. Kaplan-Meier and Cox regression analyses were applied to determine the impact of high and low lymphocyte density on 5-year overall survival, in subgroup analysis of right colon, left colon, and rectum. High CD8+ cell density was a favourable prognostic factor for patients with right-sided colon tumours (hazard ratio [HR]=0.53, 95% confidence interval [CI] 0.29-0.95), independent of age, sex, TNM stage, differentiation grade, and vascular invasion, with a significant prognostic interaction between CD8+ cells and right-sidedness (p = 0.031). High FoxP3+ cell density was an independent favourable prognostic factor only in patients with rectal tumours (HR=0.54, 95% CI 0.30-0.99), and CD3+ cell density was an independent favourable prognostic factor for tumours in the right colon and rectum, but there was no significant prognostic interaction between CD3+ or FoxP3+ cells and sidedness. These results demonstrate that the prognostic impact of tumour-infiltrating lymphocytes in CRC differs by primary tumour site, further indicating that tumour location may be an important factor to take into consideration in therapeutic decisions, including eligibility for immunotherapy. This article is protected by copyright. All rights reserved.



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Connexin 43 Upregulation by Dioscin Inhibits Melanoma Progression via Suppressing Malignancy and Inducing M1 Polarization

Abstract

Connexin 43 (Cx43), a vital gap junction protein in tumor microenvironment (TME), is a novel molecular target for melanoma chemotherapeutics due to its tumor suppressive function. Dioscin, an herbal steroidal saponin, exerts anti-tumor effects while the underlying mechanism is unclear. Using WB, FACS, and immunofluorescence methodologies, we found dioscin significantly activated the transcription and translation of Cx43 via the retinoid acid signaling pathway and simultaneously enhanced the transporting function of Cx43. Through stimulating Cx43, dioscin remarkably suppressed the migratory and invasive capacities of B16 cells, and notably decreased pluripotency markers of cancer stem cells and epithelial-to-mesenchymal transition in B16 cells and animal tumor tissues. On the other hand, dioscin improved the secretion of pro-inflammatory cytokines (IL-6, TNFα and IL-1β), and the phagocytic capacity of tumor-associated macrophages by increasing M2-to-M1 phenotype transition. More strikingly, even in Cx43 functional deficient B16 and RAW264.7 cells, dioscin still dramatically reversed the aggravated tumor malignancy and reduced macrophage phagocytic activity. Two classical metastasis animal models were utilized in vivo and results showed that dioscin showed significant anti-metastatic effects, which is closely related to the expression of Cx43 either in in situ tumor or metastatic lung nodes. In conclusion, dioscin targets Cx43 to suppress the tumor cell malignancy and activate macrophage sensitivity, thereby targeting melanoma microenvironment. This article is protected by copyright. All rights reserved.



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DS-8201a, a new HER2-targeting antibody-drug conjugate incorporating a novel DNA topoisomerase I inhibitor, overcomes HER2-positive gastric cancer T-DM1 resistance

Abstract

Anti-HER2 therapies are beneficial for patients with HER2-positive breast or gastric cancer. T-DM1 is a HER2-targeting antibody-drug conjugate (ADC) comprising the antibody trastuzumab, a linker, and the tubulin inhibitor DM1. Although effective in treating advanced breast cancer, all patients eventually develop T-DM1 resistance. DS-8201a is a new ADC incorporating an anti-HER2 antibody, a newly developed, enzymatically cleavable peptide linker, and a novel, potent, exatecan-derivative topoisomerase I inhibitor (DXd). DS-8201a has a drug-to-antibody-ratio (DAR) of 8, higher than that of T-DM1 (3.5). Owing to these unique characteristics and unlike T-DM1, DS-8201a is effective against cancers with low-HER2 expression. In the present work, T-DM1-resistant cells (N87-TDMR), established using the HER2-positive gastric cancer line NCI-N87 and continuous T-DM1 exposure, were shown to be susceptible to DS-8201a. The ATP-binding cassette (ABC) transporters ABCC2 and ABCG2 were upregulated in N87-TDMR cells, but HER2-overexpression was retained. Furthermore, inhibition of ABCC2 and ABCG2 by MK571 restored T-DM1 sensitivity. Therefore, resistance to T-DM1 is thought to be caused by efflux of its payload DM1, due to aberrant expression of ABC transporters. In contrast to DM1, DXd payload of DS-8201a inhibited the growth of N87-TDMR cells in vitro. This suggests that either DXd may be a poor substrate of ABCC2 and ABCG2 in comparison to DM1, or the high DAR of DS-8201a relative to T-DM1 compensates for increased efflux. Notably, N87-TDMR xenograft tumor growth was prevented by DS-8201a. In conclusion, the efficacy of DS-8201a as a treatment for patients with T-DM1-resistant breast or gastric cancer merits investigation. This article is protected by copyright. All rights reserved.



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VEGF and TWIST1 in a 16-biomarker immunoprofile useful for prognosis of breast cancer patients

Abstract

This study concerns the expression of biomarkers involved in diverse pathways, such as progression, DNA repair mechanisms and angiogenesis, in order to establish an immunoprofile capable of characterizing sporadic versus familial breast cancers (BCs). The aim was to identify a patient subgroup with a different clinical outcome, which could then be directed towards new targeted therapies. Hierarchical cluster analysis (HCA) was carried out using the immunohistochemical score from tissue microarray sections of an initial cohort of 183 (88 sporadic and 95 familial) patients with invasive BC. For the survival analysis, only those patients with complete follow-up were considered. The HCA revealed a 16-protein immunoprofile, 9 of which represent the core, as was also found when familial and sporadic BCs were analysed individually. The 16-biomarker immunoprofile was able to identify a group of patients (Group 1) with a more aggressive tumour phenotype. Survival analyses showed that VEGF+/TWIST1- patients with familial BC of Group 1 tended to demonstrate a lower DFS than the VEGF-/TWIST1+ sporadic BC patients of Group 2 (p=0.052). Moreover, the entire cohort of VEGF+/TWIST1- patients showed a statistically worse DFS than the patients with VEGF-/TWIST1+ expression (p=0.034). In conclusion, we found that tumour stratification based on an immunoprofile is useful to predict the patient clinical behaviour. In particular, our study indicates that the clustering of tumors on the basis of this immunoprofile suggests the possibility to differentiate familial from sporadic BCs and to clinically select those patients who are more likely to benefit from inhibition of the VEGF pathway. This article is protected by copyright. All rights reserved.



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