Hypoxia Imaging and Biological Evaluation of the Radiosensitizing Effect of Oleanolic Acid

Background and Purpose. The aim of this study was to evaluate the radiosensitizing effect of oleanolic acid (OA) on C6 rat glioma and the changes in tumor biology during radiosensitization therapy on 18F-fluoromisonidazole (18F-FMISO) positron emission tomography/computed tomography (PET/CT). Methods. The radiosensitizing effect of OA on C6 tumors was assessed in vivo by measuring the tumor inhibitory rate and rat survival time. Meanwhile, rats with C6 tumors were imaged with 18F-FMISO PET/CT during radiosensitization therapy. Tumor-to-muscle ratio (TMR) of 18F-FMISO maximum uptake was calculated by region of interest analysis. Changes in tumor biology after therapy were assessed with immunohistochemical staining. 18F-FMISO uptake was analyzed in relation to expression of tumor biomarkers including hypoxia-inducible factor (HIF)-1α, glucose transporter (Glut-1), the proliferation antigen Ki67, tumor suppressor P53, and microvessel density (MVD). Results. The results showed that OA combined with radiation inhibited the growth rates of tumors and prolonged the survival period of tumor-bearing rats effectively (χ2 = 12.5, p

https://ift.tt/2wl8OHT