Validation of altered miRNAs in ovarian cancer tumors

Ovarian cancer is the fifth most fatal cancer type in developing populations. 90% of ovarian cancer varieties have epithelial histology and they are called epithelial ovarian cancer. Early diagnosis is important for survival in ovarian cancer. 5-year survival rate reaches 90% when it is diagnosed at an early stage. Early diagnosis cannot be diagnosed due to the mild symptoms of ovarian cancer and a lack of biomarker with high specificity and sensitivity. MicroRNAs are small non-coding RNA families and are effective in regulating a wide range of biological processes including carcinogenesis. As a result of the researches, it has been emphasized that the change of microRNA expressions is an important contribution to the development and progression of ovarian cancer. With the whole wide genomic analysis, microRNAs have been found to change their expression in many cancers, including ovarian cancer and it is emphasized that microRNAs may be an effective biomarker. In the thesis, tissue samples were collected from 10 patients with epithelial ovarian cancer in the same age range and ovarian cyst tissue samples were collected from 10 individuals as control group and 3 microRNAs (hsa-mir-200c-3p, hsa-mir-4665-3p and hsa-mir-6737-3p) that were previously determined and differentiation of their expression by microarray method were validated by Real-Time PCR method. According to the results of the microarray method, these 3 microRNAs were found to be increased in the epithelial ovarian cancer tissues. Hsa-mir-200c-3p, hsa-mir-4665-3p and hsa-mir-6737-3p were validated by Real-Time PCR method, bioinformatic analysis of obtained Ct values were done by "Wilcoxon test". The genes targeted in ovarian cancer were determined by using "Pathway studio", "DIANA TOOLS" and "TargetScan" databases. The expression of hsa-mir-200c-3p (p=0.0273, AUC=0.83) was found to be significantly increased in epithelial ovarian cancer tissue samples. Increase of hsa-mir-4665-3p (p=0.13, AUC=0.83) and hsa-mir-6737-3p's (p=0.8457, AUC=0.50) expression were not significant.