The investigation of expression levels of miR-16-5p, miR-17-5p, miR-638 in patients with ovarian cancer

Ovarian cancer is a lethal gynecologic malignancy among women. More than 70% of women with ovarian cancer are diagnosed in advanced stages and most of these cases are incurable. Although most patients respond well to primary chemotherapy, tumors become resistant to treatment. MicroRNAs (miRNAs) are 19-25 nucleotide-long, small non-protein coding RNAs that regulate gene expression at the post-transcriptional level through translational inhibition and degredation of their target mRNAs. Many miRNAs have been determined to act as oncogenes, tumor suppressors, and even modulators of cancer stem cells and metastasis. Based on the findings obtained from the microarray study by our research team previously, we concluded that the miR-16-5p, miR-17-5p, miR-638 could be important in the etiology of ovarian cancer and had to be searched and validated in larger ovarian cancer cohort and healthy controls. The aim of the presented study was to determine whether they have a biomarker potential for the early diagnosis of patients with ovarian cancer and prognosis of the disease in larger ovarian cancer patients cohort and healthy controls. For this purpose, peripheral blood samples of 142 patients with ovarian cancer and 97 healthy controls which were ethnicity, age and gender-matched were used. For gene expression analysis, RNA isolation from lymphocytes, cDNA synthesis specific to miRNAs followed by Real-Time PCR methods were performed. As a result of the study, it was seen that miRNA gene expression levels increased more than twice in the patient groups compared to healthy controls groups and it was statistically significant (p <0.05). The p values obtained for each miRNA; miR-16-5p, p <0.001; miR-17-5p, p <0.001 miR-638, p = 0.005. In addition, when miRNA expression levels were compared with the clinical data of the patients; There was a significant difference between smoking status of patients and increased expression level of miR-17-5p (p = 0.007). There was also a significant difference between the increased expression level of miR-638 and patients with locally advanced disease (p = 0.03). The findings suggest that the miRNAs examined have an oncogenic character in cancer patients and thus, trigger the locally advanced disease. The miR-16-5p, miR-17-5p and miR-638 molecules are thought to be highly likely to be potential biomarkers for detecting ovarian cancer and demonstrating prognosis.