Differentially Expressed MiRNAs in Epithelial Ovarian Cancer Tissue and Serum Samples by MiRNA Microarray Analysis

Epithelial ovarian cancer (EOC) is the type of ovarian cancer having the highest mortality rate. Because of the asymptomatic characteristic and a few diagnostic tests, it is mostly diagnosed at advanced stages. Therefore, this study aims to gain the predictive and/or early diagnostic novel circulating miRNAs for EOC. Firstly, microarray analysis of miRNA expression level is performed on plasma samples from pathologically confirmed EOC patients and matching healthy individuals; EOC tissue samples and benign ovarian neoplastic tissues. 31 significantly dysregulated miRNAs in serum and 3 miRNAs in tissue were identified by microarray. The results were validated using RT-qPCR. KEGG database was used for the target gene and pathway analysis. Three miRNA from EOC serum (hsa-miR-1909-5p, hsa-miR-885-5p, hsa-let-7d-3p) and one microRNA from tissue samples (hsa-miR-200c-3p) were validated as significant enough to distinguish EOC patients from healthy individuals. KEGG pathway enrichment analysis showed 7 significant pathways, which are prion diseases, proteoglycans in cancer, oxytocin signaling pathway, hippo signaling pathway, adrenergic signaling in cardiomyocytes, oocyte meiosis, and thyroid hormone signaling pathway, in which our validated miRNAs have a role. It supports our hypothesis that several miRNAs, in our case validated 4 miRNAs, can have the potential to be a biomarker of EOC diagnosis and treatment. Microarray analysis of miRNA expression level is performed on a total of 32 plasma samples from pathologically confirmed 8 EOC patients and 8 matching healthy individuals; 8 EOC tissue samples and 8 benign ovarian neoplastic tissues. 31 significantly dysregulated miRNAs in serum and 3 miRNAs in tissue were identified by microarray.