MicroRNA 130b enhances drug resistance in human ovarian cancer cells.

MicroRNAs (miRNAs) have recently been identified as a novel class of gene regulators, playing an important role in various malignancies. In the present study, we investigated the role of miRNA-130b in the development of drug resistance in ovarian cancer cells. The human ovarian carcinoma cell line A2780 and paclitaxel-resistant A2780/Taxol cells were exposed to the chemotherapeutic agent cisplatin or paclitaxel in the presence or absence of transfected miR-130b. Cell viability assays were then performed using the Cell Counting Kit-8 (CCK-8) assay. Reverse transcription polymerase chain reaction and Western blotting were used to assess the messenger RNA (mRNA) and protein expression levels of glutathione S-transferase (GST)-π, multidrug resistance (MDR)1, or P-glycoprotein (P-gp). Following transfection, we found higher expression levels of miR-130b in A2780/Taxol cells than in A2780 cells (p < 0.05). Both A2780 and A2780/Taxol cells showed decreased sensitivity to paclitaxel and cisplatin compared with mock-transfected and negative control cancer cells (p < 0.05). The mRNA expression levels of MDR1 and GST-π (p < 0.05) and the protein expression levels of P-gp and GST-π were downregulated following miR-130b transfection in comparison to mock-transfected and negative control cancer cells. Our findings suggest that miRNA-130b may be involved in the development of drug resistance in ovarian cancer.