microRNA 490-3P enhances the drug-resistance of human ovarian cancer cells

Background: MicroRNAs (miRNAs) are non-coding, single-stranded small RNAs that regulate gene expression negatively, which is involved in fundamental cellular processes. In this study, we investigated the role of miR-490-3P in the development of drug resistance in ovarian cancer cells. Methods: The human ovarian carcinoma cell line A2780 and A2780/Taxol were exposed to paclitaxel in the presence or absence of microRNA 490-3P transfection, after which cell viability were performed by CCK-8 assay. Reverse transcription polymerase chain reaction (RT-PCR) and western blotting were used to assess the mRNA and protein expression levels of GST-p, MDR1 or P-gp. Results: Our results showed higher miR-490-3P mRNA expression level in A2780/Taxol cells than in A2780 cells (p < 0.05). Following miR-490-3P transfection, both A2780 and A2780/Taxol cells showed decreased sensitivity to paclitaxel. The mRNA expression levels of MDR1, GST-p (p < 0.05) and protein expression levels of P-gp, GST-p were down-regulated after miR-490-3P transfection in comparison to mock and negative control cancer cells. Conclusion: Our results demonstrate for the first time that microRNA 490-3P may be involved in the development of drug resistance in ovarian cancer.