miRNA-34a decreases ovarian cancer cell proliferation and chemoresistance by targeting HDAC1

This study aimed to explore the roles of miRNA-34a (miR-34a) in ovarian cancer (OC) cells and uncover possible mechanisms. The proliferation of OC cells was measured with an MTT assay and soft agar colony formation assay. TargetScan analysis, real-time PCR, and a luciferase reporter assay were used to demonstrate the downstream target of miR-34a in OC cells. HDAC1 expression levels were detected by immunoblot analysis. miR-34a inhibited the proliferation of SKOV3 and OVCA433 cells and enhanced cisplatin sensitivity in cisplatin-resistant SKOV3cp cells. The results of TargetScan analysis, real-time PCR, and luciferase reporter assay confirmed that miR-34a downregulated HDAC1 expression by directly targeting the 3'-UTR of HDAC1 mRNA. The overexpression of HDAC1 decreased cisplatin sensitivity and promoted proliferation in OC cells. MTT assay and soft agar colony formation assay showed that HDAC1 overexpression blocked the suppressive effects of miR-34a on SKOV3 cell proliferation. In addition, treatment with the miR-34a mimic partially recovered the cisplatin sensitivity of SKOV3cp cells, whereas HDAC1 overexpression blocked the above phenomena caused by treatment with the miR-34a mimic. miR-34a exhibited suppressive effects on OC cells via directly binding and downregulating HDAC1 expression, which subsequently decreased the resistance to cisplatin and suppressed proliferation in OC cells.