Research Of Inhibition Of MicroRNA-23A Expression Increased Sensitivity Of Cisplatin For Ovarian Cancer Cells And Its Molecular Mechanisms

Background Ovarian cancer is one of the most common malignant tumors of female genital,posed a serious threat to women’s lives.Tumor resistance often leads to reduced sensitivity of cancer cells to chemotherapy drugs,therefore,the study of ovarian cancer tumor cells drug resistance,ways to enhance tumor cell drug sensitivity in cancer therapy and prolong the survival time of cancer patients has very important meaning.However,the most barrier is that cancer cells resistant to platinum,and with the similar chemical structures of platinum,how to overcome the resistance and improve the sensitivity to platinum is a big issue and has great meanings.Objective MicroRNAs(miRNAs)are small non-coding RNA molecules that regulate growth,development,and programmed death of cells.In ovarian cancer tumor cells resistant to Cisplatin,miR-23 A expressde highly.This research analyze sensitivity change and its preliminary mechanism of inhibition of miR-23 a expression fot the resistant A2780 ovarian cancer cells to supply new clinic ways of chemotherapeutic drug Cisplatin resistance.Methods After the A2780 cells were cultured,they were divided into two groups,group A was ovarian tumor cells resistant to Cisplatin,group B was non-resistant cells.RT-PCR detectde the expression of miR-23 A,Cell proliferation inhibition rate after treating by antagomir-23 a and Cisplatin detected by MTT assay;Cell cycle distribution detected by flow cytometric analysis;Apoptotic morphological changes detected by Hoechst33258 staining;Glycoprotein P-gp expression changes detected by Western blot analysis.Western blot also detected the changing level of E-cardherin and N-cardherin expression.Transwell tested the different moving levelof ovarian tumor cells.SPSS 20.0 was used to analyze all the datas we collected.Results Inhibition of miR-23 A and after platinum treatment,cell proliferation inhibition rate increased significantly(P <0.01),middle concentration of drug efficacy IC50 is 17.89 μmol/L,compared with the control group IC50 110.18 μmol/L decreased 83.76%(P <0.01);Cells were arrested in G0/G1 phase and apoptosis rate increased(P <0.01);Hoechst33258 staining nuclei concentration,staining increased.Western blot analysis suggested cell expression of P-gp protein concentration increased with cisplatin gradually reduced(P <0.01).After miR-23 A was depressed,E-cardherin and N-cardherin also decreased,the invasitity of cells decreased.Transwell shows that moving ability of cells decrease after miR-23 A was depressed.Conclusion After inhibition of miR-23 A expression of resistant ovarian carcinoma A2780 cells,the sensitivity of cisplatin for cells increased significantly,which with related miR-23 A target genes to ease the negative regulatory factors,and thus lead to inhibition of P-gp protein expression related.Furthermore,our data indicated with the miR-23 A expression increased,Runx3 expression decreased by miR-23 A binding its 3’UTR.Additionally,the expression of MDR1 was also decreased,thus,P-gp protein in A2780 cells expressed highly,showing a classic way of drug resistance.Whereas if the expression of miR-23 A was depressed,P-gp protein expression decreased,which depressde the way of classic resistance,making A2780 cells sensitive to drup Cisplatin.