Impact Of MiR-1271 On Cisplatin Resistance In Human Ovarian Cancer Cell Line SKOV3/DDP And Its Mechanism Research

Objective: To investigate the possible role of mi R-1271 in the development of cisplatin resistance in human ovarian cancer cell line SKOV3/DDP by detecting the expression of mi R-1271 in ovarian cancer cell lines.Methods: 1.The expression of mi R-1271 was detected by real-time PCR quantitative in cisplatin-resistant human ovarian cancer cell line SKOV3/DDP.2.MTT was used to detect the sensitivity of ovarian cancer SKOV3/DDP cells to cisplatin after transient transfection of mi R-1271 mimic into the cell lines.3.Flow cytometry was used to detect the apoptosis of SKOV3/DDP cells after transient transfection of mi R-1271 mimic into the cell lines.4.XIAP-3'-untranslated region-based luciferase reporter plasmids was constructed to verify the target gene of mi R-1271.5.After transient transfection of mi R-1271 mimic into the cell lines,Western blotting was used to detect the expression difference of antiapoptotic protein XIAP in cisplatin-resistant human ovarian cancer cell line SKOV3/DDP and its parental SKOV3 cell line,respectively.Results: 1.Mi R-1271 was downregulated in cisplatin-resistanthuman ovarian cancer cell line SKOV3/DDP,thesignificantlydownregulation in cisplatin-resistant human ovarian cancer cell line SKOV3/DDP,compared with the parental SKOV3 cell line.The downregulated fold was 4.7±0.3.P<0.01.2.Compared with the control group,the IC50 was 4.1±0.4 ?g/ml,while the IC50 of cisplatinin mi RNA mimic control transfected group was16.8±0.4 ?g/ml.P<0.01.3.Overexpression of mi R-1271 also sensitized SKOV3/DDP cells to DDP-induced apoptosis.In SKOV3/DDP cells,apoptosis evaluated by flow cytometry showed that a marked increase in apoptosis in mi R-1271 mimic transfected cells after DDP treatment,compared with the mi RNA mimic control transfected cells.The apoptosis rate was 14.5±1.1% and 6.1±0.8%,respectively.4.The luciferase activity of XIAP-3'-untranslated region-based reporters constructed in SKOV3/DDP cells suggested that XIAP was the direct target gene of the mi R-1271.In SKOV3/DDP cells,a significant decrease in relative luciferase activity was noted when p GL3-XIAP-3'-UTR was cotransfected with the mi R-1271 mimic in comparison with the control.The downregulated fold change was1.9±0.1.P<0.01.5.The antiapoptotic protein XIAP was significnatly upregulated in cisplatin-resistant human ovarian cancer cell line SKOV3/DDP,compared with the parental SKOV3 cell line.The upregulated fold change was 1.8±0.1.P<0.01.6.After the transfection,significantly decreased XIAP protein level in mi R-1271 mimic transfected cells was found,compared with the mi RNA mimic control transfected cells.The downregulated fold change was 2.2±0.2.P<0.01.Conclusion: 1.Compared with the parental ovarian cancer cell line SKOV3,the expression of mi R-1271 in cisplatin resistant ovarian cancer cell line SKOV3/CDDP was decreased while the expression of XIAP was increased.2.After transient transfection of mi R-1271 mimic into the SKOV3/DDP cell lines,the sensitivity of cisplatin resistant ovarian cancer cell line SKOV3/DDP to cisplatin was increased while the expression of XIAP was decreased.3.XIAP is a direct target gene of mi R-1271.4.Mi R-1271 could increase the sensitivity of human ovarian cancer cell line SKOV3/DDP to cisplatin by inhibiting XIAP's expression.