Effects of miR-135a on HOXA10 expression, proliferation and apoptosis of ovarian cancer cells / 中华妇产科杂志

ABSTRACT

Objective To investigate the effects of miR-135a on HOXA10 expression,proliferation and apoptosis of SKOV3 cells.Methods (1) Through computer-aided algorithms,the predicted target gene of miR-135a (HOXA10)were determined.(2) miR-135a mimics,miR-135a inhibitor and negative control were transfected into SKOV3 cells,respectively.Reverse transcription (RT)-PCR,western blot analysis were used to examine the expression levels of HOXA10 at different times (24,48 and 72 hours).(3) A luciferase reporter assay was used to confirm the direct regulation between miR-135a and HOXA10.(4) SKOV3 cells proliferation at different times (24,48 and 72 hours) was detected by methyl thiazolyl tetrazolium(MTT) assay [quantified by absorbance(A)].Western blot was used to examine the expression of apoptosis-associated protein bcl-2,bax and caspase-3 in SKOV3 cells after 48 hours transfection.Results (1) HOXA10 was predicted to be the target gene of miR-135a by computer-aided algorithms.(2) RT-PCR shown that HOXA10 mRNA levels were decreased over time (24,48 and 72 hours) after miR-135a mimics transfectionin SKOV3 cells (0.94 ±0.04 vs 0.78 ±0.03 vs 0.70 ±0.03,P ＜0.05).While,the expression of HOXA10 mRNA was increased over time after miR-135a inhibitor transfection (1.14 ± 0.05 vs 1.16 ±0.03 vs 2.60 ±0.08,P ＜0.05).After transfected with miR-135a mimics or miR-135a inhibitor over 48 and 72 hours,the HOXA10 expression levels in SKOV3 cells were significantly lower or higher than each control group,respectively (all P ＜ 0.01).Western blot analysis of HOXA10 expression in SKOV3 cells confirmed the results of RT-PCR detected.(3) After cotransfection of miR-135a plasmid and pMIR-REPORT luciferase plasmid containing HOXA10,luciferase reporter assays showed that the luciferase activity reduced by 67.8％ (P ＜0.01).(4) MTT showed that SKOV3 cells growth after miR-135a mimics transfection for 48 and 72 hours were significantly lower than those in control group (0.38 ± 0.03 vs 0.52 ± 0.05,0.67 ±0.05 vs 0.75 ± 0.06 ; respectively,all P ＜ 0.05).While,SKOV3 cells transfected with miR-135a inhibitor for 72 hours grew significantly faster than that in control group (0.95 ± 0.05 vs 0.75 ± 0.06,P ＜ 0.01).After miR-135a mimics transfection,the level of bcl-2 protein was significantly lower than that in control group (0.28 ±0.06 vs 0.76 ±0.09,P ＜0.01).The activity of caspase-3 was significantly higher than that in control group (115.0 ± 2.4 vs 95.4 ± 2.1,P ＜ 0.01).While,there was no statistical difference of bax expression (P =0.142).However,after miR-135a inhibitor transfection,the expression level of bcl-2 protein was significantly higher than that in control group (0.92 ± 0.03 vs 0.76 ± 0.09,P =0.037) and the activity of caspase-3 was significantly lower than that in control group (59.5 ± 4.1 vs 95.4 ± 2.1,P ＜ 0.01).There was also no statistical difference of bax expression (P =0.066).Conclusion miR-135a may play an important role in cell proliferation and apoptosis of ovarian cancer cells by regulating HOXA10 and its downstream pathways.