Effect of miR-145 on migration and invasion of ovarian cancer cells

Objective To evaluate the effect of miR-145 on migration and invasion of ovarian cancer cells. Methods The effect of miR-145 overexpression on the expression levels of miR-145 and zeb-2 were detected with qRT-PCR and Western blotting. The changes of in vitro migration and invasion were examined using Transwell assay. Target genes of miR-145 were predicted by bioinformatics software. Dual-luciferase reporter assay were used to verify zeb-2 as a direct target of miR-145. zeb-2 siRNA was transiently transfected in SK0V3 and 3AO cells, Transwell was used to examine in vitro migration and invasion abilities. Results The migration and proliferation of SK0V3 (t = 10.752, P = 0.000; t = 5.617, P = 0.005) and 3AO cells (t = 10.111, P = 0. 001; t =21.746, P =0.000) decreased significantly after overexpression of miR-145. The results of dual-luciferase reporter assay showed that the relative luciferase activity of co-transfected miR-145 mimic and WT 3 ' UTR expression vectors was significantly lower than that of co-transfected mimic control and WT 3 ' UTR expression vectors (SKOV3: t = 4.572, P = 0.010; 3AO: t = 3.528, P= 0.024) . There was no significant difference in relative luciferase activity between co-transfected miR-145 mimic/MUT 3 ' UTR expression vector cells and co-transfected mimic control/MUT 3 ' UTR expression vector cells (SKOV3: t = 0.227, P =0.831; 3AO: t = 0.040, P = 0.970) . Real-time quantitative PCR showed that the zeb-2 expressions in SKOV3 (t = 1.490, P =0.211) and 3AO cells (t =0.114, P =0.914) were not significantly different from negative control after 48 h of miR-145 overexpression. Western blot analysis showed that the expression of zeb-2 protein in SKOV3 (t = 3.769, P = 0.020) and 3AO cells (t =4.452, P = 0.011) decreased significantly compared with negative control after 72 h of miR-145 overexpression. Seventy-two hours after transfection of zeb-2 siRNA, Western blotting showed that the expression of zeb-2 protein in SKOV3 (t = 4 . 6 6 0, P =0.010) and 3AO cells (t = 4 . 5 9 4, P =0. 010) was significantly down-regulated. Transwell assay showed that the migration and invasion abilities of SKOV3 (t = 18.655, P=0.000: t = 18.026, P=0.000) and 3 AO cells (t = 5 . 5 0 0, P = 0. 005; t = 8 . 7 8 0, P =0. 001) were significantly decreased. Conclusion miR-145 may inhibit the migration and invasion of ovarian cancer cells by targeting zeb-2.