Effect of microRNA-26a on proliferation and migration of breast cancer cell via targeting regulation expressions of E2F7

Abstract

Objective To explore effect of microRNA (miRNA, miR)-26a on proliferation and migration of breast cancer cell via targeting regulation expressions of nuclear transcription factor (E2F7). Methods The expression of miR-26a and E2F7 in BT549, MDA-MB-231, MDA-MB-435, MCF-7 breast cancer cell and MCF-10A normal mammary epithelial cell was detected by real-time quantitative polymerase chain reaction (Real-time PCR) and Western blotting, respectively. miR-26a mimics and miR-26a NC were transfected into MDA-MB-231 cell by liposome Lipofectamine™3000. The expression of miR-26a, cell viability, cell apoptotic rate, cell migration ability, the expression of E2F7 protein and mRNA was detected. Luciferase reporter analysis was performed. Results The expression of miR-26a in BT549 (0.40±0.04), MDA-MB-231 (0.35±0.02), MDA-MB-435 (0.42±0.03), MCF-7 (0.55±0.05) breast cancer cell was lower than that in MCF-10A (1.46±0.14) normal mammary epithelial cell (P<0.01). The expression of E2F7 in BT549 (1.25±0.12), MDA-MB-231 (3.10±0.31), MDA-MB-435 (2.18±0.21), MCF-7 (0.36±0.02) breast cancer cell was higher than that in MCF-10A (0.15±0.01) normal mammary epithelial cell (P<0.01). The expression of miR-26a in miR-26a mimics group (1.84±0.18) was higher than that in miR-26a NC group (0.36±0.03) (P<0.01). Cells’ viability in miR-26a mimics group (0.383±0.036) was lower than that in miR-26a NC group (0.589±0.060) (P<0.01). Cells’ early apoptotic rate [(16.51±1.65)%] and late apoptotic rate [(23.47±2.35)%] in miR-26a mimics group was higher than that in miR-26a NC group [ (2.58±0.26)%, (3.20±0.32)%] (P<0.01). Cells’ migration ability in miR-26a mimics group (42.36±4.23) was lower than that in miR-26a NC group (189.53±15.64) (P<0.01). The expression of E2F7 protein and mRNA in miR-26a mimics group was lower than that in miR-26a NC group (P<0.01), miR-26a mimics targeted regulation the expression of E2F7. Conclusion Over-expression of miR-26a could inhibit MDA-MB-231 cell proliferation and migration by targeting down-regulation expression of E2F7. Key words: Breast cancer; MicroRNA-26a; Nuclear transcription factor; Proliferation; Migration