Effect and mechanism of silencing microRNA-10b on biological behavior of human triple-negative breast cancer cell

Abstract

Objective To investigate the eff~t of silencing microRNA-10b,on the biological behavior of hunan triple-negative breast cancer MDA-MB-231 cells and the mechanism Methods MDA-MB-231 cells were transfected with artificially synthesized miR-10b inhibitor.Glank cell group and nonsence sequence-transfected group were established as a control.Real-time quantitative polymerase chain reaction (Real-time PCR) was conducted to detect the expression of miR-10b after transfection.Cell counting kit-8 (CCK-8) assays,flow cytometry and Transwell assays were used to detect variations in cell proliferation,apoptosis,invasion and migration respectively.Real-time PCR and Western blotting were used to detect the expression of T lymphoma invasion and metastasis inducing factor 1 (TIAM1) mRNA and protein respec-tively.Results As compared with control group,the value of 2-△△Dt(0.26 ± 0.01) in miR-10b inhibitor-transfected group was significantly reduced (P ＜ 0.01),suggesting the expression of miR-10b was sup-pressed by miR-10b inhibitor successfully.The proliferation rate at 48 h [(409.10 ± 8.38) ％] and at 72 h [(610.70 ± 17.59) ％] was significantly increased (P ＜ 0.01) after silencing miR-10b.Proliferation effect occured at 48 h and continued to 72 h.Early apoptosis rate (1.77％) and late apoptosis rate (1.61％) were significantly reduced (P ＜0.05).The number of invasion (212.17 ± 13.57) and migration (322.67 ± 8.62) cells was significantly increased (P ＜ 0.01).TIAM1 gene had no significant changes at mRNA level (P ＞ 0.05),but the protein expression was up-regurated (P ＜ 0.05).Conclusion Silencing miR-10b could promote proliferation,invasion and migration,and inhibit apoptosis of MDA-MB-231 cells,which is probably related to the positive regulation of TIAM1 protein at the post-transcriptional 1 evel. Key words: Triple-negative breast cancer; microRNA-10b; T lymphoma invasion and metastasis inducing factor 1 ; Invasion