[Effects of FBI-1 silencing on proliferation and apoptosis of triple-negative breast cancer cell line MDA-MB-231].

This work aimed to observe the effects of short hairpin RNA (shRNA)-silenced FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) on proliferation and apoptosis of triple-negative breast cancer cell line MDA-MB-231. qRT-PCR and Western blot analysis were applied to detect the mRNA and/or protein expression of FBI-1, Bcl-2, Bax, cleaved-Caspase 3 and Survivin. RNA interference method was used to silence FBI-1 expression in MDA-MB-231 cells. CCK-8 and colony formation assay were employed to detect the cell proliferation. Flow cytometry was employed for examining cell apoptosis. In vivo tumorigenicity of MDA-MB-231 cells was detected by tumor transplantation in nude mice. The results showed that the mRNA and protein expressions of FBI-1 were higher in MDA-MB-231 cells compared with those in normal human mammary epithelial cells MCF-10A. FBI-1 gene silencing inhibited proliferation and induced apoptosis of MDA-MB-231 cells in vitro, together with decreased Bcl-2 and Survivin protein expression, increased Bax protein expression and activated Caspase 3. Moreover, FBI-1 gene silencing inhibited the tumorigenesis of MDA-MB-231 cells in vivo. These results suggest that silencing of FBI-1 gene inhibits proliferation, induces apoptosis and suppresses the tumorigenesis of MDA-MB-231 cells.