Effects of RNA interference targeting Semaphorin 4D on proliferation, cell cycle and migration of human breast cancer cells

Objective: To study the effects of Semaphorin 4D (Sema 4D) gene silencing on proliferation, cell cycle and migration of breast cancer cells, and investigate the role of Sema 4D protein in occurrence and development of breast cancer.Methods: The expression levels of Sema 4D mRNA and protein in two breast cancer cell lines MDA-MB-231 and MCF-7 with different metastatic potentials were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The MDA-MB-231 cell line with stable down-regulated expression of Sema 4D was established by infection of lentivirus containing Sema 4D-short hairpin RNA (shRNA). Then the changes of cell proliferation, cell cycle distribution and migration ability were detected by cell counting kit-8 (CCK-8), flow cytometry, wound healing assay and Transwell migration experiment, respectively.Results: The expression level of Sema 4D in MDA-MB-231 cells was significantly higher than that in MCF-7 cell (P < 0.05). The expression of Sema 4D was significantly down-regulated in MDA-MB-231 cells after Sema 4D-shRNA lentivirus infection. Compared with the blank control group, the proliferation of MDA-MB-231 cells was significantly inhibited in Sema 4D-shRNA interference group (P < 0.05), and the proportion of cells at G0/G1 phase was significantly increased (P < 0.05), as well as the migration ability was obviously reduced (P < 0.05).Conclusion: Sema 4D is expressed at a high level in breast cancer MDA-MB-231 cells with high metastatic potential. Down-regulation of Sema 4D expression by shRNA interference can significantly inhibit the proliferation and migration of MDA-MB-231 cells, and block the cell cycle at G1 phase. DOI:10.3781/j.issn.1000-7431.2015.11.726