RESUMO
BACKGROUND: Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. This study is aimed to investigate the effects of silencing the HAS-2 gene on the proliferation and apoptosis of human breast cancer cells. METHODS: MCF-7 cells were collected and assigned into control, scrambled siRNA and HAS-2- siRNA groups. After transfection, the morphological changes in the MCF-7 cells were observed using phase contrast microscopy. qRT-PCR and Western blot assays were used to detect the mRNA and protein expression of apoptosis-related proteins. CCK-8 and flow cytometry were performed to evaluate cell proliferation, the cell cycle and apoptosis. RESULTS: In the control and the scrambled siRNA groups, cells grew adhered to the wall and mainly showed a spindle shape with a clear nucleolus. Compared with the control and scrambled siRNA groups, increases in the number of cells in early apoptosis and metaphase cells in apoptosis were observed in the HAS-2-siRNA group. The HAS-2-siRNA group showed decreased expression of HAS-2 relative to that in the control and scrambled siRNA groups. No significant differences in cell proliferation, cell cycle distribution or apoptosis were noted between the control and scrambled siRNA groups. In the HAS-2-siRNA group, the cell proliferation ability decreased significantly, but the number of cells in the G0/G1 stage, the number of apoptotic cells and the expression of caspase-3 and caspase-9 increased significantly. CONCLUSION: Our findings indicate that HAS-2 gene silencing may inhibit proliferation and promote apoptosis in the MCF-7 human breast cancer cell line.