Effects of hypoxia inducible factor-2α siRNA on proliferation of human breast cancer cells

Purpose To investigate the effects of hypoxia inducible factor-2α( HIF-2α) siRNA on proliferation of human breast cancer MCF-7 cells and its mechanism. Methods Cells were treated with CoCl 2. RNA interference was used to silence the expression of HIF-2α in MCF-7 cells. RT-PCR was used to detect the expression of HIF-2α mRNA in MCF-7 cells. Cell growth rate and doubling time were observed by growth curve. Cell cycle were determined by flow cytometry. Expressions of proliferation related genes were detected by RT-PCR. Results Hhypoxia model successfully was established. HIF-2α mRNA expression of hypoxia + siRNA groups were significantly lower than that in simple hypoxia group( P 0. 05). Cell growth speed was significantly slow,doubling time was significantly prolonged in hypoxia + siRNA groups than that in simple hypoxia group( P 0. 05). Compared with the simple hypoxia group, the proportion of S phase and G 2 / M phase cells decreased significantly in hypoxia + siRNA groups( P 0. 05). RT-PCR results showed that p21 mRNA expression was significantly increased( P 0. 05) and Cyclin B mRNA expression was significantly decreased( P 0. 05) in hypoxia + siRNA groups than that in simple hypoxia group( P 0. 05). Conclusion HIF-2α siRNA may inhibit proliferation of MCF-7 cells,which may be related with increase of p21 gene expression and decrease of Cyclin B gene expression.