[Effects of 7-difluoromethy-5, 4'-dimethoxygenistein on proliferation and apoptosis of human cervical cancer cells and its mechanism].

OBJECTIVE: To investigate the effects of 7-difluoromethy-5, 4'- dimethoxygenistein (DFMG) on inhibiting proliferation and inducing apoptosis of human cervical cancer HeLa cells and its possible molecular mechanism in vitro. METHODS: HeLa cells were cultured in vitro. The effect of DFMG on inhibiting proliferation was determined using MTT assay. The effects of DFMG on inducing apoptosis were assessed using flow cytometry with AV-PI staining, AO/EB staining, and agarose gel electrophoresis. Multiple molecular techniques, such as RT-PCR, Western blot, siRNA transfection, and cDNA transfection, were used to explore its possible molecular mechanism. RESULTS: DFMG presented with dramatically inhibiting proliferation effect of HeLa cells in a time-and dose-dependent manner ranging from 0.25 to 64 μg/mL and from 24 to 72 h in vitro, and its IC(50) was 4.62 μg/mL for 48 h. The cells treated with DFMG for 48 h showed typical morphological change of apoptosis, typical DNA ladder of agarose gel electrophoresis, and the sub-G(1) population increased in a dose-dependent manner. Simultaneously the expressions of c-myc mRNA, c-myc protein and its downstream genes, such as bax, cyto-c and caspase-9, were up-regulated, while bcl-2 protein was down-regulated. Down-regulation of c-myc by siRNA attenuated DFMG-induced cell proliferation inhibition and inducing apoptosis. Up-regulation expression of c-myc by cDNA transfection could enhance the effects of DFMG-induced cell proliferation inhibition and inducing apoptosis. CONCLUSION: DFMG could inhibit the proliferation and induce the apoptosis of human cervical cancer HeLa cells in vitro, and its mechanism may be closely related to regulate c-myc and its down-stream gene expression.