Objective:To investigate the effects of bone morphogenetic protein 9 on the proliferation

cell cycle and apoptosis of breast cancer cell line MDA-MB-231.Methods:The expression of BMP9 in high-metastatic cell line MDA-MB-231 and low-metastatic cell line MCF-7 were detected by Semi-quantitative PCR respectively

MDA-MB-231 were transfected with AdBMP9(as experimental groups) and AdGFP(as control groups) respectively

Then the ability of cell proliferation was detected by MTT

cell cycle and apoptosis were detected by flow cytometry.Results:The BMP9 mRNA was not detected in human breast cancer cell line MDA-MB-231.After transfection with AdBMP9

the MDA-MB-231 cells showed an inhibited proliferation

On the fifth day

the growth rate of experimental groups(0.886 0±0.053 2)was significantly lower than that of control groups(1.224 0±0.103 1)(P<0.05);The results of flow cytometry showed that

BMP9 could induce the cell cycle arrest in MDA-MB-231

On the second day and third day after transfection

the cell number of G2/M phase increased significantly

which were 3.2 fold and 2.4 fold that of control groups respectively;It’s also found that after 72h treatment

the apoptosis rate of experimental groups(31.55%±8.26%) was significantly higher than that of control group(3.80%±0.46%)(P<0.05).Conclusion:These data demonstrated that BMP9 could inhibit the proliferation of MDA-MB-231 by blocking cell cycle and inducing apoptosis.