Mechanisms Of Inhibiting Proliferation And Inducing Apoptosis Of Human Gastric Cancer Cell Line BGC-823 By Genistein

The occurrence and development of gastric carcinoma is not only related to the abnormal hyperplasia of tumor cell, but also to the abnormal apoptosis of the tumor cells. The unusual mechanism of cell apoptosis is very important in the occurrence of tumor and anti-tumor treatment.It may be become a basic strategy to treat the gastric carcinoma by using the intervene apoptosis technology that the target is to induce the tumor cell.We found genistein can inhibit proliferation and induce apoptosis in Gastric carcinoma BGC-823.So SRB assay was used to observe the effect of Genistein after 24h on proliferation of BGC-823 cells. Cell cycle and apoptosis were analyzed by flow cytometry (FCM) . Transcription and protein level of cox-2, bcl-2 and bax was detected by RT-PCR and Western blot.Aim: Studying inhibitory effects of Genistein on BGC-823 gastric cancer cells with different concentration. To study apoptosis of BGC-823 gastric cancer cells induced by Genistein and further investigate its molecular mechanisms. Methods: The inhibitory effects of Genistein in different concentration of in different exposure time on BGC-823 gastric cancer cells were analyzed by SRB assay, AO/EB and DAPI staining. Cell cycle and apoptosis were analyzed by flow cytometry (FCM) . Transcription and protein level of cox-2, bcl-2 and bax was detected by RT-PCR and Western blot. Results: The growth inhibitions of Genistein on BGC-823 gastric cancer cells were concentration-dependent and time-dependent, the GC₅₀ value of Genistein at 24h, 48h, 72h were 294.5,111.3,83.5μmol/L, respectively. many typical apoptotic morphological features were observed by these apparatus, such as cells shrunk and distorted, the volume reduced, the shape of cell nucleuses appeared like crescent or piece. Apoptosis rate of BGC-823 gastric cancer cells was increased along with the increase of Genistein concentration, When treated with 37μmol/L～296μmol/L Genistein for 24 h, BGC-823 cells were arrested at S and G₂/M phase, meanwhile, bcl-2 and cox-2 expression at transcription and protein level were decreased , whereas bax expression at transcription level was increased and at protein level was unchanged. Conclusion: Genistein has a stronger effect on proliferation inhibition and induce apoptosis of BGC-823 gastric cancer cells. Genistein induces apoptosis of BGC-823 gastric cancer cells whose effect was correlated with inhibiting cox-2 expression and down-regulate bcl-2/bax expression.