Effect of fucoidan on inhibition of proliferation and induction of apoptosis in human breast carcinoma cell line MCF-7

AIM:To investigate the effects and related mechanism of fucoidan on the proliferation and apoptosis in breast carcinoma cell line MCF-7.METHODS:MCF-7 cells were treated with different concentrations of fucoidan(100 mg/L,300 mg/L,500 mg/L,1 000 mg/L)for 48 h.Cell viability was measured by MTT assay.Apoptosis morphological and biochemical changes were detected by Hoechst 33258 staining and agarose gel electrophoresis.The expression of bcl-2 and bax was examined by RT-PCR and Western blotting.RESULTS:Fucoidan at different concentrations(100 mg/L,300 mg/L,500 mg/L,1 000 mg/L)effectively inhibited the proliferation of MCF-7 cells(P0.01).The inhibitory ratio and apoptosis rate increased in a concentration-dependent manner.Agarose gel electrophoresis of DNA revealed the characteristic ladder pattern of apoptosis.Fucoidan down-regulated the expression of bcl-2 and up-regulated bax in the levels of mRNA and protein.The ratio of Bcl-2 to Bax decreased as the concentrations of fucoidan increased(P0.05).CONCLUSION:Fucoidan inhibits the cell proliferation by inducing cell apoptosis,and the apoptosis is related to the down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of apoptotic protein Bax.