Objective:To study the anti-tumor effect and its mechanisms of (-)-epigallocatechin- 3-gallate (EGCG) combined with 5-FU on human colon cancer cell line HT-29 in vitro.Methods:In vitro, human colon cancer cell line HT-29 was treated by EGCG and (or) 5-FU in various concentrations respectively alone or in combination.The inhibitory effect of cell growth was assayed by MTT method;cell cycles and apoptosis were analyzed by flow cytometry (FCM);the expressions of ERK,Akt,bcl-2,bax were analyzed by Western Blot.Results:The inhibitory effect of EGCG or 5-FU on the proliferation of HT-29 cell were found in dose-and-time dependent manner(P<0.05).Comparing with EGCG or 5-FU alone,the inhibitory effect of EGCG combined with 5-FU was significantly increased(P<0.05). Comparing with control group,the cell apoptosis was induced by EGCG or 5-FU alone at 48 hours, the cell apoptosis rate was significantly increased by EGCG combined with 5-FU(P<0.05).Meanwhile,the ratio of G0/G1 phase was increased and the ratio of S phase was decreased.Comparing with EGCG or 5-FU alone,G0/G1 phase was increased and S phase was decreased significantly by EGCG combined with 5-FU (P<0.05).The expression of p-ERK,p-Akt and bcl-2 were downregulated and bax was upregulated by EGCG or 5-FU alone,the expression of p-ERK,p-Akt and bcl-2 were downregulated and bax was upregulated significantly by EGCG combined with 5-FU (P< 0.05).Conclusion: The growth of HT-29 cell in vitro was inhibited by EGCG or 5-FU and in dose-and-time dependent manner. The anti-carcinoma effect was significantly enhanced by EGCG combined with 5-FU,and maybe its mechanisms were arresting cell cycle, inducing cell apoptosis through downreglating the expressions of p-ERK,p-Akt and bcl-2 and upregulating the espression of bax. |