Abstract:

Objective   To explore the mechanisms of epigallocatechin-3-gallate(EGCG) inhibiting the proliferation of human colon cancer HT-29 cells and preventing the angiogenesis in vitro. Methods   In vitro,  human colon cancer cell line HT-29 was treated by EGCG in various concentrations(0, 25,  50,  100μg /mL) for 24h. The inhibitory effect of proliferation was assayed by MTT method. The mRNA and protein expressions of transforms growth factorsβ1（TGF-β1）,  15-hydroxyprostaglandin dehydrogenase （15-PGDH）,  cyclooxygenase-2（COX-2）and vascular endothelial growth factor（VEGF） in human colon cancer cell line HT-29 were respectively examined by RT-PCR and Western blot. Results   MTT assay showed that EGCG inhibited HT-29 cells in a dose-and-time dependent manner(P＜0.05). It was found that the expressions of TGF-β1 and 15-PGDH mRNA and protein  were up-regulated and COX-2 and VEGF were down-regulated,  both in a dose-dependent manner(P<0. 05). Conclusion   EGCG inhibits the proliferation of HT-29 cells in a dose-and-time dependent manner. EGCG possibly prevents angiogenesis of HT-29 cells via activating TGF-β1/15-PGDH pathways and inhibiting COX-2 and VEGF pathways in a dose-dependent manner.

Key words: Colonic neoplasms; Epigallocatechin-3-gallate; Transforms growth factorsβ1; 15-Hydroxyprostaglandin dehydrogenase