Effect of Rapamycin on TGF-β1-induced epithelial-mesenchymal transition in LoVo colonic adenocarcinoma cells.

Abstract: Objective: To investigate the effect of Rapamycin on epithelial-mesenchymal transition(EMT) of LoVo colonic adenocarcinoma cells in vitro. Methods: Cultured LoVo colonic adenocarcinoma cells were divided into three groups: negative control group, EMT-inducing group(TGF-β₁) and EMT-interfering group(TGF-β₁ plus Rapamycin). E-cadherin expression in LoVo cells was detected by Western Blot, while the expression of vimentin was evaluated through immunocytochemistry. The Snail mRNA in LoVo cells was examined by RT-PCR. Results: TGF-β₁ induced LoVo cell switching from polygonal to spindle-shaped. TGF-β₁ enhanced the expression of vimentin, but lowered the level of E-cadherin. In contrast, Rapamycin impaired the transition induced by TGF-β₁. Rapamycin dramatically abrogated TGF-β₁-induced vimentin expression and restored E-cadherin expression in LoVo cells. Rapamycin significantly repressed the up-regulation of Snail mRNA expression induced by TGF-β₁. Conclusion: Rapamycin dramatically abrogated TGF-β₁ induced Snail mRNA expression in LoVo cells, hence inhibiting EMT of these cells in vitro. [Copyright &y& Elsevier]