Objective： To investigate the expression of hergl gene in tumor tissues from gastric carcinomas and gastric carcinoma cell lines, and study the relationship between HERG K＋ channel expressions and tumor cell proliferation and apoptosis. Methods： RT-PCR and PCR assays were used to detect the expression of hergl gene in 64 gastric carcinomas and the gastric cancer cell line SGC-7901. Blocking the HERG K＋ channels was used to evaluate their effects on tumor cell proliferation and apoptosis. Results：The statistically significant expression of hergl gene was detected in all the gastric cancers and SGC-7901 cells, but not in normal tissues. The HERG K＋ channel blocker, E-4031, increased the cell population in G0/G1（P 〈 0.05） and the number of apoptotic tumor cells（P 〈 0.05）. Conclusion： HERG K＋ channels were expressed in all gastric carcinomas tested and these channels appear to modulate tumor cell proliferation and apoptosis.
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-cadhefin. 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 upregulation 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.
Renhu Sun Jiang Li Jing Cui Qing Lv Xinghua Liu Guobin Wang
