目的：观察哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR)特异性小干扰RNA（mTOR-siRNA）干扰mTOR表达后，食管鳞癌EC9706细胞对雷帕霉素(rapamycin)敏感性的变化。方法：mTOR-siRNA转染EC9706细胞， RT-PCR检测干扰效果。mTOR-siRNA转染前后的EC9706细胞用雷帕霉素处理，Western blotting检测EC9706细胞中mTOR及其下游p70S6K蛋白的表达；流式细胞术检测EC9706细胞的周期及凋亡，CCK-8试剂盒检测EC9706细胞的增殖。结果：mTOR-siRNA下调EC9706细胞中mTOR mRNA的表达（P<0.05或P<0.01)；雷帕霉素抑制EC9706细胞中mTOR和p-p70S6K蛋白的表达（P<0.05)，并促进p70S6K蛋白表达(P<0.01)，且mTOR-siRNA转染后此作用更明显（P<0.05）。雷帕霉素可诱导EC9706细胞凋亡(P<0.01)、抑制EC9706细胞增殖(P<0.05或P<0.01)、使EC9706细胞阻滞于G1期(P<0.01)，且mTOR-siRNA转染后这些作用更强（P<0.05）。结论：mTOR-siRNA能特异性下调食管鳞癌EC9706细胞中mTOR表达，提高EC9706细胞对雷帕霉素的敏感性。

Objective:To investigate the sensitivity of esophageal squamous cell carcinoma EC9706 cells to rapamycin after silencing mTOR expression by small interfering RNA targeting mTOR (mTOR-siRNA). Methods: EC9706 cells were transfected with mTOR-siRNA and the interference effect was investigated by RT-PCR. EC9706 cells were treated with rapamycin before and after mTOR-siRNA transfection, and the expressions of mTOR and its downstream p70S6K were detected by Western blotting analysis. Cell cycle, apoptosis and proliferation of EC9706 cells were determined by flow cytometry and CCK-8 kit, respectively. Results: mTOR-siRNA down-regulated the expression of mTOR mRNA in EC9706 cells(P<0.05 or P<0.01). Rapamycin inhibited mTOR and phosphorylated p70S6K (p-p70S6K) expressions and increased p70S6K expression in EC9706 cells(all P<0.05), and these effects of rapamycin were further enhanced by mTOR-siRNA transfection (P<0.05). Rapamycin also induced apoptosis, inhibited proliferation and arrested cell cycle in G1 phase of EC9706 cells (all P<0.01), and transfection with mTOR-siRNA significantly promoted these effects of rapamycin in EC9706 cells (P<0.05). Conclusion: mTOR-siRNA can specifically down-regulate mTOR expression in esophageal squamous cell carcinoma EC9706 cells, and increase the sensitivity of EC9706 cells to rapamycin.

国家自然科学基金资助项目（No. 30901778）；郑州大学引进人才基金资助项目