Zhang Zhi-yong, Zhang Xie-fu
Department of General Surgery, Zhengzhou University, Zhengzhou, China.
Zhonghua Yi Xue Za Zhi. 2011 Nov 8;91(41):2899-902.
To explore the expression of mammalian target of rapamycin (mTOR) in colon cancer and the inhibitory effect of mTOR siRNA on the proliferation and apoptosis of human colon cancer HT-29 cells.
Immunohistochemistry was employed to detect the expression of phosphorylated mTOR (p-mTOR) in colon cancer tissues (n = 50) and normal colon tissues (n = 50) from First Affiliated Hospital of Zhengzhou University (October 2009 to June 2010). The correlations were examined between the expression of p-mTOR and such clinical pathological data as colon cancer staging and lymph node metastasis. The oligonucleotide templates of mTOR siRNA were designed and employed to transfect HT-29. The nonsense control groups were established accordingly by siRNA with an insignificant order. And the blank group had no transfection. The protein level of mTOR was measured by Western blotting. The method of MTT was used to detect the cell proliferation. And the method of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was employed to detect the apoptosis.
The expression of p-mTOR was higher in the colon cancer group than the control group [60% (30 cases) vs 14% (7 cases), P < 0.05]. And the expression level was correlated with the degree of lymph node metastasis and tumor differentiation (r = 0.311, 0.427, both P < 0.05). The expression of mTOR protein in the transfection group was lower than the blank and the nonsense control groups (0.39 ± 0.25 vs 1.18 ± 0.05, 1.46 ± 0.09, both P < 0.05). The proliferation was lower than those of the blank and the nonsense control groups (0.275 ± 0.033 vs 0.460 ± 0.028, 0.450 ± 0.037, both P < 0.05). The apoptotic indices were higher than those of the blank and control groups (12.33 ± 1.53 vs 0.33 ± 0.31, 1.67 ± 0.58, both P < 0.05).
The expression of mTOR was higher in colon cancer tissues than that in normal colon tissues. The RNA interference of mTOR in HT-29 cell line can effectively knock down the expression of mTOR so as to significantly inhibit cell proliferation and promote cell apoptosis.
探讨雷帕霉素靶蛋白（mTOR）在结肠癌中的表达情况以及mTOR小干扰RNA（siRNA）对人结肠癌HT-29细胞增殖和凋亡的抑制作用。
采用免疫组织化学法检测郑州大学第一附属医院2009年10月至2010年6月收集的50例结肠癌组织和50例正常结肠组织中磷酸化mTOR（p-mTOR）的表达。分析p-mTOR表达与结肠癌分期、淋巴结转移等临床病理资料的相关性。设计mTOR siRNA寡核苷酸模板转染HT-29细胞，同时以无意义序列siRNA设立阴性对照组，未转染细胞的作为空白组。采用蛋白质免疫印迹法检测mTOR蛋白水平；采用噻唑蓝（MTT）法检测细胞增殖；采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测细胞凋亡。
结肠癌组p-mTOR表达高于对照组[60%（30例）比14%（7例），P<0.05]。其表达水平与淋巴结转移程度及肿瘤分化程度相关（r=0.311、0.427，均P<0.05）。转染组mTOR蛋白表达低于空白组和阴性对照组（0.39±0.25比1.18±0.05、1.46±0.09，均P<0.05）；细胞增殖能力低于空白组和阴性对照组（0.275±0.033比0.460±0.028、0.450±0.037，均P<0.05）；细胞凋亡指数高于空白组和阴性对照组（12.33±1.53比0.33±0.31、1.67±0.58，均P<0.05）。
结肠癌组织中mTOR表达高于正常结肠组织。对HT-29细胞株进行mTOR的RNA干扰可有效下调mTOR表达，显著抑制细胞增殖并促进细胞凋亡。
