摘要目的 探讨不同分化程度的食管鳞癌细胞对雷帕霉素的敏感性差异以及以p70S6K-siRNA干扰p70S6K表达后食管鳞癌EC9706细胞对雷帕霉素敏感性的变化.方法 以细胞计数盒8(CCK-8)法检测雷帕霉素对不同分化程度食管鳞癌细胞(EC9706、TE-1、Eca109、KYSE790、KYSE450)增殖的影响,并根据检测结果,选取对雷帕霉素不敏感的EC9706细胞株转染p70S6K-siRNA.采用CCK-8法、流式细胞术和裸鼠成瘤实验,检测转染前后EC9706细胞对雷帕霉素敏感性的变化.结果 CCK-8法检测结果显示,5株食管鳞癌细胞对低浓度雷帕霉素(≤100 nmol/L)均敏感,而低分化细胞株TE-1和EC9706对高浓度雷帕霉素却易产生耐药性.经50、100、200、500和1 000 nmol/L雷帕霉素+p70S6K-siRNA处理后,EC9706细胞的增殖率分别为(48.67±1.68)％、(15.45±1.54)％、(14.00±0.91)％、(10.97±0.72)％和(2.70±0.32)％,均分别明显低于50、100、200、500和1000 nmol/L雷帕霉素+对照siRNA处理组[(74.53±1.71)％、(68.27± 1.35)％、(71.74±2.44)％、(76.23±1.02)％和(80.21±2.77)％,均P＜0.05].流式细胞仪检测结果显示,p70S6K-siRNA组、雷帕霉素组和p70S6K-siRNA+雷帕霉素组EC9706细胞中G1期细胞的比例分别为(53.82±1.78)％、(57.87±4.01)％和(73.73±3.68)％,均明显高于对照组[(46.09±2.31)％,均P＜0.05].裸鼠体内实验的结果显示,转染p70S6K-siRNA后,雷帕霉素对裸鼠体内移植瘤生长的抑制作用也增强,抑瘤率高达96.5％.结论 不同分化程度的食管鳞癌细胞对雷帕霉素的敏感性不同,p70S6K-siRNA在体内外均能提高食管鳞癌EC9706细胞对雷帕霉素的敏感性.

abstractsObjective To explore the differences in sensitivity to rapamycin of five esophageal squamous cell carcinoma cell lines with different differentiation and the changes of sensitivity of the cells after siRNA-interfered expression of p70S6K.Methods Effects of rapamycin on proliferation of ESCC cell lines with different differentiation,EC9706,TE-1,Eca109,KYSE790 and KYSE450 cells,were investigated using cell counting kit 8 (CCK-8) assay,and according to the above results,the EC9706 cells non-sensitive to rapamycin were chosen to be transfected with p70S6K-siRNA.The changes in sensitivity of cells to rapamycin were measured in vitro and in vivo using CCK-8 kit,flow cytometry and tumor formation in nude mice.Results CCK-8 results showed that all the five cell line cells were sensitive to low concentration of rapamycin (＜ 100 nmol/L),but TE-1 and EC9706 cells,which were with poor differentiation,showed resistance to high concentration of rapamycin.After EC9706 cells were treated with 50,100,200,500 and 1 000 nmol/L rapamycin and p70S6K-siRNA,the proliferation rates of EC9706 cells were (48.67± 1.68)％,(15.45 ± 1.54) ％,(14.00± 0.91) ％,(10.97 ± 0.72) ％ and (2.70± 0.32) ％,respectively,and were significantly lower than that of cells treated with 50,100,200,500 and 1 000 nmol/L rapamycin and control siRNA [(74.53±1.71)％,(68.27±1.35)％,(71.74±2.44)％,(76.23±1.02)％ and (80.21±2.77)％] (P＜0.05 for all).The results of flow cytometry showed that the ratios of cells in G1 phase of the p70S6K-siRNA,rapamycin and p70S6K-siRNA + rapamycin groups were (53.82± 1.78) ％,(57.87 ± 4.01) ％ and (73.73±3.68) ％,respectively,significantly higher than that in the control group (46.09±2.31)％ (P＜0.05 for all).The results of tumor formation test in vivo showed that the inhibitory effect of rapamycin on tumor growth was stronger after the cells were transfected with p70S6K-siRNA,and the inhibition rate was 96.5％.Conclusion ESCC cells with different differentiation have different sensitivity to rapamycin,and p70S6K-siRNA can improve the sensitivity of cells to rapamycin in vitro and in vivo.