RNAi-chk1在抑制小鼠Lewis肺癌细胞生长作用的实验研究

Suppression of The mouse Lewis lung cancer cell growth induced by siRNA-chk1 combined radiotherapy

目的观察chk1-RNAi联合放疗对Lewis肺癌细胞的抑制及凋亡情况。方法以脂质体Lipofectimine-2000介导,将chk1-536的siRNA表达载体转染小鼠Lewis肺癌细胞株,将其分为空白对照组、错义序列组、siRNA组,2Gy照射组、2Gy照射+错义序列组、2Gy照射+siRNA组。应用MTT法检测转染细胞抑制率、流式细胞术分析转染siRNA后细胞的凋亡,并应用RT-PCR检测转染细胞chk1-mRNA表达水平。结果 chk1-siRNA转染联合辐射组的Lewis肺癌细胞,与对照组相比较生长增殖受抑制、细胞凋亡增加;MTT法检测和流式细胞术分析示:chk1-siRNA转染联合辐射组的Lewis肺癌细胞生长增殖受抑制,细胞凋亡增加(P<0.05);同时,RT-PCR法检测该组细胞中chk1mRNA表达量下降(P<0.05)。并且siRNA转染可增加2Gy照射引起的Lewis肺癌细胞凋亡。结论针对chk-1的RNAi可以提高Lewis肺癌细胞的抑制率及放疗引起的肿瘤细胞的凋亡,对肿瘤有治疗作用,与放疗有协同作用。

Objective To observe the suppression and apoptosis of the Lung cancer Lewis cell by siRNA-chk1 combined radiotherapy.Methods It carried the chk1 siRNA gene into mouse Lewis lung cancer cell lines in vitro through Lipofectimine？2000.We devide into a control group、scrambled sequence group、siRNA group、2Gy radiation group、2Gy radiation ＋ scrambled sequence group and2Gy radiation ＋siRNA group.The inhibited rate of transfected cells were observed by MTT assay,cell apoptosis were observed by flow cytometry,expression of chk1 were analysised by immunohistochemical.Results Compared with control group,the cells of chk1-siRNA combined radiotherapy were slower,but apoptosis on the contrary.MTT method and FCM showed that more Lewis cells proliferated effectively slowlier and apoptosis induced with chk1 siRNA combined radiotherapy（P〈0.05）.And then the expression of chk1 of that group significantly decreased at protein level in vitro（P〈0.05）.Conclusion The chk1-RNAi can enhance inhibition of Lewis lung cancer cells and the cell apoptosis induced radiotherapy.They has therapeutic effects on the tumor and has synergistic effect with radiation therapy.