Hsa-let-7诱导肺癌细胞凋亡与G_0/G_1期阻滞及其分子机制  

Function and molecular mechanism of hsa-let-7 influencing character of lung cancer cells

作　　者：魏辉[1] 侯俊明[1] 董明[1] 杜宁[2] 任宏[2] 

机构地区：[1]陕西中医学院附属医院外二科,陕西咸阳712000 [2]西安交通大学医学院第一附属医院胸外二科,陕西西安710061

出　　处：《现代肿瘤医学》2013年第11期2398-2401,共4页Journal of Modern Oncology

基　　金：国家自然科学基金资助项目(编号:81272418)

摘　　要：目的:研究hsa-let-7对肺癌细胞功能的影响并探索其机制。方法:构建重组质粒pGenesilTM-let-7a和pGenesilTM-control,经脂质体介导稳定转染人肺鳞癌细胞系KUM-LK2、肺腺癌细胞系A549,小细胞肺癌细胞系H446,经qRT-PCR检测转染后3种肺癌细胞中let-7a的表达差异,Western blot检测let-7a下游基因Ras、ERK的表达差异,流式细胞仪检测细胞凋亡率及细胞周期,探索let-7a通过MAPK信号转导通路影响肺癌细胞的功能及机制。结果:转染pGenesilTM-let-7a后,let-7a在实验组肺癌细胞中的表达显著高于对照组肺癌细胞,Western blot证实p-Ras、p-ERK在实验组细胞中的表达显著低于对照组(P<0.05),而t-Ras及t-ERK的表达差异不显著(P>0.05);同时实验组肺癌细胞的凋亡率显著高于对照组肺癌细胞,实验组肺癌细胞S期比例显著低于对照组,而G0/G1期比例显著高于对照组(P<0.05)。结论:Let-7a通过作用于靶基因Ras,影响ERK的表达,调节MAPK信号转导通路,促进肺癌细胞的凋亡,使G0/G1期肺癌细胞比例增加,可能在肺癌的发生发展中起重要的作用。Objective：To explore the function and mechanism of hsa-let-7 influencing characteristic of lung cancer cells.Methods：We firstly constructed pGenesilTM-let-7a and pGenesilTM-control,which were transfected into KUM-LK2,A549 and H446 respectively,then applied qRT-PCR to detect the expression levels of let-7a in these six groups.Tested the apoptosis rates and cell cycles the expressions of downstream Ras and ERK were tested by using Western blot.Results：After transfection of let-7a into KUM-LK2,A549 and H446,the expression of let-7a in positive groups was significantly increased.For t-Ras and t-ERK there were no difference between positive group and control group,（P ＞ 0.05）.Expression of p-Ras,p-ERK were lower in positive group than in control group （P ＜ 0.05）.The apoptosis rates of let-7a positive cells were higher than that of let-7a negative cells,the proportion of let-7a positive cancer cells in G0/G1 phase increased,while the proportion of cells in S phase decreased（P ＜ 0.05）.The proportion of control group cells in G0/G1 phase devreased,while the proportion of cells in S phase increased （P ＜ 0.05）.Conclusion：By influencing target gene,increased let-7a could down regulate p-Ras,therefore affect p-ERK,regulate MAPK signal pathways,promoting cancer cells death,which made let-7 an important role in the generation and development of lung cancer.

关 键 词：肺癌 KUM-LK2 A549 H446 hsa-let-7 MAPK 

分 类 号：R73-362[医药卫生—肿瘤] R734.2[医药卫生—临床医学]