摘要
目的探讨转化生长因子β1(TGF-β1)诱导人肝癌细胞系凋亡及其与p53基因及Smad4的关系。方法选用3种含有不同p53基因状态的人肝癌细胞系,均分为TGF-β1诱导组(实验组)和对照组;应用脱氧核糖核苷酸末端转移酶介导的dUTP缺口末端标记技术(TUNEL)对TGF-β1诱导的肝癌细胞的凋亡进行定量检测;另外,应用Lipofectamine2000把含有Smad4结合元件和荧光素酶基因的TGF-β1可诱导的荧光素酶报告质粒对细胞进行转染,再经TGF-β1作用,分别检测其相对荧光素酶活性。结果在应用TUNEL检测的3个细胞系中,TGF-β1能诱导HepG2细胞(野生型p53)凋亡,其细胞凋亡率实验组明显高于对照组(P<0.05);而Huh-7(突变型p53)和Hep3B细胞(缺失型p53)凋亡细胞较少,其细胞凋亡率实验组与对照组差异无统计学意义(P>0.05)。荧光素酶检测提示,HepG2细胞的Smad4表达活性实验组明显高于对照组(P<0.05);而Huh-7和Hep3B细胞的Smad4表达较低,实验组与对照组差异无统计学意义(P>0.05)。结论HepG2细胞系比Huh-7和Hep3B细胞系更易发生TGF-β1诱导的凋亡,Smad4是TGF-β1信号转导途径的主要调控因子之一。
Objective To investigate the apoptosis induced by TGF-β1 in human hepatic carcinoma cell lines and its relationship with p53 gene and Smad. Methods Three human hepatic carcinoma cell lines which involving in various status of the p53 gene were used in this study. TGF-β1-induced apoptosis in hepatic carcinoma cell lines was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） assay. To study the mechanism of TGF-β1-induced apoptosis, these cell lines were transfected with a TGF-β1-inducible luciferase reporter plasmid containing Smad 4 binding elements （SBE） and luciferase gene using Lipofectamine 2000, then treated with TGF-β1, relative luciferase activity was assayed. Results Of three cell lines studied with TUNEL assay, TGF-β1 induced apoptosis was observed in HepG2 cells （wild type p53）. Huh-7 （mutant p53） and Hep3B （deleted p53） cell lines showed less apoptosis. Luciferase activity assay indicated that the response to TGF-β1 induction in HepG2 cells was increased dramatically but was not significant in Huh-7 and Hep3B cell lines. Conclusion HepG2 cells seem to be highly susceptible to TGF-β1-induccd apoptosis compared with Hep3B and Huh-7 cell lines. Smad 4 is a central mediator of the TGF-β1 signal transduction pathway.
出处
《中国普外基础与临床杂志》
CAS
2005年第5期480-482,487,共4页
Chinese Journal of Bases and Clinics In General Surgery
关键词
转化生长因子Β1
凋亡
肝癌细胞系
信号转导途径
Transforming growth factor-β1 Apoptosis Hepatoma cell line Signal transductionpathway
