摘要
目的探讨转录因子Stat5a对人类乳腺癌细胞(MCF-7)增殖的影响及表观遗传学机制。方法利用腺病毒介导的基因转移技术,使MCF-7大量表达转录因子Stat5a,应用活细胞计数(MTS)法检测细胞增殖情况,并以染色质免疫共沉淀(ChIP)方法,检测p53基因启动子区域组蛋白甲基化程度。最后以实时定量PCR进一步确认p53基因表达水平。结果携带Stat5a cDNA的腺病毒感染后,MCF-7的数量呈剂量依赖式地增加。当病毒感染增殖活性(MOI)分别为10、20及30时,MCF-7的细胞密度较对照组细胞分别增加7.603 1%、18.123 7%及24.898 7%。染色质免疫共沉淀分析表明,Stat5a明显导致p53基因启动子区域组蛋白甲基化(H3K27Me3)增加,p53基因表达水平下降。结论 Stat5a导致MCF-7抑癌基因p53启动子组蛋白甲基化,使启动子活性降低,导致细胞的异常增殖。
Objective To investigate and clarify the effect of StatSa on proliferation of human breast cancer cells （MCF-7） and to detect the changes of epigenetic signature on the promoter region of p53 gene. Methods Stat5a was over expressed in human breast cancer cells （MCF-7） by using adenovirus mediated gene transfer technology. The cell proliferation was examined by MTS assay. ChIP assay was used to check the trimethylation of lysine 27 on histone 3 （H3K27Me3） of p53 gene promoter region. Fur- thermore,qRT-PCR and western blot were also applied to confirm the expression of p53 gene. Results The number of MCF 7 in- creased in a dose dependent manner. Compared with that of control group, the cell density of MCF-7 increased 7. 603 1%, 18. 123 7% and 24. 898 7% when the MOI were 10,20 and 30. Chromatin Immunoprecipitation showed that StatSa significantly in- creased H3K27Me3 and down regulated the expression level of p53 gene. Conclusion Stat5a promotes proliferation of breast cancer cells through trimethylation of H3K27 and inhibition of p53 gene expression.
出处
《重庆医学》
CAS
北大核心
2015年第19期2596-2599,共4页
Chongqing medicine
基金
国家自然科学基金资助项目(81172497
81260396)
吉首大学研究生科研创新资助项目(JGY201317)
