干扰素诱导蛋白AIM2诱发乳腺癌细胞凋亡的分子机制  

Molecular mechanisms of absent in melanoma AIM2 inducing breast cancer cell apoptosis

作　　者：刘志勇[1] 易坚[1] 刘凤恩[1] 

机构地区：[1]赣南医学院第一附属医院血管乳腺科,赣州医学硕士研究生341000

出　　处：《医学研究生学报》2015年第7期696-700,共5页Journal of Medical Postgraduates

基　　金：江西省卫生计生委科技计划课题(20155420)

摘　　要：目的人类干扰素诱导基因家族之一的人类干扰素诱导蛋白(absent in melanoma 2,AIM2)被视为抑癌基因,但目前其抑癌机制仍不清楚。文中研究AIM2诱发乳腺癌细胞凋亡的分子机制。方法建立Tet-Off诱导模式系统来诱发AIM2大量表达,MCF-7 t TA-AIM2细胞为实验组,MCF-7 t TA-Luc细胞为对照组。Western blot检测AIM2在乳腺癌细胞株的表达及亚细胞定位,XTT assay分析AIM2对细胞增殖的影响。应用膜联蛋白V-FITC和碘化丙啶染色行检测细胞凋亡,Western blot检测细胞凋亡的机制。结果文中建立的Tet-Off诱导系统可使t TA结合到TRE,从而促进AIM2基因转录,进而使AIM2蛋白大量表达。在诱导4 d后,可在细胞质及细胞核中检测到AIM2的表达,随诱导天数的增加其表达量增加。AIM2表达于细胞质及细胞核中。由XTT assay可知,MCF-7 t TA-AIM2细胞株在诱导6 d后生长速率减慢。诱导AIM2大量表达后,其FITC荧光凋亡百分比显著增加(2.36%vs 14.45%,P<0.01)。AIM2大量表达后抑制抗凋亡蛋白-Bcl-x L表达,增加促凋亡蛋白-Bad、Bax,并且活化caspases进而造成DNA修复蛋白PARP裂解。结论在乳腺癌Tet-Off诱导系统中,AIM2影响细胞增殖,刺激线粒体促使细胞走向凋亡。Objective The human IFN-inducible protein absent in melanoma 2 （AIM2） has been regarded as a tumour sup-pressor, however, the molecular mechanisms of its antitumor activity still remain unclear.This research is to study the molecular mech-anisms of AIM2 inducing breast cancer cell apoptosis. Methods Tet-Off induction model system was established to induce AIM2 ex-pression in great quantities, MCF-7 tTA-AIM2 cells as the experimental group and MCF-7 tTA-Luc cells as control group.Western blotting was used to detect AIM2 expression in breast cancer cell lines and subcellular localization.XTT assay was applied to analyze the effects of AIM2 on cell proliferation.Apoptosis were detected by Annexin V-FITC and propidium iodide staining, and the apoptosis mechanism were investigated by west blot. Results The established Tet-off guidance system could combine tTA to TRE, thereby promoting AIM2 gene transcription and inducing great expression of AIM2 protein.4 days after induction, the expression of AIM2 could be detected in cytoplasm and nucleus, and AIM2 expression increased with the increasing days.XTT assay detected the growth speed of MCF-7 tTA-AIM2 cell lines slowed down 6 days after induction.After abundant expression of induced AIM2, the percentage of FITC fluorescence apoptosis increased significantly （2.36%vs 14.45%, P〈0.01） .Increased AIM2 expression inhibited the expression of the anti-apoptotic protein Bcl-xL, increased the expression of the apoptosis proteins Bad and Bax, and activated caspases, resulting in the cleavage of DNA repair protein PARP. Conclusion In breast cancer Tet-off induction system, AIM2 will express in cytoplasm and nucleus, influence cell proliferation, and stimulate the mitochondria to cell apoptosis.

关 键 词：干扰素诱导蛋白2 乳腺癌细胞 细胞周期 细胞凋亡 

分 类 号：R737.9[医药卫生—肿瘤]