SIRT1对野生型和R273H突变型TP53结直肠癌细胞凋亡的影响及机制研究  

Effect and its mechanism of SIRT1 on apoptosis of colorectal carcinoma cells harboring wild-type and R273H mutant TP53 genes

作　　者：王敏敏 张静 曾淑俊 屈玉玲 徐红 黄欣怡 米志宽[1] WANG Minmin;ZHANG Jing;ZENG Shujun;QU Yuling;XU Hong;HUANG Xinyi;MI Zhikuan(Department of Pathophysiology,Yan'an Medical College of Yan'an University,Yan'an 716000,China;State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Xijing Hospital of Department of Pathology,Fourth Military Medical University,Xi'an 710032,China)

机构地区：[1]延安大学延安医学院病理生理学教研室,陕西延安716000 [2]空军军医大学西京医院病理科,消化系肿瘤整合防治全国重点实验室,陕西西安710032

出　　处：《延安大学学报（医学科学版）》2024年第4期7-14,共8页Journal of Yan'an University:Medical Science Edition

基　　金：肿瘤生物学国家重点实验室(空军军医大学)自主课题(CBSKL2022ZZ27)。

摘　　要：目的探究沉默信息调节因子1(silencing information regulator 1,SIRT1)对携带野生型和R273H突变型TP53基因的结直肠癌细胞凋亡的影响及其相关分子机制。方法TUNEL染色和Western blot法分别比较SIRT1过表达(LV-SIRT1)和SIRT1敲低(sh-SIRT1)的结直肠癌HCT116细胞(携带野生型TP53基因)、SW620和SW480细胞(携带R273H突变型TP53基因)在细胞凋亡以及凋亡蛋白(Bcl-2、Bax和p53)以及K382位点乙酰化的p53蛋白(Ac-p53)水平的差异;利用SIRT1特异性激动剂SRT1720和抑制剂EX527分别处理亲本细胞,比较SIRT1去乙酰化酶活性改变对凋亡蛋白和Ac-p53表达水平的影响;采用环己酰亚胺处理SRT1720或EX527预处理的结直肠癌亲本细胞,比较各组细胞在Ac-p53蛋白稳定性上的差异。结果SIRT1对野生型p53蛋白和R273H突变型p53蛋白均具有去乙酰化作用,乙酰化修饰能够增强野生型p53蛋白的稳定性,但降低R273H突变型p53蛋白的稳定性,上调SIRT1表达抑制结直肠癌细胞的凋亡,而敲减SIRT1促进细胞凋亡。结论SIRT1通过去乙酰化野生型和R273H突变型p53蛋白影响其稳定性,参与对结直肠癌细胞的凋亡调控。Objective To explore the effect of SIRT1 on apoptosis of colorectal adenocarcinoma cells harboring wild-type TP53 gene and R273H mutant TP53 gene and their related molecular mechanism.Methods TUNEL staining and western blot analysis were used to compare the apoptotic levels and the expression levels of apoptosis proteins(Bcl-2,Bax and p53)and K382 acetylated p53(Ac-p53)protein in colorectal adenocarcinoma HCT116 cells(harboring wild-type TP53 gene),SW620 and SW480 cells(harboring R273H mutant TP53 gene)with overexpression of SIRT1(LV-SIRT1)and knockdown SIRT1(sh-SIRT1),respectively.The parental cells were treated with SIRT1-specific agonist SRT1720 or inhibitor EX527 to compare the protein expression levels of apoptosis proteins and Ac-p53 protein.The parents of colorectal cancer cells pretreated with SRT1720 or EX527 were treated with cycloheximide to compare the differences in the stability of Ac-p53 protein among the groups.Results SIRT1 could deacetylate both wild-type p53 protein and R273H mutant p53 protein.Acetylated modification enhanced the stability of wild-type p53 protein but reduced the R273H mutant p53 protein stability.The up-regulated SIRT1 expression inhibited apoptosis of colorectal carcinoma cells,while knockdown SIRT1 expression promoted apoptosis.Conclusion SIRT1 affects the stability of wild-type and R273H mutant p53 by deacetylating their proteins,which regulates the apoptosis of colorectal carcinoma cells.

关 键 词：结直肠癌 细胞凋亡 SIRT1 野生型P53 突变型P53 

分 类 号：R363[医药卫生—病理学]