SIRT1增强人慢性粒系白血病K562细胞耐药性  

SIRT1 enhances drug resistance of CML K562 cells

作　　者：毛蓓蓓[1] 宋崴[1] 吕湘[1] 陈厚早[1] 刘德培[1] 

机构地区：[1]中国医学科学院基础医学研究所医学分子生物学国家重点实验室,北京100005

出　　处：《基础医学与临床》2011年第11期1223-1228,共6页Basic and Clinical Medicine

基　　金：国家重点基础研究发展计划(973项目)(2011CB964803)

摘　　要：目的研究Ⅲ类去乙酰化酶SIRT1对人慢性粒系白血病K562细胞耐药性的影响及其机制。方法分别将酶活性缺失突变型SIRT1-H363Y和SIRT1 shRNA表达质粒转染K562细胞,G418筛选稳定克隆后用H2O2和依托泊甙(et-oposide)处理细胞,Western blot检测caspase3剪切,BAX表达及DNA损伤标志物H2A.X磷酸化;在MCF-7和293A中过表达野生型SIRT1,检测H2O2和etoposide处理后的H2A.X磷酸化。结果 K562细胞中SIRT1-H363Y表达和SIRT1干扰均能促进H2 O2和etoposide诱导的caspase3剪切及BAX表达,并显著抑制H2 O2诱导的H2A.X磷酸化(对照vs SIRT1-H363Y:0.54±0.03 vs 0.23±0.01)(P<0.01)和etoposide(对照vs SIRT1 H363Y:1.36±0.20 vs 0.68±0.14)(P<0.05);(对照vs SIRT1 RNAi:0.68±0.06 vs 0.44±0.04)(P<0.01);在MCF-7和293A细胞中,野生型SIRT1过表达能明显增加etoposide诱导的H2A.X磷酸化(MCF-7:0.26±0.04 vs 0.46±0.02)(P<0.01);(293A:0 vs0.42±0.09)(P<0.05)。结论 SIRT1能保护K562细胞对抗DNA损伤药物诱导的凋亡,增强DNA损伤修复信号。Objective To explore the function of SIRT1 in drug resistance of chronic myelogenous leukemia（CML） K562 cells.Methods K562 cells stably expressing dominate negative SIRT1-H363Y or SIRT1 shRNA were treated with H2O2 and etoposide.Cleaved caspase3,BAX and γ-H2A.X signals were detected by Western blot;MCF-7 and 293A cells overexpressing wild type SIRT1 were treated with H2O2 and etoposide.γ-H2A.X was detected by Western blot.Results SIRT1-H363Y and SIRT1 shRNA expression in K562 cells could enhance the cleavage of caspase3 and the expression of BAX,but inhibit the formation ofγ-H2A.X induced by H2O2（control vs SIRT1-H363Y： 0.54± 0.03 vs 0.23±0.01）（P0.01）and etoposide（control vs SIRT1-H363Y： 1.36±0.20 vs 0.68±0.14）（P0.05）;（control vs SIRT1 RNAi： 0.68±0.06 vs 0.44±0.04）（P0.01）.On the contrary,overexpression of wild type SIRT1 in MCF-7 and 293A cells promotes the formation of γ-H2A.X（MCF-7： 0.26±0.04 vs 0.46±0.02）（P0.01）;（293A： 0 vs 0.42±0.09）（P0.05）.Conclusions SIRT1 may enhance the drug resistance and signal for DNA repair in K562 cells.

关 键 词：SIRT1 DNA损伤 耐药性 K562细胞 

分 类 号：R733.72[医药卫生—肿瘤]