伊马替尼调控Survivin基因表达的分子机制  

Molecular mechanisms of Survivin gene expression regulated by imatinib

作　　者：方志鸿[1] 赵金涛[1] 骆宜茗[1] 樊亚群[1] 韩忠朝[2] 

机构地区：[1]厦门大学附属第一医院血液科,361003 [2]中国医学科学院北京协和医学院血液学研究所实验血液学国家重点实验室

出　　处：《白血病．淋巴瘤》2012年第12期727-731,共5页Journal of Leukemia & Lymphoma

摘　　要：目的探讨伊马替尼对ber—abl转化细胞中的抗凋亡基因Survivin表达的影响。方法应用PCR和Westernblot法检测伊马替尼作用后32Dcl3和320．ber．abl细胞Survivin表达变化。克隆和构建Survivin启动子与荧光素酶基因融合的报告载体，采用缺失突变和点突变方法鉴定Survivin启动子上伊马替尼相关的作用元件。应用染色质免疫共沉淀技术检测c．myc和Surivinv启动子的结合作用。应用10058．F4抑制c—myc活性，观察其联合伊马替尼对白血病细胞的杀伤作用。结果伊马替尼显著抑制bcr—abl转化的32D—bcr—abl细胞中SurvivinmRNA和蛋白的表达，染色质免疫共沉淀技术证实c—myc与Survivin启动子上E—box元件结合。10058-F4能够增强耐药细胞系K562／G01对伊马替尼的敏感性。结论伊马替尼可能通过c—mye调控Survivin的转录表达，干预c．myc活性有望成为白血病耐药治疗的一种新策略。Objective To investigate the influences of imatinib on Survivin gene expression in ber-abl-transformed leukemia cells. Methods Firstly, PCR and Western blot were carried out to detected Survivin expression with imatinib treatment in 32Dc13 and 32D-ber-abl cell lines. Then the luciferase reporter plasmids containing human Survivin promoter as well as its deletion and site-directed mutation were constructed to identify the esseotial responsive elements for suppressing Survivin promoter activity by imatinib. Chromatin immunopreeipitation was performed to confirm the binding of c-mye to Survivin promoter. I0058-F4, a small molecule c-myc inhibitor, was used to disrupt c-myc activity and evaluate its anti-leukemic effect combined with imatinib. Results Both of mRNA and protein level of Survivin in bcr-abl-transformed cells were downregulated upon imatinib treatment. The decrease of Survivin expression was controlled at the transcriptional level through a mechanism in which imatinib repressed survivin promoter activity by disturbing the interaction between c-myc and E-box elements. Interruption of c-myc activity by 10058-F4 exerted an anti-leukemia effect with enhancing the sensibility of K562/G01 cells to imatinib. Conclusion Imatinib down-regulates Survivin expression through c-myc-mediated transcription and interference with c-myc might be a potential utility for treatment of imatinib resistant leukemia.

关 键 词：伊马替尼 SURVIVIN c—myc 抗药性 肿瘤 白血病 

分 类 号：R733.7[医药卫生—肿瘤]