CBFβ/MYH11融合基因转录本检测及其致白血病机制的研究  

Detection of CBFβ/MYH11 fusion transcripts and study of the mechanism of leukemogenesis of CBFβ/SMHHC fusion protein

作　　者：徐世才[1] 杨琳[1] 邹煦[1] 冯敏[1] 郝玉书[1] 肖志坚[1] 

机构地区：[1]中国医学科学院,中国协和医科大学血液学研究所,血液病医院实验血液学国家重点实验室,天津300020

出　　处：《中华血液学杂志》2005年第6期332-335,共4页Chinese Journal of Hematology

基　　金：国家自然科学基金资助项目(30270573)

摘　　要：目的探讨CBFβ/MYH11融合基因转录本类型及其编码融合蛋白CBFβ/SMHHC致白血病的机制。方法用RTPCR联合序列分析检测CBFβ/MYH11融合基因。用pMCSFRluc作为报告质粒进行转录分析。用亚细胞蛋白组分Westernblot和双免疫荧光染色进行基因编码蛋白亚细胞定位分析。结果26例CBFβ/MYH11融合基因阳性患者中发现2种类型转录本,以A型为主(26例中24例,92%),其次为D型(8%)。CBFβ/SMHHC融合蛋白在CBF对MCSFR启动子转录激活过程中起抑制作用,且与CBFβ/SMHHC水平呈正相关;CBFα亚单位(AML1)为核蛋白,CBFβ/SMHHC融合蛋白与CBFβ亚单位一样为胞浆蛋白,CBFβ与AML1共表达时,大部分CBFβ仍定位于胞浆,少部分进入胞核,CBFβ/SMHHC与AML1共表达时,CBFβ/SMHHC则均进入胞核。结论①我国患者CBFβ/MYH11融合基因转录本类型分布与国外文献报道基本一致;②CBFβ/SMHHC显性负抑制CBF对其靶基因的转录调控活性机制之一是与野生型CBFβ竞争性结合AML1。Objective To explore CBFβ/MYH11 fusion transcripts and its expressing product CBFβ/SMHHC fusion protein in mechanism of leukemogenesis. Methods CBFβ/MYH11 fusion transcripts were detected by combined RT-PCR with sequencing. Transcription assays were examined using pM-CSFR-Luc as reporting plasmid, and subcellular localization of encoding proteins were assayed by double immunofluorescent staining and Western blot. Results Two types of CBFβ/MYH11 fusion transcripts were found in 26 patients with acute leukemia, most being of type A(23/26 cases,92%)and a few of type D(2/26 cases,8%). The inhibition of CBF-mediated M-CSFR promotor transactivation by CBFβ/SMHHC fusion protein was increasing with the increase in amount of the fusion protein. CBFα subunit(AML1) located in nucleus, both CBFβ subunit (CBFβ) and CBFβ/SMHHC located in cytoplasm. When AML1 and CBFβ were coexpressed, CBFβ still located mainly in cytoplasm, but when AML1 and CBFβ/SMHHC were coexpressed, CBFβ/ SMHHC located mainly in nucleus. Conclusions ①The types of CBFβ/MYH11 fusion transcripts of Chinese leukemia patients are almost the same as that reported in western literature. ②CBFβ/SMHHC inhibits CBF-mediated transactivation through competing with CBFβ for binding to AML1.

关 键 词：CBFβ/MYH11 融合基因转录本 检测 白血病 

分 类 号：R733.7[医药卫生—肿瘤]