B淋巴瘤细胞Syk基因启动子区甲基化及5-aza-CDR对细胞增殖和凋亡影响的研究  

Effect of methylation of Syk promoter region and 5-aza-CDR on proliferation and apoptosis of human B lymphomas cells

作　　者：单保恩[1] 彭华[1] 宋小珍[1] 艾军[1] 李巧霞[1] 

机构地区：[1]河北医科大学第四医院科研中心,河北石家庄050011

出　　处：《中华肿瘤防治杂志》2008年第22期1686-1690,共5页Chinese Journal of Cancer Prevention and Treatment

基　　金：国家自然科学基金(30371753)

摘　　要：目的:探讨B淋巴瘤细胞Syk基因启动子区5′CpG甲基化情况及甲基化抑制剂5-氮杂脱氧胞苷(5-aza-2′-deoxycytidine,5-az-a-CDR)对淋巴瘤细胞的作用机制。方法:采用RT-PCR方法检测人B淋巴瘤细胞株Raji和Ramos中Syk mRNA的表达,用甲基化特异性PCR(MSP)方法检测Syk基因启动子区甲基化情况;采用MTT法检测5-aza-CDR对细胞增殖作用的影响,应用DNA凝胶电泳、流式细胞技术和电镜分析5-aza-CDR对B淋巴瘤细胞增殖、细胞周期和超微结构的影响。结果:Raji细胞Syk基因呈阳性表达,Ramos细胞未检测出Syk mRNA表达。Raji和Ramos细胞中均未检测到Syk基因启动子区的甲基化状态。5-aza-CDR可明显抑制Raji和Ramos细胞增殖,P<0.05;并存在明显的量效和时效依赖关系。5-aza-CDR可诱导Raji和Ramos细胞凋亡,P<0.05。DNA凝胶电泳检测结果显示明显的"DNAladder",并且有明显的细胞凋亡超微结构变化。然而,5-aza-CDR对Raji和Ramos细胞周期未见明显影响。结论:在Raji和Ramos细胞中,Syk基因沉默可能与甲基化无关;5-aza-CDR能明显抑制B淋巴瘤细胞增殖,诱导细胞凋亡,但对细胞周期无明显影响。OBJECTIVE： To investigate the methylation status of 5＇CpG in the promoter region of Syk gene of B lympho- ma cells, and the mechanism of 5-aza-CDR inhabiting human B lymphoma cells to proliferate. METHODS： Human B lymphoma cells were detected for expression of Syk gene by RT-PCR. Methylation specific PCR was used to detect methylation of Syk promoter region. The proliferation activities of cells were meas- ured by a MTT assay. The cell cycle progression and apoptosis induced by 5-aza CDR on Raji and Ramos cells were determined by flow cytometry, DNA agarose gel electrophoresis and elec- tron microscopy. RESULTS： The expression of Syk mRNA was detected in Raji cells, but abscent in Ramos cells. No methyla- tion in the Syk gene promoter was found in Raji and Ramos cells. The proliferations of Raji and Ramos were markedly inhib- ited by 5-aza-CDR in both of dose and time-dependant manner, P^0.05. The apoptosis rates of Raji and Ramos cells were sig- nificantly high in the group treated with 5-aza-CDR, P〈0.05. The agarose gel electrophoresis showed that there was a clear ＂DNA ladder＂ and uhramicrostructure changes of apoptosis, hut the cell cycles of Raji and Ramos cells were not obviously al- tered, P^0.05. CONCLUSIONS： There is no significant corre- lation between the silencing of Syk gene and gene methylation in Raji and Ramos cells. 5-aza-CDR could obviously inhibit the pro- liferation and augment apoptosis, but not alter the cell cycle. Chin J Cancer Prey Treat, 2008,15 （22） ： 1686-- 1690

关 键 词：淋巴瘤 B细胞 基因 Syk 甲基化 脱氧胞苷/药理学 细胞周期 细胞凋亡 启动区(遗传学) 

分 类 号：R733.1[医药卫生—肿瘤]