人结肠癌细胞系中癌相关基因的表达及表型遗传修饰的影响  

Expression and epigenetic modification of tumor-associated genes in human colonic cancer cells

作　　者：陈萦晅[1] 房静远[1] 陆娟[1] 杨丽[1] 朱红音[1] 童菊芳[1] 沈冠凤[1] 罗鸿妤[1] 邱德凯[1] 萧树东[1] 

机构地区：[1]上海第二医科大学附属仁济医院,上海市消化疾病研究所,上海200001

出　　处：《临床与实验病理学杂志》2003年第5期533-538,共6页Chinese Journal of Clinical and Experimental Pathology

基　　金：国家自然科学基金 (No 3 0 170 413 );高等学校全国优秀博士学位论文作者专项资金 ( 199946);上海市教委重点学科科研经费资助

摘　　要：目的　观察DNA甲基化和组蛋白乙酰化对人结肠癌细胞系癌相关基因的表达和细胞周期的影响。方法　培养 2种结肠癌细胞系SW 1 1 1 6和Colo 32 0 ,分别以去甲基化制剂 5 氮脱氧胞苷 (5 aza 2′ deoxycytidine ,5 aza dC)和 (或 )组蛋白脱乙酰化酶 (histonedeacetylase ,HDAC)抑制剂trichostatinA(TSA)及丁酸盐干预细胞。提取细胞总RNA ,以RT PCR和定量RT PCR法研究抑癌基因p1 6 INK4A、APC、p2 1 WAF1 、p5 3和 p73以及癌基因c myc和c Ki ras、凋亡抑制基因survivinmRNA表达水平 ;并运用流式细胞术检测细胞周期变化。结果　正常情况下 ,SW 1 1 1 6和Colo 32 0细胞系中均有较弱的 p1 6 INK4A和APC表达 ;两种结肠癌细胞系 p2 1 WAF1 表达缺如 ,而 p5 3、p73和c myc、c Ki ras以及survivin均表达。以 5 aza dC干预后 ,p1 6 INK4A和APC表达增强 ,且不同的结肠癌细胞系表达增强最明显时 5 aza dC干预的时间与浓度不同。相反 p2 1 WAF1 仍无明显表达。值得注意的是这两个细胞系经TSA或丁酸盐处理后 ,p2 1 WAF1 转录水平显著上调。p5 3、p73、c myc、c Ki ras和survivin基因在干预前后表达无明显变化。另外 ,5 aza dC并不能改变细胞周期 ,而TSA或丁酸盐使细胞阻滞于G1 期。结论　两种人结肠癌细胞系中 ,p1Purpose To investigate the effects of DNA methylation and histone acetylation on the expression of tumor associated genes and cell cycle progression in human colonic cancer cells. Methods Two colonic cancer cell lines (SW1116 and Colo 320) were treated with the DNA methyltransferase (DNMT) inhibitor, 5 aza 2′ deoxycytidine (5 aza dC) or/and the histone deacetylase (HDAC) inhibitor, trichostatin A(TSA) or sodium butyrate. The expression of p16 INK4A , APC, p21 WAF1 , p53, p73 and c myc, c Ki ras and survivin genes mRNA was detected by RT PCR and real time RT PCR. Cell cycle distribution was studied by flow cytometry (FCM). Results Expression of p16 INK4A and APC was detected slightly and p21 WAF1 expression was lost, as well as p53, p73, c myc, c Ki ras, survivin genes expressed in SW1116 and Colo 320 cells before treatment. In SW1116 and Colo 320 cells, the expression of p16 INK4A and APC genes was markedly increased after treatment of 5 aza dC, although 5 aza dC treatment did not activate the expression of p21 WAF1 gene. Interestingly, the treatment of TSA or sodium butyrate resulted in the significantly over expression of p21 WAF1 in these two cell lines. Most genes including p53, p73, c myc, c Ki ras and survivin genes did not change following 5 aza dC or TSA or sodium butyrate treatment. In addition, 5 aza dC treatment failed to affect cell cycle distribution, but TSA or sodium butyrate blocked cells mainly in the G 1 phases. Conclusions The expression of p16 INK4A and APC genes is regulated by DNA methylation, and histone hyperacetylation is the major mechanism of up regulation of p21 WAF1 gene, and the transcription level of p53, p73, c myc, c Ki ras, survivin genes is not regulated by either methylation or histone acetylation in two human colonic cancer cell lines. In these two cell lines, histone hyperacetylation causes a G 1 cell cycle arrest.

关 键 词：人结肠癌细胞系 癌 相关基因 基因表达 表型遗传修饰 细胞周期 

分 类 号：R735.35[医药卫生—肿瘤] R329.25[医药卫生—临床医学]