5-氮杂-2'-脱氧胞苷对SW48结肠腺癌细胞生物学行为的影响

Effect of demethylating agent 5-Aza- 2'-deoxycytidine on human colonic carcinoma cell line SW48

目的:研究去甲基化5-氮杂2'-脱氧胞苷(5-Aza-CdR)对SW48结肠腺癌细胞株生长周期及凋亡的影响,探讨其临床治疗的可能性.方法:分别使用浓度为0.4,1.6,6.4,25.6,102.4μmol/L特异型DNA甲基转移酶抑制剂5-Aza-CdR处理大肠腺癌细胞株.通过MTT来检测5-Aza-CdR对大肠癌细胞株存活率的影响.应用流式细胞检测甲基化5-Aza-CdR对SW48结肠腺癌细胞株生长周期及凋亡的影响.RT-PCR检测处理前后抑癌基因RASSF1AmRNA表达的改变.结果:5-氮杂2'-脱氧胞苷在1.6μmol/L就可以明显的抑制SW48结肠腺癌细胞的增殖,细胞周期中处于G0/G1期的细胞明显的增多,阻滞于G1期,凋亡率增高,而且以上作用与药物作用浓度,时间在一定范围内呈正相关.5-Aza-CdR处理后,无RASSF1A表达的SW48结肠腺癌细胞株可检测出基因RASSF1A的重新表达.结论:5-氮杂2'-脱氧胞苷可消除某些抑癌基因启动子甲基化状态,使其重新表达而抑制SW48结肠腺癌细胞株的生长,并促进其凋亡.

AIM： To explore the effect of demethylating agent 5-Aza-2′-deoxycytidine （5-Aza-CdR） on the growth of human colonic carcinoma cell line SW48, and to investigate the possibility of its application in clinical treatment. METHODS： Human colonic carcinoma SW48 cells were treated with 0.4, 1,6, 6.4, 25.8, and 102.4 mol/L 5-Aza-CdR, respectively. Then the growth of the cells was observed by MTT assay. The cell cycle and apoptosis were analyzed by flow cytometry. The expression of the tumor suppressor gene RASSF1A mRNAwas detected by reverse transcription polymerase chain reaction （RT-PCR）. RESULTS： 5-Aza-CdR inhibited the proliferation of SW48 cells in a time- and concentration-dependent manner （1-5 d, 0.4-102.4 mol/L）. After 5-Aza-CdR treatment, the number of Go/G1 cells was increased, and 5-Aza-CdR blocked the cell cycle at G1 phase. The apoptotic rate was also increased significantly.RASSF1A gene was reactivated by 5-Aza-CdR in SW48 cells not expressing RASSF1A. CONCLUSION： 5-Aza-CdR can inhibit the growth, and promote the apoptosis of SW48 cells by eliminating the methylation status of RASSF1A promoter.