目的：研究甜菜碱对人肝癌细胞HepG2内基因组范围DNA甲基化的影响。方法：以浓度0. 1、0. 2、0. 4mol/L甜菜碱作用于人肝癌细胞HepG2 24、48 h后, 通过高效毛细管电泳仪(HPCE)检测肿瘤细胞中DNA水解产物中5-甲基-2'-脱氧胞嘧啶(5-methyl-2'-deoxycytidine, 5 mdC)水平, 来检测甜菜碱对HepG2内基因组范围DNA甲基化表达的影响。结果：随着甜菜碱的浓度增大, 5 mdC占总体胞嘧啶的峰面积的百分比也相应增大, 且有剂量依赖性。结论：甜菜碱作为甲基供体, 促进HepG2细胞基因组范围DNA甲基化的表达, 从而调控细胞周期抑制肿瘤的生长。

Objective: To study the effect of betaine on the DNA methylation in HepG2 genome. Methods: After betaine at concentration of 0.1, 0.2, and 0.4 mol/mL wasappliedtoHepG2cells for 24 and 48 h, the level of 5-methyl-2-deoxycytidine(5 mdC)in the DNA hydrolytic product in the tumor cells was tested using HPCE. Results: As the concentraion of betaine increased。the percent age of 5mdC in the peak area of totalcytidinealso increased in adosg-dependent manner. Conclusion: As a methyl donor, betaine could promote the expression of DNA methylation in the genome of HepG2 cells, thusregulating the cell cycle of cells and inhibiting tumor growth.

国家自然科学基金资助项目(30400352);教育部科学技术研究重点项目(205045);黑龙江省自然科学基金资助项目(D200611);黑龙江省研究生创新基金项目(YJSCX2006-0077HSD)