癌相关基因在结肠癌中的表达及其甲基化调控

目的 探讨癌相关基因APC、p16^INK4A,p21^WAF1和c-myc等在结肠癌中的表达及其受甲基化的调控。方法 培养结肠癌细胞SWlll6、Colo-320、HT29，分别用不同浓度的5-aza-dC干预细胞。提取细胞的RNA，用RT-PCR的方法检测p16INK4A、,021WAFl、APC和c-myc等多种基因的表达情况；同时以流式细胞仪分析SWlll6和Colo-320的细胞周期。结果 (1)三种细胞在干预前有较弱的p16^INK4A和APC的表达，而在用5-aza-dC干预后表达增强，且在不同的结肠癌细胞株5-aza-dC作用发挥最佳的时间与浓度不同。(2)p21WAF1在干预前后均不表达，c-myc在干预前后表达无明显变化。结论 三株人结肠癌细胞中，5-aza-dC均可诱导p16^INK4A和APC的表达，但对p21WAF1和c-myc无明显影响。

Regulation of DNA methylation on the expression of tumor suppressor gene and oncogene in human colon cancer cell lines

Objective To investigate the effects of DNA methylation on tumor suppressor gene and oncogene in human colon cancer cells. Methods Three colon cancer cell lines(HT29, SW1116 and Colo 320) were treated with the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC). The expression of p16 INK4A , p21 WAF1 , APC and c-myc was assayed by RT-PCR. Cell cycle analysis by flow cytometry was performed. Results The expression of p16 INK4A and APC were slightly detected in all three colon cancer cells. However, the expressions of them were elevated to different extent after exposing to 5-aza-dC with different concentration and time for SW1116 and Colo 320 cells. p21 WAF1 didn't expressed before and after 5-aza-dC treatment. The expression of c-myc was not significant different in SW116 and Colo-320 cells treated by 5-aza-dC. Conclusion The expression of p16 INK4A and APC genes was regulated by DNA methylation in three human colon cancer cells.