大肠癌组织Runx3基因启动子甲基化的研究

目的:检测大肠癌患者肿瘤组织及其相应的癌旁组织中Runx3基因表达和启动子区域甲基化状态,探讨甲基转移酶抑制剂5-aza-dc对结肠癌细胞系中Runx3表达的作用。方法:将手术切除的37例大肠癌组织和对应癌旁组织提取RNA和基因组DNA,采用RT-PCR检测Runx3基因的表达,甲基化特异PCR方法(MSP)检测Runx3基因启动子区域甲基化状态,用5-aza-dC处理结肠癌细胞系后,RT-PCR方法检测Runx3基因的表达。结果:37例大肠癌和对应癌旁组织中Runx3基因表达阳性率分别为100%(37/37),2.7%(1/37)。癌组织中Runx3基因表达明显降低(P<0.01)。MSP检测发现11例(30%)大肠癌标本及1例(3%)癌旁正常组织中Runx3基因呈甲基化状态。癌组织中Runx3基因甲基化明显高于癌旁组织(P<0.05)。结肠癌细胞系HT29 5-aza-dC处理后Runx3基因表达水平增加。结论:Runx3基因启动子甲基化和Runx3基因表达在大肠癌的癌旁组织和原发癌灶间存在显著性差异,可能与结肠癌的发生发展有关。

Study the expression and methylation of Runx3 gene promoter region in colorectal cancer tumor tissues

Objective: To study the expression and methylation of Runx3 gene promoter region in colorectal cancer tumor tissues and adjacent no tumor tissues,and explore the Runx3 expression in colon cancer cell lines effected by the methyltransferase inhibitor 5-aza-dc.Methods: Runx3 gene expression and promoter methylation were detected in 37 pairs of colorectal cancers and corresponding normal tissues by RT-PCR and methylation-specific polymerase chain reaction(MSP).Runx3 gene expression in two colon cancer cell lines was assayed by RT-PCR after 5-aza-dC treatment.Results: In 37 cases of colorectal cancer,Runx3 expression was detected at 100%(37/37) and 2.7%(1/37) in cancer tissues and corresponding normal tissues respectively.Runx3 gene expression in cancer was lower than that in normal tissues(P<0.01).Methylation of Runx3 promoter in 11(30%) of 37 colorectal cancers and 1(3%) corresponding normal tissues by MSP.Runx3 gene methylation was significantly higher in cancer than in adjacent tissue(P<0.01).Runx3 gene expression was reactivated in HT29 cells after 5-aza-dC treatment.Conclusion: Methylation of Runx3 promoter leads to inhibition of Runx3 gene expression in colorectal cancer and may functions in the progression of colorectal cancer.