非小细胞肺癌血清MGMT、RASSF2、RUNX3及RASSF1A基因启动子CpG岛甲基化的联合检测及意义

Joint detection and significance of non-small cell lung cancer serum MGMT, RASSF2, RUNX3 and RASSF1A gene promoter CpG island methylation

目的探讨非小细胞肺癌患者血清中人类O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)、RASSF2、人类Runt相关转录因子3、RAS相关区域家族1A基因启动子区域甲基化状况及其临床意义。方法基因测序法检测62例NSCLC患者(肺癌组)和30例肺部良性疾病患者和16例健康体检者(对照组)血清中MGMT、RASSF2、RUNX3、RASSF1A基因启动子区域甲基化状况,并分析目标基因启动子区域甲基化状况与临床特征的关系。结果肺癌组MGMT基因甲基化频率为27.42%(17/62),而对照组为0(0/46)(x2=14.97,P<0.01);MGMT基因甲基化状态与年龄、性别、病理类型和分化状况无明显相关(P>0.05)。甲基化组吸烟指数(620.78±135.34)高于非甲基化组(498.96±150.87)(t=2.91,P<0.05)。MGMT基因甲基化多见于晚期患者,Ⅰ～Ⅱ期甲基化率为0(0/11)而Ⅲ～Ⅳ期为33.33%(17/51)(Fisher精确概率法,P<0.05)。肺癌组RASSF2基因甲基化频率为38.71%(24/62),而对照组为0(0/46)(x2=22.89,P<0.01);NSCLC患者血清RASSF2基因甲基化检出率与年龄、性别、病理类型、临床分期、分化程度无明显相关(P>0.05),不吸烟者RASSF2甲基化率高于吸烟者(61.90%vs26.83%,x2=7.20,P<0.05)。结论 MGMT、RASSF2、RUNX3、RASSF1A等基因异常甲基化在NSCLC患者外周血中有较高的发生率。MGMT、RASSF2、RUNX3、RASSF1A等基因异常甲基化状态可能和患者临床资料有一定关系。MGMT、RASSF2、RUNX3、RASSF1A等基因异常甲基化可能在NSCLC发生、发展中起重要作用。MGMT、RASSF2、RUNX3、RASSF1A等基因异常甲基化状态有望成为NSCLC辅助诊断和预后判断的分子标记。

Objective To detect the promoter hypermethylation status of O^6-methylguanine-DNA-methyl transferase, RAS association domain family 2, human runt-relat-ed transeription factor 3, RAS association domainfamily 1A gene in serum DNA of non-small cell lung cancer patients and discuss its clinical significance. Methods Serum DNA was extracted from 62 patients with NSCLC（lung cancer group,LG ）and 30 patients with benign pulmonary disease and 16 health subjects with medical check-up（control group,CG）.The Methylalion status of MGMT, RASSF2, RUNX3, RASSF1A gene were detected by bisnlfite genomic sequenee anti the correlalion of melhylation profiles with clinical characteristic was statistically analyzed. Results Aberrant promoter methylation of MGMT was detected in 17 of 62 （27.42%） LG patients, but in none of patients in CG （ Fisher exacl probabilities test, P 〈 0.05 ）.The promoter hypermethylation of MGMT did not correlate with age, gentler, histopathology or differentiation in I,G patients （P 〉 0.05）. The situation of smoking among methylated patients was heavier than those nnmethylated （ 620.78 ± 135.34 vs 498.96 ±150.87, t=2.91 , P 〈 0.05 ）.The incidence of aberrant prornoter methylation of MGMT was more in late stage （stage Ⅰ- Ⅱ ,0 （0/11）vs slage Ⅲ - Ⅳ ,33.33% （ 17/51 ））（Fisher exact probabilities test, P 〈 0.05）. Conclusion The incidence of aberrant promoter methylation of MGMT, RASSF2, RUNX3, RASSFI A gene were high in peripheral serum of NSCLC patients.The situation of promoter hypermethylation of MGMT, RASSF2, RUNX3, RASSF1A gene may correlate with the clinical data of NSCLC patients.The aberrant promoter methylation of MGMT, RASSF2, RUNX3, RASSFIA gene may play an important role in the tumorigenesis and progression in NSCLC. The situation of promoter hypermethylation of MGMT, RASSF2, RUNX3, RASSF1A gene are hopeful to become apromising novel biomarker for diagnosis and prediction in NSCLC.