摘要
背景与目的对肺癌组织基因组DNA异常甲基化进行筛选与分析,探索肺癌发病的表遗传致癌机制。材料与方法从肺癌和癌旁组织中分别提取基因组DNA,经Mse1(甲基化非敏感性酶)单独消化或Mse1和BstU1(甲基化敏感性酶)联合消化,消化产物用甲基化敏感性内切酶指纹法(PCR-basedtechnique-Methylation-sensitiveRestrictionFingerprinting,MSRF)进行分析,肺癌组织出现异常甲基化基因片段,进一步将异常甲基化DNA片段进行亚克隆和序列测定,再与基因文库中的基因进行类比分析,同时按年龄、性别及吸烟状况分组并分析其与肺癌DNA异常甲基化的关系。结果84.5%(49/58)的肺癌样本出现异常甲基化现象,但肺鳞癌(82.1%)与肺腺癌(88.5%)的异常甲基化率差异无统计学意义(χ2=0.073,P>0.05);在异常甲基化DNA片段中,高甲基化现象占83%,低甲基化为17%,发现2条重要的高甲基化基因片段,它们分别与抑癌基因WT-1(Wilm'stumorsuppressorgene)和细胞周期调控基因CCNC(humancyclinCgene)匹配;经统计学分析,吸烟、年龄和性别与肺癌DNA异常甲基化无关。结论基因组DNA的异常甲基化,特别是高甲基化现象,可能在肺癌发生发展中起重要作用,这可能是肺癌发病的表遗传机制。
BXCKGROUND ＆ AIM： To study the aberrant DNA methylation of genomic DNA in lung cancer tissues as a possible epigenetic mechanism in the development of lung cancer. MATERIAL AND METHODS： Genomic DNA isolated from lung cancer and its adjacent tissue was restriction digested with Mse 1 （methylation non-sensitive） alone or with Mse1 and BstU1 （methylation sensitive） . The resulting DNA was analyzed for aberrant methylation using a PCR-based technique-Methylation-sensitive Restriction Fingerprinting （MSRF）. Several DNA fragments differentially methylated in the transformed cells compared with the non-transformed cells were identified by MSRF. These fragments were subcloned, sequenced and compared with GenBank. At the same time, the DNA methylation was analyzed according to age, sex and smoking status. RESULTS： As compared with the control tissues, 84.5% （49/ 58） of lung cancer tissues were found to have aberrant DNA methylation, but the methylation rate did not differ significantly among the squamous carcinoma （82.1%）, and adenocarcinoma （88.5%） and other cancer types （75.0%） （χ^2= 0.073, P 〉 0.05）. Among the fragments methylated, 83% was hypermethylated and 17% was hypomethylated. We have identified the fragments encoding for human cyclin C （CCNC） and Wilms tumor （WF-1） . When smoking, age and sex were considered as factors, no significant differences were observed. CONCLUSION： The aberrant DNA methylation, especially hypermethylation, seemed to play an important role in the development of lung cancer. It appeared to be a possible epigenetic mechanism for lung cancer.
出处
《癌变·畸变·突变》
CAS
CSCD
2006年第5期344-347,共4页
Carcinogenesis,Teratogenesis & Mutagenesis
基金
广东省医学科研基金资助(编号:A2003275)
