Association of Methylation of the RAR-beta Gene with Cigarette Smoking in Non-Small Cell Lung Cancer with Southern-central Chinese Population

作者:Li, Wen; Deng, Jing*; Wang, Shuang Shuang; Ma, Liang; Pei, Jiang; Zeng, Xiao Xi; Tang, Jian Xin
来源:Asian Pacific Journal of Cancer Prevention, 2014, 15(24): 10937-10941.
DOI:10.7314/APJCP.2014.15.24.10937

摘要

Pathogenesis of lung cancer is a complicated biological process including multiple genetic and epigenetic changes. Since cigarette smoking is confirmed as the most main risk factor of non-small cell lung cancer (NSCLC), the aim of this study was to determine whether tobacco exposure plays a role in gene methylation. Methylation of the RAR-beta gene were detected using methylation-specific polymerase chain reaction in DNA from 167 newly diagnosed cases with NSCLC and corresponding 105 controls. A significant statistical association was found in the detection rate of the promoter methylation of RAR-beta gene between NSCLC and controls (x(2)=166.01; p<0.01), and hypermethylation of the RAR-beta gene was significantly associated with smoking status (p=0.038, p<0.05). No relationship was found between RAR-beta gene methylation and pathologic staging including clinical stage, cell type, gender and drinking (p>0.05), and the methylation of RAR-beta gene rate of NSCLC was slightly higher in stages III+IV (80.0%) than in I+II (70.8%). Similar results were obtained for methylation of the RAR-beta gene between squamous cell carcinoma (77.9%) and other cell type lung cancer (73.9%). These results showed that the frequency of methylation increased gradually with the development of clinical stage in smoking-associated lung cancer patients, and tobacco smoke may be play a potential role in RAR-beta gene methylation in the early pathogenesis and process in lung cancer, particularly squamous cell carcinoma. Aberrant promoter methylation is considered to be a promising marker of previous carcinogen exposure and cancer risk.