Gene expression profiles in lung cancer using cDNA arrays

超过90%的肺癌病例是由吸烟引起的，然而，吸烟在肺部引起的精确的分子改变，导致癌症和影响生存，仍然不清楚。为了确定与吸烟相关的分子特征，我们使用HG-U133A affytrix芯片对135个新鲜冷冻腺癌组织样本和配对的非受损伤肺组织样本进行了基因表达分析，这些样本来自目前、以前和从不吸烟者，具有生化验证的吸烟信息。我们使用了校正潜在混杂因素的方差分析，进行了基因集富集分析和go功能分类，p值<0.001,fold change >1.5，错误发现率用于基因选择。我们在原始组织样本中进行了RT-PCR验证，并在独立的肿瘤和非肿瘤组织中进行了两项研究。我们发现了吸烟的一个基因表达特征。这一特征与腺癌的发展和生存有关。细胞周期基因的变化，特别是有丝分裂纺锤体形成中的基因变化（如NEK2、TTK、BIRC5），强烈区分了吸烟者与非吸烟者以及早期肿瘤与非受损伤肺组织，这与该途径在吸烟相关肺癌发生中的重要作用一致。这些变化甚至在戒烟后几十年仍然存在。非受累肺组织中NEK2和TTK的表达也与吸烟者肺癌死亡风险增加3倍有关。我们的工作为吸烟如何诱发肺癌和影响生存提供了新的见解，并确定了吸烟者肺癌化学预防和治疗的靶点。

Tobacco smoking is responsible for over 90% of lung cancer cases, and yet the precise molecular alterations induced by smoking in lung that elaborate into cancer and impact survival have remained obscure. To identify the molecular signature associated with smoking, we conducted gene expression analysis using HG-U133A affymetrix chips on 135 fresh frozen tissue samples of adenocarcinoma and paired noninvolved lung tissue from current, former and never smokers, with biochemically validated smoking information. We used ANOVA analysis adjusted for potential confounders, Gene Set Enrichment Analysis, and GO-functional classification were conducted, with p-value<0.001, fold change >1.5, and false discovery rate used for gene selection. We validated in the original tissue samples by RT-PCR, and confirmed in independent tumor and non-tumor tissues from two studies. We identified a gene expression signature characteristic of smoking. This very signature was associated with adenocarcinoma development and survival. Cell cycle gene changes, particularly those in the mitotic spindle formation (e.g., NEK2, TTK, BIRC5), strongly differentiated both smokers from non smokers and early stage tumor from noninvolved lung tissue, consistent with an important role for this pathway in smoking-related lung carcinogenesis. These changes persisted even decades after smoking cessation. NEK2 and TTK expression in the noninvolved lung tissue was also associated with a 3-fold increased risk of mortality from lung cancer in smokers. Our work provides novel insights on how smoking induces lung cancer and affects survival, and identifies targets for chemoprevention and treatment against lung cancer in smokers.