Gene expression profiles in lung cancer using cDNA arrays

吸烟是导致超过90%的肺癌病例的原因，然而吸烟引起的肺部精确分子改变导致癌症并影响生存率仍然不清楚。为了识别与吸烟相关的分子特征，我们使用HG-U133 A亲和素芯片对135例新鲜冷冻腺癌组织样本和来自当前，以前和从不吸烟者的配对非受累肺组织进行了基因表达分析，并提供了生物化学验证的吸烟信息。我们使用针对潜在混杂因素调整的ANOVA分析，进行基因集富集分析和GO功能分类，其中p值<0.001，倍数变化>1.5，并且错误发现率用于基因选择。我们通过RT-PCR在原始组织样本中进行了验证，并在两项研究的独立肿瘤和非肿瘤组织中进行了确认。我们发现了一个吸烟的基因表达特征。这个特征与腺癌的发展和生存有关。细胞周期基因变化，特别是有丝分裂纺锤体形成中的基因变化（例如，NEK 2、TTK、BIRC 5），强烈区分吸烟者与非吸烟者以及早期肿瘤与未受累肺组织，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NEK 2和TTK的表达也与吸烟者肺癌死亡风险增加3倍相关。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.