Chromatin Accessibility Reveals Potential Prognostic Value of the Peak Set Associated with Smoking History in Patients with Lung Adenocarcinoma

Considerable differences in molecular characteristics have been defined between non-smoker and smokers in patients with lung adenocarcinoma (LUAD), yet study of open chromatin patterns associated with LUAD progression caused by smoking is still lacking. Here, we constructed a novel network based on correlations between each ATAC-seq peak from TCGA data using our previously developed algorithm. Subsequently, principal component analysis was performed on LUAD samples with retained peaks filtered by the correlation network and pathway analysis was conducted for potential pathways identification. Results were verified in an independent dataset from primary LUAD samples. We identified a set of peaks that clearly differentiated long-term from short-term smokers in LUAD patients and also significantly associated with overall survival of these patients. We then investigated the gene set related to those peaks and found that the comprising genes are strongly associated with LUAD development, such as B3GNT3, ACTN4 and CLDN3 . They are consistent with the important roles for the associated pathways in LUAD oncogenesis induced by smoking, including glycosphingolipid biosynthesis and tight junction pathways. In summary, our study may provide valuable insights on exploration of ATAC-seq peaks and on smoking-related LUAD carcinogenesis from a perspective of open chromatin changes.