Abstract 1337: Pan-cancer analysis of immune-associated genes and pathways dysregulated by tobacco reveals osteopontin as a key mediator of smoking-associated carcinogenesis

Abstract

Abstract Background: Smoking remains a primary etiological agent of 12 different cancers. However, current understanding of the pathogenesis and progression of these smoking-induced cancers remains unclear. Though vaping has been proposed as a safer alternative to cigarette smoking, more research is needed to fully understand its potential to cause cancer. In particular, the chemicals in e-cigarette (e-cig) vapor have previously been demonstrated to cause immune dysregulation, similar to conventional cigarette smoke. In this study, we aimed to investigate the immune-associated (IA) genomic and transcriptomic landscapes of a panel of smoking-induced cancers in order to identify common and unique elements among these cancers and to determine whether certain immune dysregulations may be shared between smoking and vaping. Methods: Whole genome sequencing data from tumors and adjacent normal samples was obtained from The Cancer Genome Atlas (TCGA) to compare the IA landscapes of 5 different smoking-induced cancers: head and neck squamous cell carcinoma (HNSCC), esophageal carcinoma (ESCA), bladder urothelial carcinoma (BLCA), lung adenocarcinoma (LUAD), and lung squamous cell carcinoma (LUSC). Differentially expressed genes were identified and correlated to tumor stage and patient survival. Gene Set Enrichment Analysis and ReactomeFi were used to correlate IA gene expression to cancer pathway enrichment. The REVEALER algorithm was used to correlate gene expression to copy number variations and mutations. Results: We found that the genomic landscapes of smoking-induced cancers were largely unique. However, Osteopontin (OPN), an IA gene capable of regulating the EGFR and CD44 signaling cascades, was found to be upregulated along with its downstream targets in HNSCC, LUAD, LUSC, and ESCA smoking patients. Such upregulation was correlated to poorer prognosis for all 4 cancers. In vitro study indicated an upregulation of OPN and its downstream targets in cell lines exposed to both e-cig vapor and cigarette smoke. Conclusions: Despite few similarities among the IA landscapes of these smoking-induced cancers, we suggest the importance of OPN upregulation in HNSCC, LUSC, LUAD, and ESCA pathogenesis caused by smoking and, potentially, vaping. Citation Format: Jaideep Chakladar, Neil Shende, Wei Tse Li, Weg M. Ongkeko. Pan-cancer analysis of immune-associated genes and pathways dysregulated by tobacco reveals osteopontin as a key mediator of smoking-associated carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1337.