Arsenic contamination in drinking water is one of the major health issues worldwide. Over 140 million people from 50+ countries are exposed to drinking water containing arsenic at levels above “safe” levels of 10 μg/L. Several studies indicate that chronic arsenic exposure is associated with the development of carcinogenic changes in the lungs, bladder, liver, and skin and other potential health problems. In this project, we aim to characterize bladder cancer mutational signatures and somatic mutations in a cohort of bladder cancer patients known to have been highly exposed to arsenic in northern Chile by using whole-exome sequencing (WES). We analyzed WES data and identified somatic mutations and mutational signatures using Mutec2 and SigProfiler. Preliminary analyses from a small number of exposed patients identified two mutational signatures, previously described as having “unknown” etiology, that showed an association with arsenic exposure. We are currently validating these findings in additional samples and with functional studies. Alma Poceros-Coba Ph.D. Candidate is the recipient of the Conacyt-UC-MEXUS Doctoral Fellowship and is the recipient of the UCDCCC Travel Award.

Citation Format: Alma A. Poceros-Coba, Ana Estrada-Florez, Ted Toal, Paul Lott, Macarena Garrido, Craig Steinmaus, Catterina Ferrecio R., Luis Carvajal-Carmona. Elucidating arsenic dependent carcinogenesis in humans [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 229.