Abstract 555: Role of TRIM31 in the pathogenesis of esophageal adenocarcinoma

Abstract Background: Esophageal adenocarcinoma (EAC) is one the deadliest cancers in United States (US) and the only major cancer in the US with increasing incidence. Gastroesophageal reflux disease (GERD) can cause Barrett’s esophagus (BE), a columnar metaplasia of the esophagus strongly associated with the development of EAC. GERD leading to BE is a common pre-occurrence in EAC patients, but the mechanism remains obscure. To explore the mechanism and its components, we compared gene expression in BE and EAC cells with normal esophageal cells and found high expression of tripartite motif-containing protein 31 (TRIM31) in BE and EAC compared to normal esophagus (NE) by transcriptomic profiling of RNA extracted from human esophageal tissues. E3 ubiquitin ligase TRIM 31 is a new member of TRIM family and it has been reported to have oncogenic potentials in some cancers. However, its role in EAC pathogenesis is yet to be understood. Methods: RNA sequencing and transcriptomic profiling were performed on human NE, BE, and EAC epithelial tissue samples. TRIM31 expression in NE cell line (Het-1A) and EAC cell lines (OE19, Flo-1, OE33, SK-GT-2, and OACM5.1C) were identified by Western blot analysis. The Het-1A cell line, after exposure to acidic pH and bile acids, was assessed for variable TRIM31 expression. Cell morphology and viability analyses of NE and EAC cell lines after exposure to acidic pH and bile acids either alone or in combinations were observed by microscopy and WST-1 assay respectively. Results: Transcriptomic analysis showed that BE and EAC are similar in their differential gene expression with upregulation of the TRIM31 compared to that in NE. Concordant with their columnar phenotype, BE and EAC groups displayed a multitude of differentially expressed genes relative to NE samples; however, less differentially expressed genes were found comparing BE and EAC groups. Western blot demonstrated frequent overexpression of TRIM31 in EAC cell lines with very low expression of TRIM31 in NE epithelial cell line. When NE epithelial cell line Het-1A was exposed to acidic pH as well as bile acids in acidic pH, we saw a change in cell morphology that may correlate with the metaplasia of these cells to more resilient forms, as seen in human BE and EAC. Interestingly, bile acids in acidic pH increased TRIM31 expression in NE cell line Het-1A. Bile acids had a greater effect on decreasing cell viability at high concentrations and that effect is enhanced when bile acids were added in acidic pH. WST-1 cell viability assay revealed that EAC cells were more resistant to bile acids as well as bile acids in acidic pH induced decreased in cell viability compared to that in NE cell line Het-1A. The sustained cell viability of EAC cell lines under these harsh conditions correlates with the upregulation of TRIM31. Conclusions: Thus, TRIM31 may be an important oncogenic factor in GERD-induced EAC development and may be an innovative therapeutic target and marker for EAC. Citation Format: Md Sazzad Hassan, Jesse Mast, Annie Ritter, Saisantosh Ponna, Niranjan Awasthi, Urs von Holzen. Role of TRIM31 in the pathogenesis of esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 555.