Abstract 3347: Characterization of extracellular POTE-2 protein in liver cancer

Abstract

Abstract Liver cancer is projected to be the 5th and 7th leading cause of mortality in males and females in 2022. The top two forms of liver cancer diagnosed are hepatocellular carcinoma and cholangiocarcinoma, with a percentage of 75% and 11%. In recent years, Texas has had the highest incidence, with a rate of 11.6 per 100,000, with the Hispanic population having one of the highest rates. In South Texas, the Rio Grande Valley contains a high Hispanic population and faces multiple health disparities leading to a higher prevalence of liver cancer. These factors and the insufficient diagnostic methods for liver cancer lead to a need to identify faster and early biomarkers. Recently, we have identified an extracellular cancer-testis antigen, POTE-2, which belongs to the POTE gene family. Our preliminary data show that POTE-2 has an increased expression in liver cancer and can be associated with cancer progression. In this study, we will discuss the characterization of the extracellular face of POTE-2 in liver cancer. Lentiviral plasmids created an overexpressing and a knockdown POTE-2 cell line. The exosomes and conditioned media were collected from the cell lines to analyze POTE-2 protein expression through immunoblotting and ELISA. Antibodies targeting varying protein regions were produced and characterized for use in extracellular characterization. Exosome isolation and collection of conditioned media showed the expression of extracellular POTE-2 protein. Using varying antibodies targeting different regions determined the protein domain cleaved through secretion. These studies will aid in discovering novel characteristics of POTE-2 protein function and further explore its potential in liver cancer progression. Citation Format: Samantha Lopez, Kyle D. Doxtater, Adithya Anilkumar, Sophia Leslie, Amayrani Sanchez, Kristopher Ezell, Subhash Chauhan, Manish K. Tripathi. Characterization of extracellular POTE-2 protein in liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3347.