Abstract 113: Investigating the role of high mobility group a2 (HMGA2) truncated isoform in promoting oxidative stress in PCa cells

Abstract Prostate cancer (PCa) is one of the most commonly diagnosed malignancies among men worldwide and remains the second leading cause of cancer related death in the United States. Oxidative stress has been shown to be increase in several cancers including prostate cancer. In fact, oxidative stress in prostate cancer is suggested to be a direct result of cell exposure to reactive oxygen species (ROS). High mobility group A 2 (HMGA2), a non-histone protein, is an oncogene that is up-regulated in several cancers. This protein has ability to undergo chromosomal rearrangement and alternative splicing, causing its full length/wild type HMGA2 (HMGA2-WT) to become the truncated losing its 3’UTR leading to the generation of HMGA2 truncated (HMGA2-TR). We have previously shown HMGA2-WT’s involvement in epithelial mesenchymal transition (EMT), however, the functional role of HMGA2-TR has not yet been dissected. We hypothesize that truncated HMGA2’s involvement with oxidative stress leads to prostate cancer progression. We analyzed the baseline expression of wild-type vs.truncated HMGA2 in prostate patient tissue and cells lines by real-time PCR and western blot analyses. Prostate cancer patient tissue and some cell lines expressed increasing amounts of both wild-type and truncated HMGA2with increasing tumor grade, when compared to normal epithelial cells. RNA-Seq analysis of LNCaP prostate cancer cells stably overexpressing HMGA2-WT, HMGA2-TR, or empty vector (Neo) control revealed thatHMGA2-TR cells display increased oxidative stress compared to HMGA2-WT or Neo control cells. This was also confirmed by analysis of basal reactive oxygen species (ROS) levels, and the ratio of GSH/GSSG andNADP/NADPH utilizing metabolomics. Additionally, proteomic analysis showed that HMGA2-TR protein interacted with several proteins, including a cytoplasmic stress granule protein G3BP1 that responds to oxidative stress. Transient knockdown of G3BP1 increased ROS in HMGA2-TR cells. These studies may therefore uncover novel role for truncated HMGA2 in oxidative stress. Acknowledgements: These studies were supported by the NIH/NIMHD/RCI Grant #5G12MD007590-31,NIH/NIGMS/RISE Grant #5R25GM060414 Citation Format: Taaliah Campbell, Ohuod Hawsawi, Nathan Bowen, Valerie Odero-Marah. Investigating the role of high mobility group a2 (HMGA2) truncated isoform in promoting oxidative stress in PCa cells [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 113.