Novel roles for HMGA2 isoforms in regulating oxidative stress and sensitizing to RSL3-Induced ferroptosis in prostate cancer cells

Taaliah Campbell; Ohuod Hawsawi; Veronica Henderson; Precious Dike; Bor-Jang Hwang; Yusuf Liadi; ElShaddai Z White; Jin Zou; GuangDi Wang; Qiang Zhang; Nathan Bowen; Derrick Scott; Cimona V Hinton; Valerie Odero-Marah

doi:10.1016/j.heliyon.2023.e14810

Novel roles for HMGA2 isoforms in regulating oxidative stress and sensitizing to RSL3-Induced ferroptosis in prostate cancer cells

Heliyon. 2023 Apr 7;9(4):e14810. doi: 10.1016/j.heliyon.2023.e14810. eCollection 2023 Apr.

Affiliations

¹ Center for Cancer Research and Therapeutic Development, Department of Biological Sciences, Clark Atlanta University, Atlanta, GA, 30314, USA.
² Center for Urban Health Disparities Research and Innovation, Department of Biology, Morgan State University, Baltimore, MD, 21251, USA.
³ Department of Chemistry, Xavier University, New Orleans, LA, 70125, USA.
⁴ Department of Biological Sciences, Delaware State University, Dover, DE, 19901, USA.

Abstract

Oxidative stress is increased in several cancers including prostate cancer, and is currently being exploited in cancer therapy to induce ferroptosis, a novel nonapoptotic form of cell death. High mobility group A2 (HMGA2), a non-histone protein up-regulated in several cancers, can be truncated due to chromosomal rearrangement or alternative splicing of HMGA2 gene. The purpose of this study is to investigate the role of wild-type vs. truncated HMGA2 in prostate cancer (PCa). We analyzed the expression of wild-type vs. truncated HMGA2 and showed that prostate cancer patient tissue and some cell lines expressed increasing amounts of both wild-type and truncated HMGA2 with increasing tumor grade, compared to normal epithelial cells. RNA-Seq analysis of LNCaP prostate cancer cells stably overexpressing wild-type HMGA2 (HMGA2-WT), truncated HMGA2 (HMGA2-TR) or empty vector (Neo) control revealed that HMGA2-TR cells exhibited higher oxidative stress compared to HMGA2-WT or Neo control cells, which was also confirmed by analysis of basal reactive oxygen species (ROS) levels using 2', 7'-dichlorofluorescin diacetate (DCFDA) dye, the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and NADP/NADPH using metabolomics. This was associated with increased sensitivity to RAS-selective lethal 3 (RSL3)-induced ferroptosis that could be antagonized by ferrostatin-1. Additionally, proteomic and immunoprecipitation analyses showed that cytoplasmic HMGA2 protein interacted with Ras GTPase-activating protein-binding protein 1 (G3BP1), a cytoplasmic stress granule protein that responds to oxidative stress, and that G3BP1 transient knockdown increased sensitivity to ferroptosis even further. Endogenous knockdown of HMGA2 or G3BP1 in PC3 cells reduced proliferation which was reversed by ferrostatin-1. In conclusion, we show a novel role for HMGA2 in oxidative stress, particularly the truncated HMGA2, which may be a therapeutic target for ferroptosis-mediated prostate cancer therapy.

Keywords: Ferroptosis; HMGA2; Oxidative stress; Prostate cancer; Truncated HMGA2.

Grants and funding

U54 MD007590/MD/NIMHD NIH HHS/United States