Abstract 1615: Targeting PGK1 to enhance ferroptosis in breast cancer

Abstract A key feature common to triple-negative breast cancer is metabolic reprogramming that contributes to the malignant phenotype. Dysregulation of phosphoglycerate kinase 1 (PGK1), an essential player in glycolysis, is involved in several oncogenic pathways. In the current study, we aimed to determine whether PGK1-mediated glucose metabolism impacts the induction of ferroptosis in breast cancer. We found that expression of PGK1 varies in TNBC cell lines, with MDA-MB-231, MDA-MB-458 and MDAMB-453 lines showing significantly higher PGK1 expression than BT-549 and HCC70, and than the luminal breast tumor cell lines MCF7 and T47D. Depletion of PGK1 by siRNA or inhibition of the kinase by the small molecule inhibitor NG52 resulted in elevations of the core ferroptosis markers, ACSL4, CD71 and TFRC, but led to a decreased level of GPX4 - a key enzyme in the regulation of ferroptosis via detoxifying lipid peroxides to their corresponding alcohols using glutathione as a co-factor. Induction of ferroptosis was glucose-dependent, as the higher glucose-containing culture caused increased cell death. Notably, depletion of PGK1 sensitized TNBC cells to ferroptotic cell death induced by erastin, an activator of ferroptosis, and decreased colony formation and attenuated migratory ability of tumor cells. Similar observation was made in the murine TNBC cell line, mammary 4T1 adenocarcinoma. Furthermore, we demonstrated that the glycolytic inhibitor, sodium dichloroacetate (DCA), enhanced ferroptosis, while the glycolysis inducers such as hypoxia and oligomycin reduced ferroptotic cell death, in the tumor cells subjected to PGK1 depletion. Immunofluorescence assay demonstrated an interaction of PGK1 with GPX4, the anti-ferroptosis peroxidase, and the pulse-chase experiment showed that the proteasomal turnover of GPX4 protein was faster in the PGK1-depleted tumor cells than that in the tumor cells without depletion of PGK1. Moreover, the tumor cells with depletion of PGK1 showed an upregulation of pyruvate dehydrogenase as compared with the cells without PGK1 depletion, suggesting that PGK1 mediated-down-regulation of pyruvate dehydrogenase plays a role in ferroptosis resistance in TNBC cells. Animal studies are ongoing to recapitulate our in vitro findings on the role of PGK1 in ferroptosis resistance using 4T1 TNBC mouse model. This study demonstrates that PGK1 inhibition can attenuates GPX4, elevate pyruvate dehydrogenase expression, and cause a metabolic shift, thereby sensitizing tumor cells to ferroptosis induction. Thus, PGK1 may be exploited as a therapeutic target for overcoming ferroptosis resistance in breast cancer. Citation Format: Felix F. Oyelami, Andrew T. Shinkle, Chrispus M. Ngule, Xingcong Ren, Folake A. Oyelami, Oluwafunminiyi Obaleye, Jin-Ming Yang. Targeting PGK1 to enhance ferroptosis in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1615.