PTEN/PKM2/ERα-Driven Glyoxalase 1 Overexpression Sustains PC3 Prostate Cancer Cell Growth Through MG-H1/RAGE Pathway Desensitization Leading to H2O2-Dependent KRIT1 Downregulation

Glyoxalase 1 (Glo1) functions as a catalyst that neutralizes methylglyoxal (MG), a highly reactive glycating agent predominantly produced during glycolysis—a metabolic pathway upregulated in cancer cells. MG primarily reacts with the amino groups of proteins (especially at arginine residues), leading to the formation of a major advanced glycation end product known as MG-derived hydroimidazolone 1 (MG-H1). We previously demonstrated in PC3 human prostate cancer (PCa) cells that the PTEN/PKM2/ERα axis promotes their aggressive phenotype by regulating the Glo1/MG-H1 pathway. In this study, after confirming our earlier findings, we investigated the downstream mechanisms of the PTEN/PKM2/ERα/Glo1/MG-H1 axis in controlling PC3 cell growth, focusing on the role of RAGE, a high-affinity receptor for MG-H1; hydrogen peroxide (H2O2); and Krev interaction trapped 1 (KRIT1), an emerging tumor suppressor. Using genetic approaches and specific inhibitors/scavengers, we demonstrated that the PTEN/PKM2/ERα/Glo1/MG-H1 axis promotes PC3 cell growth—measured by proliferation and etoposide-induced apoptosis resistance—through a mechanism involving MG-H1/RAGE pathway desensitization that leads to H2O2-mediated KRIT1 downregulation. These findings support and expand the role of PTEN signaling in PCa progression and shed light on novel mechanistic pathways driven by MG-dependent glycative stress, involving KRIT1, in this still incurable stage of the disease.