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.

The neurotransmitter acetylcholine (ACh) plays a pro-carcinogenic role in various cancer types, including prostate cancer (PCa). The existing body of knowledge concerning the mechanisms that underpin the protumoral role of ACh in PCa is limited. Glyoxalase 1 (Glo1) is a metabolic enzyme that removes methylglyoxal (MG), an endogenous post-translational modification agent, generating 5-hydro-5-methylimidazolone (MG-H1). The Glo1/MG-H1 axis is involved in PCa tumorigenesis and progression. By using LNCaP and PC3 PCa cells, representing extensively studied cell models of poorly aggressive and bone metastasis-derived PCa, respectively, we found that ACh specifically sustains LNCaP cell migration, invasion and proliferation through Glo1-dependent MG-H1 accumulation with the involvement of osteopontin (OPN), thus providing a novel mechanism underlying ACh’s protumoral role in PCa cells. The findings of this study unveil a hitherto unidentified mechanism implicated in the progression of PCa, which is initiated by ACh and involves both the Glo1/MG-H1 axis and OPN. This discovery provides the basis for new avenues of in vivo investigation into the physiological relevance of the roles of the ACh-driven Glo1/MG-H1 axis and OPN in PCa progression and for further research aimed at exploring new ways of managing PCa progression, with the aim of preventing the disease from becoming incurable.

Glyoxalase 2 (Glo2) is a key enzyme of the glyoxalase system that catalyzes the conversion of S-lactoylglutathione (LSG) into glutathione (GSH) and D-lactate. In prostate cancer (PCa), we previously demonstrated that the oncogenic PTEN-PI3K–AKT–mTOR–ERα signaling pathway upregulates Glo2, leading to intracellular D-lactate accumulation and enhanced cell migration, invasiveness, and expression of epithelial-to-mesenchymal transition (EMT)-associated markers. However, whether D-lactate acts as a bioactive metabolic signal contributing to tumor aggressiveness remains unclear. Here, after confirming our previous findings, we demonstrate—using Glo2 silencing, ectopic expression, pharmacological inhibitors, and exogenous D-lactate supplementation—that Glo2-dependent D-lactate accumulation promotes EMT-like plasticity, migration, and invasion in PTEN-deficient PCa cells via a functional link with FAK/Src signaling. Collectively, these results suggest that the Glo2–D-lactate axis may contribute to metabolic rewiring associated with aggressive behavior in PTEN-deficient PCa, warranting further in vivo studies to evaluate its potential as a therapeutic target to limit tumor progression.

Dietary advanced glycation end-products (dAGEs) contained in high-sugar/fat and ultra-processed foods of the “Western diet” (WD) pattern predispose to several diseases by altering protein function or increasing oxidative stress and inflammation via RAGE (receptor for advanced glycation end-products). Although elevated endogenous AGEs are associated with loss of muscle mass and functionality (i.e., muscle wasting; MW), the impact of dAGEs on MW has not been elucidated. Here, we show that the most common dAGEs or their precursor, methylglyoxal (MGO), induce C2C12 myotube atrophy as endogenous AGE-derived BSA. ROS production, mitochondrial dysfunction, mitophagy, ubiquitin–proteasome activation, and inhibition of myogenic potential are common atrophying mechanisms used by MGO and AGE-BSA. Although of different origins, ROS are mainly responsible for AGE-induced myotube atrophy. However, while AGE-BSA activates the RAGE-myogenin axis, reduces anabolic mTOR, and causes mitochondrial damage, MGO induces glycolytic stress and STAT3 activation without affecting RAGE expression. Among thirty selected natural compounds, Vaccinium macrocarpon (VM), Camellia sinensis, and chlorophyll showed a surprising ability in counteracting in vitro AGE formation. However, only the standardized VM, containing anti-glycative metabolites as revealed by UHPLC-HRMS analysis, abrogates AGE-induced myotube atrophy. Collectively, our data suggest that WD-linked dAGE consumption predisposes to MW, which might be restricted by VM food supplements.

Individuals with Laron syndrome, a rare condition characterized by congenital insulin-like growth factor 1 (IGF-1) deficiency, display a remarkably low incidence of cancer, suggesting the existence of protective mechanisms linking reduced IGF-1 signaling to decreased cancer susceptibility. Consistent with this observation, IGF-1 is a recognized promoter of prostate cancer (PCa) progression, although the underlying mechanisms remain incompletely understood. Methylglyoxal (MG)-derived glycative stress, reflected by the accumulation of MG-derived hydroimidazolone 1 (MG-H1), has been implicated in PCa progression but has never been investigated in Laron syndrome. We found that liver tissues from Laron mice exhibited lower MG-H1 levels, suggesting reduced MG-derived glycative stress associated with low IGF-1 signaling. These findings prompted us to investigate whether MG-derived glycative stress contributes to IGF-1-driven PCa progression. Compared with the less aggressive LNCaP cells, PC3 cells displayed higher basal IGF-1 and MG-H1 levels, consistent with a potential association between IGF-1 and MG-derived glycative stress in PCa progression. Moreover, IGF-1 stimulation of LNCaP cells increased MG-H1 accumulation, proliferation, colony formation, invasiveness, and expression of matrix metalloproteinase (MMP)-1, MMP-7, MMP-9, receptor for advanced glycation end-products (RAGE), and Osteopontin (OPN), all of which were markedly attenuated by the MG scavenger, aminoguanidine (AG). Collectively, these findings support a potential contribution of MG-derived glycative stress to IGF-1-driven PCa progression.

Individuals with Laron syndrome, a rare condition characterized by congenital insulin-like growth factor 1 (IGF-1) deficiency, display a remarkably low incidence of cancer, suggesting the existence of protective mechanisms linking reduced IGF-1 signaling to decreased cancer susceptibility. Consistent with this observation, IGF-1 is a recognized promoter of prostate cancer (PCa) progression, although the underlying mechanisms remain incompletely understood. Methylglyoxal (MG)-derived glycative stress, reflected by the accumulation of MG-derived hydroimidazolone 1 (MG-H1), has been implicated in PCa progression but has never been investigated in Laron syndrome. We found that liver tissues from Laron mice exhibited lower MG-H1 levels, suggesting reduced MG-derived glycative stress associated with low IGF-1 signaling. These findings prompted us to investigate whether MG-derived glycative stress contributes to IGF-1-driven PCa progression. Compared with the less aggressive LNCaP cells, PC3 cells displayed higher basal IGF-1 and MG-H1 levels, consistent with a potential association between IGF-1 and MG-derived glycative stress in PCa progression. Moreover, IGF-1 stimulation of LNCaP cells increased MG-H1 accumulation, proliferation, colony formation, invasiveness, and gene expression of matrix metalloproteinase (MMP)-1, MMP-7, MMP-9, receptor for advanced glycation end-products (RAGE), and Osteopontin (OPN), all of which were markedly attenuated by the MG scavenger aminoguanidine (AG). Collectively, these findings support a potential contribution of MG-derived glycative stress to IGF-1-driven PCa progression.