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.

The Sertoli cells (SeCs) of the seminiferous tubules secrete a multitude of immunoregulatory and trophic factors to provide immune protection and assist in the orderly development of germ cells. Grafts of naked or encapsulated SeCs have been proved to represent an interesting therapeutic option in a plethora of experimental models of diseases. However, whether SeCs have immunosuppressive or immunomodulatory effects, which is imperative for their clinical translatability, has not been demonstrated. We directly assessed the immunopotential of intraperitoneally grafted microencapsulated porcine SeCs (MC-SeCs) in murine models of fungal infection (Aspergillus fumigatus or Candida albicans) or cancer (Lewis lung carcinoma/LLC or B16 melanoma cells). We found that MC-SeCs (i) provide antifungal resistance with minimum inflammatory pathology through the activation of the tolerogenic aryl hydrocarbon receptor/indoleamine 2,3-dioxygenase pathway; (ii) do not affect tumor growth in vivo; and (iii) reduce the LLC cell metastatic cancer spread associated with restricted Vegfr2 expression in primary tumors. Our results point to the fine immunoregulation of SeCs in the relative absence of overt immunosuppression in both infection and cancer conditions, providing additional support for the potential therapeutic use of SeC grafts in human patients.