Targeting host glycolysis as a strategy for antimalarial development

Glycolysis controls cellular energy, redox balance, and biosynthesis. Antiglycolytic therapies are under investigation for treatment of obesity, cancer, aging, autoimmunity, and microbial diseases. Interrupting glycolysis is highly valued as a therapeutic strategy, because glycolytic disruption is generally tolerated in mammals. Unfortunately, anemia is a known dose-limiting side effect of these inhibitors and presents a major caveat to development of antiglycolytic therapies. We developed specific inhibitors of enolase - a critical enzyme in glycolysis - and validated their metabolic and cellular effects on human erythrocytes. Enolase inhibition increases erythrocyte susceptibility to oxidative damage and induces rapid and premature erythrocyte senescence, rather than direct hemolysis. We apply our model of red cell toxicity to address questions regarding erythrocyte glycolytic disruption in the context o

Structure-guided microbial targeting of antistaphylococcal prodrugs

Carboxy ester prodrugs are widely employed to increase oral absorption and potency of phosphonate antibiotics. Prodrugging can mask problematic chemical features that prevent cellular uptake and may enable tissue-specific compound delivery. However, many carboxy ester promoieties are rapidly hydrolyzed by serum esterases, limiting their therapeutic potential. While carboxy ester-based prodrug targeting is feasible, it has seen limited use in microbes as microbial esterase-specific promoieties have not been described. Here we identify the bacterial esterases, GloB and FrmB, that activate carboxy ester prodrugs i

Prodrugs of a 1-Hydroxy-2-Oxopiperidin-3-Yl Phosphonate Enolase Inhibitor for the Treatment of ENO1-Deleted Cancers

Cancers harboring homozygous deletion of the glycolytic enzyme enolase 1 (ENO1) are selectively vulnerable to inhibition of the paralogous isoform, enolase 2 (ENO2). A previous work described the sustained tumor regression activities of a substrate-competitive phosphonate inhibitor of ENO2, 1-hydroxy-2-oxopiperidin-3-yl phosphonate (HEX) (5), and its bis-pivaloyoxymethyl prodrug, POMHEX (6), in an ENO1-deleted intracranial orthotopic xenograft model of glioblastoma [Nature Metabolism 2020, 2, 1423-1426]. Due to poor pharmacokinetics of bis-ester prodrugs, this study was undertaken to identify potential non-esterase prodrugs for further development. Whereas phosphonoamidate esters were efficiently bioactivated in ENO1-deleted glioma cells, McGuigan prodrugs were not. Other strategies, including cycloSal and lipid prodrugs of 5, exhibited low micromolar IC50 values in ENO1-deleted glioma cells and improved stability in human serum over 6. The activity of select prodrugs was also probed using the NCI-60 cell line screen, supporting its use to examine the relationship between prodrugs and cell line-dependent bioactivation

Homozygous MTAP deletion in primary human glioblastoma is not associated with elevation of methylthioadenosine.

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) in cancers such as glioblastoma represents a potentially targetable vulnerability. Homozygous MTAP-deleted cell lines in culture show elevation of MTAP\u27s substrate metabolite, methylthioadenosine (MTA). High levels of MTA inhibit protein arginine methyltransferase 5 (PRMT5), which sensitizes MTAP-deleted cells to PRMT5 and methionine adenosyltransferase 2A (MAT2A) inhibition. While this concept has been extensively corroborated in vitro, the clinical relevance relies on exhibiting significant MTA accumulation in human glioblastoma. In this work, using comprehensive metabolomic profiling, we show that MTA secreted by MTAP-deleted cells in vitro results in high levels of extracellular MTA. We further demonstrate that homozygous MTAP-deleted primary glioblastoma tumors do not significantly accumulate MTA in vivo due to metabolism of MTA by MTAP-expressing stroma. These findings highlight metabolic discrepancies between in vitro models and primary human tumors that must be considered when developing strategies for precision therapies targeting glioblastoma with homozygous MTAP deletion

Therapeutic potential of PRMT5 and MAT2A as synthetic lethal targets in MTAP-deficient GBM tumors

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) is a frequent genetic alteration found in approximately 15% of all human cancers, including glioblastoma, pancreatic cancer, mesothelioma, urothelial bladder carcinoma, and lung squamous cell carcinoma. MTAP is a critical metabolic enzyme in the methionine salvage pathway responsible for the breakdown of methylthioadenosine (MTA). As a result, MTAP-deleted cells cannot metabolize MTA, leading to the accumulation of MTA. High levels of MTA in MTAP-deleted cells partially inhibit the activity of protein arginine methyltransferase 5 (PRMT5), making these cells sensitive to PRMT5 and MAT2A inhibition. Although elevated levels of MTA in vitro define a promising actionable metabolic vulnerability, the clinical relevance relies on exhibiting significant MTA accumulation in human tumors. Here, we demonstrate that, unlike cells in culture, MTA levels in MTAP-deleted primary human GBM tumors are not significantly higher compared to MTAP-intact tumors. This discrepancy is due to the secretion of MTA into the extracellular environment and its subsequent metabolism by stromal cells expressing MTAP. We also have demonstrated that the presence of MTAP-intact cells near MTAP-deleted cancer cells attenuates their sensitivity to PRMT5-MTA complex inhibitors. Moreover, we have demonstrated that putrescine, a metabolite in the polyamine biosynthesis pathway, can stimulate MTA production, and enhance the efficacy of PRMT5 inhibitor treatment in MTAP-deleted cells across multiple tumor cell lines, even in the presence of MTAP-intact cells. In summary, our findings highlight the metabolic discrepancies between in vitro models and primary human tumors, the influence of stromal infiltration on the synthetic lethal relationship between MTAP-deletion and PRMT5 inhibition, and the potential of co-treatment with putrescine and PRMT5 inhibitors to enhance this therapeutic approach

Magnetic and structural properties of CoPt nanoparticles embedded in Ag

Hadjipanayis, George C.L10 CoPt nanoparticles have very high magnetocrystalline energy that makes them potential candidate for high density recording media. In this study, I have investigated the structural and magnetic properties of CoPt particles embedded in silver. The CoPt nanoparticles were produced from CoPt/Ag multilayers. The thickness of CoPt layer was kept the same, and the thickness of Ag layer was varied. The as-made samples had the fcc structure. Particles with the ordered L10 structure were obtained by annealing the multilayers at a high temperature. The highest coercivity and particle size were found in samples with larger Ag layer thickness. Also, samples with larger Ag layer thickness showed the ordering in lower annealing time and temperature. Samples with smaller Ag layer thickness shows larger degree of ordering in comparison with the ones with larger Ag layer thickness.University of Delaware, Department of Physics and AstronomyM.S

Re-evaluating the mechanism of histone lactylation

Recent work by Zhang et al. published in Nature identified a unique non-metabolic role of the glycolysis end-product lactate, in post-translational lactylation of histones. The original study as well as follow-up editorials allude that lactate after being activated as lactyl-CoA mediates histone lactylation. Review of the experiments performed and the controls employed in the original study raises doubts on the proposed source and mechanism of lactylation. Herein, guided by findings from multiple labs including metabolomic studies from our own, we argue that S-lactoyl-glutathione is a more plausible substrate for histone lactylation