Rable to inhibition from the paralogous isoform, enolase 2 (ENO2). A preceding perform described the sustained tumor regression activities of a substrate-competitive phosphonate inhibitor of ENO2, 1-hydroxy-2-oxopiperidin-3-yl phosphonate (HEX) (five), and its bis-pivaloyoxymethyl prodrug, POMHEX (6), in an ENO1-deleted intracranial orthotopic xenograft model of glioblastoma [Nature Metabolism 2020, 2, 1423-1426]. As a consequence of poor pharmacokinetics of bis-ester prodrugs, this study was undertaken to recognize prospective non-esterase prodrugs for further improvement. Whereas phosphonoamidate esters have been effectively bioactivated in ENO1-deleted glioma cells, McGuigan prodrugs have been not. Other techniques, like cycloSal and lipid prodrugs of five, exhibited low micromolar IC50 values in ENO1-deleted glioma cells and enhanced stability in human serum over 6. The activity of select prodrugs was also probed employing the NCI-60 cell line screen, supporting its use to examine the partnership among prodrugs and cell line-dependent bioactivation.INTRODUCTION Glycolysis inhibition is an aspirational therapeutic target in cancer therapy, as elevated glycolytic flux facilitates cellular growth and proliferation.1-3 Nevertheless, as glycolysis is definitely an important metabolic approach for all cells, building therapeutics that possess a sufficiently wide therapeutic window among cancer and normal cells has remained a persistent challenge.four We previously identified a subset of 1p36 homozygous deleted cancers harboring passenger deletions from the gene encoding the glycolytic enzyme enolase 1 (ENO1).5,6 Such cancers, which include poorly prognosed subtypes, for instance glioblastoma (GBM), hepatocellular carcinoma, cholangiocarcinoma, and large-cell neuroendocrine tumors, are exceptionally sensitive to pharmacological inhibition from the paralogous minor isoform, ENO2 (Figure 1a,b).7,8 Simply because homozygous deletion of ENO1 is a cancer-specific occasion, inhibition of ENO2 benefits in selective killing of cancerous but not normal cells. Enolase catalyzes the dehydration of 2-phosphoglycerate (2PG) to phosphoenolpyruvate (PEP) inside the penultimate step of glycolysis (Figure 1a).IGF-I/IGF-1, Mouse In an effort to recognize appropriate inhibitors of enolase, we first turned towards the literature and discovered phosphoacetohydroxamate (PhAH, 1; PDB: 4ZA0) to become the most potent, substrate-competitive, pan-enolase inhibitor described in the time.ASPN Protein web 9 Working with PhAH as a beginning point, we conducted molecular docking research to recognize derivatives with improved specificity for human ENO2.PMID:24118276 2022 The Authors. Published by American Chemical SocietyHuman ENO1 and ENO2 share 84 sequence identity bearing even larger resemblance inside the active site.10,11 Maximizing inhibitor specificity for ENO2 was an essential design and style goal to prevent inhibition of erythrocytic ENO1the sole isoform present in erythrocyteswhich can result in anemia.12,13 With these constraints, we identified a cyclic derivative of PhAH, deoxySF2312 (two), which bore close resemblance for the all-natural solution antibiotic, SF2312 (three; PDB: 4ZCW).eight We clarified the stereochemical specifications for active site binding by SF2312 by synthesizing a C-methyl derivative of SF2312 (mSF2312, 4; PDB: 5EU9), which showed that ENO2 binding was particular for the 3S, 5S enantiomer.14 Additional structure-activity connection (SAR) studies aimed at improving ENO2 specificity led to the identification of 1-hydroxy-2-oxopiperidin-3-yl phosphonate (HEX, five; Figure 1, PDB: 5IDZ).12 Of those 4 candidates (Figure 1c.