Malignant peripheral nerve sheath tumors (MPNST) are highly aggressive soft-tissue sarcomas that arise from neural tissues and carry a poor prognosis. Previously, we found that the glutamine amidotransferase inhibitor JHU395 partially impeded tumor growth in preclinical models of MPNST. JHU395 inhibits de novo purine synthesis in human MPNST cells and murine tumors with partial decreases in purine monophosphates. On the basis of prior studies showing enhanced efficacy when glutamine amidotransferase inhibition was combined with the antimetabolite 6-mercaptopurine (6-MP), we hypothesized that such a combination would be efficacious in MPNST. Given the known toxicity associated with 6-MP, we set out to develop a more efficient and well-tolerated drug that targets the purine salvage pathway. Here, we report the discovery of Pro-905, a phosphoramidate protide that delivered the active nucleotide antimetabolite thioguanosine monophosphate (TGMP) to tumors over 2.5 times better than equimolar 6-MP. Pro-905 effectively prevented the incorporation of purine salvage substrates into nucleic acids and inhibited colony formation of human MPNST cells in a dose-dependent manner. In addition, Pro-905 inhibited MPNST growth and was well-tolerated in both human patient-derived xenograft (PDX) and murine flank MPNST models. When combined with JHU395, Pro-905 enhanced the colony formation inhibitory potency of JHU395 in human MPNST cells and augmented the antitumor efficacy of JHU395 in mice. In summary, the dual inhibition of the de novo and purine salvage pathways in preclinical models may safely be used to enhance therapeutic efficacy against MPNST.

• MeSH
• antimetabolity terapeutické užití   MeSH
• glutamin MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory nervové pochvy * farmakoterapie   MeSH
• neurofibrosarkom * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antimetabolity MeSH
• glutamin MeSH
• JHU395 MeSH Prohlížeč

6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist that suppresses cancer cell metabolism but concurrently enhances the metabolic fitness of tumor CD8+ T cells. DON showed promising efficacy in clinical trials; however, its development was halted by dose-limiting gastrointestinal (GI) toxicities. Given its clinical potential, we designed DON peptide prodrugs and found DRP-104 [isopropyl(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5-oxo-hexanoate] that was preferentially bioactivated to DON in tumor while bioinactivated to an inert metabolite in GI tissues. In drug distribution studies, DRP-104 delivered a prodigious 11-fold greater exposure of DON to tumor versus GI tissues. DRP-104 affected multiple metabolic pathways in tumor, including decreased glutamine flux into the TCA cycle. In efficacy studies, both DRP-104 and DON caused complete tumor regression; however, DRP-104 had a markedly improved tolerability profile. DRP-104's effect was CD8+ T cell dependent and resulted in robust immunologic memory. DRP-104 represents a first-in-class prodrug with differential metabolism in target versus toxicity tissue. DRP-104 is now in clinical trials under the FDA Fast Track designation.

• MeSH
• CD8-pozitivní T-lymfocyty metabolismus   MeSH
• diazooxonorleucin farmakologie   terapeutické užití   MeSH
• glutamin metabolismus   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• lidé MeSH
• nádory * farmakoterapie   MeSH
• prekurzory léčiv * farmakologie   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• diazooxonorleucin MeSH
• glutamin MeSH
• inhibitory enzymů MeSH
• prekurzory léčiv * MeSH

The carbon and nitrogen components of glutamine are used for multiple biosynthetic processes by tumors. Glutamine metabolism and the therapeutic potential of glutamine antagonists (GA), however, are incompletely understood in malignant peripheral nerve sheath tumor (MPNST), an aggressive soft tissue sarcoma observed in patients with neurofibromatosis type I. We investigated glutamine dependence of MPNST using JHU395, a novel orally bioavailable GA prodrug designed to circulate inert in plasma, but permeate and release active GA within target tissues. Human MPNST cells, compared with Schwann cells derived from healthy peripheral nerve, were selectively susceptible to both glutamine deprivation and GA dose-dependent growth inhibition. In vivo, orally administered JHU395 delivered active GA to tumors with over 2-fold higher tumor-to-plasma exposure, and significantly inhibited tumor growth in a murine flank MPNST model without observed toxicity. Global metabolomics studies and stable isotope-labeled flux analyses in tumors identified multiple glutamine-dependent metabolites affected, including prominent effects on purine synthesis. These data demonstrate that glutamine antagonism is a potential antitumor strategy for MPNST.

• MeSH
• glutamin antagonisté a inhibitory   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory nervové pochvy farmakoterapie   MeSH
• prekurzory léčiv farmakologie   MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• glutamin MeSH
• prekurzory léčiv MeSH

2-(Phosphonomethyl)-pentanedioic acid (2-PMPA) is a potent (IC50 = 300 pM) and selective inhibitor of glutamate carboxypeptidase II (GCPII) with efficacy in multiple neurological and psychiatric disease preclinical models and more recently in models of inflammatory bowel disease (IBD) and cancer. 2-PMPA (1), however, has not been clinically developed due to its poor oral bioavailability (<1%) imparted by its four acidic functionalities (c Log P = -1.14). In an attempt to improve the oral bioavailability of 2-PMPA, we explored a prodrug approach using (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (ODOL), an FDA-approved promoiety, and systematically masked two (2), three (3), or all four (4) of its acidic groups. The prodrugs were evaluated for in vitro stability and in vivo pharmacokinetics in mice and dog. Prodrugs 2, 3, and 4 were found to be moderately stable at pH 7.4 in phosphate-buffered saline (57, 63, and 54% remaining at 1 h, respectively), but rapidly hydrolyzed in plasma and liver microsomes, across species. In vivo, in a single time-point screening study in mice, 10 mg/kg 2-PMPA equivalent doses of 2, 3, and 4 delivered significantly higher 2-PMPA plasma concentrations (3.65 ± 0.37, 3.56 ± 0.46, and 17.3 ± 5.03 nmol/mL, respectively) versus 2-PMPA (0.25 ± 0.02 nmol/mL). Given that prodrug 4 delivered the highest 2-PMPA levels, we next evaluated it in an extended time-course pharmacokinetic study in mice. 4 demonstrated an 80-fold enhancement in exposure versus oral 2-PMPA (AUC0-t: 52.1 ± 5.9 versus 0.65 ± 0.13 h*nmol/mL) with a calculated absolute oral bioavailability of 50%. In mouse brain, 4 showed similar exposures to that achieved with the IV route (1.2 ± 0.2 versus 1.6 ± 0.2 h*nmol/g). Further, in dogs, relative to orally administered 2-PMPA, 4 delivered a 44-fold enhanced 2-PMPA plasma exposure (AUC0-t for 4: 62.6 h*nmol/mL versus AUC0-t for 2-PMPA: 1.44 h*nmol/mL). These results suggest that ODOL promoieties can serve as a promising strategy for enhancing the oral bioavailability of multiply charged compounds, such as 2-PMPA, and enable its clinical translation.

• Klíčová slova
• 2-PMPA, glutamate carboxypeptidase II, oral bioavailability, pharmacokinetics, prodrugs,
• MeSH
• aplikace orální MeSH
• biologická dostupnost MeSH
• jaterní mikrozomy metabolismus   MeSH
• myši MeSH
• organofosforové sloučeniny aplikace a dávkování   chemie   metabolismus   farmakokinetika   MeSH
• prekurzory léčiv aplikace a dávkování   chemie   metabolismus   farmakokinetika   MeSH
• psi MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• 2-(phosphonomethyl)pentanedioic acid MeSH Prohlížeč
• organofosforové sloučeniny MeSH
• prekurzory léčiv MeSH

6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist with robust anticancer efficacy; however, its therapeutic potential was hampered by its biodistribution and toxicity to normal tissues, specifically gastrointestinal (GI) tissues. To circumvent DON's toxicity, we synthesized a series of tumor-targeted DON prodrugs designed to circulate inert in plasma and preferentially activate over DON in tumor. Our best prodrug 6 (isopropyl 2-(6-acetamido-2-(adamantane-1-carboxamido)hexanamido)-6-diazo-5-oxohexanoate) showed stability in plasma, liver, and intestinal homogenates yet was readily cleaved to DON in P493B lymphoma cells, exhibiting a 55-fold enhanced tumor cell-to-plasma ratio versus that of DON and resulting in a dose-dependent inhibition of cell proliferation. Using carboxylesterase 1 knockout mice that were shown to mimic human prodrug metabolism, systemic administration of 6 delivered 11-fold higher DON exposure to tumor (target tissue; AUC0- t = 5.1 nmol h/g) versus GI tissues (toxicity tissue; AUC0- t = 0.45 nmol h/g). In summary, these studies describe the discovery of a glutamine antagonist prodrug that provides selective tumor exposure.

• MeSH
• acetylace MeSH
• diazooxonorleucin aplikace a dávkování   farmakokinetika   MeSH
• karboxylesterhydrolasy genetika   MeSH
• lékové transportní systémy * MeSH
• lidé MeSH
• lysin chemie   MeSH
• myši knockoutované MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• plocha pod křivkou MeSH
• prasata MeSH
• prekurzory léčiv chemie   MeSH
• protinádorové látky aplikace a dávkování   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• carboxylesterase 1, mouse MeSH Prohlížeč
• diazooxonorleucin MeSH
• karboxylesterhydrolasy MeSH
• lysin MeSH
• prekurzory léčiv MeSH
• protinádorové látky MeSH

There are a number of clinically effective treatments for stress-associated psychiatric diseases, including major depressive disorder (MDD). Nonetheless, many patients exhibit resistance to first-line interventions calling for novel interventions based on pathological mechanisms. Accumulating evidence implicates altered glutamate signaling in MDD pathophysiology, suggesting that modulation of glutamate signaling cascades may offer novel therapeutic potential. Here we report that JHU-083, our recently developed prodrug of the glutaminase inhibitor 6-diazo-5-oxo-L-norleucine (DON) ameliorates social avoidance and anhedonia-like behaviors in mice subjected to chronic social defeat stress (CSDS). JHU-083 normalized CSDS-induced increases in glutaminase activity specifically in microglia-enriched CD11b+ cells isolated from the prefrontal cortex and hippocampus. JHU-083 treatment also reverses the CSDS-induced inflammatory activation of CD11b+ cells. These results support the importance of altered glutamate signaling in the behavioral abnormalities observed in the CSDS model, and identify glutaminase in microglia-enriched CD11b+ cells as a pharmacotherapeutic target implicated in the pathophysiology of stress-associated psychiatric conditions such as MDD.

• MeSH
• antigeny CD11b * MeSH
• chování zvířat účinky léků   MeSH
• deprese etiologie   prevence a kontrola   MeSH
• diazooxonorleucin * farmakologie   MeSH
• glutaminasa účinky léků   MeSH
• hipokampus účinky léků   imunologie   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• prefrontální mozková kůra účinky léků   imunologie   metabolismus   MeSH
• prekurzory léčiv * farmakologie   MeSH
• psychický stres komplikace   MeSH
• signální transdukce MeSH
• zánět farmakoterapie   imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antigeny CD11b * MeSH
• diazooxonorleucin * MeSH
• glutaminasa MeSH
• Itgam protein, mouse MeSH Prohlížeč
• prekurzory léčiv * MeSH