ABSTRACT
AICARFT is a folate dependent catalytic site within the ATIC gene, part of the purine biosynthetic pathway, a pathway frequently upregulated in cancers. LSN3213128 is a potent (16 nM) anti-folate inhibitor of AICARFT and selective relative to TS, SHMT1, MTHFD1, MTHFD2 and MTHFD2L. Increases in ZMP, accompanied by activation of AMPK and cell growth inhibition, were observed with treatment of LY3213128. These effects on ZMP and proliferation were dependent on folate levels. In human breast MDA-MB-231met2 and lung NCI-H460 cell lines, growth inhibition was rescued by hypoxanthine, but not in the A9 murine cell line which is deficient in purine salvage. In athymic nude mice, LSN3213128 robustly elevates ZMP in MDA-MB-231met2, NCI-H460 and A9 tumors in a time and dose dependent manner. Significant tumor growth inhibition in human breast MDA-MB231met2 and lung NCI-H460 xenografts and in the syngeneic A9 tumor model were observed with oral administration of LSN3213128. Strikingly, AMPK appeared activated within the tumors and did not change even at high levels of intratumoral ZMP after weeks of dosing. These results support the evaluation of LSN3213128 as an antineoplastic agent.
Subject(s)
Aminoimidazole Carboxamide/analogs & derivatives , Antineoplastic Agents , Enzyme Inhibitors/pharmacology , Hydroxymethyl and Formyl Transferases/antagonists & inhibitors , Lung Neoplasms , Multienzyme Complexes/antagonists & inhibitors , Neoplasm Proteins/antagonists & inhibitors , Nucleotide Deaminases/antagonists & inhibitors , Ribonucleotides , Aminoimidazole Carboxamide/pharmacokinetics , Aminoimidazole Carboxamide/pharmacology , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Female , Humans , Hydroxymethyl and Formyl Transferases/metabolism , Lung Neoplasms/drug therapy , Lung Neoplasms/enzymology , Lung Neoplasms/pathology , Mice , Mice, Nude , Multienzyme Complexes/metabolism , Neoplasm Proteins/metabolism , Nucleotide Deaminases/metabolism , Ribonucleotides/pharmacokinetics , Ribonucleotides/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
NMR conformational analysis of a hydroxyethylamine peptide isostere developed as an aspartic protease inhibitor shows that it is a flexible architecture. Cyclization to form pyrrolidines, piperidines, or morpholines results in a preorganization of the whole system in solution. The resulting conformation is similar to the conformation of the inhibitor in the active site of BACE-1. This entropic gain results in increased affinity for the enzyme when compared with the acyclic system. For morpholines 27 and 29, the combination of steric and electronic factors is exploited to orient substituents toward S1, S1', and S2' pockets both in the solution and in the bound states. These highly preorganized molecules proved to be the most potent compounds of the series. Additionally, the morpholines, unlike the pyrrolidine and piperidine analogues, have been found to be brain penetrant BACE-1 inhibitors.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Ethylamines/chemistry , Ethylamines/pharmacology , Peptides/chemistry , Peptides/pharmacology , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Amyloid Precursor Protein Secretases/metabolism , Animals , Aspartic Acid Endopeptidases/metabolism , Brain/metabolism , Crystallography, X-Ray , Cyclization , Drug Design , Ethylamines/pharmacokinetics , Humans , Magnetic Resonance Spectroscopy , Mice , Models, Molecular , Morpholines/chemistry , Morpholines/pharmacokinetics , Morpholines/pharmacology , Peptides/pharmacokinetics , Protease Inhibitors/pharmacokinetics , Structure-Activity RelationshipABSTRACT
A hallmark of cancer is unbridled proliferation that can result in increased demand for de novo synthesis of purine and pyrimidine bases required for DNA and RNA biosynthesis. These synthetic pathways are frequently upregulated in cancer and involve various folate-dependent enzymes. Antifolates have a proven record as clinically used oncolytic agents. Our recent research efforts have produced LSN 3213128 (compound 28a), a novel, selective, nonclassical, orally bioavailable antifolate with potent and specific inhibitory activity for aminoimidazole-4-carboxamide ribonucleotide formyltransferase (AICARFT), an enzyme in the purine biosynthetic pathway. Inhibition of AICARFT with compound 28a results in dramatic elevation of 5-aminoimidazole 4-carboxamide ribonucleotide (ZMP) and growth inhibition in NCI-H460 and MDA-MB-231met2 cancer cell lines. Treatment with this inhibitor in a murine based xenograft model of triple negative breast cancer (TNBC) resulted in tumor growth inhibition.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Folic Acid Antagonists/chemistry , Folic Acid Antagonists/therapeutic use , Phosphoribosylaminoimidazolecarboxamide Formyltransferase/antagonists & inhibitors , Triple Negative Breast Neoplasms/drug therapy , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Breast/drug effects , Breast/metabolism , Breast/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Discovery , Female , Folic Acid Antagonists/pharmacokinetics , Folic Acid Antagonists/pharmacology , Humans , Male , Mice , Mice, Nude , Models, Molecular , Phosphoribosylaminoimidazolecarboxamide Formyltransferase/metabolism , Sulfonamides/chemistry , Sulfonamides/pharmacokinetics , Sulfonamides/pharmacology , Sulfonamides/therapeutic use , Thiophenes/chemistry , Thiophenes/pharmacokinetics , Thiophenes/pharmacology , Thiophenes/therapeutic use , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathologyABSTRACT
1. Nuclear magnetic resonance (NMR), a non-selective and inherently quantitative method, has not been widely used as a quantitative tool for characterizing the disposition of lead molecules prior to clinical development. As a test case, we have chosen a fluoropyrimidine compound in lead optimization phase and evaluated its disposition following oral administration to rats using 19F NMR. 2. Urine, bile and feces from individual rats were profiled and the amount of dose eliminated in each matrix was calculated. The results indicated that, in male rats, the mean dose eliminated over 0-48 h was 40%, with 28% in urine, 9% in bile and 3% in feces. In female rats, the mean dose recovered in excreta over the same period was 55%, with 40% in urine, 8% in bile and 7% in feces. 3. In addition, plasma from rats and plasma from toxicology study in dogs were also profiled and exposure of circulating entities was determined. Plasma exposure determined by 19F NMR was in good agreement with those determined by conventional LC-MS/MS method, suggesting quantitative 19F NMR can be reliably used to estimate single dose or steady-state systemic exposure of circulating entities in animals and humans.
Subject(s)
Drug Discovery/methods , Fluorine Radioisotopes/pharmacokinetics , Magnetic Resonance Spectroscopy/methods , Animals , Bile/chemistry , Biotransformation , Dogs , Feces/chemistry , Female , Humans , Isotope Labeling , Male , Pyrimidines/pharmacokinetics , Pyrimidines/toxicity , Rats , Rats, Sprague-Dawley , Tissue DistributionABSTRACT
Herein we report investigations into the p38alpha MAP kinase activity of trisubstituted imidazoles that led to the identification of compounds possessing highly potent in vivo activity. The SAR of a novel series of imidazopyridines is demonstrated as well, resulting in compounds possessing cellular potency and enhanced in vivo activity in the rat collagen-induced arthritis model of chronic inflammation.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Imidazoles/pharmacology , Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Pyridines/pharmacology , Adenosine Triphosphate/analogs & derivatives , Adenosine Triphosphate/metabolism , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacokinetics , Benzimidazoles/chemistry , Benzimidazoles/pharmacokinetics , Benzimidazoles/pharmacology , Edema/drug therapy , ErbB Receptors/metabolism , Humans , Imidazoles/chemistry , Imidazoles/pharmacokinetics , Mice , Mice, Inbred BALB C , Peptide Fragments/metabolism , Pyridines/chemistry , Pyridines/pharmacokinetics , Rats , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Structure-activity relationship studies are described, which led to the discovery of novel selective estrogen receptor modulators (SERMs) for the potential treatment of uterine fibroids. The SAR studies focused on limiting brain exposure and were guided by computational properties. Compounds with limited impact on the HPO axis were selected using serum estrogen levels as a biomarker for ovarian stimulation.
Subject(s)
Leiomyoma/drug therapy , Ovary/drug effects , Selective Estrogen Receptor Modulators/pharmacology , Animals , Brain/metabolism , Dose-Response Relationship, Drug , Drug Design , Estrogens/blood , Female , Humans , Models, Chemical , Ovary/metabolism , Rats , Rats, Sprague-Dawley , Selective Estrogen Receptor Modulators/chemistry , Software , Structure-Activity RelationshipABSTRACT
The design of a novel selective estrogen receptor modulator (SERM) for the potential treatment of uterine leiomyoma is described. 16 (LY2066948-HCl) binds with high affinity to estrogen receptors alpha and beta (ERalpha and ERbeta, respectively) and is a potent uterine antagonist with minimal effects on the ovaries as determined by serum biomarkers and histologic evaluation.
