title: Design, synthesis, and in vitro testing of alpha-methylacyl-CoA racemase inhibitors.
abstract: The enzyme alpha-methylacyl-CoA racemase (AMACR) is overexpressed in prostate, colon, and other cancers and has been partially validated as a potential therapeutic target by siRNA knockdown of the AMACR gene. Analogs of the natural substrate branched chain alpha-methylacyl coenzyme A esters, possessing one or more beta-fluorine atoms, have been synthesized using Wittig, conjugate addition, and asymmetric aldol reactions and found to be reversible competitive inhibitors. Each diastereomer of the previously reported inhibitor ibuprofenoyl-CoA was also tested. The compounds had Ki values of 0.9-20 microM and are the most potent inhibitors yet known. The presence of beta-fluorine on the alpha-methyl group or the acyl chain results in a significant lowering of the Ki value compared with nonfluorinated analogs, and this is attributed to a lowering of the pKa of the alpha-proton, facilitating enolization and binding. Several of the CoA ester inhibitors were formed by incubating the free carboxylic acid precursors with cell free extracts and CoA. alpha-Trifluoromethyltetradecanoic acid, the precursor to the most potent inhibitor, was shown to inhibit growth of cancer cell lines PC3, CWR22 Rv1, and Du145 in a dose-dependent manner and could be related to the expression level of AMACR.
authors.affiliation: Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom. acarnell@liv.ac.uk
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Carnell
authors.forename: Ian
authors.initials: I
authors.lastname: Hale
authors.forename: Simone
authors.initials: S
authors.lastname: Denis
authors.forename: Ronald J A
authors.initials: RJ
authors.lastname: Wanders
authors.forename: William B
authors.initials: WB
authors.lastname: Isaacs
authors.forename: Brice A
authors.initials: BA
authors.lastname: Wilson
authors.forename: Sacha
authors.initials: S
authors.lastname: Ferdinandusse
mesh_terms: D000214:Acyl Coenzyme A / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001665:Binding Sites; D049109:Cell Proliferation / Q000187:drug effects; D018360:Crystallography, X-Ray; D015195:Drug Design; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008297:Male; D009226:Myristates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011471:Prostatic Neoplasms; D019998:Racemases and Epimerases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000214:Acyl Coenzyme A; D000970:Antineoplastic Agents; D009226:Myristates; C520848:alpha-trifluoromethyltetradecanoic acid; C520849:alpha-trifluoromethyltetradecanoyl-CoA; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase