title: Metabolic transformation of antitumor acridinone C-1305 but not C-1311 via selective cellular expression of UGT1A10 increases cytotoxic response: implications for clinical use.
abstract: The acridinone derivates 5-dimethylaminopropylamino-8-hydroxytriazoloacridinone (C-1305) and 5-diethylaminoethylamino-8-hydroxyimidazoacridinone (C-1311) are promising antitumor agents with high activity against several experimental cellular and tumor models and are under evaluation in preclinical and early phase clinical trials. Recent evidence from our laboratories has indicated that both compounds were conjugated by several uridine diphosphate-glucuronyltransferase (UGT) isoforms, the most active being extrahepatic UGT1A10. The present studies were designed to test the ability and selectivity of UGT1A10 in the glucuronidation of acridinone antitumor agents in a cellular context. We show that in KB-3 cells, a HeLa subline lacking expression of any UGT isoforms, both C-1305 and C-1311 undergo metabolic transformation to the glucuronidated forms on overexpression of UGT1A10. Furthermore, UGT1A10 overexpression significantly increased the cytotoxicity of C-1305, but not C-1311, suggesting that the glucuronide was more potent than the C-1305 parent compound. These responses were selective for UGT1A10 because documented overexpression of UGT2B4 failed to produce glucuronide products and failed to alter the cytotoxicity for both compounds. These findings contribute to our understanding of the mechanisms of action of these agents and are of particular significance because data for C-1305 contradict the dogma that glucuronidation typically plays a role in detoxification or deactivation. In summary, these studies suggest that extrahepatic UGT1A10 plays an important role in the metabolism and the bioactivation of C-1305 and constitutes the basis for further mechanistic studies on the mode of action of this drug, as well as translational studies on the role of this enzyme in regulation of C-1305 toxicity in cancer.
authors.affiliation: Department of Pharmaceutical Technology and Biochemistry, Chemical Faculty, Gdańsk University of Technology, Gdańsk, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Pawlowska
authors.forename: Rong
authors.initials: R
authors.lastname: Chu
authors.forename: Barbara
authors.initials: B
authors.lastname: Fedejko-Kap
authors.forename: Ewa
authors.initials: E
authors.lastname: Augustin
authors.forename: Zofia
authors.initials: Z
authors.lastname: Mazerska
authors.forename: Anna
authors.initials: A
authors.lastname: Radominska-Pandya
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Chambers
mesh_terms: D000166:Acridines / Q000378:metabolism* / Q000494:pharmacology*; D000609:Aminoacridines / Q000378:metabolism* / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000378:metabolism* / Q000494:pharmacology*; D001711:Biotransformation; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D020719:Glucuronides / Q000378:metabolism / Q000494:pharmacology; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D014162:Transfection; D014230:Triazoles / Q000378:metabolism* / Q000494:pharmacology*; D002583:Uterine Cervical Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: D000166:Acridines; D000609:Aminoacridines; D000970:Antineoplastic Agents; C488734:C 1305; D020719:Glucuronides; D014230:Triazoles; C476725:bilirubin uridine-diphosphoglucuronosyl transferase 1A10; D014453:Glucuronosyltransferase; C486404:UGT2B4 protein, human; C098965:C 1311