title: Identification of novel inhibitors of DNA methylation by screening of a chemical library.
abstract: In order to discover new inhibitors of the DNA methyltransferase 3A/3L complex, we used a medium-throughput nonradioactive screen on a random collection of 1120 small organic compounds. After a primary hit detection against DNA methylation activity of the murine Dnmt3A/3L catalytic complex, we further evaluated the EC50 of the 12 most potent hits as well as their cytotoxicity on DU145 prostate cancer cultured cells. Interestingly, most of the inhibitors showed low micromolar activities and little cytotoxicity. Dichlone, a small halogenated naphthoquinone, classically used as pesticide and fungicide, showed the lowest EC50 at 460 nM. We briefly assessed the selectivity of a subset of our new inhibitors against hDNMT1 and bacterial Dnmts, including M. SssI and EcoDam, and the protein lysine methyltransferase PKMT G9a and the mode of inhibition. Globally, the tested molecules showed a clear preference for the DNA methyltransferases, but poor selectivity among them. Two molecules including Dichlone efficiently reactivated YFP gene expression in a stable HEK293 cell line by promoter demethylation. Their efficacy was comparable to the DNMT inhibitor of reference 5-azacytidine.
authors.affiliation: CNRS-MNHN UMR 7196, 43 rue Cuvier, 75005 Paris, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ceccaldi
authors.forename: Arumugam
authors.initials: A
authors.lastname: Rajavelu
authors.forename: Sergey
authors.initials: S
authors.lastname: Ragozin
authors.forename: Catherine
authors.initials: C
authors.lastname: Sénamaud-Beaufort
authors.forename: Pavel
authors.initials: P
authors.lastname: Bashtrykov
authors.forename: Noé
authors.initials: N
authors.lastname: Testa
authors.forename: Hana
authors.initials: H
authors.lastname: Dali-Ali
authors.forename: Christine
authors.initials: C
authors.lastname: Maulay-Bailly
authors.forename: Séverine
authors.initials: S
authors.lastname: Amand
authors.forename: Dominique
authors.initials: D
authors.lastname: Guianvarc'h
authors.forename: Albert
authors.initials: A
authors.lastname: Jeltsch
authors.forename: Paola B
authors.initials: PB
authors.lastname: Arimondo
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects*; D000090205:DNA Methyltransferase 3A; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D054852:Small Molecule Libraries / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: C000717967:DNMT3A protein, human; C000715535:Dnmt3a protein, mouse; D004791:Enzyme Inhibitors; D054852:Small Molecule Libraries; D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A