title: Laccaic acid A is a direct, DNA-competitive inhibitor of DNA methyltransferase 1.
abstract: Methylation of cytosines in CpG dinucleotides is the predominant epigenetic mark on vertebrate DNA. DNA methylation is associated with transcriptional repression. The pattern of DNA methylation changes during development and with disease. Human DNA methyltransferase 1 (Dnmt1), a 1616-amino acid multidomain enzyme, is essential for maintenance of DNA methylation in proliferating cells and is considered an important cancer drug target. Using a fluorogenic, endonuclease-coupled DNA methylation assay with an activated form of Dnmt1 engineered to lack the replication foci targeting sequence domain, we discovered that laccaic acid A (LCA), a highly substituted anthraquinone natural product, is a direct inhibitor with a 310 nm Ki. LCA is competitive with the DNA substrate in in vitro methylation assays and alters the expression of methylated genes in MCF-7 breast cancer cells synergistically with 5-aza-2'-deoxycytidine. LCA represents a novel class of Dnmt-targeted molecular probes, with biochemical properties that allow it to distinguish between non DNA-bound and DNA-bound Dnmt1.
authors.affiliation: Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Fagan
authors.forename: Diane E
authors.initials: DE
authors.lastname: Cryderman
authors.forename: Levy
authors.initials: L
authors.lastname: Kopelovich
authors.forename: Lori L
authors.initials: LL
authors.lastname: Wallrath
authors.forename: Charles
authors.initials: C
authors.lastname: Brenner
mesh_terms: D000634:Aminoquinolines / Q000737:chemistry / Q000494:pharmacology; D000880:Anthraquinones / Q000494:pharmacology; D001374:Azacitidine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D001391:Azo Compounds / Q000737:chemistry / Q000494:pharmacology*; D001483:Base Sequence; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics; D004247:DNA / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects / Q000235:genetics; D004261:DNA Replication / Q000187:drug effects; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D005470:Fluorometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D061986:MCF-7 Cells; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011743:Pyrimidines / Q000737:chemistry / Q000494:pharmacology; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D044366:Transition Temperature
chemical_list: D000634:Aminoquinolines; D000880:Anthraquinones; D001391:Azo Compounds; D004791:Enzyme Inhibitors; D011743:Pyrimidines; C581203:SGI-1027; C498247:anthraquinone-2-carboxylic acid; C009765:lac dye; D000077209:Decitabine; D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases; D001374:Azacitidine
keywords: Cancer Therapy; Chemical Biology; DNA Methylation; DNA Methyltransferase; Drug Action; Drug Discovery; Enzyme Inhibitors; Fret; Gene Silencing; Microarray