title: Small-molecule inhibitors of the protein methyltransferase SET7/9 identified in a high-throughput screen.
abstract: Aberrant expression of chromatin-modifying enzymes (CMEs) is associated with a range of human diseases, including cancer. CMEs are now an important target area in drug discovery. Although the role that histone and protein (lysine) methyltransferases (PMTs) play in the regulation of transcription and cell growth is increasingly recognized, few small-molecule inhibitors of this class of enzyme have been reported. Here we describe an assay suitable for primary compound screening for the identification of PMT inhibitors. The assay followed the methylation of histones in the presence of the PMT SET7/9 and the radioactive cofactor S-adenosyl-methionine using scintillating microplates (FlashPlate) and was used to screen approximately 65 000 compounds (% coefficient of variation = 10%; Z' = 0.6). The hits identified from a library of more than 63 000 diverse small molecules included a series of rhodanine compounds with micromolar activity. A screen of the National Cancer Institute Diversity Set (2000 compounds) identified an orsein derivative that inhibited SET7/9 (~20 µM) and showed modest growth inhibition associated with the expected cellular phenotype of reduced histone methylation in a human tumor cell line. The assay represents a useful tool for the identification of inhibitors of PMT activity.
authors: Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, Sutton, UK.
authors: Nicola-Jane
authors: NJ
authors: Francis
authors: Martin
authors: M
authors: Rowlands
authors: Paul
authors: P
authors: Workman
authors: Keith
authors: K
authors: Jones
authors: Wynne
authors: W
authors: Aherne
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D005001:Ethionine / Q000031:analogs & derivatives / Q000378:metabolism; D015200:Fluoroimmunoassay; D045325:HCT116 Cells; D057166:High-Throughput Screening Assays / Q000379:methods*; D006657:Histones / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D011496:Protein Methyltransferases / Q000037:antagonists & inhibitors*; D012588:Scintillation Counting; D054852:Small Molecule Libraries / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D006657:Histones; D054852:Small Molecule Libraries; C012167:S-adenosylethionine; D011496:Protein Methyltransferases; D000241:Adenosine; D005001:Ethionine