title: Degron protease blockade sensor to image epigenetic histone protein methylation in cells and living animals.
abstract: Lysine methylation of histone H3 and H4 has been identified as a promising therapeutic target in treating various cellular diseases. The availability of an in vivo assay that enables rapid screening and preclinical evaluation of drugs that potentially target this cellular process will significantly expedite the pace of drug development. This study is the first to report the development of a real-time molecular imaging biosensor (a fusion protein, [FLuc2]-[Suv39h1]-[(G4S)3]-[H3-K9]-[cODC]) that can detect and monitor the methylation status of a specific histone lysine methylation mark (H3-K9) in live animals. The sensitivity of this sensor was assessed in various cell lines, in response to down-regulation of methyltransferase EHMT2 by specific siRNA, and in nude mice with lysine replacement mutants. In vivo imaging in response to a combination of methyltransferase inhibitors BIX01294 and Chaetocin in mice reveals the potential of this sensor for preclinical drug evaluation. This biosensor thus has demonstrated its utility in the detection of H3-K9 methylations in vivo and potential value in preclinical drug development.
authors.affiliation: Molecular Imaging Program at Stanford, Bio-X Program, Stanford University School of Medicine , Stanford, California, United States.
authors.forename: Thillai V
authors.initials: TV
authors.lastname: Sekar
authors.forename: Kira
authors.initials: K
authors.lastname: Foygel
authors.forename: Rammohan
authors.initials: R
authors.lastname: Devulapally
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Paulmurugan
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D045744:Cell Line, Tumor; D004353:Drug Evaluation, Preclinical; D044127:Epigenesis, Genetic; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors* / Q000235:genetics; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007930:Leucine / Q000235:genetics / Q000378:metabolism; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D051379:Mice; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D039904:Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D006657:Histones; D011480:Protease Inhibitors; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; C533711:G9a protein, mouse; D011495:Histone-Lysine N-Methyltransferase; D007930:Leucine; D008239:Lysine