title: 2´-deoxy-5,6-dihydro-5-azacytidine - a less toxic alternative of 2´-deoxy-5-azacytidine: a comparative study of hypomethylating potential.
abstract: Restoration of transcriptionally silenced genes by means of methyltransferases inhibitors plays a crucial role in the current therapy of myelodysplastic syndromes and certain types of leukemias. A comparative study of hypomethylating activities of a series of 5-azacytidine nucleosides: 5-azacytidine (AC), 2'-deoxy-5-azacytidine (DAC) and its α-anomer (α-DAC), 5,6-dihydro-5-azacytidine (DHAC), 2'-deoxy-5,6-dihydro-5-azacytidine (DHDAC, KP-1212) and its α-anomer (α-DHDAC), and of a 2-pyrimidone ribonucleoside (zebularine) was conducted. Methylation-specific PCR was employed to detect the efficiency of individual agents on cyclin-dependent kinase inhibitor 2B and thrombospondin-1 hypermethylated gene loci. Overall changes in DNA methylation level were quantified by direct estimation of 5-methyl-2'-deoxycytidine-5'-monophosphate by HPLC using digested genomic DNA. Flow cytometric analysis of cell cycle progression and apoptotic markers was used to determine cytotoxicity of the compounds. mRNA expression was measured using qRT-PCR. 2'-deoxy-5,6-dihydro-5-azacytidine was found to be less cytotoxic and more stable than 2'-deoxy-5-azacytidine at the doses that induce comparable DNA hypomethylation and gene reactivation. This makes it a valuable tool for epigenetic research and worth further investigations to elucidate its possible therapeutic potential.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i.; Gilead Sciences and IOCB Research Center, Prague, Czech Republic.
authors.forename: Marika
authors.initials: M
authors.lastname: Matoušová
authors.forename: Ivan
authors.initials: I
authors.lastname: Votruba
authors.forename: Miroslav
authors.initials: M
authors.lastname: Otmar
authors.forename: Eva
authors.initials: E
authors.lastname: Tloušťová
authors.forename: Jana
authors.initials: J
authors.lastname: Günterová
authors.forename: Helena
authors.initials: H
authors.lastname: Mertlíková-Kaiserová
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D019175:DNA Methylation / Q000187:drug effects*; D000077209:Decitabine; D005786:Gene Expression Regulation; D056426:Genetic Loci; D015894:Genome, Human; D006801:Humans; D015394:Molecular Structure; D012333:RNA, Messenger / Q000235:genetics; D019700:Thrombospondin 1 / Q000235:genetics
chemical_list: C561961:2'-deoxy-5,6-dihydro-5-azacytidine; D012333:RNA, Messenger; D019700:Thrombospondin 1; D000077209:Decitabine; D001374:Azacitidine