title: The effect of methionine and 5-azacytidine on fragile X expression.
abstract: The cellular mechanism for the expression of the fragile site at Xq28 is unknown. We tested the effect of 5-azacytidine and methionine on fragile X expression in lymphocytes and lymphoblastoid cells in an attempt to determine if DNA methylation was involved. We were unable to demonstrate a consistent dosage effect of methionine on fragile X expression. While 5-azacytidine was found to inhibit the fragile X in both males and females, it did so only at relatively high concentrations. We conclude that the role, if any, of DNA methylation in fragile X expression is likely to be secondary, the primary effect being due to thymidylate depletion.
authors.forename: M A
authors.initials: MA
authors.lastname: Abruzzo
authors.forename: M
authors.initials: M
authors.lastname: Mayer
authors.forename: P A
authors.initials: PA
authors.lastname: Jacobs
mesh_terms: D001374:Azacitidine / Q000494:pharmacology*; D002478:Cells, Cultured; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D003470:Culture Media; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008715:Methionine / Q000494:pharmacology*; D008745:Methylation; D014960:X Chromosome
chemical_list: D003470:Culture Media; D004247:DNA; D008715:Methionine; D001374:Azacitidine