title: Fragile X expression is decreased by 5-azacytidine and S-adenosylhomocysteine.
abstract: A lymphoblastoid cell line derived from a patient with fragile X chromosome exhibited fragility only when 5-fluoro-2'-deoxyuridine (FUdR) was added to the culture medium. Addition of methionine with FUdR greatly increased the frequency of fragile X. Addition of 5-azacytidine (an inhibitor of methylation at the level of DNA) or S-adenosylhomocysteine (an inhibitor of the synthesis of the methyl group donor S-adenosylmethionine) reversed the effect of methionine as well as that of FUdR. It is proposed that DNA methylation is in some way involved in the mechanism of fragile X expression.
mesh_terms: D001374:Azacitidine / Q000494:pharmacology*; D002460:Cell Line; D003470:Culture Media; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005467:Floxuridine; D005600:Fragile X Syndrome / Q000235:genetics* / Q000378:metabolism; D006710:Homocysteine / Q000031:analogs & derivatives*; D006801:Humans; D007621:Karyotyping; D008715:Methionine / Q000378:metabolism*; D008745:Methylation; D012435:S-Adenosylhomocysteine / Q000494:pharmacology*; D012436:S-Adenosylmethionine / Q000494:pharmacology; D012729:Sex Chromosome Aberrations / Q000235:genetics*
chemical_list: D003470:Culture Media; D005467:Floxuridine; D006710:Homocysteine; D012436:S-Adenosylmethionine; D004247:DNA; D012435:S-Adenosylhomocysteine; D008715:Methionine; D001374:Azacitidine