title: Zidovudine (AZT) resistance in H9 cells due to decreased TK expression is associated with hypermethylation of TK gene.
abstract: AZT resistant human T-lymphoid H9 cells, deficient in TK gene expression, re-expressed TK mRNA and regained the ability to metabolize AZT by exposure to the demethylation agent azacytidine (AzaCd). Cytotoxic and anti-HIV-1 effects of AZT were increased in H9 AZT resistant cells treated with AzaCd when compared to untreated cells. This leads to the assumption that drug induced DNA hypermethylation was involved in the TK gene-silencing mechanism. Our results suggest approaches using modulation of gene methylation for increasing antiviral efficiency of drugs.
authors.affiliation: Institute of Medical Virology, Johann Wolfgang Goethe University, Frankfurt/M., Germany.
authors.forename: B
authors.initials: B
authors.lastname: Gröschel
authors.forename: G
authors.initials: G
authors.lastname: Höver
authors.forename: H W
authors.initials: HW
authors.lastname: Doerr
authors.forename: J
authors.initials: J
authors.lastname: Cinatl
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D001374:Azacitidine / Q000494:pharmacology; D019175:DNA Methylation / Q000187:drug effects; D024882:Drug Resistance, Viral / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D020868:Gene Silencing; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000235:genetics*; D015215:Zidovudine / Q000494:pharmacology*
chemical_list: D019380:Anti-HIV Agents; D015215:Zidovudine; D013937:Thymidine Kinase; D001374:Azacitidine