title: Mutagenicity of 2-amino-N6-hydroxyadenine to TK6 human lymphoblast cells.
abstract: TK6 human lymphoblast cells (tk +/-; hprt+) were treated with various concentrations of 2-amino-N6-hydroxyadenine (AHA) for 24 h. AHA was quite toxic to TK6 cells in the dose range 0-0.05 micrograms/ml, but additional toxicity was not observed between 0.05 and 0.10 micrograms/ml. AHA induced mutations at 2 distinct genetic loci: the autosomal thymidine kinase (tk) and the X-linked hypoxanthine-guanine phosphoribosyl transferase (hprt). Significant levels of both tk-NG mutants (normal growth rate of 16-18 h, colonies visible after 10-11 days incubation) and tk-SG mutants (slow growth rate of greater than 24 h, colonies visible after 18 days incubation) were induced. 15 hprt- mutants were isolated and analyzed by Southern blot. 8 of these had normal restriction fragment patterns after digestion with PstI, EcoRI, and HindIII, and were defined as 'point' mutations; the remaining 7 had partial deletions of the hprt gene. 32 tk- mutants were also isolated. 3 of 22 normal growth mutants and 6 of 10 slow growth mutants had lost the active tk allele. These data suggest that both point mutations and larger-scale alterations are induced by AHA.
authors.affiliation: Department of Cancer Biology, Harvard School of Public Health, Boston, MA 02115.
authors.forename: H L
authors.initials: HL
authors.lastname: Liber
authors.forename: C M
authors.initials: CM
authors.lastname: Denault
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000633:toxicity; D015139:Blotting, Southern; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes; D009153:Mutagens; D013937:Thymidine Kinase / Q000235:genetics
chemical_list: D009153:Mutagens; C030632:2-amino-N(6)-hydroxyadenine; D013937:Thymidine Kinase; D000225:Adenine