title: Effect of ethylnitrosourea on HPRT gene in human promyelocytic leukemia cells.
abstract: OBJECTIVE
  To explore the molecular spectra and mechanism of human hypoxanthine guanine phosphoribosyl transferase (HPRT) gene mutation induced by ethyluitrosourea (ENU).
  
  
  METHODS
  Single cell cloning culture, two-way screening, multiple PCR amplification and electrophoresis technique were used.
  
  
  RESULTS
  With dose of ENU increasing, cell plating efficiency reduced (in the group with 100-200 micro g/ml doses, P < 0.01) and mutation frequency increased (in the group with 12.5-200.0 micro g/ml doses, P < 0.05) significantly. There was no all exons deletion in spontaneous mutations, and only 7.7% of them were detected as single exon deletion. But, deletion was found in 79.7% of ENU-induced mutations (62.5%-89.4%, P < 0.01), and deletion mutations in all nine exons of HPRT gene. Most of ENU-induced mutations were chain deletion with multiple exons (88.1%).
  
  
  CONCLUSIONS
  The spectra in spontaneous mutations differed completely from ENU-induced ones. ENU was liable to cause bigger changes in genetic structure, which suggested a stronger ENU's mutagenesis.
authors.affiliation: Department of Health Toxicology, Third Military Medical University, Chongqing 400038, China.
authors.forename: Shengxue
authors.initials: S
authors.lastname: Liu
authors.forename: Jia
authors.initials: J
authors.lastname: Cao
authors.forename: Hui
authors.initials: H
authors.lastname: An
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology*; D005038:Ethylnitrosourea / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics / Q000378:metabolism*; D007951:Leukemia, Myeloid / Q000473:pathology; D009154:Mutation / Q000187:drug effects*; D014410:Tumor Stem Cell Assay
chemical_list: D000477:Alkylating Agents; D007041:Hypoxanthine Phosphoribosyltransferase; D005038:Ethylnitrosourea