Formation of DNA adducts in HL-60 cells treated with the toluene metabolite p-cresol: a potential biomarker for toluene exposure

Chem Biol Interact. 2003 May 6;145(2):149-58. doi: 10.1016/s0009-2797(02)00249-1.

Abstract

We have examined DNA adduct formation in myeloperoxidase containing HL-60 cells treated with the toluene metabolite p-cresol. Treatment of HL-60 cells with the combination of p-cresol and H(2)O(2) produced four DNA adducts 1: (75.0%), 2: (9.1%), 3: (7.0%) and 4: (8.8%) and adduct levels ranging from 0.3 to 33.6 x 10(-7). The levels of DNA adducts formed by p-cresol were dependent on concentrations of p-cresol, H(2)O(2) and treatment time. In vitro incubation of p-cresol with myeloperoxidase and H(2)O(2) produced three DNA adducts 1: (40.5%), 2: (28.4%) and 3: (29.7%) with a relative adduct level of 0.7x10(-7). The quinone methide derivative of p-cresol (PCQM) was prepared by Ag(I)O oxidation. Reaction of calf thymus DNA with PCQM produced four adducts 1: (18.5%), 2: (36.4%), 3: (29.0%) and 5: (16.0%) with a relative adduct level 1.6x10(-7). Rechromatography analyses indicates that DNA adducts 1-3 formed in HL-60 cells treated with p-cresol and after myeloperoxidase activation of p-cresol were similar to those formed by reaction of DNA with PCQM. This observation suggests that p-cresol is activated to a quinone methide intermediate in each of these activation systems. Taken together, these results suggest PCQM is the reactive intermediate leading to the formation of DNA adducts in HL-60 cells treated with p-cresol. Furthermore, the DNA adducts formed by PCQM may provide a biomarker to assess occupational exposure to toluene.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Cresols / metabolism*
  • Cresols / pharmacology*
  • Cresols / toxicity
  • DNA Adducts / analysis
  • DNA Adducts / metabolism*
  • Dose-Response Relationship, Drug
  • Environmental Monitoring / methods
  • HL-60 Cells
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Molecular Structure
  • Peroxidase / metabolism
  • Time Factors
  • Toluene / metabolism*
  • Toluene / toxicity

Substances

  • Cresols
  • DNA Adducts
  • 4-cresol
  • Toluene
  • Hydrogen Peroxide
  • Peroxidase