Tobacco smoke-associated N7-alkylguanine in DNA of larynx tissue and leucocytes

Carcinogenesis. 1996 Mar;17(3):501-6. doi: 10.1093/carcin/17.3.501.

Abstract

The presence of N7-alkylguanine adducts in DNA was analysed in a group of 46 patients with larynx tumours. All patients were subjected to laryngectomy and the tissues accessible for analysis by (32)P-post-labelling assay were larynx tumour, larynx non-tumour and peripheral blood leucocytes. N7-Alkylguanine adducts were detected in all the studied DNA samples. The average level of N7-alkylguanines was 26.2/10(7) nucleotides in tumour cells, 22.7/10(7) in non-tumour cells and 13.1/10(7) in blood leucocytes. There was significantly higher level of N7-alkylguanines in the larynx tissues in males than in females. The effect of tobacco smoking on DNA adduct levels was shown by an increase in the average levels of N7-alkylguanines in the subject groups classified according to their smoking habits. A moderate age-related increase in levels of N7-alkylguanine was demonstrated in larynx tumour tissue. The levels of N7-alkylguanine adducts in larynx cells were compared with that of aromatic DNA adducts. Pearson correlation coefficients (0.28 for tumour tissue and 0.30 for non-tumour tissue) indicate independent formation and removal of N7-alkylguanine and aromatic DNA adducts resulting from tobacco smoke exposure.

MeSH terms

  • Adult
  • Aged
  • Alkylating Agents / analysis*
  • DNA Adducts / analysis*
  • Female
  • Guanine / analogs & derivatives
  • Guanine / analysis*
  • Humans
  • Laryngeal Neoplasms / chemistry*
  • Larynx / chemistry*
  • Leukocytes / chemistry
  • Male
  • Middle Aged
  • Nicotiana / chemistry*
  • Plants, Toxic*
  • Smoke*

Substances

  • Alkylating Agents
  • DNA Adducts
  • Smoke
  • Guanine