Inhibition of apoptosis in colon tumors induced in the rat by 2-amino-3-methylimidazo[4,5-f]quinoline | Academic Article individual record

The cooked meat mutagen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) produces tumors at multiple sites in the F344 rat, including adenocarcinomas of the colon. In the present study, the development of IQ-induced colorectal tumors was shown to be accompanied by the progressive inhibition of programmed cell death. This was associated with increased expression of the antiapoptosis protein Bcl-2 and decreased expression of bax, a known activator of apoptosis. Carcinomas bearing high levels of bcl-2 expression exhibited low levels of p53, the tumor suppressor protein that in some circumstances has been shown to down-regulate bcl-2. Because they lack mutations in the genes commonly associated with increased cell proliferation (APC, Ki-ras, and p53) and show no evidence of microsatellite instability, IQ-induced colon tumors might arise via the deregulation of bcl-2 expression, leading to inhibition of programmed cell death.

author list (cited authors)
Hayashi, R., Luk, H., Horio, D., & Dashwood, R.
publication date
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  • Colonic Neoplasms
  • Carcinogens
  • Neoplasm Proteins
  • Rats
  • Male
  • Gene Expression Regulation, Neoplastic
  • Proto-Oncogene Proteins C-bcl-2
  • Immunoenzyme Techniques
  • Microscopy, Fluorescence
  • Quinolines
  • Tumor Suppressor Protein P53
  • Rats, Inbred F344
  • Adenocarcinoma
  • Animals
  • Apoptosis