A look beyond the priority: A systematic review of the genotoxic, mutagenic, and carcinogenic endpoints of non-priority PAHs.

The ultimate objective of animal studies of cancer is to achieve a better understanding of factors responsible for human disease in the hope that this may be ultimately eliminated or controlled. In order to establish the basic biologic mechanisms governing the development of human cancer, systematic controlled experiments are required. For practical and ethical reasons, these are impossible to carry out with humans so animal models have to be sought.

Animal Models for Tumors of the Ovary and Uterus

The autoradiographic pattern of the cervix epithelium after iterated application of the carcinogen 3,4-benzpyrene was investigated in 100 C57B1 mice. There was a gradual increase in the proportion of labelled cells with increasing degree of atypias. Labelling of superficial layers occurred in almost all cases with severe atypias (grade III) and in 8 per cent of those with moderate atypias (grade II). The labelling of superficial cells in moderate atypias (grade II) suggests that, despite cytoplasmic maturation, their nuclei retained the property of less mature or of undifferentiated cells, i.e. the capacity to synthesize DNA. The highest number of labelled cells was found in mice presenting severe atypias with epithelial buds protruding into the stroma.

D.B. Coulson

Papers

Histopathology and cytogenetics of tumors induced by the application of 7, 12-dimethylbenz[a]anthracene (DMBA) in mouse cervix