Review article

New Aspects in Classification of Carcinogens

Heidi Foth
Gisela H. Degen
Hermann M. Bolt

Abstract

The existing systems of classification of carcinogens should include a distinction between genotoxic and non-genotoxic chemicals. For non-genotoxic chemicals, permissible exposure levels can be derived at which no relevant human cancer risks are anticipated. While genotoxic carcinogens can induce chromosomal effects without mutagenic action, non-DNA-reactive genotoxins affecting topoisomerase or the spindle, or those having an exclusively aneugenic effect can be carcinogenic only at high, toxic doses. Specific mechanisms of clastogenicity and processes of carcinogenesis based on reactive oxygen have practical thresholds. Since reactive oxygen species (ROS) are generally genotoxic, the question is whether chemicals that increase ROS production will add to endogenously produced background levels and lead to nonlinear dose-effect relationships. Taking into account the presence of endogenous carcinogens, it is now becoming evident that carcinogenic risk extrapolation to low doses must be considered according to the mode of action.

Keywords

carcinogenesis; chromosomal genotoxins; dose-reponse; endogenous carcinogens; genotoxicity; reactive oxygen; treshold

Hrčak ID:

146

URI

https://hrcak.srce.hr/146

Publication date:

23.5.2005.

Article data in other languages: croatian

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