EXPERIMENTAL CHEMICAL CARCINOGENESIS IN FISH

Experimental carcinogenesis using fish species as alternative models i s a dynamic field of research. The 1940's expansion of synthetic chemi cal producing industries coincided with a number of pollution-associat ed fish neoplasia epizootics, with polycyclic aromatic hydrocarbons as significant components of contaminated sediment in several cases. Epi zootics of primarily liver and skin neoplasia in benthic species near coastal urban or industrial areas indicated the sensitivity of fish sp ecies to known mammalian carcinogens. Stressing a mechanistic approach , investigators have used data compiled from epizootics as the backbon e of current research efforts to define carcinogenesis in fish species . With liver as the focus, patterns of neoplastic development similar to those seen in rodent bioassays have been induced in various fish sp ecies by genotoxic carcinogens. Similarities between fish and rodent m odels include chemical and species-specific responses to exposure and the development of predictable preneoplastic and neoplastic lesions. T he expression of molecular molecules related to carcinogenesis is curr ently under investigation, which includes alterations in certain prote ins, enzyme activity, and oncogene/tumor suppressor gene function. The potential for the application of research findings to both human and environmental health issues makes fish species attractive and valuable alternative models in carcinogenesis and toxicity research.