Assay of Chemically Induced Transformation of Human Cells

Abstract

Many experimental systems have been developed as short-term tests for chemical carcinogens (Fig. 30.1). However, there have been three major problems for the extrapolation of the results obtained from these systems into human risk assessment. The first problem is species difference in the response to chemical carcinogens. It may ultimately be shown that the fundamental process of cancer development is common to all organisms. However, the rate-limiting factor can be quite different owing to small differences in the metabolism involved. For example, it is possible that point mutation is a major rate-limiting factor of carcinogenesis in the mouse whose control of chromosomes is unstable, but not in the human whose diploidy is quite stable. At least for quantitative assessment of human risk, the species difference is crucial. Secondly, the markers used in these test systems are widely different and their relation to induction of human cancer is unclear. The third problem is the genetic heterogeneity of the human population.KeywordsDilution RatioChemical CarcinogenHuman Fibroblastic CellHuman Diploid CellTransformation AssayThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.