title: Induction of malignant transformation by various chemicals in Balb/3T3 clone A31-1-1 cells and biological characterization of some transformants.
abstract: Balb/c A31-1-1 cells were used for the study of transformation induction by chemicals with different mutagenic specificities. We show that survival of these cells and therefore the calculated transformation frequency per cells at risk is dependent upon the cell density at the time of treatment. It is suggested that equal cell densities should be used for measuring survival values and transformation induction. The quantitative results obtained are discussed in the light of the known mutagenic mechanisms of the chemicals tested. We also characterized morphologically transformed foci induced by different chemicals with respect to some biological properties. Anchorage independence was determined by testing growth in soft agar, loss of contact inhibition was quantitated by measuring maximum cell densities and malignancy was tested by tumor induction in nude mice. Although no very close correlation between these parameters and morphology was observed, the most malignant clones are also the ones with the highest values in the other tests. Our data make one or few genetical targets for transformation induction likely. We therefore speculate that the diverse phenotypes obtained might be due to differential activation of one or very few transforming genes in these cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced*; D005347:Fibroblasts / Q000187:drug effects / Q000637:transplantation; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009153:Mutagens / Q000494:pharmacology*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000139:chemically induced
chemical_list: D009153:Mutagens