title: The effect of cell passage on the susceptibility of BALB/3T3 clone A31-1-1 cells to 3-methylcholanthrene-induced morphological transformation.
abstract: The response of BALB/3T3 clone A31-1-1 cells to chemically induced morphological transformation was evaluated using 3-methylcholanthrene (MCA). Stock cultures were initiated from cryopreserved cells, grown in T25 flasks containing 5 ml of medium, and replated at subconfluency. Serially transferred cells were then subjected to transformation assay. After 24-hr seeding, cells were incubated 48 hr with MCA in a 5% CO2 incubator. They were then rinsed and incubated for an additional 4 weeks with twice weekly medium change. Type III foci were scored after fixation and staining with Giemsa. With serial passage from the frozen state, cells of passages 3-14 had a low level of spontaneous transformation; zero to 6 type III foci per 20 dishes were counted. In the MCA-treated cultures the number of transformed foci, however, increased with passage. Such passage-related sensitivity to MCA was demonstrated for cells cultured in two batches of sera: one from MA Bioproducts (Lot no. 2E052) and the other from Armour Pharmaceuticals (Lot no. Y65801). The passage-related increase in number of transformed foci was not related to doubling time, cloning efficiency, or MCA-induced growth inhibition.
mesh_terms: D000818:Animals; D002455:Cell Division; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D002478:Cells, Cultured; D002999:Clone Cells; D003470:Culture Media; D008748:Methylcholanthrene / Q000633:toxicity*; D051379:Mice
chemical_list: D003470:Culture Media; D008748:Methylcholanthrene