Spontaneous and chemically-induced transformation of mouse fibroblasts in culture, biochemical aspects of the transformed cells

: Fibroblast cultures were established from the lung tissue of CBA T6T6 mouse embryos. Lines characterized by infinite growth transformation (MFL) were used as untreated controls till the 21st and 29th passages, respectively. After that period, an unrestrained growth transformation developed spontaneously. The cell line was then designated as STMFL. At the 8th passage of an MFL, 20-methylcholanthrene (MC) treatment was performed. The treatment resulted in a cell line (MCMFL) characterized also by unrestrained growth transformation. The nuclear protein pattern obtained by two-dimensional gel electrophoresis showed differences between STFL and MCMFL. The activity of two microsomal enzymes - aryl hydrocarbon hydroxylase and ethylmorphin demethylase - measured in the exponential growth stage of the cultures showed a decrease in the case of STMFL, compared to the MFL, and practically disappeared in the case of MCMFL.