Cell surface features associated with differentiation-induction of methylcholanthrene-transformed AKR-2B fibroblasts by N,N-dimethylformamide.
Methylcholanthrene-transformed AKR-2B mouse embryonal fibroblasts (AKR-MCA cells) were examined for cell surface alterations after growth in culture medium containing N,N-dimethylformamide (DMF) using the lactoperoxidase-glucose oxidase radioiodination procedure with subsequent electrophoresis. DMF has been shown to induce maturational changes in a variety of transformed cells in vitro and has been reported to produce a more normal phenotype when applied to cultured AKR-MCA cells. The electrophoretic profile of 125I-labeled surface proteins from AKR-MCA cells exhibited a prominent peak of labeled material with a molecular weight of approximately 85,000. After growth of AKR-MCA cells in medium containing DMF, the Mr 85,000 peak was substantially reduced, while there was a large increase in Mr 200,000 to 250,000 radioiodinated surface material. This cell surface labeling pattern was virtually identical to that of the nontransformed AKR-2B fibroblasts from which AKR-MCA cells were derived. The cell surface alterations observed upon exposure of AKR-MCA cells to DMF occurred as a function of time of growth in DMF and DMF concentration. Growth of AKR-MCA cells in DMF resulted in a steady increase in cell surface 125I incorporation up to the fourth day of exposure to DMF. At this time, the incorporation level was 22.9-fold greater than that for untreated AKR-MCA cells. Incorporation of radiolabel was decreased after the fifth and sixth days of AKR-MCA exposure to DMF. This trend was also manifested by AKR-2B fibroblasts grown in the presence of DMF. The data suggest that there was increased expression of the Mr 200,000 to 250,000 surface protein on both AKR-2B and AKR-MCA cells when grown in DMF. DMF also inhibited morphological transformation and the cell surface changes associated with transformation of AKR-2B cells by exogenous transforming growth factors.
D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000032:analysis* / Q000187:drug effects / Q000473:pathology; D004126:Dimethylformamide / Q000494:pharmacology*; D005347:Fibroblasts / Q000032:analysis; D007457:Iodine Radioisotopes; D008565:Membrane Proteins / Q000032:analysis*; D008748:Methylcholanthrene; D051379:Mice; D008970:Molecular Weight; D010455:Peptides / Q000494:pharmacology; D015291:Transforming Growth Factors
D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D010455:Peptides; D008748:Methylcholanthrene; D015291:Transforming Growth Factors; D004126:Dimethylformamide