Reversible induction of anchorage independent growth from normal mouse epidermal keratinocytes, MSK-C3H-NU, in soft agar medium by 12-O-tetradecanoylphorbol-13-acetate and epidermal growth factor.

The induction of anchorage independent growth occurred in nontumorigenic, mouse epidermal keratinocyte, MSK-C3H-NU cells when inoculated in a 0.3% soft agar medium with 12-O-tetradecanoylphorbol-13-acetate and/or epidermal growth factor. Colonies appeared about 3 weeks after incubation and keratinization of various forms occurred in them. 10-43 cells, a subline of higher subcultivation level, showed a rather sensitive response to these chemicals. 12-O-tetradecanoylphorbol-13-acetate and epidermal growth factor each induced anchorage independent growth but additive effects were also observed. Cell lines were established from clonal growths recovered from these induced colonies in soft agar. Morphologically, they retained their original normal clonal growth and keratinization patterns. Anchorage independent growth was not retained. Response to 12-O-tetradecanoylphorbol-13-acetate and epidermal growth factor, however, became more sensitive in some of the recovered cell lines when compared to their original cells. These data show that the induction of anchorage independent growth in soft agar is reversible in the MSK-C3H-NU cell system.