A cell culture assay for tumor-promoter-dependent progression toward neoplastic phenotype: detection of tumor promoters and promotion inhibitors.


Mouse epidermal cell lines have been identified which respond to tumor-promoting (but not nonpromoting) phorbol esters with an irreversible shift in anchorage independence, an in vitro marker of neoplastic phenotype. This response may be analogous to a later stage of tumor promotion in vivo. The shift occurs at TPA concentrations as low as 0.1 ng/ml (1.6 x… (More)