Elimination of metabolic co-operation and the induction of sister chromatid exchanges are not properties common to all promoting or co-carcinogenic agents.
High densities of wild-type, 6-thioguanine sensitive V79 cells reduce the recovery of 6-thioguanine resistant (6TGR) cells when they are co-cultivated. This metabolic co-operation effect has been reported previously to be eliminated by the tumour promoter 12-O-tetradecanoylphorbol-13-acetate and the accompanying enhancement of 6TGR colony recovery has been postulated as a rapid assay for tumour promoters. Elimination of metabolic co-operation, however, does not appear to be a characteristic of either the promoting agents anthralin, iodoacetic acid, oleic acid and delta-haemolysin or the co-carcinogenic/carcinogenic agents griseofulvin, diethylstilboestrol and stilboestrol diproprionate. Moreover, with the exception of stilboestrol diproprionate, none of these agents induce sister chromatid exchanges, but are all, with the exception of delta-haemolysin, associated with limited numerical chromosome changes and in four cases low level aberration induction. None of the agents were mutagenic.
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D002450:Cell Communication / Q000187:drug effects*; D002460:Cell Line; D002869:Chromosome Aberrations; D003043:Cocarcinogenesis; D006224:Cricetinae; D003412:Cricetulus; D003434:Crossing Over, Genetic / Q000187:drug effects*; D009152:Mutagenicity Tests; D010703:Phorbol Esters / Q000633:toxicity; D012854:Sister Chromatid Exchange / Q000187:drug effects*
D002273:Carcinogens; D010703:Phorbol Esters