Effects of tumour promoters on metabolic cooperation between human hepatoma cells

Metabolic cooperation between cells from three human hepatoma cell lines was studied by the clonogenic method and by autoradiography. It was found that human HGPRT+/HGPRT- SK-HEP-1 cells only, showed a metabolic cooperation capacity that was inhibited by tumour promoters 12-O-tetradecanoylphorbol-13-acetate (TPA) and phenobarbital, and was not inhibited by the non-promoter 4-O-methyl TPA, provided suitable experimental conditions (short exposure times) were used. This biological system might be the basis of a new in vitro short-term screening test for potential tumour-promoting chemicals.