CATECHOL INTERFERES WITH TGF-BETA-INDUCED ELIMINATION OF TRANSFORMED-CELLS BY NORMAL-CELLS - IMPLICATIONS FOR THE SURVIVAL OF TRANSFORMED-CELLS DURING CARCINOGENESIS

We have recently shown that TGF-beta-treated normal fibroblasts are ab le to induce apoptosis of transformed fibroblasts, leading to their el imination. Here we describe a test system that allows the quantitative analysis of the elimination of G418-resistant transformed cells by TG F-beta-treated normal cells. This assay system was used to screen for substances that interfere with the elimination of transformed cells, C atechol and hydroquinone, but not resorcinol, were found to represent potent antagonists of TGF-beta-induced elimination of transformed cell s by normal cells. Protection of transformed cells from negative effec ts derived from their cellular environment defines a hitherto unrecogn ized crucial mechanism for the survival of transformed cells. The prot ective effect of catechol as seen in this experimental system may act in concert with its co-carcinogenic and promoting activities during ca rcinogenesis. (C) 1995 Wiley-Liss, Inc.