3-AMINOBENZAMIDE PROTECTS CELLS FROM UV-B-INDUCED APOPTOSIS BY ACTINGON CYTOSKELETON AND SUBSTRATE ADHESION

3-aminobenzamide (3-ABA) is an inhibitor of poly-(ADP-ribose)-polymera se, an enzyme involved in numerous subcellular processes, including ce ll death. Recently, a target effect of the drug on some cytoskeletal e lements has also been described (Malorni et al., Biochem. Biophys. Res . Commun. 202: 915-922, 1994). In this study we evaluated the ability of 3-ABA to interfere with UV-B ray-induced apoptosis in cells selecte d for their cytoskeletal features and their different capability to ad here to the substrate. Human melanoma (M14) and epithelial (A431) cell lines and murine primary fibroblastic cultures (MFC) were studied. Ou r results indicate that cytoskeleton is indeed an important cellular t arget of 3-ABA, which can prevent apoptotic cell death by UV-B through a specific effect on the adhesion properties of the cells. indeed, an inverse correlation was observed between sensitivity to UV-B-induced apoptosis (M14>A431>MFC) and substrate adhesion (MFC>A431>M14). The po tential relevance of these observations to understand the possible rel ationships among apoptosis, cytoskeletal functions and substrate adhes ion is discussed. (C) 1995 Academic Press, Inc.