Involvement of caspase-3 in epigallocatechin-3-gallate-mediated apoptosis of human chondrosarcoma cells.
Biochem Biophys Res Commun 2000 Apr 21;270(3):793-7
Islam S; Islam N; Kermode T; Johnstone B; Mukhtar H; Moskowitz RW; Goldberg VM; Malemud CJ; Haqqi TM
Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland Ohio 44106, USA.
Green tea polyphenol-(-)epigallocatechin-3-gallate (EGCG)-is a potent chemopreventive agent in many test systems and has been shown to inhibit tumor promotion and induce apoptosis. In this study we describe a novel observation that EGCG displayed strong inhibitory effects on the proliferation and viability of HTB-94 human chondrosarcoma cells in a dose-dependent manner and induced apoptosis. Investigation of the mechanism of EGCG-induced apoptosis revealed that treatment with EGCG resulted in DNA fragmentation, induction of caspase-3/CPP32 activity, and cleavage of the death substrate poly(ADP-ribose)polymerase (PARP). Pretreatment of cells with a synthetic pan-caspase inhibitor (Z-VAD-FMK) and a caspase-3-specific inhibitor (DEVD-CHO) prevented EGCG-induced PARP cleavage. The induction of apoptosis by EGCG via activation of caspase-3/CPP32-like proteases may provide a mechanistic explanation for its antitumor effects.