Inhibition of epigallocatechin gallate-induced apoptosis by CoCl2 in human oral tumor cell lines.
Epigallocatechin gallate (EGCG) induced apoptotic cell death in two human oral tumor cell lines (HSC-2, HSG), as judged by TUNEL method which detects DNA nick. Furthermore, the cytoplasm of EGCG-treated HSG cells was stained by M30 monoclonal antibody, which detects the degradation product of cytokeratin by activated caspase. The apoptosis-inducing activity of EGCG was significantly reduced by millimolar concentrations of CoCl2. CoCl2 also inhibited the cytotoxic activity of sodium ascorbate, gallic acid and curcumin, but not that of sodium-5, 6-benzylidene-L-ascorbate (SBA). This suggests that SBA, an antitumor agent, induces cell death by a different mechanism from that of other antioxidants used in this study. The possible role of CoCl2 for cell survival was discussed.
Ishino
A
A
Department of Dental Pharmacology, Meikai University School of Dentistry, Saitama, Japan. ishino@dent.meikai.ac.jp
Kusama
K
K
Watanabe
S
S
Sakagami
H
H
D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D009062:Mouth Neoplasms / Q000473:pathology*; D012468:Salivary Gland Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D003035:Cobalt; D002392:Catechin; C045651:epigallocatechin gallate; C018021:cobaltous chloride