Epigallocatechin gallate reduces hypoxia-induced apoptosis in human hepatoma cells.
Cell detachment from extracellular matrix is closely related to induction of apoptosis. Epigallocatechin gallate (EGCG) has been shown to have antioxidant effect and to protect hypoxia-induced damage. We investigated whether EGCG reduced hypoxia-induced apoptosis and cell detachment in HepG2 cells. EGCG prevented cell death by hypoxia (0.5% O2) in a dose-dependent manner (hypoxic cell viability, 54.67%). RT-PCR and caspase3 activity assay showed that the hypoxia-induced cell death was caused by apoptosis increasing mRNA level of BAX, CASP3, and caspase3 activity. EGCG reduced increase of these mRNA and caspase3 activity. Western blot analysis and immunocytochemistry showed that EGCG increased cell adhesion proteins including E-cadherin (CDH1), tumor-associated calcium signal transducer 1 (TACSTD1), and protein tyrosine kinase 2 (PTK2) decreased by hypoxia. Hypoxia-induced apoptosis in HepG2 cells, and EGCG contributed to the HepG2 cell survival by attenuating the apoptosis.
Park
Hae Jeong
HJ
Department of Pharmacology, Kohwang Medical Research Institute, College of Medicine, Kyung Hee University, Seoul 130-701, South Korea.
Shin
Dong-Hoon
DH
Chung
Woo Jin
WJ
Leem
Kanghyun
K
Yoon
Seo Hyun
SH
Hong
Mee Suk
MS
Chung
Joo-Ho
JH
Bae
Jae-Hoon
JH
Hwang
Jae Seok
JS
D000951:Antigens, Neoplasm / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D015820:Cadherins / Q000096:biosynthesis; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D004396:Coloring Agents; D000071858:Epithelial Cell Adhesion Molecule; D019254:Genes, bcl-2 / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008113:Liver Neoplasms / Q000473:pathology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D000951:Antigens, Neoplasm; D015820:Cadherins; D015815:Cell Adhesion Molecules; D004396:Coloring Agents; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D002392:Catechin; C045651:epigallocatechin gallate