Epigallocatechin gallate reduces hypoxia-induced apoptosis in human hepatoma cells

Life Sci. 2006 May 8;78(24):2826-32. doi: 10.1016/j.lfs.2005.11.001. Epub 2006 Jan 27.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / metabolism
  • Apoptosis / drug effects*
  • Blotting, Western
  • Cadherins / biosynthesis
  • Carcinoma, Hepatocellular / pathology*
  • Catechin / analogs & derivatives*
  • Catechin / pharmacology
  • Cell Adhesion Molecules / metabolism
  • Cell Hypoxia
  • Cell Line, Tumor
  • Coloring Agents
  • Epithelial Cell Adhesion Molecule
  • Genes, bcl-2 / physiology
  • Humans
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Liver Neoplasms / pathology*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • bcl-2-Associated X Protein / metabolism

Substances

  • Antigens, Neoplasm
  • Cadherins
  • Cell Adhesion Molecules
  • Coloring Agents
  • EPCAM protein, human
  • Epithelial Cell Adhesion Molecule
  • RNA, Messenger
  • bcl-2-Associated X Protein
  • Catechin
  • epigallocatechin gallate