Green tea polyphenol targets the mitochondria in tumor cells inducing caspase 3-dependent apoptosis

Anticancer Res. Mar-Apr 2003;23(2B):1533-9.

Abstract

Induction of apoptosis by green tea polyphenols has been observed in various tumor cell systems, but whether green tea polyphenol-induced apoptosis requires caspase 3 for execution has not been confirmed. We previously reported that green tea polyphenol-induced apoptosis involved Apaf-1 accumulation and caspase 3 activation in the cytosol. In the current study, tumor cells either with deleted caspase 3 gene or expressing wild-type caspase 3 were treated with increasing concentrations of green tea polyphenol(s), followed by morphological analysis and caspase 3 activity assay. The caspase 3 null parental cell line was further examined in comparison with a well-characterized, caspase 3 wild type oral carcinoma cell line by MTT assay and BrdU incorporation assay. The results demonstrated that, while the mitochondrial function gradually declined to insignificant levels, caspase 3 null cells did not undergo apoptosis, which suggested that green tea polyphenol-induced apoptosis is a mitochondria-targeted, caspase 3-executed mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / enzymology
  • Adenocarcinoma / pathology
  • Apoptosis / drug effects*
  • Apoptotic Protease-Activating Factor 1
  • Bone Neoplasms / enzymology
  • Bone Neoplasms / pathology
  • Breast Neoplasms / enzymology
  • Breast Neoplasms / pathology
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / secondary
  • Caspase 3
  • Caspases / deficiency
  • Caspases / genetics
  • Caspases / physiology*
  • Catechin / analogs & derivatives*
  • Catechin / pharmacology
  • DNA Replication / drug effects
  • Female
  • Flavonoids*
  • Gene Deletion
  • Gingival Neoplasms / pathology
  • Humans
  • Keratinocytes / cytology
  • Lymphatic Metastasis
  • Mitochondria / drug effects*
  • Mouth Neoplasms / pathology
  • Neoplasm Proteins / deficiency
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Osteosarcoma / enzymology
  • Osteosarcoma / pathology
  • Phenols / pharmacology*
  • Plant Extracts / pharmacology*
  • Polymers / pharmacology*
  • Proteins / metabolism
  • Tea / chemistry*
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / enzymology
  • Tumor Cells, Cultured / pathology

Substances

  • APAF1 protein, human
  • Apoptotic Protease-Activating Factor 1
  • Flavonoids
  • Neoplasm Proteins
  • Phenols
  • Plant Extracts
  • Polymers
  • Proteins
  • Tea
  • Catechin
  • epicatechin gallate
  • epigallocatechin gallate
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • gallocatechol