Annexin-I as a potential target for green tea extract induced actin remodeling

Int J Cancer. 2007 Jan 1;120(1):111-20. doi: 10.1002/ijc.22164.

Abstract

Using a multistep human urothelial model, we previously showed that green tea extract (GTE) selectively modulates actin remodeling in transformed cells (MC-T11), which resulted in increased cell adhesion and reduced cell motility (Lu et al., Clin Cancer Res 2005;11:1675-83). This study further analyzed which actin binding proteins (ABPs) might be involved in this process. Proteomic profiles of GTE treated and untreated MC-T11 cells using two-dimensional gel electrophoresis coupled with liquid chromatography tandem mass spectrometry (LC/MS/MS) and matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) identified 20 GTE-induced proteins. Among them, 3 were ABPs (tropomodulin, cofilin and annexin-I), and only annexin-I showed a dose- and time-dependent expression. The increased annexin-I correlated with actin remodeling, and was the result of transcription level up-regulation, as determined by RT-PCR, pull-down immunoblot and siRNA analyses. 5-Azacytidine, a DNA methylation inhibitor, exhibited no effect on annexin-I expression when used alone, but had an additive effect for GTE-induced annexin-I expression. Immunohistochemistry of bladder cancer tissue array showed a decrease of annexin-I expression in carcinoma in situ and low grade papillary carcinoma (n = 32, 0% positive) compared to nontumor urothelium (n = 18, 89% positive) (p < 0.001 by Fisher exact test), but increased in some (6 of 15, 40%) high-grade tumors. Together, GTE induced annexin-I expression plays a role in regulating actin remodeling and decreased annexin-I expression is a common event in early stage of bladder cancer development.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Annexin A1 / antagonists & inhibitors
  • Annexin A1 / genetics
  • Annexin A1 / metabolism*
  • Carcinoma in Situ / metabolism
  • Carcinoma in Situ / pathology
  • Carcinoma, Papillary / metabolism
  • Carcinoma, Papillary / pathology
  • Case-Control Studies
  • Cell Line, Transformed
  • Electrophoresis, Gel, Two-Dimensional
  • Fluorescent Antibody Technique
  • Humans
  • Immunoblotting
  • Immunoenzyme Techniques
  • Immunoprecipitation
  • Peptide Mapping
  • Plant Extracts / pharmacology*
  • Proteome
  • RNA, Small Interfering / pharmacology
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Tea*
  • Tissue Array Analysis
  • Urinary Bladder Neoplasms / metabolism
  • Urinary Bladder Neoplasms / pathology
  • Urothelium / metabolism
  • Urothelium / pathology

Substances

  • Actins
  • Annexin A1
  • Plant Extracts
  • Proteome
  • RNA, Small Interfering
  • Tea