Annexin-I as a potential target for green tea extract induced actin remodeling.
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.
Xiao
Gui-Shan
GS
Department of Clinic Molecular Pharmacology, Comprehensive Cancer Center at City of Hope National Medical Center, Duarte, California, USA.
Jin
Yu-Sheng
YS
Lu
Qing-Yi
QY
Zhang
Zuo-Feng
ZF
Belldegrun
Arie
A
Figlin
Robert
R
Pantuck
Allan
A
Yen
Yun
Y
Li
Frederick
F
Rao
Jianyu
J
D000199:Actins / Q000378:metabolism*; D017305:Annexin A1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002278:Carcinoma in Situ / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D002461:Cell Line, Transformed; D015180:Electrophoresis, Gel, Two-Dimensional; D005455:Fluorescent Antibody Technique; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D010449:Peptide Mapping; D010936:Plant Extracts / Q000494:pharmacology*; D020543:Proteome; D034741:RNA, Small Interfering / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013662:Tea; D046888:Tissue Array Analysis; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000473:pathology; D019459:Urothelium / Q000378:metabolism / Q000473:pathology
D000199:Actins; D017305:Annexin A1; D010936:Plant Extracts; D020543:Proteome; D034741:RNA, Small Interfering; D013662:Tea