Green tea induces annexin-I expression in human lung adenocarcinoma A549 cells: involvement of annexin-I in actin remodeling.
Green tea polyphenols exhibit multiple antitumor activities in various in vitro and in vivo tumor models, and the mechanisms of action are not clear. Previously, we found that green tea extract (GTE) regulates actin remodeling in different cell culture systems. Actin remodeling plays an important role in cancer cell morphology, cell adhesion, motility, and invasion. Using proteomic approaches, we found GTE-induced expression of annexin-I, a multifunctional actin binding protein, in these cell lines. In this study, we aimed to further define the functional role of GTE-induced annexin-I expression in actin remodeling, cell adhesion, and motility in lung adenocarcinoma A549 cells. We found that GTE stimulates the expression of annexin-I in a dose-dependent fashion. The GTE-induced annexin-I expression appears to be at the transcription level, and the increased annexin-I expression mediates actin polymerization, resulting in enhanced cell adhesion and decreased motility. Annexin-I specific interference resulted in loss of GTE-induced actin polymerization and cell adhesion, but not motility. In fact, annexin-I specific interference itself inhibited motility even without GTE. Together, annexin-I plays an important role in GTE-induced actin remodeling, and it may serve as a potential molecular target associated with the anticancer activities of green tea.
Lu
Qing-Yi
QY
Department of Medicine, Center for Human Nutrition, University of California at Los Angeles, Los Angeles, CA 90095-1732, USA.
Jin
Yu Sheng
YS
Zhang
Zuo-Feng
ZF
Le
Anh D
AD
Heber
David
D
Li
Frederick P
FP
Dubinett
Steven M
SM
Rao
Jian Yu
JY
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism*; D017305:Annexin A1 / Q000235:genetics / Q000378:metabolism*; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D028241:Camellia sinensis / Q000737:chemistry*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology*; D011108:Polymers; D040901:Proteomics; D012333:RNA, Messenger / Q000378:metabolism
D000199:Actins; D017305:Annexin A1; D016588:Anticarcinogenic Agents; D010936:Plant Extracts; D011108:Polymers; D012333:RNA, Messenger