Direct inhibition of insulin-like growth factor-I receptor kinase activity by (-)-epigallocatechin-3-gallate regulates cell transformation.
Insulin-like growth factor-I receptor (IGF-IR) has been implicated in cancer pathophysiology. Furthermore, impairment of IGF-IR signaling in various cancer cell lines caused inhibition of the transformed phenotype as determined by the inhibition of colony formation in soft agar and the inhibition of tumor formation in athymic nude mice. Thus, the IGF-IR might be an attractive target for cancer prevention. We showed that the tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), is a small-molecule inhibitor of IGF-IR activity (IC50 of 14 micromol/L). EGCG abrogated anchorage-independent growth induced by IGF-IR overexpression and also prevented human breast and cervical cancer cell phenotype expression through inhibition of IGF-IR downstream signaling. Our findings are the first to show that the IGF-IR is a novel binding protein of EGCG and thus may help explain the chemopreventive effect of EGCG on cancer development.
Li
Ming
M
Hormel Institute, University of Minnesota, 801 16th Avenue Northeast, Austin, MN 55912, USA.
He
Zhiwei
Z
Ermakova
Svetlana
S
Zheng
Duo
D
Tang
Faqing
F
Cho
Yong-Yeon
YY
Zhu
Feng
F
Ma
Wei-Ya
WY
Sham
Yuk
Y
Rogozin
Evgeny A
EA
Bode
Ann M
AM
Cao
Ya
Y
Dong
Zigang
Z
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D051379:Mice; D008819:Mice, Nude; D010641:Phenotype; D017526:Receptor, IGF Type 1 / Q000037:antagonists & inhibitors*; D015398:Signal Transduction
D016588:Anticarcinogenic Agents; D002392:Catechin; C045651:epigallocatechin gallate; D017526:Receptor, IGF Type 1