TY - JOUR
T1 - Multiple FAS1 domains and the RGD motif of TGFBI act cooperatively to bind αvβ3 integrin, leading to anti-angiogenic and anti-tumor effects
AU - Son, Hye Nam
AU - Nam, Ju Ock
AU - Kim, Soyoun
AU - Kim, In San
N1 - Funding Information:
This study was supported by grants from the National R&D Program for Cancer Control, funded by the Ministry of Health & Welfare, Republic of Korea ( 0720550-2 ), the National Research Foundation of Korea (NRF) grant funded by the Korean government (MEST) ( 2010-0029206 ), and the Basic Science Research Program through the National Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology ( 2008-0061863 ).
PY - 2013/10
Y1 - 2013/10
N2 - TGFBI, a transforming growth factor β-induced extracellular matrix protein, circulates at a level of ~300ng/ml in humans and modulates several integrin-mediated cellular functions. The protein contains an N-terminal EMI domain, four consecutive FAS1 domains, and the RGD motif. Each FAS1 domain and the RGD motif have been known to interact with avb3 integrin. Here, we found that the binding affinity (Kd) of TGFBI for αvβ3 integrin was approximately 3.8×10-8M, a value ~2300-fold higher than that of a single FAS1 domain, and demonstrated that this greater affinity was due to the cooperative action of the four FAS1 domains and the RGD motif. Moreover, TGFBI exhibited more potent anti-angiogenic and anti-tumorigenic activities, even at a 100-fold lower molar dose than the reported effective dose of the FAS1 domain. Finally, our data showed that TGFBI specifically targeted the tumor vasculature and accumulated at the tumor site. Collectively, our results support the theory that TGFBI acts as a potent endogenous anti-tumor and anti-angiogenic molecule by targeting αvβ3 integrin, and highlights the importance of physiological circulating TGFBI levels in inhibiting tumor growth.
AB - TGFBI, a transforming growth factor β-induced extracellular matrix protein, circulates at a level of ~300ng/ml in humans and modulates several integrin-mediated cellular functions. The protein contains an N-terminal EMI domain, four consecutive FAS1 domains, and the RGD motif. Each FAS1 domain and the RGD motif have been known to interact with avb3 integrin. Here, we found that the binding affinity (Kd) of TGFBI for αvβ3 integrin was approximately 3.8×10-8M, a value ~2300-fold higher than that of a single FAS1 domain, and demonstrated that this greater affinity was due to the cooperative action of the four FAS1 domains and the RGD motif. Moreover, TGFBI exhibited more potent anti-angiogenic and anti-tumorigenic activities, even at a 100-fold lower molar dose than the reported effective dose of the FAS1 domain. Finally, our data showed that TGFBI specifically targeted the tumor vasculature and accumulated at the tumor site. Collectively, our results support the theory that TGFBI acts as a potent endogenous anti-tumor and anti-angiogenic molecule by targeting αvβ3 integrin, and highlights the importance of physiological circulating TGFBI levels in inhibiting tumor growth.
KW - Angiogenesis
KW - Anti-tumor effect
KW - FAS1 domain
KW - TGFBI
KW - αvβ3 integrin
UR - http://www.scopus.com/inward/record.url?scp=84880266999&partnerID=8YFLogxK
U2 - 10.1016/j.bbamcr.2013.06.012
DO - 10.1016/j.bbamcr.2013.06.012
M3 - Article
C2 - 23792174
AN - SCOPUS:84880266999
SN - 0167-4889
VL - 1833
SP - 2378
EP - 2388
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
IS - 10
ER -