scholarly journals The Role of the TGF-β Coreceptor Endoglin in Cancer

2010 ◽  
Vol 10 ◽  
pp. 2367-2384 ◽  
Author(s):  
Eduardo Pérez-Gómez ◽  
Gaelle del Castillo ◽  
Juan Francisco Santibáñez ◽  
Jose Miguel Lêpez-Novoa ◽  
Carmelo Bernabéu ◽  
...  

Endoglin (CD105) is an auxiliary membrane receptor of transforming growth factor beta (TGF-β) that interacts with type I and type II TGF-β receptors and modulates TGF-β signaling. Endoglin is overexpressed in the tumor-associated vascular endothelium, where it modulates angiogenesis. This feature makes endoglin a promising target for antiangiogenic cancer therapy. In addition, recent studies on human and experimental models of carcinogenesis point to an important tumor cell–autonomous role of endoglin by regulating proliferation, migration, invasion, and metastasis. These studies suggest that endoglin behaves as a suppressor of malignancy in experimental and human epithelial carcinogenesis, although it can also promote metastasis in other types of cancer. In this review, we evaluate the implication of endoglin in tumor development underlying studies developed in our laboratories in recent years.

1994 ◽  
Vol 269 (31) ◽  
pp. 20172-20178 ◽  
Author(s):  
H. Yamashita ◽  
P. ten Dijke ◽  
P. Franzén ◽  
K. Miyazono ◽  
C.H. Heldin

1994 ◽  
Vol 14 (6) ◽  
pp. 3810-3821
Author(s):  
J Cárcamo ◽  
F M Weis ◽  
F Ventura ◽  
R Wieser ◽  
J L Wrana ◽  
...  

Transforming growth factor beta (TGF-beta) and activin bind to receptor complexes that contain two distantly related transmembrane serine/threonine kinases known as receptor types I and II. The type II receptors determine ligand binding specificity, and each interacts with a distinct repertoire of type I receptors. Here we identify a new type I receptor for activin, ActR-IB, whose kinase domain is nearly identical to that of the recently cloned TGF-beta type I receptor, T beta R-I. ActR-IB has the structural and binding properties of a type I receptor: it binds activin only in the presence of an activin type II receptor and forms a heteromeric noncovalent complex with activin type II receptors. In Mv1Lu lung epithelial cells, ActR-IB and T beta R-I signal a common set of growth-inhibitory and transcriptional responses in association with their corresponding ligands and type II receptors. The transcriptional responses include elevated expression of fibronectin and plasminogen activator inhibitor 1. Although T beta R-I and ActR-IB are nearly identical in their kinase domains (90% amino acid sequence identity), their corresponding type II receptor kinase domains are very different from each other (42% amino acid sequence identity). Therefore, signaling of a specific set of responses by TGF-beta and activin correlates with the presence of similar type I kinases in their complex. Indeed, other TGF-beta and activin type I receptors (TSR-I and ActR-I) whose kinase domains significantly diverge from those of T beta R-I and ActR-IB do not substitute as mediators of these growth-inhibitory and extracellular matrix transcriptional responses. Hence, we conclude that the type I receptor subunits are primary specifiers of signals sent by TGF-beta and activin receptor complexes.


2000 ◽  
pp. 705-710 ◽  
Author(s):  
H Machida ◽  
K Ogawa ◽  
M Funaba ◽  
T Mizutani ◽  
M Tsujimoto

OBJECTIVE: Intracellular signaling of activin and transforming growth factor-beta (TGF-beta) is thought to be mediated by the same molecules (Smad2/3 and Smad4). Although differentiation of murine erythroleukemia F5-5.fl cells is induced by activin, it is not induced by TGF-beta, suggesting that at some point TGF-beta signaling is defective. The aim of this study was to investigate the unresponsiveness of F5-5.fl cells to TGF-beta. DESIGN: mRNA expression of ligands, receptors, and signal mediators for the TGF-beta family was examined in F5-5.fl cells using RT-PCR. RESULTS: Activin induced erythrodifferentiation of F5-5.fl cells in a dose-dependent manner. Neither TGF-beta1 nor bone morphogenetic protein (BMP)-4 affected the differentiation of F5-5.fl cells in the presence or absence of activin. Although mRNAs of TGF-betas (TGF-beta1, TGF-beta2 and TGF-beta3) were detected, those of inhibin/activin (alpha-, betaA- and betaB-subunits) and BMPs (BMP-2, BMP-4 and BMP-7) could not be detected in the cells, suggesting that neither activins nor BMPs are produced in F5-5.fl cells. The expression of both type I (ALK-4/ActRIB) and type II (ActRII) receptors for activin was detected in F5-5.fl cells. In contrast, while the expression of type I receptor for TGF-beta (ALK-5/TbetaRI) was detected, that of type II receptor (TbetaRII) was not. The mRNA of all Smads examined was detected in F5-5.fl cells. CONCLUSIONS: A defect in the type II receptor might cause unresponsiveness to TGF-beta in F5-5.fl cells. An erythrodifferentiation assay using F5-5.fl cells would be useful for measuring net activin activity because it would not be necessary to consider endogenous activins and BMPs.


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