An extracellular β-propeller module predicted in lipoprotein and scavenger receptors, tyrosine kinases, epidermal growth factor precursor, and extracellular matrix components 1 1Edited by P. E. Wright

1998 ◽  
Vol 283 (4) ◽  
pp. 837-862 ◽  
Author(s):  
Timothy A. Springer
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinases ◽  
Scavenger Receptors ◽  
Extracellular Matrix Components ◽  
Epidermal Growth ◽  
Matrix Components

Regulation of mesenchymal extracellular matrix protein synthesis by transforming growth factor-beta and glucocorticoids in tumor stroma

1995 ◽  
Vol 108 (6) ◽  
pp. 2153-2162 ◽  
Author(s):  
J.F. Talts ◽  
A. Weller ◽  
R. Timpl ◽  
M. Ekblom ◽  
P. Ekblom
Keyword(s):  
Extracellular Matrix ◽  
Growth Factors ◽  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tenascin C ◽  
Extracellular Matrix Components ◽  
Growth Factor Beta ◽  
Matrix Components

We have here studied the composition and regulation of stromal extracellular matrix components in an experimental tumor model. Nude mice were inoculated with WCCS-1 cells, a human Wilms' tumor cell line. In the formed tumors the stroma was found to contain mesenchymal extracellular matrix proteins such as tenascin-C, fibulins-1 and 2 and fibronectin, but no nidogen. Nidogen was confined to basement membranes of tumor blood vessels. Since glucocorticoids have been shown to downregulate tenascin-C expression in vitro, we tested whether dexamethasone can influence biosynthesis of extracellular matrix components during tumor formation in vivo. A downregulation of tenascin-C mRNA and an upregulation of fibronectin mRNA expression by dexamethasone was noted. Transforming growth factor-beta 1 mRNA levels were unaffected by the dexamethasone treatment. Glucocorticoids can thus downregulate tenascin-C synthesis although local stimulatory growth factors are present. The competition between a negative and a positive extrinsic factor on synthesis of stromal extracellular matrix components was studied in a fibroblast/preadipocyte cell line. Transforming growth factor-beta 1 stimulated tenascin-C synthesis but did not affect fibronectin or fibulin-2 synthesis. Dexamethasone at high concentrations could completely suppress the effect of transforming growth factor-beta 1 on tenascin-C mRNA expression. Transforming growth factor-beta 1 could in turn overcome the downregulation of tenascin-C mRNA expression caused by a lower concentration of dexamethasone. We therefore suggest that the limited expression of tenascin-C in part is due to a continuous suppression by physiological levels of glucocorticoids, which can be overcome by local stimulatory growth factors when present in sufficient amounts.

An epidermal growth factor receptor/ret chimera generates mitogenic and transforming signals: evidence for a ret-specific signaling pathway

1994 ◽  
Vol 14 (1) ◽  
pp. 663-675
Author(s):  
M Santoro ◽  
W T Wong ◽  
P Aroca ◽  
E Santos ◽  
B Matoskova ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinases ◽  
Mammalian Cells ◽  
Egf Receptor ◽  
Biological Effects ◽  
Ectopic Expression ◽  
Growth Factor Receptor ◽  
Dependent Signal ◽  
Epidermal Growth

A chimeric expression vector which encoded for a molecule encompassing the extracellular domain of the epidermal growth factor (EGF) receptor (EGFR) and the intracellular domain of the ret kinase (EGFR/ret chimera) was generated. Upon ectopic expression in mammalian cells, the EGFR/ret chimera was correctly synthesized and transported to the cell surface, where it was shown capable of binding EGF and transducing an EGF-dependent signal intracellularly. Thus, the EGFR/ret chimera allows us to study the biological effects and biochemical activities of the ret kinase under controlled conditions of activation. Comparative analysis of the growth-promoting activity of the EGFR/ret chimera expressed in fibroblastic or hematopoietic cells revealed a biological phenotype clearly distinguishable from that of the EGFR, indicating that the two kinases couple with mitogenic pathways which are different to some extent. Analysis of biochemical pathways implicated in the transduction of mitogenic signals also evidenced significant differences between the ret kinase and other receptor tyrosine kinases. Thus, the sum of our results indicates the existence of a ret-specific pathway of mitogenic signaling.

scholarly journals What are the markers of aggressiveness in prolactinomas? Changes in cell biology, extracellular matrix components, angiogenesis and genetics

2007 ◽  
Vol 156 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Alper Gürlek ◽  
Niki Karavitaki ◽  
Olaf Ansorge ◽  
John A H Wass
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Growth Factor ◽  
Molecular Mechanisms ◽  
Cellular Migration ◽  
Tumour Suppressor Genes ◽  
Suprasellar Region ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
E Cadherin

Prolactinoma is the most common pituitary tumour in adults. Macroprolactinomas, particularly in men, may occasionally exhibit a very aggressive clinical course as evidenced by progressive growth, invasion through bone into the sphenoid sinus, cavernous sinus, suprasellar region or the nasopharynx. Some may even progress to pituitary carcinoma with craniospinal or systemic metastases. Aggressive tumours have low cure rates despite appropriate medical and surgical treatment. The mechanisms underlying this aggressive biological behaviour have not yet been fully clarified. Recent immunohistochemical, molecular and genetic studies have provided some insight in this respect. Invasive prolactinomas may be associated with a high Ki-67/MIB-1 labelling index indicating increased cell proliferation, although this is not a universal finding. The AA polymorphism in the cyclin adenine (A)/guanine (G) gene is more frequently detected in invasive prolactinomas. Increased expression of the polysialylated neural cell adhesion molecule (NCAM) and reduced expression of the E-cadherin/catenin complex implies a contribution of altered cell-to-cell adhesion and cellular migration. Extracellular matrix components (ECM), matrix metalloproteinases (MMPs) and their inhibitors play important roles in the context of angiogenesis and invasion. The induction of fibroblast growth factor and vascular endothelial growth factor via oestrogen-induced overexpression of novel genes (PTTG, hst and Edpm5) enhance cell growth, proliferation and angiogenesis contributing to invasiveness in prolactinomas. Although mutations in proto-oncogenes like Ras are uncommon, loss of tumour suppressor genes at loci 11q13, 13q12–14, 10q and 1p seem to be associated with invasiveness. Of the described mechanisms, only reduced E-cadherin/catenin expression and overexpression of hst gene seem to be relatively specific markers for prolactinoma invasiveness compared with other pituitary adenomas. Further research is needed to clarify the molecular mechanisms behind the aggressive course of some prolactinomas to predict those with a potentially poor clinical outcome, and to devise treatments that will eventually enable the cure of these challenging tumours.

scholarly journals Hepatocyte Growth Factor (HGF) Modulates Leydig Cell Extracellular Matrix Components

2009 ◽  
Vol 31 (3) ◽  
pp. 306-313 ◽  
Author(s):  
A. Catizone ◽  
G. Ricci ◽  
M. A. Tufano ◽  
B. Perfetto ◽  
R. Canipari ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Leydig Cell ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
Hepatocyte Growth
Sign in / Sign up

Export Citation Format

Share Document