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Plasma Fibronectin (plasma + fibronectin)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Ethanol Enhances the Interaction of Breast Cancer Cells Over-Expressing ErbB2 With Fibronectin

ALCOHOLISM, Issue 5 2010
Mei Xu
Background:, Ethanol is a tumor promoter and may enhance the metastasis of breast cancer. However, the underlying cellular/molecular mechanisms remain unknown. Amplification of ErbB2 or HER2, a receptor tyrosine kinase of the ErbB family, is found in 20 to 30% of patients with breast cancer. We have previously demonstrated that the effect of ethanol on the migration/invasion of breast cancer cells positively correlated with the expression levels of ErbB2. Adhesion to the extracellular matrix (ECM) is an important initial step for cancer cell invasion and metastasis. In this study, we investigated the effects of ethanol on the adhesion of MCF7 breast cancer cells over-expressing ErbB2 (MCF7ErbB2) to human plasma fibronectin. Methods:, To test the hypothesis that ethanol may enhance the attachment of human breast cancer cells to fibronectin, an important component of the ECM, we evaluated the effect of ethanol on the expression of focal adhesions, cell attachment, and ErbB2 signaling in cultured MCF7ErbB2 cells. Results:, Exposure to ethanol drastically enhanced the adhesion of MCFErbB2 cells to fibronectin and increased the expression of focal adhesions. Ethanol induced phosphorylation of ErbB2 at Tyr1248, FAK at Tyr861, and cSrc at Try216. Ethanol promoted the interaction among ErbB2, FAK, and cSrc, and the formation of a focal complex. AG825, a selective ErbB2 inhibitor, attenuated the ethanol-induced phosphorylation of ErbB2 and its association with FAK. Furthermore, AG825 blocked ethanol-promoted cell/fibronectin adhesion as well as the expression of focal adhesions. Conclusions:, Our results suggest that ethanol enhances the adhesion of breast cancer cells to fibronectin in an ErbB2-dependent manner, and the FAK pathway plays an important role in ethanol-induced formation of a focal complex. [source]

Characterization of fibronectin assembly by platelets adherent to adsorbed laminin-111

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2006
J. CHO
Summary.,Background: Various types of laminin (LN) are ubiquitous components of basement membrane and exposed to blood upon localized damage of vascular endothelial cells. Fibronectin is a plasma protein that is insolubilized into fibrils in a regulated fashion by, for example, lysophosphatidic acid (LPA)-stimulated fibroblasts or platelets spread on supportive adhesive ligands. Objective: To study assembly of plasma fibronectin by LPA-activated platelets adherent to LN-111 via ,6,1 integrin. Results: Platelets adherent to LN-111-bound plasma fibronectin or its N-terminal 70 kD fragment in fibrillar arrays at the periphery of spread platelets under static but not shear conditions. Formation of fibronectin arrays under static conditions was inhibited by co-incubation with the N-terminal 70 kD fragment or with a 49-amino acid peptide that binds to the N-terminal region of fibronectin. Approximately 7000 fibronectin dimers bound per adherent platelet with a Kd of 50 nm. Bound 70 kD fragment was readily solubilized with deoxycholate (DOC), whereas bound fibronectin became progressively insoluble. Bound 70 kD fragment became resistant to DOC extraction after treatment with a cell-impermeable, reducible crosslinker. Crosslinked 70 kD fragment was found in a high molecular weight complex. As with fibroblasts, signaling molecules modulating actin cytoskeletal organization controlled expression of binding sites for the N-terminal 70 kD region of fibronectin on adherent platelets. Conclusions: These results indicate that platelets adherent to LN-111 via ,6,1 support subsequent assembly of fibronectin, but possibly only under conditions of intermittent or stagnant blood flow. [source]

Fibronectin concentrations in catheter sepsis

CLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2000
B. Nemet
Objectives To investigate the role of fibronectin in the pathogenesis of biomaterial-related infections and the influence of catheter sepsis on the concentration of plasma fibronectin during various stages of bacteremia. Methods Plasma fibronectin concentrations were determined by the simple radial immunodiffusion method. Four groups of subjects were used: one group comprised patients with catheter sepsis, the second patients with local inflammation of the catheter insertion site caused by slime-positive, coagulase-negative staphylococci, the third patients with slime-negative, coagulase-negative staphylococci isolated from the catheter, and the fourth demonstrably healthy persons. Results In patients with catheter sepsis, fibronectin concentrations were found after the disappearance of catheter sepsis and 3,5 days after the removal of the catheter. A statistically significant decrease in fibronectin concentration was detected in the plasma of patients with catheter sepsis compared with other groups of patients and control subjects. Conclusions The above results indicate a pathogenic role for fibronectin in biomaterial-related infections. [source]