fibrinopeptide-b and Neoplasms

Endothelial cells (EC) interact with fibrin at sites of vascular injury, thrombosis, inflammation and tumor growth, whereas they are quiescent when exposed to circulating fibrinogen. To determine the structural basis for specific interaction with fibrin we have characterized the response of EC to fibrin of varying structure. Fibrin was prepared with thrombin, which cleaves both fibrinopeptide A (FPA) and fibrinopeptide B (FPB), with Reptilase, which cleaves only FPA, and with contortrix procoagulant to cleave only FPB. Fibrin with FPB cleavage stimulated release of von Willebrand factor from EC Weibel-Palade bodies and also supported cell spreading. Involvement of the amino terminus of the fibrin beta chain in the response was shown by stimulation of von Willebrand factor release by the peptide beta 15-42. Also, fibrin prepared from a fibrinogen derivative lacking residues 15-42 of the beta chain failed to support EC spreading. EC adhesion was unaffected by the pattern of fibrinopeptide cleavage or by the removal of peptide beta 15-42 from fibrin. The results indicate that separate sites on the fibrin molecule mediate adhesion and spreading, and that the latter requires cleavage of FPB and the new amino terminus of the beta chain. They further suggest that cellular responses to fibrin are regulated by the proteolytic cleavages and conformational changes that convert fibrinogen to fibrin and may also be modulated by plasmic or elastase degradation.

Topics: Amino Acid Sequence; Animals; Cell Adhesion; Endothelium, Vascular; Fibrin; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Inflammation; Macromolecular Substances; Molecular Sequence Data; Neoplasms; Platelet Adhesiveness; Thrombosis; von Willebrand Factor

Peripheral blood monocytes generate the procoagulant tissue factor in vitro and in vivo in response to stimulation by a variety of agents. Monocytes from cancer patients generate significantly increased tissue factor and a quantitative relationship exists between the levels of monocyte tissue factor (MTF) and levels of circulating fibrinopeptide A (FPA), a marker of in vivo clotting activation. Furthermore, monocytes from cancer patients have a greater procoagulant response to stimulation by endotoxin in vitro, which appears independent of lymphocyte regulation. These findings suggest a priming process in vivo, and may reflect exposure of monocytes to tumor antigen(s) or components of the immune response to tumors.

Topics: Animals; Anticoagulants; Blood Coagulation Factors; Fibrinopeptide B; Humans; Monocytes; Neoplasms; Neoplasms, Experimental; Thromboplastin

The mutual relationships between malignant tumours and mechanisms of blood coagulation are presented in a brief survey. In this connection, the mechanisms of a tumour cell entering the circulation through the vessel well and its leaving into the tissues are discussed, the theory of microtrauma being used for explaining these processes. Subsequently, the alterations to be found in the count and function of thrombocytes after contact with a malignant cell and the impact on this cell by blood platelets are represented. As a third factor the activation of blood coagulation which is exercised by substances with a procoagulatory effect produced by the malignant tissue and the frequently observed thrombosis in the course of neoplastic diseases are dealt with in connection with blood level changes of some coagulation factors. In a fourth section the significance of fibrinolysis, its activation and inhibition as well as the production of fibrinolytic activators by neoplasms are discussed.

Topics: Animals; Blood Coagulation Factors; Blood Platelets; Disseminated Intravascular Coagulation; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysis; Fibrinopeptide A; Fibrinopeptide B; Humans; Neoplasms; Neoplastic Cells, Circulating; Plasminogen Activators; Platelet Aggregation; Thromboembolism

Topics: Animals; Antithrombin III Deficiency; Blood Coagulation; Blood Coagulation Disorders; Diabetes Complications; Estrogens; Female; Fibrinopeptide B; Hemostasis; Humans; Male; Myocardial Infarction; Neoplasms; Partial Thromboplastin Time; Postoperative Complications; Pregnancy; Prospective Studies; Thrombosis

Although most time-of-flight (TOF) mass spectrometers come equipped with vacuum matrix-assisted laser desorption/ionization (MALDI) sources, the atmospheric pressure MALDI (API-MALDI) source is an attractive option because of its ability to be coupled to a wide range of analyzers. This article describes the use of an API-MALDI source coupled to a TOF mass spectrometer for evaluation of the effects of medium- and long-term storage on peptidomic profiles of cryopreserved serum samples from healthy women. Peptides were purified using superparamagnetic beads either from fresh sera or after serum storage at -80°C for 18 months or at -20°C for 8 years. Data were preprocessed using newly developed bioinformatic tools and then were subjected to statistical analysis and class prediction. The analyses showed a dramatic effect of storage on the abundance of several peptides such as fibrinopeptides A and B, complement fractions, bradykinin, and clusterin, indicated by other authors as disease biomarkers. Most of these results were confirmed by shadow clustering analysis, able to classify each sample in the correct group. In addition to demonstrating the suitability of the API-MALDI technique for peptidome profiling studies, our data are of relevance for retrospective studies that involve frozen sera stored for many years in biobanks.

Topics: Atmospheric Pressure; Bradykinin; Clusterin; Complement System Proteins; Cryopreservation; Female; Fibrinopeptide A; Fibrinopeptide B; Humans; Neoplasms; Peptides; Specimen Handling; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Topics: Aged; Blood Coagulation; Cerebral Infarction; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinopeptide A; Fibrinopeptide B; Humans; Middle Aged; Myocardial Infarction; Neoplasms; Peptide Fragments