Biomaterial Database

Measurement of plasminogen activator activity from human fibrosarcoma cells by a new microassay. 1987

M Rezaee, and L Chen, and R H Kramer

Department of Anatomy, School of Medicine, University of California, San Francisco 94143.

Elevated levels of plasminogen activator (PA) activity have been correlated with neoplasia and may have an important role in tumor-cell invasion and metastasis. We have developed a new caseinolytic assay that uses an immunochemical approach to measure the activity of PA elaborated by malignant tumor cells. The highly sensitive assay consists in incubating a source of PA (viable tumor cells, cell extracts, or conditioned medium) with purified plasminogen in microtiter plates precoated with a suitable protein substrate such as casein. Clearance of the immobilized protein substrate by PA-generated plasmin is then measured by a technique based on the enzyme-linked immunosorbent assay. In experiments using urokinase as a source of PA, the assay displayed near linearity over several log units of urokinase activity and could detect as little as 10(-2) Ploug units of PA activity. Besides successfully measuring PA activity produced by the human HT 1080 fibrosarcoma cell line, the assay permitted detection of significant plasminogen-independent proteolytic activity generated by intact tumor cells cultured in direct contact with immobilized protein substrates.

UI	MeSH Term	Description	Entries
D008832	Microchemistry	The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
D009363	Neoplasm Proteins	Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.	Proteins, Neoplasm
D010958	Plasminogen	Precursor of plasmin (FIBRINOLYSIN). It is a single-chain beta-globulin of molecular weight 80-90,000 found mostly in association with fibrinogen in plasma; plasminogen activators change it to fibrinolysin. It is used in wound debriding and has been investigated as a thrombolytic agent.	Profibrinolysin,Glu-Plasminogen,Glutamic Acid 1-Plasminogen,Glutamyl Plasminogen,1-Plasminogen, Glutamic Acid,Glu Plasminogen,Glutamic Acid 1 Plasminogen,Plasminogen, Glutamyl
D010960	Plasminogen Activators	A heterogeneous group of proteolytic enzymes that convert PLASMINOGEN to FIBRINOLYSIN. They are concentrated in the lysosomes of most cells and in the vascular endothelium, particularly in the vessels of the microcirculation.	Extrinsic Plasminogen Activators,Plasminogen Activator,Uterine-Tissue Plasminogen Activator,Uterine Tissue Plasminogen Activator
D002364	Caseins	A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.	alpha-Casein,gamma-Casein,AD beta-Casein,Acetylated, Dephosphorylated beta-Casein,Casein,Casein A,K-Casein,Sodium Caseinate,alpha(S1)-Casein,alpha(S1)-Casein A,alpha(S1)-Casein B,alpha(S1)-Casein C,alpha(S2)-Casein,alpha-Caseins,beta-Casein,beta-Caseins,epsilon-Casein,gamma-Caseins,kappa-Casein,kappa-Caseins,AD beta Casein,Caseinate, Sodium,K Casein,alpha Casein,alpha Caseins,beta Casein,beta Caseins,beta-Casein Acetylated, Dephosphorylated,beta-Casein, AD,epsilon Casein,gamma Casein,gamma Caseins,kappa Casein,kappa Caseins
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D005354	Fibrosarcoma	A sarcoma derived from deep fibrous tissue, characterized by bundles of immature proliferating fibroblasts with variable collagen formation, which tends to invade locally and metastasize by the bloodstream. (Stedman, 25th ed)	Fibrosarcomas
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014568	Urokinase-Type Plasminogen Activator	A proteolytic enzyme that converts PLASMINOGEN to FIBRINOLYSIN where the preferential cleavage is between ARGININE and VALINE. It was isolated originally from human URINE, but is found in most tissues of most VERTEBRATES.	Plasminogen Activator, Urokinase-Type,U-Plasminogen Activator,Urinary Plasminogen Activator,Urokinase,Abbokinase,Kidney Plasminogen Activator,Renokinase,Single-Chain Urokinase-Type Plasminogen Activator,U-PA,Single Chain Urokinase Type Plasminogen Activator,U Plasminogen Activator,Urokinase Type Plasminogen Activator