Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The highly metastatic human melanoma cell line BLM was transfected with the E1A or E1A + E1B regions of adenovirus 5 (Ad5). A series of progression markers, correlated with the malignant phenotype of parental BLM (including calcyclin, thymosin beta 10, plasminogen activator inhibitors types 1 and 2, urokinase type and tissue type plasminogen activators, vimentin, tissue type transglutaminase, and interleukin-6), was collectively repressed in the transfectants, whereas several control genes were not affected or even induced. The apparently coordinate repression of a set of markers by the same regulator gene, Ad5 E1A in this case, suggests the existence of one pathway under the control of a main switch and predicts that one or more as yet unidentified cellular master genes normally exert this function. A reduced oncogenicity was observed after subcutaneous inoculation of the E1A transfectants into nude mice and provides additional evidence in support of a tumor suppressor function of Ad5 E1A.
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PMID:Simultaneous suppression of progression marker genes in the highly malignant human melanoma cell line BLM after transfection with the adenovirus-5 E1A gene. 878 Jun 94

Quality control of immunochemical and/or immunocytochemical analyses warrants constant reproducibility and reliability of assay performance. In this respect, stable reference preparations containing known quantities of the components to be assessed may serve purposes in the quality assessment of antigen expression levels, including those of the plasminogen activation system. Quality control preparations for the immunocytochemical assessment of urokinase-type plasminogen activator (uPA) were developed using different combinations of cultured cell lines (BLM and IF6), each expressing immunochemically well-defined (by enzyme-linked immunosorbent assay[ELISA]) amounts of the respective component. Cytospins and frozen sections cut from sucrose/Tissue-Tek blocks containing these cell lines demonstrated stable and homogeneous expression of uPA. An excellent correlation was found between the immunocytochemical staining results and the data obtained by ELISA. Because these cell lines are available in practically unlimited quantities, large numbers of nearly identical quality control preparations can be made over a long period of time. Therefore, the incorporation of (combinations of) cell lines in cytospins or sucrose/Tissue-Tek blocks represents a simple model system in establishing quality control preparations for immunocytochemical assessment of components of the plasminogen activator system.
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PMID:Development of quality control preparations for immunocytochemical assessment of urokinase-type plasminogen activator. 1155 58

Recent reports suggest that elevated levels of plasminogen activator inhibitor-1 (PAI-1) may contribute to tumour progression. The studies reported here were designed to help elucidate PAI-1's contribution to the invasive and migratory phenotype. Antibodies to PA-1 dose-dependently, and significantly, inhibited the invasive and migratory potential of human HT1080 fibrosarcoma cells, as did an antibody to uPA and the plasmin inhibitor aprotinin. Invasion of the human melanoma cell line, BLM, was also attenuated by the anti-PAI-1 monoclonal antibody MAI-12. The non-invasive human melanoma cell line, IF6, which does not express uPA, provided further confirmation of PAI-1 and uPA's role as, upon transfection with uPA, this cell line attained an invasive phenotype, which was again attenuated by MAI-12. Although antibodies to PAI-1 did not affect the adhesion of HT1080 cells to vitronectin, the antibody to uPA reduced their attachment. Addition of exogenous PAI-1, however, prevented HT1080 cell adhesion (IC50 180 nM) and promoted cell detachment from vitronectin. Furthermore melanoma cells transfected with a uPA variant, which had an impaired interaction with PAI-1, were not invasive and had impaired binding to vitronectin. These data highlight the importance of a balanced proteolysis and suggest an additional role for PAI-1 distinct from its role in proteolysis. These data also suggest that uPA and PAI-1 may co-operate in the migratory process by respectively facilitating the attachment to, and subsequent detachment from, vitronectin in the extracellular matrix. These results support the clinical findings and indicate that modulation of PAI-1 activity may be of therapeutic benefit for the treatment of cancer.
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PMID:Antibodies to PAI-1 alter the invasive and migratory properties of human tumour cells in vitro. 1159 1