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 decrease of tumorigenicity by mouse melanoma clone B559 after growth in the presence of 5-bromodeoxyuridine (BrdU) has been correlated with a decrease in detectable cellular plasminogen activator. Reduction of both activities occurs after one to two cell divisions in the presence of this thymidine analog and is virtually complete within three to four cell cycles. These changes are fully reversible; four to five cell divisions in the absence of BrdU are sufficient to allow both tumorigenicity and plasminogen activator levels to return to normal. These results support the hypotheses that (a) the expression of a cellular plasminogen activator is closely associated with the transformation of normal to malignant cells and that (b) the suppression of tumorigenicity by BrdU reflects the capacity of this base analog to inhibit the expression of specialized functions which accompany the malignant state.
 ...
PMID:Correlated suppression by 5-bromodeoxyuridine of tumorigenicity and plasminogen activator in mouse melanoma cells. 12 36

To determine whether a relationship exists among urokinase plasminogen activator (u-PA) activity, tissue plasminogen activator (t-PA) activity, and the malignant transformation of human fibroblasts, we measured receptor-bound and secreted u-PAs and t-PA activity in fibroblast cell strains of a unique cell lineage and compared the results with the values obtained in human fibrosarcoma-derived cell lines and control cell lines. The lineage consists of four nonmalignant, infinite life span cell strains, clonally derived from a finite life span, neonatal foreskin-derived cell line or one of its derivatives and 10 malignant cell strains clonally derived from that same derivative. Seven of the latter were malignantly transformed by K-, H-, or N-ras oncogene transfection, two were obtained following carcinogen treatment, and one arose spontaneously. All 10 malignant strains in this lineage exhibited significantly higher levels of activity of receptor-bound u-PA than was found in the cell strain from which they arose or the nonmalignant cell strains derived from it. The ras oncogene-transformed malignant strains also exhibited significantly higher levels of activity of receptor-bound t-PA than their cell strain of origin. The other three malignant strains showed undetectable levels, consistent with their attaining the malignant state by an alternate process. The five fully malignant fibrosarcoma-derived cell lines tested also showed high levels of receptor-bound u-PA and t-PA. The majority (greater than or equal to 80%) of the nonmalignant control cell lines did not do so. The 10 malignant cell strains in the lineage also exhibited higher levels of activity of secreted high molecular weight u-PA or t-PA than did their cell strain of origin and the nonmalignant cell strains derived from it, as did the malignant fibrosarcoma-derived cell lines. The data suggest that the malignant state of human fibroblasts is always associated with high levels of activity of receptor-bound u-PA, and in addition cells transformed to the malignant state are very likely to exhibit high levels of receptor-bound t-PA and secreted forms of plasminogen activators.
 ...
PMID:Malignant transformation of human fibroblasts correlates with increased activity of receptor-bound plasminogen activator. 184 59

Plasminogen activator (PA) is a specific serine protease which catalyses conversion of the inactive plasminogen into the broad-spectrum protease, plasmin. PA exists in two structurally related forms known as tissue-type PA (tPA) and urokinase-type PA (uPA). Conversion of normal cells into a malignant state frequently leads to increased production of uPA. There is increasing evidence that uPA is directly involved in the process of metastasis. High levels of uPA in human breast cancers is a marker for poor prognosis. Finally, uPA may be a target for anti-metastatic agents, either by inhibition of its synthesis, inhibition of its activity or its binding to receptor.
 ...
PMID:Plasminogen activators and cancer. 213 47

Increased plasminogen activator (PA) secretion has been observed in malignant cells and tissue and PA is thought to be involved in the processes of tumorigenesis, cancer invasion and metastasis. Recently two types of plasminogen activator--tissue type PA(tPA) and urokinase type PA(uPA)--have been detected in human plasma. In this study, to investigate the relationship between circulating PA and the malignant state, we measured the plasma PA concentrations (PA activity, tPA and uPA antigen) in 69 women with gynecologic malignancies (cervical cancer 50, ovarian cancer 19). These concentrations were compared to those in control groups of 33 women with benign gynecologic tumors (uterine tumor 8, ovarian tumor 25). An enzyme-linked immunoassay for tPA and uPA antigens was performed by the modified method described by Takada et al. (1986). PA activity was measured by the sensitive spectrophotometric assay of Verheijen et al. (1982). The blood samples were taken from an arm vein with a minimum of venous occlusion before treatment. There was no correlation between PA activity or uPA antigen levels and the malignant state. However, in the case of uterine tumors, a significantly higher concentration of tPA antigen (10.5 +/- 5.1 ng/ml) was found in patients with cervical cancer, in stage IV, than in those in the benign group (5.2 +/- 2.0 ng/ml). Moreover the tPA antigen concentration in cervical cancer, stage IV, was higher than in stages 0-III.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Study on the plasma plasminogen activators in patients with malignant gynecologic tumors]. 251 Dec 60