Inhibition of a plasminogen activator from oncogenic virus-transformed mouse cells by rabbit antibodies against the enzyme

Danø, Keld; Nielsen, Lene; Möller, Vanessa; Engelhart, Merete

doi:10.1016/0304-4165(80)90146-4

Cited by 59 publications

(38 citation statements)

References 18 publications

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“…Extracts from a variety of murine tissues contain both u-PA and t-PA (19,41, and unpublished observations). Rabbit antibodies directed against murine u-PA completely inhibited its enzyme activity, without inhibiting t-PA (13). Addition of rabbit antimurine u-PA in the assay, therefore, enabled us to determine the proportion of enzyme activity due to u-PA.…”

Section: Resultsmentioning

confidence: 99%

“…All other materials were those described previously (2,3,10,13,16,19,41,42), or of the best commercially-available grade.…”

Section: Methodsmentioning

confidence: 99%

“…Antibodies : Antibodies against highly-purified murine u-PA were produced by immunization of rabbits, as described (13) . The IgG fraction was purified by sodium sulphate precipitation and DEAE-Sephadex ion exchange chromatography (45) .…”

Section: Methodsmentioning

confidence: 99%

“…In parallel assays, 0 .25 ag affinity purified antimurine a-PA IgG (l3) was added . This completely inhibited the enzymatic activity of the purified pro-u-PA and u-PA, while it did not inhibit murine t-PA (13). Pro-u-PA/u-PA in the samples was calculated as that part of the activity that was inhibited by the antimurine u-PA IgG.…”

Section: Methodsmentioning

confidence: 99%

“…We have reported the purification of murine u-PA (41), the development of rabbit antibodies against the purified enzyme (13), and the use of these antibodies for an immunocytochemical mapping ofthe distribution ofu-PA in the normal mouse (19). We now report their use for the immunocytochemical detection of u-PA in the invasivelygrowing, transplanted Lewis lung carcinoma.…”

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confidence: 99%

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Immunocytochemical localization of urokinase-type plasminogen activator in Lewis lung carcinoma.

Skriver¹,

Li²,

Kielberg³

et al. 1984

The Journal of Cell Biology

165

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The invasively growing and metastasizing Lewis lung carcinoma consistently contained urokinase-type plasminogen activator (u-PA) enzyme activity. When investigated immunocytochemically with antibodies against u-PA, different parts of individual tumors showed a pronounced heterogeneity in staining intensity. Strong staining was found in areas with invasive growth and degradation of surrounding normal tissue, while other areas were completely devoid of staining. Immunoreactivity occurred both with a perinuclear cytoplasmic localization in tumor cells and associated with apparently extracellular material. SDS PAGE of tumor extracts, under both reducing and nonreducing conditions, followed by immunoblotting, showed only one immunocytochemically stainable band with an electrophoretic mobility corresponding to that of purified proenzyme to u-PA, while no two-chain u-PA was detected. This indicates that the major part of the activator in Lewis lung carcinoma is present as one-chain pro-u-PA.

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Section: Resultsmentioning

confidence: 99%

“…All other materials were those described previously (2,3,10,13,16,19,41,42), or of the best commercially-available grade.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Immunocytochemical localization of urokinase-type plasminogen activator in Lewis lung carcinoma.

Skriver¹,

Li²,

Kielberg³

et al. 1984

The Journal of Cell Biology

165

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Plasminogen activator and its enhancement in differentiating mouse friend erythroleukemia cells

Amici

Benedetto²,

Saksela

et al. 1989

Intl Journal of Cancer

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Urokinase-type plasminogen activator (u-PA) activity was found in the medium as well as in the lysates of cultured uninduced Friend leukemia (FL) cells. PA activity progressively increased during the cell differentiation induced by dimethyl sulphoxide (DMSO), 4-hydroxy-3-methoxybenzaldehyde or hypoxanthine. Both the differentiation and the enhancement of PA activity in cultures of DMSO-induced cells were blocked by treating the cells with 1 microM dexamethasone. A highly significant correlation (rs = 0.93) was found between the number of hemoglobinized cells and the rate of PA secretion, indicating that the increase in PA activity coincides with late events of the differentiation process. FL cells specifically adhere to fibronectin-coated surfaces but tend to lose this property during the differentiation process. Anti-u-PA IgG antibodies promoted the attachment of differentiating cells to fibronectin-coated surfaces, suggesting that u-PA plays a role in the detachment of FL cells from fibronectin immobilized on the growth substratum.

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A cleaved form of the receptor for urokinase‐type plasminogen activator in invasive transplanted human and murine tumors

Solberg

Rømer

Brünner

et al. 1994

Intl Journal of Cancer

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It was recently found that urokinase-type plasminogen activator (uPA) is involved in the cleavage of its receptor (uPAR) on cultured cells, thereby releasing one of the receptor's 3 domains (the ligand binding domain I) and leaving the 2 others [uPAR(2 + 3)] anchored to the cell surface. With monoclonal antibodies (MAbs) we have now identified human uPAR(2 + 3) in lysates of invasive human MDA-MB-231 mammary carcinomas xenografted into nude mice. The production of peptide antibodies recognizing different domains of murine uPAR made it possible to identify a similar cleaved form of uPAR, murine uPAR(2 + 3), in extracts of primary Lewis lung carcinomas. Cleavage of uPAR also occurs in cultured MDA-MB-231 cells and Lewis lung carcinoma cells. This cleavage is inhibited by anticatalytic antibodies to either human or murine uPA, respectively, indicating that it is catalyzed by either uPA or plasmin generated by uPA. The amount of uPAR(2 + 3) may therefore be directly related to the activity of the uPA system and it is possible that the level of uPAR(2 + 3) in cancer tissue may prove to be a stronger prognostic parameter than the levels of either full-length uPAR or UPA.

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Inhibition of a plasminogen activator from oncogenic virus-transformed mouse cells by rabbit antibodies against the enzyme

Cited by 59 publications

References 18 publications

Immunocytochemical localization of urokinase-type plasminogen activator in Lewis lung carcinoma.

Immunocytochemical localization of urokinase-type plasminogen activator in Lewis lung carcinoma.

Plasminogen activator and its enhancement in differentiating mouse friend erythroleukemia cells

A cleaved form of the receptor for urokinase‐type plasminogen activator in invasive transplanted human and murine tumors

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