Prognostic value of tissue-type plasminogen activator (tPA) and its complex with the type-1 inhibitor (PAI-1) in breast cancer.

The prognostic value of tissue-type plasminogen activator (tPA) measured in samples derived from 865 patients with primary breast cancer using a recently developed enzyme-linked immunosorbent assay (ELISA) was evaluated. Since the assay could easily be adapted to the assessment of the complex of tPA with its type-1 inhibitor (PAI-1), it was investigated whether the tPA:PAI-1 complex also provides prognostic information. To this end, cytosolic extracts and corresponding detergent extracts of 100,000 g pellets obtained after ultracentrifugation when preparing the cytosolic fractions for routine steroid hormone receptor determination were assayed.

ELISA for complexes of urokinase-type and tissue-type plasminogen activators with their type-1 inhibitor (uPA-PAI-1 and tPA-PAI-1).

An ELISA has been developed for the assessment of complexes between the urokinase-type (uPA) and the tissue-type plasminogen (tPA) activators with their inhibitor type-1 (PAI-1) in cell-culture medium and cytosolic extracts of breast tumours. The "4-stage/2-site" ELISA involves 2 polyclonal antibodies in the pre-analyte stage 2 and in the post-analyte stage. For the specific measurement of the uPA-PAI-1 complex, 2 assay formats may be employed, uPA/PAI-1 and PAI-1/uPA.

Prognostic impact of urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) in cytosols and pellet extracts derived from 892 breast cancer patients.

To evaluate the clinical relevance of urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-1) measured by a recently developed enzyme-linked immunosorbent assay (ELISA), we analysed both components in samples derived from 892 patients with primary breast cancer (median follow-up 99 months). The assays were performed in cytosolic extracts as well as in corresponding detergent extracts of pellets obtained after ultracentrifugation, which was carried out when preparing the cytosolic fractions for routine steroid hormone receptor determination. Statistically significant correlations were found between the cytosolic levels and those determined in the pellet extracts (Spearman correlation coefficient r = 0.

External quality assessment of trans-European multicentre antigen determinations (enzyme-linked immunosorbent assay) of urokinase-type plasminogen activator (uPA) and its type 1 inhibitor (PAI-1) in human breast cancer tissue extracts.

High levels of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) in breast cancer tissue extracts have been associated with rapid disease progression. In these studies, different enzyme-linked immunosorbent assay (ELISA) kits have been applied for the quantification, and consequently the ranges of uPA and PAI-1 levels reported differ considerably. Therefore, the Receptor and Biomarker Study Group (RBSG) of the European Organization for Research and Treatment of Cancer (EORTC) and a consortium of the BIOMED-1 project 'Clinical Relevance of Proteases in Tumor Invasion and Metastasis' initiated three collaborative between-laboratory assessment trials aimed at controlling uPA and PAI-1 antigen analyses.

Complexes between urokinase-type plasminogen activator and its receptor in blood as determined by enzyme-linked immunosorbent assay.

Complexes between urokinase-type plasminogen activator (uPA) and its receptor (uPAR) were assessed in plasma and serum from 39 breast cancer patients and from 20 healthy individuals, applying a recently developed enzyme-linked immunosorbent assay (ELISA) for the analysis of these complexes in tumor tissue extracts. The assay is based on a combination of rabbit polyclonal anti-uPA antibodies for catching and a mouse anti-uPAR monoclonal antibody (MAb) for detection. The specificity of the assessment of uPA:uPAR complexes was verified by simultaneous analysis of the individual blood samples in corresponding non-sense ELISA formats, in which either the anti-uPA catching antibody or the anti-uPAR detecting antibody was substituted with an irrelevant antibody.