Plasminogen activating enzyme in cultured glioblastoma cells. An immunofluorescence study with monoclonal antibody.
A monoclonal antibody against a 52,000 dalton human plasminogen activating enzyme (HPA52) was used for immunofluorescence staining of cultured glioblastoma cells. The fluorescence was located in the cytoplasm of the cells. A pronounced variation in the staining intensity was observed between the individual cells. The specificity of the fluorescent stain was supported by the findings that 1) no staining was obtained with a monoclonal antibody of the same subclass, but with irrelevant specificity (anti-2,4,6-trinitrophenyl); 2) adsorption with HPA52 purified to homogeneity removed the ability of anti-HPA52 to mediate staining; 3) the glioblastoma cells contained HPA52, as measured by enzymatic assay, while melanoma cells that were not stained did not contain HPA52 activity; 4) dexamethasone reduced both the enzymatically determined HPA52 content and the immunofluorescence in parallel, while progesterone affected none of these parameters; 5) we have previously found that culture fluid conditioned by the glioblastoma cells apart from HPA52 does not contain detectable amounts of any protein that binds to anti-HPA52. Several advantages of immunohistochemical detection of plasminogen activators compared with enzyme histochemical methods are discussed, among these that the immunohistochemical method distinguishes between plasminogen activators of different types.
D000911:Antibodies, Monoclonal; D002460:Cell Line; D003593:Cytoplasm / Q000201:enzymology*; D003907:Dexamethasone / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D005910:Glioma; D006801:Humans; D008545:Melanoma; D010960:Plasminogen Activators / Q000032:analysis* / Q000276:immunology; D011374:Progesterone / Q000494:pharmacology; D013194:Staining and Labeling
D000911:Antibodies, Monoclonal; D011374:Progesterone; D003907:Dexamethasone; D010960:Plasminogen Activators