Invasion of brain tissue by primary glioma: evidence for the involvement of urokinase-type plasminogen activator as an activator of type IV collagenase.
The immunocharacterization of a metalloproteinase isolated from rat glioma cell conditioned medium is described and confirms that the enzyme is identical to type IV collagenase. Free, active plasminogen activator (PA) and PA-PAI complexes were identified as being secreted by the same cells. Using affinity-purified metalloproteinase we demonstrate that the enzyme can be partially activated by u-PA but not by plasmin in vitro. On the basis of these findings and previous published work we propose a scheme for the proteolytic degradation of normal brain tissue during tumour invasion.
Reith
A
A
Rowett Research Institute, Bucksburn, Aberdeen, Scotland, U.K.
Rucklidge
G J
GJ
D000818:Animals; D001932:Brain Neoplasms / Q000201:enzymology / Q000473:pathology*; D002460:Cell Line; D002846:Chromatography, Affinity; D004789:Enzyme Activation; D005342:Fibrinolysis; D005910:Glioma / Q000201:enzymology / Q000473:pathology*; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D003012:Microbial Collagenase / Q000302:isolation & purification / Q000378:metabolism*; D008954:Models, Biological; D008970:Molecular Weight; D009361:Neoplasm Invasiveness; D051381:Rats; D010959:Tissue Plasminogen Activator / Q000302:isolation & purification / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000302:isolation & purification / Q000378:metabolism*
D007527:Isoenzymes; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator; D003012:Microbial Collagenase