Expression of plasminogen activators and plasminogen activator inhibitor 1 in dedifferentiated chondrosarcoma.
BACKGROUND
The plasminogen activator system plays an important role in different malignant tumors. These enzymes participate in the destruction of intercellular matrices and basement membranes and/or can modulate the growth potency of tumor cells and may even promote metastases. In this study, the expression of three glycoproteins that play a role in the plasminogen activator system as activators of proteolysis-urokinase type plasminogen activator (u-PA), tissue type plasminogen activator (t-PA), and plasminogen activator inhibitor type 1 (PAI-1) were studied in various components of dedifferentiated chondrosarcomas of bone.


METHODS
The expression of u-PA, t-PA, and PAI-1 was investigated in 10 dedifferentiated chondrosarcomas and 14 conventional chondrosarcomas. The plasminogen activator/inhibitor glycoproteins were visualized immunohistochemically on paraffin sections and the levels of expression were assessed semiquantitatively.


RESULTS
In dedifferentiated chondrosarcoma, high grade dedifferentiated components displayed strong, diffuse coexpression of u-PA, t-PA, and PAI-1. For all glycoproteins studied, the immunoreactivity was significantly increased compared with the reactions in the low grade cartilaginous component of the same tumor and conventional chondrosarcoma. In the latter, u-PA, t-PA, and PAI-1 expression was found to be enhanced at invasive foci and in regions of endochondral ossification.


CONCLUSIONS
The current study documents the overexpression of u-PA, t-PA, and PAI-1 in dedifferentiated chondrosarcoma and suggests involvement of the plasminogen activator system in the biology of these tumors.
Häckel
C
C
Department of Pathology, Otto von Guericke University Magdeburg, Germany.
Czerniak
B
B
Ayala
A G
AG
Radig
K
K
Roessner
A
A
D001859:Bone Neoplasms / Q000378:metabolism*; D002813:Chondrosarcoma / Q000378:metabolism*; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D010960:Plasminogen Activators / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
D009363:Neoplasm Proteins; D017395:Plasminogen Activator Inhibitor 1; D015842:Serine Proteinase Inhibitors; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator