Fibrinolytic system in plasma and pleural fluid in malignant pleural mesothelioma.
The two major fibrinolytic activators, urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA) may play role in tumor spread and metastasis. Malign pleural mesothelioma (MPM) is a kind of tumor with predominantly local invasion and low incidence of distant metastasis. In this study, u-PA, t-PA and PA activator-1 (PAI-1) antigen and activity were measured in plasma and pleural fluid samples from patients with MPM, lung cancer and benign effusion. When compared to the control group, in MPM group, plasma u-PA and t-PA antigen levels were higher, but plasma u-PA and t-PA activity were comparable. PAI-1 antigen was also higher in MPM group. These findings were in contrast to the lung cancer group, in which both activity and immunologic measurement of u-PA and t-PA were higher, but PAI-1 antigen was similar as compared to the control group. It is concluded that excess t-PA and u-PA are balanced in complexes with PAI-1 in MPM, whereas the amount of PAI-1 in plasma is insufficient to overcome the elevated t-PA and u-PA, in lung cancer. Based on these findings, it may be suggested that the balanced fibrinolytic system is responsible for the low incidence of distant metastasis in MPM.
Hacettepe University Medical School, Department of Internal Medicine, Ankara, Turkey.
O
O
Ozdemir
S
S
Emri
Y
Y
Karakoca
N
N
Sayinalp
H
H
Akay
S
S
Dündar
I
I
Bariş
D000328:Adult; D005260:Female; D005342:Fibrinolysis; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008654:Mesothelioma / Q000097:blood* / Q000503:physiopathology; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D010960:Plasminogen Activators / Q000097:blood; D010996:Pleural Effusion / Q000097:blood* / Q000503:physiopathology; D010997:Pleural Neoplasms / Q000097:blood* / Q000503:physiopathology; D014568:Urokinase-Type Plasminogen Activator / Q000097:blood
D017395:Plasminogen Activator Inhibitor 1; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator