Ozdemir O, Emri S, Karakoca Y, Sayinalp N, Akay H, Dündar S, Bariş I
Hacettepe University Medical School, Department of Internal Medicine, Ankara, Turkey.
Thromb Res. 1996 Oct 15;84(2):121-8. doi: 10.1016/0049-3848(96)00167-3.
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.
两种主要的纤溶激活剂，尿激酶型纤溶酶原激活剂（u-PA）和组织型纤溶酶原激活剂（t-PA）可能在肿瘤扩散和转移中起作用。恶性胸膜间皮瘤（MPM）是一种主要以局部浸润为主且远处转移发生率低的肿瘤。在本研究中，对MPM患者、肺癌患者和良性胸腔积液患者的血浆和胸腔积液样本中的u-PA、t-PA和纤溶酶原激活物抑制剂-1（PAI-1）抗原及活性进行了测定。与对照组相比，MPM组血浆u-PA和t-PA抗原水平较高，但血浆u-PA和t-PA活性相当。MPM组PAI-1抗原也较高。这些发现与肺癌组形成对比，在肺癌组中，u-PA和t-PA的活性及免疫测定值均较高，但PAI-1抗原与对照组相似。结论是，在MPM中，过量的t-PA和u-PA与PAI-1形成复合物达到平衡，而在肺癌中，血浆中PAI-1的量不足以克服升高的t-PA和u-PA。基于这些发现，可能提示平衡的纤溶系统是MPM远处转移发生率低的原因。
