TUMOR-ASSOCIATED FIBRINOLYSIS IN OVARIAN CARCINOMA - HPLC AND N-TERMINAL AMINO ACID ANALYSIS REVEAL THE PATHWAY OF DEGRADATION OF CROSSLINKED FIBRIN

Crosslinked fibrin has been demonstrated by immunohistochemi-cal tests to occur around tumor plugs, on the surface and in the stroma of the tumor in ovarian cancer. High levels of D-Dimer (200-800μg/ml), the characteristic terminal degradation product of crosslinked fibrin, are found in ascitic fluid of patients with advanced ovarian cancer. These findings suggest that fibrin polymerisation and degradation are related to and even may influence tumor growth. The kind of proteases which are responsible for degradation of crosslinked fibrin is, however, unknown.lt was the aim of this study to evaluate whether plasmin and/or other proteases are involved in tumor-associated fibrinolysis. Therefore the total high-molecular-weight fibrin degradation products in ascitic fluid were purified by protamine sulfate precipitation, gel filtration, immunoadsorption and compared with the components of plasmin-degraded crosslinked fibrin, i.e. DD,DY,YX,DXD and DXY, by direct SDS-PAGE in the absence of mercaptoethanol and after excision of the bands, mercaptolysis and re-electrophoresis. Pronounced similarity between the two sets of fragments was observed. For further information the fragments from the two sources were mercaptolysed and their polypeptide chain components separated by reversed-phase high-performance liquid chromatography, the components being identified by N-terminal sequence analysis and SDS-PAGE. Highly similar patterns were obtained and components corresponding to γ-γ ,γ-γ1, β, β2 and α1 could be recognized. The findings provide strong evidence for plasmin being the primary protease involved in ovarian carcinoma-related fibrinolysis, (supported by Deutsche Forschungsgemeinschaft.SFB 207, A2).