Urinary trypsin inhibitor suppresses migration of malignant mesothelioma

Urinary trypsin inhibitor (UTI), an inhibitor of urokinase plasminogen activator relevant to proteolytic processing from the inactive into the active form of platelet-derived growth factor-D (PDGF-D) to activate PDGF-betabeta receptor (PDGF-betabetaR), inhibited fetal bovine serum-stimulated migration of human malignant mesothelioma, with the extent varying among the cell types. The more effective inhibition was found in NCIH-2052 and -2452 cells, with the higher expression of PDGF-betabetaR. The results of the present study suggest that UTI suppresses malignant mesothelioma cell migration by neutralizing active dimer of PDGF-D (PDGF-DD)/PDGF-betabetaR-mediated signal transduction.