Increased plasma levels of urokinase plasminogen activator and matrix metalloproteinase-9 in nonsmall cell lung cancer patients.

Background: The involvements of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA) in the pathogenesis of various types of lung cancers have been established. The aim of the present study was to determine the concentrations of MMP-9 and uPA in the plasma of nonsmall cell lung cancer (NSCLC) patients.

Methods: Gelatin zymography and ELISA were used to measure MMP-9 and uPA concentrations, respectively, in 90 NSCLC patients and 50 control subjects.

Results: Compared with that of control subjects, MMP-9 and uPA levels were significantly higher in the plasma of NSCLC patients (P<0.001 and P<0.01, respectively). Further statistical analysis for clinic pathological parameters revealed that MMP-9 and uPA levels were significantly increased in patients with metastasis (P<0.01 and P<0.05, respectively). Furthermore, the MMP-9 level was significantly different between smokers and nonsmokers (P<0.05) while uPA levels varied between histological types (P<0.05).

Conclusions: Plasma MMP-9 and uPA might play an important role in the metastasis of NSCLC by involvement in the processes of invasion and metastasis.