Matrix metalloproteinase activity in early-stage lung cancer.

BACKGROUND The matrix metalloproteinases (MMPs)-2, -9 and -7 are thought to be associated with tumor invasion, metastasis, and angiogenesis. However, their possible roles in early-stage lung cancer are not clear. We measured the activity of MMP-2, -7 and -9 in early-stage lung cancer tissues. MATERIAL AND METHODS Normal lung tissues and cancer tissues were collected from 60 consecutive stage-I non-small cell lung cancer (NSCLC) patients. The activities of MMP-2 and MMP-9 were determined by gelatin zymography, and the activity of MMP-7 was determined by casein zymography. Furthermore, the ratio of the active form of MMP-2 in tumor tissue (T) compared with normal tissue (N) was determined, and the survival in the groups with different MMP-2 T:N ratio was compared. RESULTS The activity of both MMP-2 and MMP-9 was detected in all cancer and normal tissues. Interestingly, MMP-9 activity was significantly reduced, whereas MMP-2 activity was significantly increased, in cancer tissues compared to normal tissues. The survival rate of the MMP-2 T:N ratio > 2.5 group was 57.45%, which was significantly reduced compared with that of the T:N ratio ≤ 2.5 group (86.78%). CONCLUSION Our findings suggest that MMP-2, but not MMP-9 and MMP-7, may be implicated in early-stage tumor invasion, metastasis, and angiogenesis in NSCLC.