Lumican: a new inhibitor of matrix metalloproteinase-14 activity.

We previously showed that lumican regulates MMP-14 expression. The aim of this study was to compare the effect of lumican and decorin on MMP-14 activity. In contrast to decorin, the glycosylated form of lumican was able to significantly decrease MMP-14 activity in B16F1 melanoma cells. Our results suggest that a direct interaction occurs between lumican and MMP-14. Lumican behaves as a competitive inhibitor which leads to a complete blocking of the activity of MMP-14. It binds to the catalytic domain of MMP-14 with moderate affinity (KD∼275 nM). Lumican may protect collagen against MMP-14 proteolysis, thus influencing cell-matrix interaction in tumor progression.