Enzyme Offers Cancer Treatment Hope

Japanese researchers have discovered and identified a new matrix metalloproteinase enzyme which could help in the development of new agents which inhibit tumor growth and spread. The work is published in Nature (July 7).

The scientists, led by Motoharu Seiki of Kanazawa University, believe they have identified a new metalloproteinase from a tumor cell complementary DNA library with properties which suggest it could be an important factor in matrix destruction around a tumor, allowing cells to spread to surrounding and distant tissues.

Membrane-Type Metalloproteinases are essential components of membranes which allow for cell migration, a process which is necessary for normal tissue mechanisms such as development, inflammation and tissue repair. Companies such as British Bio-technology have identified inhibitors of secreted MMPs which are in clinical trials, but the new research is the first to identify an MMP which is membrane-bound. The researchers have demonstrated that membrane-type MMP (MT-MMP) can activate pro-gelatinase A, probably in close association with its plasma membrane binding site, to form gelatinase A, a potent enzyme which degrades collagen types IV and V, elastin and laminin and itself stimulates further elements in the proteolytic cascade which leads to matrix breakdown.