Matrix metalloproteinases: new directions toward inhibition in the fight against cancers.

Matrix metalloproteinases are zinc-dependent enzymes whose main function is to cleave the components of the extracellular matrix. Their overexpression is evident in all cancers but to date there is no satisfactory way to inhibit their actions. Here, we look at their types, their structures, their functions and the developing understanding we have of them in the search for ways to drug them and inhibit their actions selectively. We investigate their subtle but exploitable differences in order that we can develop drugs to target them and even to target specific substrates and functions that they carry out. To date there are no new matrix metalloproteinase inhibitors developed to treat cancer, but we are progressing in our understanding of them, which is leading us ever closer to our goal.