Cell surface is the major interface for cell communication with the environment. Many proteins on the cell surface are involved in this process and these include various types of ligands, receptors, cell adhesion molecules, and accessory molecules. These proteins are regulated not only at transcription level but also by post-translational regulations such as glycosylation, vesicle transport, internalization, and subcellular localization etc. Proteolysis is also an important post-translational system to regulate the fate of all the proteins in an irreversible manner. Most of the extracellulr proteases belong to serine- or metallo-proteases, and they are of particular importance in regulating the proteins in the extracellular milieu. These proteases are either secreted or membrane-anchored forms. Our group has been particularly interested in the membrane-anchored proteases that play critical roles in regulation of the proteins at the cell-ECM (extracellular matrix) interface and act as important modulators of cellular functions.

Cancer cells develop as a result of multiple defects in the regulatory systems for cell growth and death. According to the progression of cancer, the systems regulating cell communication in tissue also break down successively. Aberrant usage of proteases is frequently associated with malignant tumors and contributes to the rapid tumor growth and spread to secondary sites. The aim of our study is to understand the cellular strategy to use the membrane proteases, such as MT1-MMP, to regulate tumor cell functions in tissue environment and to apply our knowledge to cancer therapy.