Cancer metastasis and hyaluronan

Abstract

Rapid advances in diagnostic and therapeutic techniques have greatly improved cancer prognosis. How ever, even at present, it is difficult to predict cancer metastasis, and the elucidation of the mechanism of can cer metastasis and its therapeutic application have just begun. Cancer progresses as a complex phenome non involving various life phenomena such as the abnormal proliferation of cells, their acquisition of motility,degradation of extracellular matrices, and changes in intercellular adhesiveness. The interaction of a very wide diversity of molecules acting inside and outside the cells controls the complex behaviors of cancer cells. In particular, molecules acting outside the cells are thought to directly specify the malignant characteristics of cancer cells; therefore, investigators are attempting to prevent cancer cell invasion and metastasis by inhibit ing their functions. The extracellularly acting molecules include a group of molecules, such as fibronectin and laminin, which interact with each other or with other molecules to form matrices and regulate tissue formation and cell functions. In general, extracellular matrix molecules such as collagen are thought to block the inva sion and metastasis of cancer cells. Conversely, hyaluronan, which is another matrix component and large sugar chain molecule, is synthesized, formed into matrices in many cancer tissues such as breast and colon cancers and gliomas, and is closely related to cancer progression. This paper focuses on hyaluronan and its matrix formation, gives an overview of studies aimed at elucidating tumor progression, and refers to recent trends towards blocking cancer invasion and metastasis by targeting the biosynthesis of hyaluronan.