Biological functions of proteoglycans: use of specific inhibitors of proteoglycan synthesis.

The use of specific inhibitors of proteoglycan synthesis have demonstrated essential functions for these molecules. Proteoglycans do not appear to be essential for cell viability or proliferation but are necessary for stable assembly of ECM and functional cell-ECM interaction. Because of their ability to nearly completely abolish ECM assembly in cell culture systems, proteoglycan synthesis inhibitors are useful tools to examine effects of ECM on the phenotypic behavior of cells. Despite its usefulness, the use of proteoglycan synthesis inhibitors has some drawbacks. The most significant of these is the fact that synthesis of all proteoglycans is inhibited, making it difficult to assign a particular function to a specific proteoglycan type. For this reason, inhibition studies need to be done in conjunction with additional biochemical, immunological or molecular biological studies.