Growth Factors: To Cleave or not to Cleave.

The Majority of growth factors are synthesized as proproteins and are proteolytically processed by the proprotein convertase-like enzymes. The cleavage of some of these molecules is crucial for the mediation of their functions, whereas the unprocessed forms of other growth factors are biologically active and in certain cases oppose the biological action of their processed forms through specific receptors. Here we review the recent advance in our understanding of the importance of growth factors processing by the proprotein convertases on the malignant phenotypes of tumor cells, tumorigenesis and angiogenesis, and the potential use of their maturation blockade/activation as a new potential therapeutic strategy [ABSTRACT FROM AUTHOR]