Currently,
the multifaceted role of the extracellular matrix (ECM) in tumorigenesis has
been realized. One ECM macromolecule exhibiting potent oncosuppressive actions
in tumorigenesis is decorin, the prototype of the small leucine-rich
proteoglycan gene family. The actions of decorin include its capability to
function as an endogenous pan-receptor tyrosine kinase inhibitor, a regulator
of both autophagy and mitophagy, as well as a modulator of the immune system. In
this review, we will discuss these topics in more detail. We will also give a
summary of preclinical studies exploring the value of decorin-mediated
oncosuppression as a potential future adjuvant therapy for epithelial cancers.