About DCN / Decorin:
DCN is a gene that encodes a member of the small leucine-rich proteoglycan family of proteins. The binding of Decorin to multiple cell surface receptors mediates its role in total tumor suppression. This includes a stimulatory effect on autophagy and inflammation. It also includes an inhibitory effect on tumorigenesis and angiogenesis. DCN, and the related gene biclygan can be the result of a gene duplication. The mutations in this gene are mostly associated with congenital stromal corneal dystrophy in humans.
DCN was named for its ability to bind to collagen fibrils. It's also known as a decorator for collagen fibrils, with a core protein of around 38kDa. This includes 10 different repeat sequences that are leucine-rich. There are three different potential GAG attachment sites, but only one is usually used for a single GAG. Targeted disruption of DCN usually leads to laxity of the skin and fragility in mice. Disruption of the biglycan gene usually ends in reduced skeletal growth and bone mass, which can lead to osteopenia.
Decorin interacts with both type I and type II collagens and the interaction is not involving the GAG chain. The binding delays collagen fibrillogenesis and could play an important role in interfibril interactions. The addition of decorin to TGF-81 can enhance the inhibitory effect on the osteoclast proliferation. Decorin is normally produced by cells in a breast tissue stroma where it's thought to be a prt of the matrix assembly. It's also an established natural oncosuppressive factor, with recent gene therapy formulations that use adenoviral vectors shown with promising results.