The tumor microenvironment plays a determining role in cancer development through
a plethora of interactions between the extracellular matrix and tumor cells. Decorin
is a prototype member of the SLRP family found in a variety of tissues and is expressed
in the stroma of various forms of cancer. Decorin has gained recognition for its essential
roles in inflammation, fibrotic disorders, and cancer, and due to its antitumor properties,
it has been proposed to act as a "guardian from the matrix." Initially identified
as a natural inhibitor of transforming growth factor-beta, soluble decorin is emerging
as a pan-RTK inhibitor targeting a multitude of RTKs, including EGFR, Met, IGF-IR,
VEGFR2, and PDGFR. Besides initiating signaling, decorin/RTK interaction can induce
caveosomal internalization and receptor degradation. Decorin also triggers cell cycle
arrest and apoptosis and evokes antimetastatic and antiangiogenic processes. In addition,
as a novel regulatory mechanism, decorin was shown to induce conserved catabolic processes,
such as endothelial cell autophagy and tumor cell mitophagy. Therefore, decorin is
a promising candidate for combatting cancer, especially the cancer types heavily dependent
on RTK signaling.
