Role of elastin-matrix interactions in tumor progression.

Data from the literature now indicate that cancer cells can specifically interact with the unique extracellular matrix protein, elastin. The interaction is mediated by two elastin-binding proteins (EBP), S-gal/EBP (organized into the elasin receptor/elastonectin complex) and galectin-3, components of two laminin receptors. Studies revealed that the expression of both EBPs is closely associated to the invasive/metastatic potential of various cancer types. This is due to the fact that elastin-ligation of S-gal/EBP induces motogenic, as well as mitogenic signals and releases various elastases from cancer cells and the induction depends on the metastatic potential. Studies also demonstrated that certain cancer cells can synthesize elastin and express lysyl oxydase, providing explanation for frequent appearance of elastic tissue in tumors such as breast or gastric cancers. Clinico-pathological data suggest some correlation with tumor progression of the presence of the elastic tumor stroma. Since elastic tissue may be a significant reservoir of angiostatic molecule(s) this extracellular matrix protein can also have a role in tumor-induced angiogenesis. Soluble elastin as well as elastin peptides are potent inhibitors of the metastatic process in experimental tumor models. On the other hand, elastin peptides can also be used to design targeted therapies exploiting the unique physicochemical nature of this matrix protein. Altogether, these data suggest a significant role for tumor cell-elastin interactions in tumor progression.