FIG. 6.

Model for QSOX1-mediated tumor cell invasion. QSOX1 activates matrix metalloproteinases (MMPs) that are capable of digesting basement membranes (46) and incorporates laminin into fibroblasts, which facilitates the migration of tumor cells into the fibroblast layer (44). The production of H₂O₂ by QSOX1 may also elicit vascular endothelial growth factor (VEGF) production by tumor cells, stimulating blood vessel growth into the tumor (62). Taken together, these events may facilitate tumor cell migration through stroma and invasion of tumor cells into blood circulation. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars