Abstract: The transmembrane metalloproteinase-disintegrin ADAM8 mediates cell adhesion and shedding of ligands, receptors, and extracellular matrix components. ADAM8 is abundantly expressed in breast tumors and derived metastases compared to normal tissue, especially in triple-negative breast cancers (TNBCs). High ADAM8 levels predicted poor patient outcome, and ADAM8 promoted an aggressive phenotype of TNBC cells in culture. Tumors derived from TNBC cells with ADAM8 knockdown failed to grow beyond a palpable size and displayed poor vascularization. Circulating tumor cells and brain metastases were also significantly reduced. ADAM8 stimulated angiogenesis through release of VEGF-A and cell migration through ?1-integrin activation. Treatment with anti-ADAM8 antibody in vivo resulted in reduced primary tumor burden and reduced metastases. Furthermore, antibody treatment of established tumors profoundly decreased metastases in a resection model.

Abstract: The transmembrane metalloproteinase-disintegrin ADAM8 mediates cell adhesion and shedding of ligands, receptors, and extracellular matrix components. ADAM8 is abundantly expressed in breast tumors and derived metastases compared to normal tissue, especially in triple-negative breast cancers (TNBCs). High ADAM8 levels predicted poor patient outcome, and ADAM8 promoted an aggressive phenotype of TNBC cells in culture. Tumors derived from TNBC cells with ADAM8 knockdown failed to grow beyond a palpable size and displayed poor vascularization. Circulating tumor cells and brain metastases were also significantly reduced. ADAM8 stimulated angiogenesis through release of VEGF-A and cell migration through ?1-integrin activation. Treatment with anti-ADAM8 antibody in vivo resulted in reduced primary tumor burden and reduced metastases. Furthermore, antibody treatment of established tumors profoundly decreased metastases in a resection model.