Multivalent dipeptidyl peptidase IV fragment-nanogold complex inhibits cancer metastasis by blocking pericellular fibronectin.

Inhibition of cancer metastasis is a fundamental challenge in cancer treatment. We have previously shown that metastasis of cancer cells in the lung is critically promoted by the interaction between the superficial dipeptidyl peptidase IV (DPP IV) expressed on lung endothelial cells and the pericellular polymeric fibronectin (polyFN) of circulating cancer cells. In the present study, we aimed to search for DPP IV fragments with high avidity to polyFN and develop FN-targeted gold nanoparticles (AuNPs) conjugated with DPP IV fragments for treating cancer metastasis.

Epitope analysis of the rat dipeptidyl peptidase IV monoclonal antibody 6A3 that blocks pericellular fibronectin-mediated cancer cell adhesion.

We previously showed that the rat dipeptidyl peptidase IV (rDPP IV) monoclonal antibody (mAb) 6A3 greatly inhibits the pericellular polymeric fibronectin-mediated metastatic cancer cell adhesion to rDPP IV. L(311)QWLRRI in rDPP IV has been proposed as the putative fibronectin-binding site. However, the inhibitory mechanism of 6A3 has been elusive.