Neuropilin 1 and Neuropilin 2: Cancer Progression and Biomarker Analysis

Neuropilins (NRP, human; Nrp, mouse) are a family of cell surface protein receptors originally named for their role in neuronal guidance during embryonic development. Over the past two decades, the expression, localization, regulation, and function of the NRP family have been intensely studied. The two-member family composed of neuropilin 1 (NRP1) and neuropilin 2 (NRP2) has now been shown to drive diverse processes including neuronal guidance, vasculogenesis, lymphangiogenesis, immunity, smooth muscle tone, epithelial cell migration and branching, epithelial-to-mesenchymal transition, and cancer progression. Although the two receptors share high sequence homology and domain structure, their unique ligand specificity, co-receptor nature, and disparate cell-specific expression patterns mediate pleiotropic functions in multiple tissue systems. Their abundant expression in a myriad of cancers and their location on the cell surface make them prime targets for antitumor therapies and potential use as surrogate biomarkers.