Neurotrophins play an important role in the perineural invasion and distant metastasis of malignant tumor

Neurotrophins (NTs) family was first discovered in nervous system and it regulates the proliferation and differentiation of many neural cell types in the peripheral and central nervous system.

Due to their perineural invasive characters, certain part of malignant tumor cases was first diagnosed because of nerve paralysis or idiopathic neuralgia caused by perineural invasion. For this reason, the study on the association between NTs and perineural invasion of malignant tumor aroused the attention of many researchers. Increasing evidence indicates that NTs and their receptors, Trks, play important roles in malignant cells, especially the exhibiting perineural invasive phenotype. It was suggested that NTs produced by neural tissue can act as a chemotactic factor, and tumor cells in which the overexpression of Trks' exists seem to be selected to invade the perineural space. Except for contributing to perineural invasion of malignant tumor, accumulated evidence proved NTs now also significantly associated with the metastasis of malignant tumor. Overexpression of NTs or Trks often correlated with the tumorigenesis, angiogenesis and anoikis resistance in these malignancies, contributing significantly to the metastasis and poor prognosis.

In summary, besides its role in development and function of nervous system, NTs also play an important role in the perineural invasion and metastasis of malignant tumor. Considering the role that NTs played in malignant tumor, we believe that further studies between NTs and malignant tumor are necessary. Research on the role of NTs pathway might allow advancements in this field.