Neural cell adhesion molecule is upregulated in nerves with prostate cancer invasion

Currently postulated mechanisms of perineural invasion (PNI) include interaction between tumor cells and nerves. Neural cell adhesion molecule (N-CAM), one of the well-known members of the immunoglobulin super-family of adhesion molecules, was implicated in PNI and metastasis in various types of cancer. Tissue microarray technology was used to build 2 sets of tissue array (with versus without PNI) from 50 prostate cancers (PCa). The slides were stained immunohistochemically, and the results were evaluated semiquantitatively using a 0 to 3+ scoring system. N-CAM staining was observed in all nerves with variable intensity. N-CAM expression was upregulated in 73% (31 of 42) of the nerves with PNI compared with nerves without PNI (P >.001). The results suggested that N-CAM is probably involved in PNI in PCa. It is conceivable that cancer cells, through a yet-to-be-established paracrine loop, signal the nerve to increase N-CAM production and increase adhesion. N-CAM upregulation in nerves may also facilitate cancer cells to migrate toward nerves and promote the process of perineural spread through increased survival using the nuclear factor kappa B pathway.