The p75 Neurotrophin Receptor Is a Central Regulator of Glioma Invasion

The invasive nature of cancers in general, and malignant gliomas in particular, is a major clinical problem rendering tumors incurable by conventional therapies. Using a novel invasive glioma mouse model established by serial in vivo selection, we identified the p75 neurotrophin receptor (p75 NTR ) as a critical regulator of glioma invasion. Through a series of functional, biochemical, and clinical studies, we found that p75 NTR dramatically enhanced migration and invasion of genetically distinct glioma and frequently exhibited robust expression in highly invasive glioblastoma patient specimens. Moreover, we found that p75 NTR -mediated invasion was neurotrophin dependent, resulting in the activation of downstream pathways and producing striking cytoskeletal changes of the invading cells. These results provide the first evidence for p75 NTR as a major contributor to the highly invasive nature of malignant gliomas and identify a novel therapeutic target.