Expression of c-Jun and Sox-2 in human schwannomas and traumatic neuromas.

ABSTRACT

AIMS: Schwann cells myelinate axons of the peripheral nervous system. This process of myelination is regulated by various transcription factors. c-Jun and Sox-2 are negative regulators of myelination and control Schwann cell differentiation and plasticity. Schwannoma cells within tumours no longer express myelin markers, and show increased proliferation and decreased apoptosis. We have shown previously that several signalling pathways are activated in schwannoma cells in situ, in particular the c-Jun N-terminal kinase (JNK) pathway. Both in vitro and in vivo we have demonstrated that c-Jun and Sox-2 are co-regulated in Schwann cells and evidence shows that both these proteins regulate myelination negatively. In this study, we aimed to characterize the expression of c-Jun and Sox-2 in schwannoma and traumatic neuroma. METHODS AND RESULTS: Immunohistochemistry using antibodies to c-Jun and Sox-2 was applied to six schwannomas, and the results were compared with those seen in traumatic neuroma and normal nerve. Increased expression of c-Jun and Sox-2 was seen in schwannoma. CONCLUSIONS: We have demonstrated increased expression of c-Jun and Sox-2 in schwannoma compared to traumatic neuroma. There was no expression of c-Jun and Sox-2 in a histologically normal peripheral nerve.