Nestin expression in brain tumors: its utility for pathological diagnosis and correlation with the prognosis of high-grade gliomas.

One of the type VI intermediate filament proteins, nestin, is expressed in neuroepithelial stem cells during neural embryogenesis. Nestin is also expressed in a variety of neoplasms. Its expression in brain tumors has not been thoroughly studied. The objectives of this study were to survey nestin expression in different types of brain tumor, and to evaluate nestin as a marker for diagnosis and prognosis. We used tissue microarrays of 257 brain tumors for an immunohistochemical overview of nestin expression: nestin was frequently expressed in gliomas and schwannomas. Most of the gliomas that expressed high levels of nestin were high-grade gliomas (anaplastic astrocytomas, anaplastic oligodendrogliomas, anaplastic oligoastrocytomas, and glioblastomas). We then focused on high-grade gliomas and performed immunohistochemistry again, using whole-mount slides. As a result, we found (1) significantly different nestin expression between glioblastomas and other high-grade gliomas, and (2) worse overall survival for high-grade gliomas with high nestin expression. Our results suggest that: (1) nestin is a useful marker for diagnosis of high-grade gliomas, (2) nestin is helpful in diagnosis of schwannomas, and (3) nestin expression is related to poor prognosis in high-grade gliomas.