Expression of tubulin beta II in neuroepithelial tumors: reflection of architectural changes in the developing human brain.

Tubulin beta II (Tub-II) is widely distributed in the developing neuronal axons and dendrites. Recent studies have demonstrated that Tub-II is also important in the early development of the human brain, and Tub-II represents a marker for progenitor and neural stem cells. To elucidate the correlation between the developing brain and neuroepithelial tumors (NETs), the present study assessed Tub-II expression by NETs and normal brain tissue using immunohistochemical and immunoblot analyses. In the gliomas, decreased numbers and staining intensities of Tub-II-positive cells tended to be associated with increased differentiation. Conversely, neuronal neoplasms displayed high percentages and strong staining intensities among the Tub-II-positive cells, irrespective of differentiation. In neuronal neoplasms and neoplasms with neuronal differentiation, Tub-II staining was far more intense and more homogeneous than Tub-II staining in gliomas. These results indicate that the expression of Tub-II in NETs may reflect architectural changes in the developing brain and may support the hypothesis that neuroepithelial tumors originate from glioneuronal progenitor cells capable of generating astrocytic, and neuronal cell types.