CD133 expression is associated with small round blue cell tumour morphology in human central nervous system neoplasms.

Aims: CD133 is considered to be a marker for brain tumour-initiating cells. However, most data on CD133 are derived from animal or in-vitro studies. The aim of this study was to characterize CD133 expression, and the distribution and morphological features of CD133(+) cells, in primary and secondary human central nervous system (CNS) neoplasms.

Immune surveillance of the normal human CNS takes place in dependence of the locoregional blood-brain barrier configuration and is mainly performed by CD3(+)/CD8(+) lymphocytes.

Despite the blood-brain barrier (BBB) the human CNS is continuously screened by blood-derived immunological cells. In certain brain areas the local BBB configuration grants passage of large molecules, whereas others are better shielded. We investigated whether these regional BBB compositions are paralleled by differences in the degree of cellular immunosurveillance by investigating tissue from 23 normal human brains for several CD markers, FoxP3, granzyme B, and perforin.

Diagnostic value of WT1 in neuroepithelial tumours.

Aims: Currently, clinical trials using WT1 (Wilms tumour gene) peptide vaccines are conducted in haematopoietic malignancies and solid cancers. Single reports showed that the Wilms tumour gene product WT1 is also expressed in astrocytic neoplasms. Our aim was to investigate WT1 expression in a large cohort of various neuroepithelial tumours of different World Health Organization (WHO) grades and in normal central nervous system (CNS) tissue specimens to test its potential value as a diagnostic marker.

Elevated HLA-E levels in human glioblastomas but not in grade I to III astrocytomas correlate with infiltrating CD8+ cells.

HLA-E is a ligand for the immune-inhibitory NKG2A receptor expressed on NK and T cells. To investigate HLA-E expression and immune cell infiltration in human astrocytic tumors in vivo, we analyzed normal CNS controls and astrocytomas of all WHO grades by immunohistochemistry. Both, CD8(+) immune cell infiltration and HLA-E expression were significantly higher in astrocytic tumors than in normal brain.

De novo erythropoietin receptor (EPO-R) expression in human neoplastic glial cells decreases with grade of malignancy but is favourably associated with patient survival.

The erythropoietin receptor (EPO-R) is mainly known as a regulator of erythropoiesis. However, recent studies revealed that the EPO-R is not exclusively expressed in haematopoietic tissues but also in various cancer cell types and normal tissue such as the central nervous system (CNS). EPO-R is up-regulated under hypoxia and is able to counteract the deleterious effects of hypoxia on tumour growth, metastasis and treatment resistance.