Expression and hypoxic up-regulation of neuroglobin in human glioblastoma cells

Neuroglobin is a recently identified globin molecule that is expressed predominantly in the vertebrate brain. Neuroglobin expression increases in oxygen-deprived neurons, suggesting it protects neurons from ischemic cell death. We report that neuroglobin transcript and protein are expressed in human glioblastoma cells, and that this expression increases in hypoxia in vitro. We also show that neuroglobin is up-regulated in hypoxic microregions of glioblastoma tumor xenografts. Our finding of hypoxic up-regulation of neuroglobin in human glioblastoma cells may provide insight into how tumor cells adapt to and survive in hypoxic microenvironments.