Dysregulation of non-heme iron metabolism in glial brain tumors.

To study iron exchange irregularities in experimental animals and patients with glial brain tumors to ascertain the role of the 'iron component' in glial brain tumor pathogenesis. A suspension of A.101.08 tumor cells was implanted in the cortex of the left-brain hemisphere of rats to model experimentally induced glial brain tumor. At 7 or 14 days after implantation, blood and tissue samples from the tumor, peritumoral tissue, and brain regions were taken for analysis. Blood and plasma samples were obtained from 23 patients as well as biopsy samples taken during tumor removal surgery. Electron resonance spectroscopy was used to determine the concentrations of transferrin iron, transferrin in whole blood and in blood cells, and chelatable and stored iron in the tissues of experimental animals and patients. Hypoferremia was found in rats with both small and large glial brain tumors, whereas hyperferremia was found to be a characteristic of malignant glial brain tumors in humans. We identified statistically significant increases in stored and chelatable iron concentrations in the tumor and peritumoral brain tissue compared to the blood and the adjacent brain tissue (probably normal) in both human malignant glial brain tumors and in rat experimental glial brain tumors. These findings suggest that iron misregulation plays a part in glial brain tumor pathogenesis and this may provide a basis for understanding the association between glial brain tumors and epilepsy.