MANGANESE SUPEROXIDE-DISMUTASE EXPRESSION IN HUMAN CENTRAL-NERVOUS-SYSTEM TUMORS

Manganese superoxide dismutase (MnSOD) is a superoxide anion scavenger located in mitochondria, Increased expression of MnSOD can diminish o xygen radical-mediated injuries and the cytotoxic effects of tumor nec rosis factor alpha, ionizing radiation, and certain chemotherapeutic a gents, We used immunohistochemical staining to analyze 42 specimens of human brain tumors and 3 normal brain controls with a polyclonal anti body recognizing human MnSOD, We measured MnSOD in cerebrospinal fluid (CSF) from 14 patients with brain tumors and 7 control patients using an ELISA. Although MnSOD is not readily detected in normal brain, mal ignant central nervous system tumors, including tumors metastatic to t he brain, displayed marked immunoreactivity to MnSOD intracellularly, in the extracellular matrix and in the tumor endothelial cells, Grade IV astrocytomas (glioblastomas), Grade III astrocytomas, and medullobl astomas were strongly immunoreactive, whereas Grade II astrocytomas ha d much less immunoreactivity. ELISA analysis of CSF samples from patie nts with malignant tumors also revealed high levels of MnSOD protein, up to 45-fold greater than the level of control CSF samples.