Proteomics of tumor-specific proteins in cerebrospinal fluid of patients with astrocytoma: Usefulness of gelsolin protein

Abstract

Changes in cerebrospinal fluid (CSF) composition have been shown to accurately reflect pathological processes in the CNS, and are potential indicators of abnormal CNS states, such as tumor growth. To detect biomarkers in high-grade astrocytomas, the differential expression of proteins in the cerebrospinal fluid was analyzed from two cases each of diffuse astrocytoma (grade II), and glioblastoma (grade IV) using agarose 2-D gel electrophoresis (2-DE). It was found that the expression of gelsolin protein decreased with histological grade. To examine whether gelsolin is a useful indicator of tumor aggressiveness or patient outcome, its expression was further studied on immunohistochemistry in 41 formalin-fixed and paraffin-embedded astrocytomas. The positive cell rate of gelsolin in tumors was 59.4% in grade II, 30.0% in grade III and 29.4% in grade IV, respectively. Gelsolin expression was significantly lower in high-grade astrocytomas (grade III or IV) than in low-grade astrocytomas (grade II; P < 0.05). Moreover, in astrocytomas the overall survival of patients in the low-expression group was significantly poorer than in the high expression group (P < 0.05). These data suggest that gelsolin is a prognostic factor in astrocytoma. © 2009 Japanese Society of Pathology.