A novel glioma expressed antigen immunogenic in glioblastoma and pilocytic astrocytoma

Glioma constitutes the most frequent brain tumor in man with glioblastoma as the most prevalent and malignant type. Despite surgery, radiation and chemotherapy, patients with glioblastoma have only a median survival time of less than one year. Although numerous chromosomal deviations have been described in glioblastoma, only few genes have been associated with these changes. It is especially necessary to identify genes involved in early glioma development and in progression to glioblastoma. Here, we describe the identification of a novel glioma expressed antigen both in the benign form of pilocytic astrocytoma and the malignant glioblastoma. We established two lambda zap expression libraries from a glioblastoma WHO grade IV and from a pilocytic astrocytoma WHO grade I and screened the libraries with the corresponding autologous patient sera. Both screenings revealed several serum positive clones, but interestingly only one clone termed glioma expressed antigen 1 (GLEA1) was found immunoreactive in the glioblastoma serum and the pilocytic astrocytoma serum. None of the control sera including sera from patients with lung carcinoma, meningioma or control persons showed an immune response to GLEA 1. GLEA appears to be a glioma specific immunogenic antigen which lends itself as a potential diagnostic marker.