Expression of eukaryotic initiation factor 4E in astrocytic tumors.

Upregulation of expression of the eukaryotic initiation factor 4E (eIF4E) has been identified in breast carcinomas, squamous cell carcinomas in the head and neck regions, and transitional cell carcinomas of urinary bladder. In this immunohistochemical study, eIF4E protein expression was investigated in human brain tissue from patients without central nervous system diseases and brain biopsy tissues from patients with anaplastic astrocytoma and glioblastoma multiforme. Expression of eIF4E protein was observed in normal pyramidal neurons but not in neuroglial components. In anaplastic astrocytoma and glioblastoma multiforme, there was diffuse uniform expression of eIF4E immunoreactivity in malignant astrocytes. A similar pattern of immunoreactivity was also present in proliferative endothelial cells and vascular lining endothelial cells in glioblastoma multiforme. This study provides evidence that eIF4E is upregulated in high-grade astrocytic tumors. As in other malignancies, a high level of eIF4E may play an important role in the neoplastic transformation, angiogenesis, and tumor growth in astrocytic tumors. Because eIF4E is crucial in regulation of tumor growth, eIF4E could be a potential target for inhibitors as an adjuvant therapy for brain tumors.