Cyclooxygenase-2 expression in ependymoma of the spinal cord.

Abstract

Cyclooxygenase-2 (COX-2), also known as prostaglandin endoperoxide synthase, has been reported to play an important role in the tumorigenicity of many types of tumors. The expression of COX-2 in spinal ependymomas, however, has not been studied. The authors evaluated COX-2 expression in ependymoma of the spinal cord. Sixteen ependymoma samples obtained in patients undergoing surgery between 1995 and 2004 were utilized for immunohistochemical studies to evaluate COX-2 and vascular endothelial growth factor (VEGF) expression. Intratumoral microvessels were also stained immunohistochemically using anti-human von Willebrand factor antibody and were quantified to determine the microvessel density (MVD). The clinical features were reviewed and recorded and the association with COX-2 expression was assessed. Seven (43.8%) of the 16 ependymoma specimens expressed COX-2. All three of the myxopapillary-type ependymomas exhibited COX-2-positive staining. Excluding the three myxopapillary-type cases, COX-2 expression was identified in four (30.8%) of 13 cellular-type ependymomas. The COX-2-positive samples exhibited a significant increase in VEGF-positive staining cells and MVD compared with COX-2-negative samples. The clinical features were not associated with COX-2 expression. The results of the present study indicate that COX-2 expression may promote angiogenesis through VEGF expression in ependymomas of the spinal cord. It is suggested that the use of selective COX-2 inhibitors may provide a new therapeutic strategy for spinal cord ependymomas due to their inhibition of the COX-2-mediated angiogenesis.