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.