Cyclooxygenase-2 (cox-2) expression and angiogenesis in intracranial ependymomas.
OBJECTIVE
Cyclooxygenase-2 (Cox-2), the inducible key enzyme in the biosynthesis of prostaglandins, appears to play a role in the regulation of progression, invasiveness and angiogenesis of various neoplasms including some glial tumors. Little is known about the role of Cox-2 in angiogenesis and proliferation of ependymomas. We studied Cox-2 expression, Ki-67 labeling index (Ki-67 LI) and microvessel density (MVD) in 30 intracranial ependymomas and analyzed the relationship among these parameters to evaluate their importance in the tumor biology of ependymomas.


RESULTS
The mean Ki-67 LI for all tumors ranged from 1 - 50% (mean 9%). Statistically significant difference was present for Ki-67 LI between ependymomas (grade II, WHO) and anaplastic ependymomas (grade III, WHO) (p < 0.001) (mean Ki-67 LI for ependymoma, 2.8%, for anaplastic ependymomas, 15.6%). Anaplastic ependymomas did not demonstrate a greater vascularization than ependymomas, and the MVD values were 84.5 +/- 39.7 for ependymomas, and 90.6 +/- 61.4 for anaplastic ependymomas. Cox-2 immunohistochemical expression was observed in 19 tumors (63%). Although Cox-2 expression was slightly higher in anaplastic ependymomas, it was not statistically significant. No correlation was found between Cox-2 expression and MVD and Ki-67 LI.


CONCLUSIONS
Similar to morphologic and prognostic heterogeneity in ependymomas, Cox-2 expression, MVD and Ki-67 LI also show a great variability. Other factors may be more important for the proliferation and angiogenesis of ependymomas.
Onguru
O
O
Department of Pathology, Gulhane Military Medical Academy, Hacettepe University Faculty of Medicine, Ankara, Turkey. onguruo@yahoo.com
Kurt
B
B
Gunhan
O
O
Soylemezoglu
F
F
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000098:blood supply* / Q000201:enzymology* / Q000473:pathology; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D004806:Ependymoma / Q000098:blood supply* / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D009389:Neovascularization, Pathologic
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D051546:Cyclooxygenase 2