Overexpression of cyclooxygenase-2 (COX-2) in human primitive neuroectodermal tumors: effect of celecoxib and rofecoxib

In this study the role of cyclooxygenase-2 (COX-2) in primitive neuroectodermal tumor (PNET) the most malignant brain tumors of childhood was investigated. COX-2 expression in human brain tumor biopsy samples (seven/seven) was about 6–8-fold higher than normal brain tissue and several PNET cell lines also express COX-2. The effect of selective COX-2 inhibitors, celecoxib and rofecoxib on the growth of two PNET cell lines (DAOY and PFSK) was determined. Celecoxib was more potent than rofecoxib in suppressing cell growth. Growth inhibition by celecoxib and rofecoxib was independent of Bcl-2 expression. Celecoxib suppressed the expression of Akt and activated the caspase-3 in DAOY and PFSK, whereas rofecoxib did not have such an effect.