title: Expression of cyclooxygenase-2 in osteosarcoma of bone.
abstract: Several studies indicate that cyclooxygenase-2 (COX-2) is overexpressed in human malignancies, where it produces high levels of prostaglandins and contributes to tumor growth. In this study we have analyzed the expression of COX-2 in a series of 48 skeletal osteosarcomas of different subtypes by immunohistochemistry. In addition, we examined the effects of the specific COX-2 inhibitor Celecoxib on the growth of the human osteosarcoma cell line SaOS-2. Immunoreactivity for COX-2 was observed in 39 out of 48 tumors (81.2%), 30 (76.9%) of which showed a moderate or diffuse immunostaining. Considering the group of 42 primary osteosarcomas, COX-2 immunoreactivity was significantly higher in high grade osteosarcomas, where moderate or diffuse expression was detected in 23 out of 32 cases (71.8%), than in low grade osteosarcomas, where moderate or diffuse expression was detected in 2 out of 10 cases (20%) (P = 0.008, Fisher exact test). In addition, low COX-2 expression was always associated with a good response to chemotherapy (5 out of 5 cases), whereas moderate or diffuse COX-2 expression was associated with a good response in 11 out of 20 cases (55%) (P = 0.12, Fisher exact test). In SaOS-2 osteosarcoma cells, which express COX-2, treatment with Celecoxib determined inhibition of cell proliferation and induction of apoptosis. These results indicate that COX-2 is expressed at high levels in high grade osteosarcomas and support the use of COX-2 inhibitors to improve both the tumor response to chemotherapy and the outcome of osteosarcoma patients.
authors.affiliation: Department of Internal Medicine, University of Florence, Florence, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Masi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Recenti
authors.forename: Sandra
authors.initials: S
authors.lastname: Silvestri
authors.forename: Pamela
authors.initials: P
authors.lastname: Pinzani
authors.forename: Monica
authors.initials: M
authors.lastname: Pepi
authors.forename: Milena
authors.initials: M
authors.lastname: Paglierani
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Brandi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Franchi
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001706:Biopsy; D000068579:Celecoxib; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D012516:Osteosarcoma / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D011720:Pyrazoles / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D011720:Pyrazoles; D013449:Sulfonamides; D051546:Cyclooxygenase 2; D000068579:Celecoxib