Abstract
PURPOSE: Patients with a malignant glioma have a very poor prognosis. Cyclooxygenase-2 (COX-2) protein is regularly upregulated in gliomas and might be a potential therapeutic target. The effects of three selective COX-2 inhibitors were studied on three human glioma cell lines.
MATERIALS AND METHODS: The selective COX-2 inhibitors NS-398, Celecoxib and Meloxicam and three human glioma cell lines (D384, U251 and U87) were used. Cell growth was assessed by a proliferation assay, the interaction with radiation (0 - 6 Gy) was studied using the clonogenic assay and cell cycle distribution was determined by FACS (fluorescence-activated cell sorting) analysis.
RESULTS: All COX-2 inhibitors reduced proliferation of the glioma cell lines irrespective of their COX-2 expression level. Incubation with 200 microM NS-398 24 h before radiation enhanced radiation-induced cell death of D384 cells and 750 microM Meloxicam resulted in radiosensitization of D384 and U87 cells. No radiosensitization was observed with COX-2 inhibitor administration after radiotherapy. Treatment of D384 with NS-398 (200 microM) or Celecoxib (50 microM) and U87 with NS-398 (200 microM) after radiation resulted even in radioprotection.
CONCLUSIONS: Effectiveness of COX-2 inhibitors on cell proliferation and radio-enhancement was independent of COX-2 protein expression. The sequence of COX-2 inhibitor addition and irradiation is very important.
Original language | English |
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Pages (from-to) | 677-85 |
Number of pages | 9 |
Journal | International journal of radiation biology |
Volume | 83 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2007 |
Keywords
- Celecoxib
- Cell Line, Tumor/drug effects
- Cell Proliferation/drug effects
- Cyclooxygenase 2 Inhibitors/pharmacology
- Cyclooxygenase 2/genetics
- Dose-Response Relationship, Radiation
- Flow Cytometry/methods
- Gene Expression Regulation, Neoplastic
- Glioma/pathology
- Humans
- Neoplasms/drug therapy
- Nitrobenzenes/pharmacology
- Pyrazoles/pharmacology
- Radiation-Protective Agents/pharmacology
- Sulfonamides/pharmacology
- Thiazines/pharmacology
- Thiazoles/pharmacology