The Cyclooxygenase-2 Inhibitor Nimesulide, a Nonsteroidal Analgesic, Decreases the Effect of Radiation Therapy in Head-and-Neck Cancer Cells

Department of Cranio-, Maxillofacial and Oral Surgery, Medical University of Vienna, Vienna, Austria.
Strahlentherapie und Onkologie (Impact Factor: 2.91). 06/2009; 185(5):310-7. DOI: 10.1007/s00066-009-1929-4
Source: PubMed


No data are available on the effects of the cyclooxygenase-2 (COX-2) inhibitor nimesulide in combination with irradiation on the survival of head-and-neck carcinoma cells.
Two head-and-neck carcinoma cell lines (SCC9 and SCC25) were treated with nimesulide (50-600 microM) and irradiated concomitantly or sequentially. Early effects on cell survival were investigated by counting cell numbers, long-term effects by colony-forming assays. Cell-cycle effects were analyzed 24-72 h after treatment with nimesulide by flow cytometry.
Unexpectedly, nimesulide solely inhibited cell proliferation without affecting colony-forming ability. In addition, no evidence for a radiosensitizing effect of nimesulide in short-term assays was seen. Nimesulide alone had no effect on clonogenic survival alone or in combination with radiation.
Nimesulide differentially affects cell proliferation and clonogenic survival and may decrease the efficacy of radiotherapy. Short-term assays to assess tumor growth may not correctly predict the clinically relevant long-term effect of COX-2 inhibitors.

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    • "However, combination of COX-2 inhibitors with radiation therapy can also lead to a reduction of efficiency of the radiotherapy. In one report, it has been shown that the selective COX-2 inhibitor nimesulide decreased radiation efficiency of two head-and-neck cancer cells lines (SCC9 and SCC25) which are COX-2 positive [139]. This suggests that the sensitization of tumor cells to radiation might be strongly dependent on tumor cell type. "
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