“…Liu et al found a radiosensitizing effect of the selective COX-2 inhibitor celecoxib in breast tumor cell line MCa-35 but not in lung carcinoma cell line A549, although both cell lines express COX-2 [25]. Both cell lines used for our study, SCC25 and SCC9, express COX-2 as has recently been demonstrated by our group [33], but neither of them is radiosensitized by the COX-2 inhibitor nimesulide. Taken together, these observations may indicate that some effects of selective COX-2 inhibitors are cell-type-or tissue-type-specific.…”