Terakado Nagaaki, Shintani Satoru, Yano Junya, Chunnan Li, Mihara Mariko, Nakashiro Koh-ichi, Hamakawa Hiroyuki
Department of Oral and Maxillofacial Surgery, Ehime University School of Medicine, Shitsukawa, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan.
Oral Oncol. 2004 Apr;40(4):383-9. doi: 10.1016/j.oraloncology.2003.09.005.
Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, is overexpressed in many types of malignant tumors, which in turn may stimulate tumor growth and protect against damage by irradiation or cytotoxic agents. The purpose of this study is to investigate the relationship between the radiation sensitivity and elevated level of COX-2. Radiation sensitivity of the eight oral SCC cell lines differed greatly in their response to radiation. Further, the level of the COX-2 expression correlated inversely with increased tumor radiation sensitivity. The similar significant association between the response to preoperative radiation therapy and COX-2 overexpression was observed in the oral SCC patients. In addition, treatment with a COX-2 selective inhibitor enhanced the radioresponse of HSC-2 cell, which constitutively expressed COX-2. These results suggested that COX-2 expression level correlates to radiation tolerance and the COX-2 selective inhibitor may be a potent enhancer for tumor radioresponse in oral SCC.
环氧化酶-2（COX-2）是环氧化酶的一种可诱导亚型，在多种恶性肿瘤中过度表达，这反过来可能刺激肿瘤生长并保护肿瘤免受辐射或细胞毒性药物的损伤。本研究的目的是探讨COX-2水平升高与放射敏感性之间的关系。八种口腔鳞状细胞癌（SCC）细胞系对辐射的反应在放射敏感性方面差异很大。此外，COX-2表达水平与肿瘤放射敏感性增加呈负相关。在口腔SCC患者中也观察到术前放射治疗反应与COX-2过表达之间存在类似的显著关联。此外，用COX-2选择性抑制剂治疗可增强组成性表达COX-2的HSC-2细胞的放射反应。这些结果表明，COX-2表达水平与放射耐受性相关，COX-2选择性抑制剂可能是口腔SCC肿瘤放射反应的有效增强剂。
