The Effect of Selective COX-2 Inhibitor on Tumor Growth of Xenografted Human Oral Cavity Cancer in Nude Mice

Lee, Kyu Suk; Paik, Sang Heum; Yang, Hoon Shik; Kim, Chun Gil; Yim, Do Hyung; Moon, Suk Kyun; Paik, Kwang Jin; Lee, Tae Jin

Abstract

BACKGROUND AND OBJECTIVES
Recent studies have demonstrated overexpression of cyclooxygenase-2 (COX-2) in various cancers including head and neck cancers. COX-2, an inducible enzyme which catalyzes the formation of prostaglandins from arachidonic acid, is expressed in some cancers. We investigated the anti-tumor effect of selective COX-2 inhibitor, Meloxicam, on the human oral cavity squamous cell carcinoma xenografted in nude mice. MATERIALS AND METHOD: We inoculated the oral cavity cancer cell (KB cell) line subcutaneously into 30 athymic mice which were divided into 3 groups 1 week after inoculation. One group received no treatment whereas two other groups received selective COX-2 inhibitor, Meloxicam, 10mg/kg and 40mg/kg three times weekly for 3 weeks. We studied mean tumor volume, apoptotic index (TUNEL) and proliferative index (Ki 67) in the control and treated groups. RESULTS: Meloxicam induced apoptosis, suppressed cell proliferation with significant difference (p<0.01), and suppressed the xenografted tumor growth with significant difference (p<0.05) in the Meloxicam treated group. All tumor expressed COX-2. CONCLUSION: This result suggested that the selective COX-2 inhibitors suppressed the growth of human oral cavity squamous carcinoma and a further study will be needed for determination of the pharmacologic pathway and efficacy of selective COX-2 inhibitor for head and neck cancers.