Objective:The aim of this study was to observe the inhibitory effect of application of COX-2 inhibitor,celecoxib,combined with cisplatin on the growth of human tongue squamous carcinoma Tca8113 cell xenograft by animal experiment.Methods:The nude mice were transplanted subcutaneously with Tca 8113 cells,and then were administrated with celecoxib,cisplatin or celecoxib combined with cisplatin respectively,and were sacrificed after 35 days.The weight of xenograft was measured to calculate the tumor inhibition rate.The histological change was studied under light and electron microscope.The COX-2 protein expression was observed by immunohistological staining.And the COX-2 mRNA expression was determined by RT-PCR.Results:Celecoxib,the COX-2 inhibitor,could not only inhibit the growth of Tca8113 cell xenograft tumor and COX-2 protein expression,but also enhance the inhibitory effect cisplatin on xenograft tumor growth significantly.The tumor inhibition rates of celecoxib group,cisplatin group and celecoxib plus cisplatin group were 15.63%,37.50% and 82.81% respectively that was statistically significant compared to control group(P < 0.01).The combined application of celecoxib and cisplatin could inhibit tumor growth more significantly than that of separated application(P < 0.01).The inhibitory effect of celecoxib on COX-2 mRNA expression of Tca 8113 cell was weaker and not significant(P = 0.073).Conclusion:Celecoxib can not only inhibit xenograft tumor growth in nude mice,but also enhance the inhibitory effect of CDDP on Tca 8113 transplanted tumor growth in nude mice.The mechanism maybe related to inhibition of COX-2 protein expression,which offers beneficial reference to further explore the mechanism between inhibition of COX-2 enzyme activity and prevention of head and neck tumor. Objective: The aim of this study was to observe the inhibitory effect of application of COX-2 inhibitor, celecoxib, combined with cisplatin on the growth of human tongue squamous carcinoma. Tca8113 cell xenograft by animal experiment. Methods: The nude mice were transplanted subcutaneously with Tca 8113 cells, and then were administered with celecoxib, cisplatin or celecoxib combined with cisplatin respectively, and were sacrificed after 35 days. The weight of xenograft was measured to calculate the tumor inhibition rate. The histological change was studied under light and electron microscope. The COX-2 protein expression was observed by immunohistological staining. And the COX-2 mRNA expression was determined by RT-PCR. Results: Celecoxib, the COX-2 inhibitor, could not only inhibit the growth of Tca8113 cell xenograft tumor and COX- 2 protein expression, but also enhance the inhibitory effect cisplatin on xenograft tumor growth significantly. Tumor inhibitance rates of celecoxib group, cisplatin grou The combined application of celecoxib and cisplatin could inhibit tumor growth more significantly than that of separated application (P <0.01). The combined application of celecoxib plus cisplatin could inhibit tumor growth more significantly than that of separated application (P <0.01) .The inhibitory effect of celecoxib on COX-2 mRNA expression of Tca 8113 cell was weaker and not significant (P = 0.073) .Conclusion: Celecoxib can not only inhibit xenograft tumor growth in nude mice, but also enhance the inhibitory effect of CDDP on Tca 8113 transplanted tumor growth in nude mice. The mechanism maybe related to inhibition of COX-2 protein expression, which offers beneficial reference to further explore the mechanism between inhibition of COX-2 enzyme activity and prevention of head and neck tumor.