Inhibitory effect of celecoxib on growth of transplant tumor of medullary thyroid carcinoma in nude mice

Abstract

Objective To observe the inhibitory effect of celecoxib on the growth of transplant tumor of medullary thyroid carcinoma in nude mice.Methods Forty mice were randomly divided into 4 groups (A,B,C and D):control group,celecoxib group,doxorubicin group and celecoxib ± doxorubicin group.All vaccination animal models were established by subcutaneous injection of 2 × 106 of human medullary thyroid carcinoma TT cells.The celecoxib was given 300 mg/(kg·d),and doxorubicin 2 mg/(kg·d).Tumor volumes and weight of mice were measured one week after administration when 0.5 cm tumor nodus appeared in the injection region,and tumor inhibition rate was calculated after 3 weeks.The expression levels of cyclooxegenase-2 (COX-2),matrix metalloproteinases-9 (MMP-9) and vascular endothelial growth factor (VEGF) in the vaccination tumor,liver and lung tissues were detected by using immunohistochemistry,Results The inhibition rate in groups A,B,C,and D was 0％,45.37％,49.71％,and 69.68％ respectively,and the inhibitory effects in groups B,C and D were increased as compared with group A (P ＜ 0.05),but there was no obvious difference among groups B,C and D.The expression levels of COX-2,MMP-9 and VEGF in group A were obviously higher.than in groups B,C and D (P ＜ 0.05),but there was no significant difference among groups B,C and D (P ＞ 0.05).In groups B,C and D,invasion of tumor cells in the liver and lung tissues was seen,and the expression of COX-2,MMP-9 and VEGF was positive.Conclusion Celecoxib can inhibit the growth of vaccination tumors of medullary thyroid carcinoma,and combination of celecoxib with doxorubicin can exert the synergistic effects. Key words: Celecoxib; Thyroid carcinoma; Cyclooxegenase-2 ; Matrix metalloproteinases-9 ; Vascular endothelial growth factor