中文摘要：

目的探讨环氧合酶-2（COX-2）反义核酸对喉癌细胞恶性表型的抑制作用。方法采用脂质体介导方法，分别构建转染COX-2反义真核表达载体和空载体的喉癌细胞系Hep-2-AS和Hep-2-P细胞。RT-PCR及Western blot分析转染细胞COX-2 mRNA及蛋白表达水平；MTT比色实验、Boyden侵袭小室法和裸鼠成瘤实验分别检测转染细胞的体外增殖速度、体外侵袭力和体内成瘤性。结果RT—PCR结果显示，Hep-2-AS细胞COX-2／磷酸甘油醛脱氢酶（GAPDH）mRNA比值（0．65）明显低于Hep-2（O．92）和Hep-2-P细胞（0．90）；Western blot结果提示Hep-2-AS细胞COX-2／β-actin比值（0．29）明显低于Hep-2细胞（0．46）和Hep-2-P细胞（0．44）；MTT比色实验显示Hep-2-AS细胞较Hep-2-P、Hep-2细胞生长速度减慢，三者倍增时间分别为3．6d、2．9d和2．9d；体外侵袭实验结果表明，Hep-2-AS侵袭细胞数（18．20±5．97）显著低于Hep-2细胞（45．40±8．12）及Hep-2-P细胞（44．10±6．47）（P〈0．01）。裸鼠成瘤实验中，Hep-2P、Hep-2细胞接种裸鼠后第5天肿瘤长出，而Hep-2-AS细胞第7天肿瘤长出；28d后Hep-2-AS细胞接种组瘤体体积[（764．85±129．61）mm^3]低于Hep-2细胞[（1181．73±360．83）mm^3]和Hep-2P细胞接种组[（1065．21±237．46）mm^3]，有显著性差异（P〈0．01）。结论喉癌细胞中COX-2过表达与细胞的恶性表型相关，反义核酸技术抑制COX-2表达可以逆转喉癌细胞的恶性表型。

英文摘要：

Objective To explore the effect of anti-sense nucleic acid of cyclooxygenase-2 （COX-2） in malignant phenotype of laryngeal cancer ceils and the mechanism of COX-2 in carcinogenesis of laryngeal cancer. Methods Using LipofectamineTM2000 reagent, the COX-2 highly expressed in human laryngeal cancer cell line Hep-2 was transfected with anti-sense eukaryotic expression vector pcDNA3.1/hCOX-2 （ - ） and control plasmid pcDNA3.1 （named as Hep-2-AS and Hep-2-P cells, respectively）. Semi-quantitative RT-PCR and Western blot were used to testify the mRNA and protein level in the transfected cells. MTT assay, Boyden chamber and tumor implantation experiment were used to detect the proliferation, invasion and tumorigenesis of the transfected cells in vitro and in vivo. Results RT-PCR analysis indicated that the ratio of COX-2 mRNA to GAPDH mRNA in Hep- 2-AS cells （0.65） was significantly lower than that in Hep-2 （0.92） and Hep-2-P cells （0.90） （P〈0.01）. Western blot showed that the ratio of COX-2 protein to β-actin protein in Hep-2-AS （0.29） was significantly lower than that in Hep-2 （0.46） and Hep-2-P （0.44） （P〈0.01）. MTT assay suggested that the Hep-2-AS cells proliferated more slowly than the Hep-2 and Hep-2-P cells with double time of 3.6, 2.9 and 2.9 d, respectively. Boyden chamber assay revealed that the cell number of the Hep-2-AS cells （18.20-4-5.97） that migrated through the filter was smaller than that of the Hep-2 （45.40±8.12） and Hep-2-P cells （44. 10±6.47）（P〈0.01）. The tumor xenografts occurred on d5 in Hep-2 and Hep-2-P cells, but on d7 in Hep-2-AS cells. On d30 after implantation, the volume of Hep-2-AS cell tumor xenografts [（764.85±129.61）mm^3] was significantly less than that of Hep-2 cells [（1 181. 73±360.83） mm^3] and Hep-2-P cells [（1 065.21±237.46）mm^3] （P（0.01）. Conclusion Overexpression of COX-2 in human laryngeal cancer cell line Hep-2 is associated with the malignant phenotype of cancer cells. Inhibition of COX