目的利用RNAi技术特异性的抑制c-myc的表达,探讨在喉癌细胞中将c-myc作为基因治疗靶点的价值。方法免疫细胞化学法检测Hep-2细胞中c-myc蛋白的表达;利用RAN干扰技术将c-myc siRNA转染到喉癌Hep-2细胞中,使用Western Blotting的方法检测c-myc蛋白的表达,RT-PCR的方法检测c-myc mR-NA的表达;流式细胞仪检测c-myc siRNA与5-Fu单独或联合应用,对喉癌细胞周期的影响。结果 c-myc蛋白在Hep-2细胞中强表达;在转染c-myc siRNA后的喉癌Hep-2细胞中,c-myc蛋白和mRNA的表达水平逐渐下调;同时在转染c-myc siRNA后,G0/G1期的细胞开始增加,同时S期的细胞逐渐减少;当转染c-mycsiRNA细胞联合使用5-Fu时,G0/G1期的细胞明显增加,同时S期的细胞明显减少。结论 c-myc siRNA可以特异性的下调c-myc的表达,抑制喉癌细胞的增殖,增加细胞对化疗药的敏感性,表明c-myc或许可以成为喉癌基因治疗中一个重要的分子靶点。 Objective To use RNAi technology to specifically inhibit the expression of c-myc and to explore the value of c-myc as a target for gene therapy in laryngeal cancer cells. Methods The expression of c-myc protein in Hep-2 cells was detected by immunocytochemistry. C-myc siRNA was transfected into Hep-2 cells by RAN interference technique. The expression of c-myc protein was detected by Western Blotting The expression of c-myc mR-NA was detected by RT-PCR. The effect of c-myc siRNA and 5-Fu alone or in combination on the cell cycle of laryngeal carcinoma was detected by flow cytometry. Results The c-myc protein was strongly expressed in Hep-2 cells. The expression of c-myc protein and mRNA was down-regulated in Hep-2 cells transfected with c-myc siRNA. After siRNA, G0 / G1 phase cells began to increase, while S phase cells gradually decreased; when transfected c-mycsiRNA cells combined with 5-Fu, G0 / G1 phase cells increased significantly, while the S phase cells decreased significantly . Conclusion c-myc siRNA can specifically down-regulate the expression of c-myc, inhibit the proliferation of laryngeal carcinoma cells and increase the sensitivity of cells to chemotherapeutic drugs, indicating that c-myc may be an important molecular target for gene therapy of laryngeal cancer .