中文摘要：

目的研究同时抑制VEGF、hTERT和Bcl-xl的表达对体内、外喉癌细胞生长增殖的影响。方法使用针对VEGF、hTERT和Bcl-xlmRNA的shRNA真核表达载体：pshRNA-VEGF-hTERT-Bcl-xl。通过脂质体的介导将该质粒转染至体外培养的喉鳞癌Hep-2细胞。四甲基偶氮唑蓝（MTT）检测该质粒对Hep-2细胞的毒性作用;构建喉鳞癌荷瘤裸鼠动物模型,采用瘤体内多点注射的方式将质粒导入瘤体内,观察质粒对移植瘤的生长抑制作用。结果质粒pshRNA-VEGF-hTERT-Bcl-xl成功转染到喉癌细胞中并表达。经质粒pshRNA-VEGF-hTERT-Bcl-xl处理后,MTT结果显示癌细胞增殖能力显著下降,与0.9%氯化钠溶液治疗的对照组比较,在处理后24h、48h和72h,细胞增殖活性分别降至62.22%,28.77%和10.24%。pshRNA-VEGF-hTERT-Bcl-xl质粒治疗组裸鼠移植瘤生长缓慢,体积明显小于对照组,首次治疗后28天抑瘤率为90.2%,与0.9%氯化钠溶液治疗的对照组比较,P〈0.01。结论同时抑制VEGF、hTERT、Bcl-xl表达可显著提高喉鳞癌的治疗效果.该实验为多基因靶向的肿瘤基因治疗提供了新思路。

英文摘要：

Objective To investigate the effects of inhibition VEGF,hTERT and Bcl-xl by RNA interference on laryngeal carcinoma in vitro and in vivo.Methods A recombinant plasmid containing 3 different short hairpin RNA （shRNA） segments termed pshRNA-VEGF-hTERT-Bcl-xl was used.Cells were treated with these plasmids.Cell viability was examined by using the MTT assay.The cytotoxic effect of pshRNA-VEGF-hTERT-Bcl-xl was evaluated in the subcutaneous xenograft tumors.Results pshRNA-VEGF-hTERT-Bcl-xl exhibited a potent antitumor effect on Hep-2 cells. MTT assay confirmed cytotoxic effect. The in vivo study showed tumor volume was significantly smaller in pshRNA-VEGF-hTERT-Bcl- xl treated group than that in control group. The inhibitory rate was 90. 2%. Conclusion Our study demonstrated that the application of vector-based RNAi technology involved in blocking multiple targets would be a promising therapeutic modality in the gene therapy of human laryngeal cancers.