中文摘要：

目的研究人端粒酶反转录酶（hTERT）基因核心启动子调控的单纯疱疹病毒胸苷激酶基因／更昔洛韦（HSV-TK／（GCV）系统对鼻咽癌移植瘤的体内杀伤作用。方法采用培养细胞移植法，将人鼻咽癌细胞系C6661接种于裸鼠腋部皮下，建立裸鼠人鼻咽癌移植瘤模型。将40只裸鼠随机分为5组：hTERTp／HSV-TK／PGL3／GCV组、CMV／HSVTK／PGL3／GCV组、HSV-TK／PGL3／GCV组、GCV组及生理盐水组，每组8只。采用脂质体介导，进行瘤内直接注射，同时经腹腔给予GCV治疗，观察各组裸鼠生存状况及肿瘤相对体积、抑瘤率，并进行荷瘤裸鼠肝肾组织的常规病理检查。结果成功构建了C6661裸鼠皮下移植瘤动物模型，hTERTp／HSV-TK／PGL3／GCV组移植瘤被明显抑制，抑瘤率达到45．51％，与HSVTK／PGL3／GCV组、GCV组及生理盐水组（抑瘤率分别为5．52％、14．31％、0．03％）比较有显著性差异（P〈0．01），肝肾病理检查发现，该组裸鼠肝肾均无明显病理学变化。CMV／HSV-TK／PGL3／GCV组的抑瘤率亦达到51．56％，但病理检查发现裸鼠出现肝肾毒性。结论hTERT启动子调控TK基因靶向治疗系统能够在体内特异性杀伤鼻咽癌移植瘤，而无明显全身毒副作用，是一种安全、有效的肿瘤靶向基因治疗系统，将为鼻咽癌临床基因治疗开辟新领域。

英文摘要：

Objective To investigate the effect of targeted gene therapy on nasopharyngeal carcinoma xenograft to nude mice with the system of hTERTp/Thymidine kinase/Ganciclovior （hTERTp/HSV tk/GCV） in vivo. Methods With the transplantation technique of cultivated cells, human nasopharyngeal carcinoma cell line C666-1 was subcutaneously injected in the armpits of 40 nude mice. The mice were randomly assigned into 5 groups （8 each）： hTERTp/HSV tk/POL3/GCV, CMV/HSV-tk/PGI3/GCV, HSV-tk/POL3/GCV,GCV and saline control group. Constructed plasmid vectors mediated by liposome were injected directly into xenograft, and at the same time GCV was intraperitoneally injected. The status of nude mice, the size of tumor mass, inhibition rate, and pathology of the liver and kidney of nude mice were determined. Results Animal model of C666-1 was successfully reproduced. The growth of tumor graft was inhibited obviously in treated group. The inhibition ratio of transplanted tumor was 45. 51% in hTERTp/HSV tk/PGL3/GCV group, which was greater than that in HSV-tk/PGL3/GCV group （5.52%）, GCV group （14.31%） and saline control group （0.08%）, and statistically significant differences on the inhibition ratios were found between the hTERTp/HSV tk/PGL3/GCV group and the other three groups （P〈0. 01）. No toxic side effect was observed in the pathology of the liver and kidney of the nude mice. The inhibition ratio ot transplanted tumor in CMV/HSV-tk/PGL3/CR2V group was 51.56%, but toxicity was observed as shown in the pathological examination of the liver and kidney of the treated mice. Concision Targeted gene therapy with the system of hTERTp/HSV-tk/GCV may specifically kill the nasopharyngeal carcinoma xenografts in nude mice in vivo without obvious toxic side effect, and is a safe and effective therapy for nasopharyngeal carcinoma.