异甘草素对人鼻咽癌CNE2细胞裸鼠移植瘤模型的放疗增敏作用

目的：观察异甘草素对鼻咽癌裸鼠移植瘤放疗的增敏效应，并探讨其与乏氧诱导因子－1α（ HIF－1α）、血管内皮生长因子（ VEGF）表达水平之间的关系。方法取低分化鼻咽癌CNE2细胞接种于雌性裸鼠皮下（共接种20只），待肿瘤结节4～6 mm时，将裸鼠随机分为4组，分别为对照组、异甘草素组（50 mg? kg－1?周－1）、放疗组、异甘草素（50 mg? kg－1?周－1）联合放疗组。依照各组不同治疗措施处理，定期测量瘤体体积，20 d后处死裸鼠，剥离瘤体称重。分别计算4组抑瘤率。采用荧光定量PCR检测瘤体组织中HIF－1α及VEGF mRNA的表达水平。结果异甘草素联合放疗组移植瘤的体积和重量显著下降，与对照组、单纯异甘草素及单纯放疗组比较差异均有统计学意义（ P ＜0．05）；异甘草素联合放疗组HIF－1α、VEGF mRNA表达水平明显下降，与对照组及放疗组相比，差异有统计学意义（ P ＜0．05）。结论异甘草素能增强鼻咽癌裸鼠移植瘤对放疗的敏感性，其作用机制可能与抑制HIF－1α、VEGF表达水平，从而抑制肿瘤血管生成作用有关。

Effects of isoliquiritin on the radiotherapy sensitization in nude mice models of transplantation tumor with nasopharyngeal carcinoma of CNE2 cells

Objective To observe the radiotherapy sensitization of isoliquiritin in nude mice models of transplantation tumor with nasopharyngeal carcinoma of CNE 2 cells,and to explore the correlation between isoliquiritin and the expression levels of HIF-1αand VEGF.Methods The nasopharygeal cell line -CNE2 cells were inoculated into 20 female nude mice, when tumor nodule reached 4 ~6mm,these mice were randomly divided into four groups:control group, isoliquiritin group (50mg? kg-1? w-1 ),radiotherapy group (20Gy), isoliquiritin (50mg? kg-1? w-1 ) combined radiotherapy (20Gy) group (combination treatment group).The tumor size was measured regularly .After 20 days,the mice were sacrificed,the volume and weight of tumors were detected , moreover , the tumor inhibition rates were calculated and the expression levels of HIF-1αand VEGF mRNA were detected by Real -time PCR in the four groups .Results The volume and weight of tumors in combination treatment group were significantly decreased ,as compared with those in the other three groups ( P <0.05). Moreover the expression levels of IF-1αand VEGF mRNA in combination treatment group were significantly decreased , as compared with those in control group and radiotherapy group ( P <0.05 ).Conclusion Isoliquiritin can enhance radiotherapy sensitization in nude mice of transplantation tumor with nasopharyngeal carcinoma ,and its action mechanism may be correlated to its inhibitory effects on expressions of HIF-1αand VEGF so us to inhibit tumor angiogenesis .