RNA干扰糖原合成激酶-3β对人胰腺癌裸鼠移植瘤生长及血管生成的影响

Effects of glycogen synthase kinase-3β knock-down on growth and angiogenensis of human pancreatic cancer xenografts in nude mice

目的 观察RNA干扰糖原合成激酶-3β（GSK-3β）对人胰腺癌裸鼠移植瘤生长及血管生成的影响.方法 将未转染和转染control短发卡RNA（shRNA）或GSK-3β shRNA的Panc-1细胞接种于裸鼠皮下,建立移植瘤模型,分为阴性对照组、载体对照组和实验组,每组各8只.接种8周后处死裸鼠,测量各组移植瘤的重量和体积,并计算抑瘤率；免疫组织化学链霉菌抗生物素蛋白-过氧化物酶（SP）法检测增殖细胞核抗原（PCNA）和CD31蛋白的表达,并计算增殖指数（SPF）和微血管密度（MVD）；实时定量聚合酶链反应（Real-time PCR）和Western blot检测血管内皮生长因子（VEGF）基因和蛋白的表达.结果 实验组移植瘤的重量和体积显著低于对照组（P＜0.05）,抑瘤率为35.27％.实验组SPF值为（69.55±2.64）％,较阴性对照组的（83.26±2.83）％和载体对照组的（83.65±2.65）％显著降低（P＜0.05）.实验组MVD值为17.2 ±2.9,与阴性对照组（27.2±3.1）和载体对照组（26.6±2.8）比较显著降低（P＜0.05）.实验组移植瘤的VEGF mRNA的相对表达量为0.089 38±0.008 84,与阴性对照组（0.139 06±0.003 35）和载体对照组（0.138 89±0.001 75）比较显著降低（P＜0.05）.实验组移植瘤的VEGF蛋白的相对值为（0.450 6±0.014 6）,与阴性对照组（0.675 8±0.026 2）和载体对照组（0.6645±0.0105）比较显著降低（P＜0.05）.而上述对照组组间差异无统计学意义（P＞0.05）.结论 在体内基因干扰GSK-3β表达可显著抑制Panc-1细胞接种的裸鼠皮下移植瘤的生长和新生血管形成,该效应可能与其下调VEGF表达有关.

Objective To study the effects of glycogen synthase kinase-3β （GSK-3β） knock-down on the growth and the angiogenesis of human pancreatic cancer xenografts in nude mice.Methods Panc-1 cells were inoculated subcutaneously in athymic nude mice to establish xenograft models.The mice were divided into negative control group,vector control group and experimental group （n =8 each）.After 8 weeks,the mice were killed.Tumor volume and weight were measured in nude mice beating xenografts.The inhibitory rate was calculated according to the weights of xenografts.The expression of proliferating cell nuclear antigen （PCNA） and CD31 proteins was assessed by using immunohistochemitry.Proliferation index （SPF） and microvessel density （MVD） were respectively counted according to PCNA and CD31 staining.The expression level of vascular endothelial growth factor （VEGF） was detected by using real-time quantitative polymerase chain reaction （Real-time PCR） and Western blotting.Results As compared with control group,the growth rate of human pancreatic cancer xenografts of nude mice in experimental group was decreased notably （P 〈0.05） and the inhibitory rate was 35.17%.In experimental group,the SPF index [（69.55 ± 2.64） %] was significantly higher than in the negative control group [（83.26 ±2.83） %] and the vector control group [（83.65 ± 2.65） %] （P 〈 0.05）.In experimental group,the MVD index [（17.2 ± 2.9）] was higher than in the negative control group [（27.2 ± 3.1）] and the vector control group [（27.2 ± 3.1）] （P 〈 0.05）.The expression levels of VEGF mRNA and protein [（0.089 38 ±0.008 84 and 0.450 6 ±0.014 6） respectively] were significandy higher in xenografts tissues than in the negative control group （0.139 06 ± 0.003 35 and 0.675 8 ± 0.026 2 respectively） and the vector control group （0.138 89 ± 0.001 75 and 0.664 5 ± 0.010 5 respectively）,but there was no significant difference between the negative control group and the vector control group （P 〉 0.05）.Conclusion In vivo GSK-3β knock-down can inhibit the growth and the angiogenesis of human pancreatic cancer xenografts in nude mice,which may be related to the down-regulation of VEGF.