靶向小干扰RNA抑制人神经母细胞瘤裸鼠荷瘤生长及转移的实验研究

Inhibition of the growth of neuroblastoma by CXCR4-siRNA

目的 探讨靶向CXCR4的小干扰RNA（siRNA）对人神经母细胞瘤QDDQNM细胞裸鼠肿瘤的生长及转移的抑制作用。方法采用本实验室已成功建立QDDQ-NM裸鼠荷瘤模型，以CXCR4为靶基因，设计合成siRNA序列及对照序列HK。通过瘤体局部多位点注射，将CXCR4-siRNA转染到裸鼠皮下荷瘤内。A组（阳性治疗组），B组（阴性治疗组），同时设立空载体对照组（C组）和空白对照组（D组）。观察肿瘤的转移及治疗前后体积变化，并用RT-PCR方法及免疫组化方法检测CXCR4的基因转录及蛋白表达情况，来评价CXCR4-siRNA对肿瘤的作用。结果A组转移率为25％明显小于其余3组对照组（75％，58％，75％），其肿瘤体积也显著低于其余3组，利用RTPCR检测CXCR4基因在转录水平的表达，A组为1．0451±0．0778，B、C、D组分别为1．4286±0．0655、1．3839±0．0037、1．3882±0．0733（P＜0．05），A组CXCR4蛋白表达水平也显著低于B、C、D组（P〈0．05）。结论脂质体介导的CXCR4-siRNA对神经母细胞瘤的生长及转移有明显抑制作用，可为下一步肿瘤治疗提供基础。

Objective To investigate the effect of CXCR4 small interfering RNA（siRNA） mediated by liposome vector on the growth of human cultured cancer cell QDDQ-NM. Methods Athymic mice were subcutaneously transplanted with human neuroblastoma QDDQ-NM cells to establish trans planted tumor model. CXCR4 siRNA was synthesized by Dharmaeon company, and then transfected into subcut transplantation tumor in athymic mice（group A）. And injection of the siRNA control was as group B, DOTAP as group C and Saline as group D. The suppression effect of CXCR4 siRNA on tumor was estimated and the change of morphocytology was compared by observing the tumor volume change at pre- and post-intervention. The expression of CXCR4 was detected by immunohistochemistry and re verse transcriptase polymerase chain reaction. Results CXCR4-siRNA significantly inhibited the growth of human neuroblastoma cell QDDQ-NM. Metastatic rate was 25% in treatment group, and it was significantly less than the remaining three groups （75%, 58%, and 75%）. And the tumor size in group A was also significantly smaller than that in the other three groups. The transcription level of CXCR4 gene in group A was 1. 0451, which was significant less than that in group B （1. 4286）, C （1. 3839）, and D （1. 3882） （P〈0. 05 ）. CXCR4 protein expression in group A was also significantly lower than that of B,C,and D group. The expression of CXCR4 mRNA in human cultured cancer cell QDDQ-NM was decreased significantly in the gene transfected group as compared to other groups. Conclusions CXCR4- siRNA mediated by liposome could inhibit the proliferation and metastasis of human neuroblastoma.