靶向尿激酶受体uPAR基因的shRNA表达载体的构建及鉴定

背景与目的：尿激酶受体（uPAR）与肿瘤的侵袭和转移密切相关,抑制uPAR的表达,可以抑制肿瘤的转移。本研究构建uPAR基因短发夹RNA（shRNA）的表达质粒,为舌鳞状细胞癌RNA干涉（RNAi）介导的基因治疗打下基础。方法：根据GenBank数据库提供的uPAR基因序列,选择设计合成能转录shRNA的DNA序列,将它们插入真核表达载体pWH1构建重组质粒,用酶切的方法进行鉴定;最后将构建成功的特异性表达载体（pWH1-uPAR）转染至舌鳞状细胞癌,通过RT-PCR、免疫细胞化学和Western blot观察其对舌鳞状细胞癌uPAR mRNA和蛋白水平表达的影响。利用MTT实验检测细胞增殖能力的变化。结果：成功构建了uPAR shRNA表达载体;与Ts细胞和转染空载体pWH1的Ts细胞相比,转染pWH1-uPAR表达载体的Ts细胞uPAR mRNA和蛋白的表达明显降低。MTT结果显示uPAR shRNA对Ts细胞增殖的抑制率为32.9%。结论：设计构建的真核表达载体可以特异性干扰uPAR基因的表达,为进一步研究uPAR基因的功能和舌鳞状细胞癌治疗提供有效的方法和手段。

Construction and identification of specific shRNA interference plasmid vector targeted to uPAR gene

Background and purpose: Urokinase-type plasminogen activator receptor is related to invasion and metastasis of tumor. Inhibition of uPAR expression in tumor cells results in reducing its metastasis. This study was aimed to construct an expression vector with short hairpin RNA (shRNA) of uPAR, which could pave the way for RNAi-mediated tongue squamous cell carcinoma therapy. Methods: Genome sequences of uPAR gene were retrieved from Genhank and cDNA was designed to code expression of shRNA for uPAR gene. The cDNA was synthesized and inserted into the eukaryotic expression vector pWH1, and the recombinant pWH1-uPAR expression vector was identified by enzyme cutting method. Then, pWH1-uPAR expression vector was transfected into tongue squamous cell carcinoma Ts cells by Lipofectomine 2000. At last, the expression of uPAR in Ts cells transfected with pWH1-uPAR expression vector was observed by RT-PCR, immunocytochemistry staining and Western blot. MTT assay was performed to measure the proliferation of Ts cell. Results: The uPAR shRNA eukaryotic expression vector was successfully constructed. Compared with Ts cells and Ts cells transfected with plasmid pWH1, the Ts cells transfected with pWHI-uPAR expression vector showed a lower mRNA and protein expression of uPAR. The inhibition rate of proliferation was 32.9% of Ts cells by transfected with pWHl- uPAR. Conclusion: The constructed uPAR shR.NA expression vector could inhibit the expression of uPAR in tongue squamous cell carcinoma, which may be helpful for further research on the function of uPAR and provide effective methods for therapy of tongue squamous cell carcinoma.