Bmi-1 shRNA慢病毒表达载体的构建及稳转U266细胞株的建立

本研究构建Bmi-1基因的shRNA慢病毒表达载体,建立U266-li稳定细胞株,为下一步Bmi-1的功能研究及应用RNAi技术治疗打下基础。设计、合成1对针对Bmi-1 mRNA的shRNA序列,退火后连接到pLVTHM干扰载体上,与psPAX2、PMD2G共转染HEK 293T细胞,包装产生慢病毒颗粒并测定病毒滴度,感染U266细胞,建立稳定细胞株;应用实时PCR和Western blot技术分别检测U266稳定细胞中Bmi-1及P14 mRNA和蛋白水平的表达,并与对照组进行比较。结果表明,成功构建了针对Bmi-1基因的shRNA慢病毒表达载体,病毒滴度为5×107 TU/ml;建立稳定转染的U266细胞株。有效干扰验证显示,shBmi-1能明显降低Bmi-1的mRNA及蛋白水平,而P14的mRNA及蛋白水平则都上调,其差异有统计学意义(P<0.05)。结论:成功构建Bmi-1基因的shRNA慢病毒表达载体,建立稳定干扰Bmi-1表达的U266细胞株。

Establishment of a U266 cell line with stable Bmi-1 silencing by lentivirus-mediated RNA interference

This study was aimed to construct lentivirus-mediated shRNA expression vector targeting Bmi-1 and establish a stable cell line U266-li, so as to pave the way for further research on function of Bmi-1 and application of shRNA to gene therapy. One pair of oligonucleotide sequences targeted at human Bmi-1 mRNA were designed and synthesized. The annealed oligonucleotide fragments were subcloned into pLVTHM vector. Virus particles were collected after the control or shRNA vectors were co-transfected with the psPAX2 packaging plasmid and the plasmid pMD2.G was enveloped into HEK-293T cells by using Lipofectamine2000. The U266 cells were transdused with 5 × 10(6) recombinant lentivirus-transdusing units plus 6 μg/ml of polybrene. Real-time PCR and Western blot were used respectively to detect the expression of Bmi-1 and P14 after lentivirus transdusion. DNA sequencing demonstrated that the lentivirus RNAi vector of Bmi-1 was constructed successfully and the virus was packaged in 293T cells. The titer of virus was 5 × 10(7) TU/ml. Stable transfected U266 cell line was established. As was expected, the mRNA and protein levels of Bmi-1 was reduced significantly in U266 cells after lentivirus transdusion, whereas the mRNA and protein levels of P14 was upregulated. It is concluded that the lentiviral RNAi vector of Bmi-1 is constructed, and U266 stable cell line is established.