摘要目的 采用RNA干扰技术沉默大肠癌SW620细胞转录因子特化蛋白1(Sp1)的表达,观察其对细胞增生的影响.方法 构建靶向人Sp1基因的干扰载体(pGenesil-1-Sp1),脂质体介导转染SW620细胞,荧光倒置显微镜下观察转染效率,应用实时荧光定量PCR和Western blotting检测其对Sp1mRNA及蛋白质水平的影响,MTT法检测SW620细胞增生活性的改变.结果 成功构建针对Sp1的干扰载体,转染后能够有效抑制大肠癌SW620细胞中Sp1 mRNA和蛋白的表达,且在转染48 h抑制作用最强.其对Sp1 mRNA和蛋白质抑制率分别为68.47%和73.82%.与对照组相比,差异有统计学意义(P<0.05).MTT实验显示,下调Sp1表达可显著抑制大肠癌SW620细胞的体外增生能力.结论 Sp1基因沉默能够抑制人大肠癌SW620细胞的增生,为以Sp1为靶点的大肠癌基因治疗提供新的思路和手段.

abstractsObjective To inhibit the expression of transcription factor special protein 1(Sp1) through RNA interference (RNAi) technique and to investigate its impact on the proliferation ability of colorectal cancer cell line SW620. Methods The recombinant plasmid of Sp1 RNAi (pGenesil-1-Sp1) was constructed and transfected into SW620 cells by Lipofectamine. The transfcction efficiency was observed under fluorescence confocal microscopy. Expression levels of Sp1 mRNA and protein from SW620 after transfection were examined by real time PCR and Western blot respectively, after transduction of the recombinant plasmid into the SW620. The proliferation ability of SW620 cell line was evaluated by MTT assay. Results The expression plasmid (pGenesil-1-Sp1) against Sp1 was successfully constructed, recombinant vectors could reduce the expressions of Sp1 mRNA and protein in SW620, the ratio of inhibition of the expression of Sp1 mRNA and protein was 68.47 % and 73.82 % in 48th hour respectively. Compared with the control group, the difference was significant (P <0.05). MTT showed that the proliferation ability of SW620 cell was degraded. Conclusion Silencing Sp1 gene by the RNAi technology can actively inhibit the proliferation of SW620 cell. The successful application of Spl SiRNA extends the list of available therapeutic modalitics in the treatment of human colon cancer.