多发性骨髓瘤特异APE1siRNA表达载体的构建及鉴定

目的构建多发性骨髓瘤(MM)特异的 APE1siRNA 表达载体 pSilencer K-IE-IgP-APE1siRNA,观察其对 MM 细胞 APE1蛋白表达的特异性敲除作用。方法设计合成的 APE1siRNAcDNA 序列与线性化 pSilencer2.0-U6母本质粒连接后,用 BamH Ⅰ、EcoR Ⅰ双酶切,插入 IgP 寡核苷酸片段;随后用 EcoR Ⅰ酶切 pSilencer IgP-APE1siRNA,将线性化载体与回收 IEcDNA 片段用 T4 DNA 连接酶连接;再用 Xho Ⅰ酶切,与回收 Kappa cDNA 片段连接,克隆出 MM 特异表达载体 pSilencer K-IE-IgPAPE1siRNA,每次连接后均经酶切鉴定和测序确认。用脂质体转染法将重组质粒转染 KM3、HOS 和MDA-231细胞,Western blot 分析其对 KM3细胞 APE1的特异性敲除作用。结果 pSilencer K-IE-IgP-APE1siRNA 能特异且有效地敲除 KM3细胞 APE1蛋白表达,转染 siRNA 后培养2d 的 KM_3细胞 APE1相对表达水平为0.118±0.047,而单独脂质体转染组,APE1相对表达水平为0.988±0.029,基因缄默效率为90%。结论成功构建了针对 MM 的 APE1siRNA 表达载体。

Construction and identification of a multiple myeloma-specific APE1 siRNA expression vector

OBJECTIVE: To construct a multiple myeloma (MM)-specific APE1siRNA expression vector, and detect the specific knock-down effect of the siRNA on expression of APE1 protein. METHODS: APE1siRNA cDNA sequence was designed, synthesized and inserted into pSilencer 2.0-U6 linear expression vector. pSilencer APE1siRNA was digested by enzyme EcoRI and BamHI, then linear vector and IgP fragments were conjugated by T4 DNA ligase. pSilencer IgP-APE1siRNA and pSilencer IE-IgP-APE1siRNA were digested by enzyme EcoRI or XhoI. Linear vector and IE or Kappa fragments were conjugated by T4 DNA ligase. Then a MM specific pSilencer K-IE-IgP-APE1siRNA was cloned. The recombinant products were identified by DNA sequencing and enzyme digestions at each step. pSilencer K-IE-IgP-APE1siRNA plasmid was transfected to KM3, HOS, MDA-231 cells by liposome. APE1 gene silence induced by RNAi was analysed by Western blot. RESULTS: APE1 protein in KM3 cells could be knocked down effectively and specifically by pSilencer K-IE-IgP-APE1siRNA vector. After 2 days, the level of APE1 protein in KM3 cells transfected with siRNA was 0.118 +/- 0.047, while that transfected with plasmid only was 0.988 +/- 0.029. The efficiency of gene silence was 90%. CONCLUSION: A MM specific APE1siRNA expression vector was successfully constructed.