摘要：
Aim To construct a lentiviral vector for stable delivery of the connexin32 (Cx32) gene in human hepatocellular carcinoma cell line Huh7,and also to detect its effect on cell proliferation.Methods Human Cx32 gene sequence was obtained by whole gene synthesis and amplified by PCR,and was then inserted into LV5-GFP lentiviral vector to construct the recombinant plasmid LV5-GFP-hCx32.Following identified by restriction endonuclease digestion and DNA sequencing,this plasmid together with lentiviral package plasmid was transfected into 293T cells to produce the lentiviral particles,and the viral titer was assessed under fluorescent microscope.Targeted Huh7 cells were infected with the lentivirus (LV5-hCx32 and LV5-NC),and the infected cells after selection with puromycin were amplified and cultured.The expression and localization of Cx32 were detected by real-time RT-PCR,Western blot and immunofluorescence assay,respectively.The gap junction (GJ) function between adjacent cells was measured by dye transfer assay.The Huh7 cell proliferation capacity was determined by MTT and colony formation assays.Results The results of double enzyme digestion and DNA sequencing proved that the recombinant lentiviral vector LV5-GFP-hCx32 was successfully constructed.After packing in 293T cells,the recombinant lentivirus LV5-GFP-hCx32 with virus drops to 3 × 1011 TU · L-1 was obtained.Huh7 cells transiently infected with the lentivirus LV5-GFP-hCx32 remarkably over-expressed Cx32 at both mRNA and protein levels.Moreover,Cx32 expression was also significantly up-regulated in stably transfected Huh7 cells,and the presence of enhanced functional GJ in intact cells could be detected due to an increased amount of Cx32 protein along the plasma membrane at cell-cell contacts.Compared to LV5-NC group,the proliferation ability in Huh7 cells with recombinant Cx32 declined (P ＜ 0.05).Conclusions The lentiviral vector over-expressing Cx32 gene is successfully constructed,and can stably transfect Huh7 cells to yield sustained over-expression of exogenous Cx32 gene,thus eventually inhibits cell proliferation.%目的 构建LV5-hCx32慢病毒表达载体,获得稳定高表达人缝隙连接蛋白32(connexin32,Cx32)的Huh7人肝癌细胞系,并研究Cx32对Huh7细胞增殖的影响.方法 采用全基因合成法并经PCR扩增得到Cx32基因序列,将所得目的片段克隆到LV5-GFP载体上,获得重组慢病毒质粒LV5-GFP-hCx32,经酶切鉴定及DNA测序鉴定后,与慢病毒包装质粒系统共转染293T细胞中,包装成重组慢病毒颗粒,经荧光显微镜测定重组慢病毒滴度.将慢病毒载体LV5-hCx32和LV5-NC感染Huh7细胞,嘌呤霉素筛选出细胞阳性克隆并扩大培养.qRT-PCR、Western blot和免疫荧光法分析Cx32的表达及定位;细胞接种荧光示踪法检测细胞缝隙连接(gap junction,GJ)功能;MTT法及克隆形成实验观察细胞增殖能力的变化.结果 双酶切及测序结果表明LV5-GFP-hCx32慢病毒载体构建成功,经293T细胞包装后,成功获得病毒滴度为3×1011TU·L-1的重组慢病毒LV5-GFP-hCx32,慢病毒瞬时感染后的Huh7细胞中Cx32 mRNA和蛋白表达水平明显增多,筛选后建立的稳定转染细胞系中Cx32也稳定高表达,并且部分表达于细胞膜,形成有功能性的GJ.过表达Cx32的Huh7细胞增殖能力减弱(P＜0.05).结论 成功构建Cx32基因过表达慢病毒载体,该载体能够稳定感染Huh7细胞,使外源基因Cx32过表达并抑制细胞的增殖能力.
