Summary： The effects of RNAi-mediated gene silencing of LR1G3 expression on cell cycle and survival of human glioma cell line GL15 and the possible mechanisms were explored. The plasmids pGenesil2-LRIG3-shRNA1 and pGenesil2-LRIG3-shRNA2 were transfected into GLI 5 glioma cells respectively by using Metafectine, and the transfected cells that stably suppressed LR1G3 expression were selected by G418. The control cells were transfected with negative control shRNA. The changes in LRIG3 mRNA and protein levels were measured by RT-PCR and Western blot. The apoptosis rate and cell cycle were analyzed by flow cytometry. As compared with the negative shRNA-transfected GL 15 cells, LRIG3 mRNA expression in GLI 5 cells transfected with pGenesil2-LRIG3-shRNA 1 and pGenesil2-LRlG3-shRNA2 was silenced by 52.4%, 63.8%, and LRIG3 protein expression was reduced by 50.9% and 67.4% respectively. The LRIG3-specific siRNA transfected cells had higher proliferation rate than control cells. Cell cycle analysis showed that silencing LRIG3 increased the percentage of G2/M phase cells and the proliferation index significantly （P〈0.01）. Silencing LRIG3 could inhibit the apoptosis of GL15 cells （P〈0.05）. These findings suggest that the siRNA targeting LRIG3 gene shows a dramatic inhibitory effect on RNA transcription and protein expression, then promoting the proliferation of GL15 cells, arresting GL15 cells in G2/M phase, and suppressing apoptosis of GL15 cells.
目的探讨构建人类富含亮氨酸重复和免疫球蛋白样结构域1(LRIG1)基因过表达慢病毒表达载体并转染胶质瘤细胞系U87细胞的技术方法,为研究LRIG1的功能提供帮助。方法用EcoRⅠ及BamHⅠ双酶切LRIG1基因和plvxDsRed-monomer-n1慢病毒载体,琼脂糖凝电泳回收LRIG1片段和载体片段;通过T4连接酶将LRIG1基因连接至慢病毒载体上;按Lenti-XHT慢病毒包装试剂盒说明包装慢病毒;用EcoRⅠ及BamHⅠ双酶切法鉴定重组慢病毒载体;然后用plvxDsRed-monomer-n1和plvxDsRed-monomer-n1-3×flagLRIG1分别转染293T细胞和胶质瘤细胞系U87细胞,荧光定量PCR和western blot检测LRIG1 m RNA和蛋白表达。结果 U87细胞感染病毒载体后经嘌呤霉素筛选显示细胞红色荧光较空载体感染细胞减弱;实时PCR结果显示LRIG1 m RNA过表达组较对照明显升高;提取感染后细胞蛋白,Western blot鉴定flag标签蛋白表达成功。结论 LRIG1基因慢病毒表达载体能感染胶质瘤细胞系U87细胞,可使外源基因获得稳定表达。
This study examined the differences in tumor formation of three bladder tumor cell lines （BIU-87, T24 and EJ） after subcutaneously transplanted into nude mice, in order to find the best technique for establishing in vivo bladder tumor model. BIU-87, T24 and EJ cells at logarithmic phase were re-suspended in serum-free medium. The cells suspensions of the identical concentration were subcutaneously transplanted into nude mice and then the success rate and tumor growth were compared among the three cell groups. The results of tumor formation were pathologically evaluated. Lung, liver and kidney tissues were also pathologically examined for distant metastasis. The proliferation of the three cells were determined by immunohistochemically detecting the PCNA expression in the tumors. The results showed that the success rates of EJ and T24 cells were significantly higher than that of BIU-87 cells and no distant metastasis was noted among the three groups. The proliferation levels of EJ and T24 cells was significantly higher than that of BIU-87. But at the later stage of tumor formation, as compared with T24 cells, EJ grew more vigorously, soon resulting in the central necrosis of tumor, which affected the measurement of the actual size of the tumors. Moreover, PCNA staining exhibited that the proliferation of EJ and T24 was significantly higher than that of BIU-87 cells. It is concluded that as compared with BIU-87 cells, EJ and T24 cells had higher success rates, with not significant differences in death rate and distant metastasis found among them. There existed no significant difference in tumor formation between EJ and T24 cells and T24 cells do not rupture easily, which makes it a better cell line for the establishment of in vivo bladder tumor model.
