Objective To construct vectors that express phosphatidylinositol-3-kinase, catalytic, beta polypeptide （PIK3cb） shRNA in eukaryon plasmid catalyzed by PI3K in rat, then test their effects on intimal hyperplasia in transplanted vein graft. Methods One hundred and fifty SD rats were randomly divided into six groups （n=25, in each group）: blank (25% Pluronic F-127), shRNA-1, shRNA-2, 1/2 （shRNA-1+shRNA-2）, negative control (pGenesil-1 scramble shRNA) and positive control （wortmannin） group. The jugular vein in rats were interpositioned autologously into the common carotid artery. shRNA and 25% Pluronic F-127 were mixed and coated around the transplanted vein in three PIK3cb shRNA groups. Every 5 samples were removed according to the time point (1, 3, 7, 14 and 28 days after operation), respectively. The thickness of intima and neointima area were calculated and analyzed by computer system. The PCNA expression was detected by Western blot and SP immunohistochemistry. Results The intimal thickness of three PIK3cb shRNA groups were lower than those in the blank group and negative control group on day 3, 7, 14, 28 after operation (P＜0.05); The neointima area in three PIK3cb shRNA groups (except shRNA-2 group on day 3, 7) began to decrease significantly from day one (P＜0.05). The protein expression of PCNA in three PIK3cb shRNA groups on day 3 after operation were decreased compared with blank group and negative group (P＜0.05). The percentage of the PCNA positive cells area in three PIK3cb shRNA groups were significantly lower than those in blank group and negative control group in each time point (Plt;0.05). There were no significant differences between blank and negative control group in different time points (Pgt;0.05). Conclusion The PIK3cb shRNA can effectively inhibit the proliferation of vascular smooth muscle cell, which may provide a new gene therapy for the prevention of vein graft restenosis after bypass grafting.
Objective To study the inhibitory effect of RNA interference (RNAi) on bcl-2 expression of vascular smooth muscle cells （VSMCs) in rabbit. Methods The expression vector of bcl-2 gene-targeting small interference RNA (pshRNA-bcl-2) was constructed and was transfected into VSMCs by lipofectamine, and the unloaded vector was used as control. The expression of bcl-2 mRNA was identified by RT-PCR and Western blot, respectively. The growth of the transfected VSMCs was examined by MTT. Results The pshRNA-bcl-2 may inhibit the expression of bcl-2 gene at the levels of transcription and translation. There were significant differences (P＜0.01) of the expressions of bcl-2 mRNA between the VSMCs that were transfected with pshRNA-bcl-2 and the ones in plasmid transfected group and control group, respectively. There was a significant difference (P＜0.01) in the growth of VSMCs between the plasmid transfected and the control groups. Conclusion The plasmid containing the small interference RNA of bcl-2 may have an inhibitory effect on the cell growth and endogenous expression of bcl-2 gene at the levels of transcription and translation in VSMCs.
Objective To investigate the inhibitory effects of RNA interference (RNAi) expression vector on the expression of survivin in pancreatic cancer cell PANC-1. Methods The protein and mRNA expressions of survivin were examined with immunofluorescence and RT-PCR. The survivin gene was cloned into the T-vector and sequenced. The RNAi expression vectors targeting survivin, named si-svv-1 and si-svv-2 respectively according to whether they harbored a mutation or no mutation, were constructed and transfected into PANC-1 cells with liposome. The expression of survivin mRNA was detected with RT-PCR. Apoptosis of PANC-1 cells was analyzed with DNA ladder and FACS. Results There was a high degree expression of survivin in PANC-1 cells. The expression of survivin was not inhibited by RNAi expression vectors si-svv-1, but inhibited about (72.43±8.04)% by si-svv-2 and the apoptosis rate of PANC-1 cells increased to （12.36±1.44）% after 72 h. Conclusion The RNAi expression vector can effectively inhibit the expression of survivin in pancreatic cancer cell PANC-1 cells and induce the apoptosis in PANC-1 cells.
Objective To observe the effect of RNA interference (RNAi) on HepG2 hepatic cancer cell by small interfering RNA (siRNA). Methods siRNA targeting vascular endothelial growth factor (VEGF) gene was transfected into HepG2 cells by LipofectimineTM 2000. The VEGF mRNA and protein were respectively detected by real-time quantitive PCR and Western blot, and the concentration of VEGF protein in the cell culture supertant was determined by ELISA at 48 h after culture. Results The average efficiency of siRNA transfection was (90.4±2.9)% after 6 h cell culture. The expressions of VEGF mRNA and protein in HepG2 cells could be effectively suppressed by siRNA, and the concentration of VEGF protein in the cell culture supertant was also decreased. Conclusion siRNA can knock down the expression of VEGF gene and decrease the concentration of VEGF protein in HepG2 cells.
Objective To investigate the influence of RNA interference targeting c-Jun gene on the proliferation of rat vascular smooth muscle cells (VSMCs). Methods The experiment was performed with c-Jun siRNA （c-Jun siRNA group）, control reverse sequence siRNA (control siRNA group) or no siRNA (control group). VSMCs were transfected with siRNA targeting c-Jun gene by liposome. Effects of c-Jun siRNA on mRNA and protein expressions of c-Jun were examined by RT-PCR analysis and Western blot respectively. MTT test and 3H-TdR incorporation were used to detect VSMCs proliferation. Cell cycle analysis of VSMCs in vitro was determined by flow cytometer. Results The expression levels of mRNA and protein of c-Jun in c-Jun siRNA group were significantly lower than those in control group （P＜0.05， P＜0.01). There was no significant difference between control group and control siRNA group （Pgt;0.05）. Proliferation activity of VSMCs decreased significantly in c-Jun siRNA group compared with that in control group （P＜0.05） and VSMCs was blocked in the G0/G1 phase of cell cycle significantly （P＜0.05）. There was no significant difference between control group and control siRNA group （Pgt;0.05）. Conclusion c-Jun gene silenced by RNA interference can inhibit VSMCs proliferation effectively in vitro.
Objective To observe whether Nogo-66 can inhibit the neurite outgrowth during the neuronal differentiation of the neural stem cells (NSCs) and remove such an inhibitory effect by the small interfering RNA (siRNA) mediated knockdown of the Nogo66 receptor (NgR). Methods NSCs derived from the rat spinal cord were collected, and were cultured by the suspension culture in vitro. NSCs were transfected by siRNA to knock downtheexpression of NgR. Immunofluorescence and Western blot were used to assess the knockdown efficiency. NSCs were divided into four groups and differentiated in the medium containing 10% FBS. In the control group, no intervention was applied to NSCs; in the Nogo-P4 group, NSCs were differentiated in the presence of Nogo-P4 (active segment of Nogo-66); in the siRNA group, NSCs were transfected by siRNA to knock down NgR before they were differentiated; in the siRNA and Nogo-P4 group, NSCs were transfected by siRNA to knock down NgR before they were differentiated in presence of Nogo-P4. The differentiated neurons were labeled by immunofluorescence, and the neurite length was measured by the ImagePro Plus 5.0 software. The differentiation of the neurite length was compared in each group. Results The suspension-cultured cells became the nerve bulb, which could positively expresses Nestin by immunofluorescence. At 1 week of the differentiation in the medium containing 10% FBS, the positively-labeled neuron specific enolase, the glial fibrillary acidic protein, and the myelin basic protein were observed. Both immunofluorescence and Western blot approved that the expression of NgR was knocked down by transfection of siRNA at 24 hours after the transfection. The knockdown efficiency was 90.35%±3.10%. The neurite length was 97.80±6.97 μm, 80.54±6.75 μm,92.14±7.27 μm, and 94.01±8.37 μm in the control group, the Nogo-P4 group, the siRNA group, and the siRNA and Nogo-P4 group, respectively. The Nogo-P4 group had a significant difference when compared with the otherthree groups (Plt;0.01), and the other three groups had no significant difference when compared with each other（Pgt;0.05）. ConclusionNogo-66 can inhibit the neuronal neurite outgrowth during the differentiation ofNSCs. Such an inhibitory effect can be removed by the siRNA mediated knockdown of NgR.
Objective To investigate the role of calcium- and integrin-binding protein-1（CIB1） in oxidized lowdensity lipoprotein（OX-LDL） inhibiting migration of mouse macrophages. Methods To silence CIB1 express of mouse macrophages by RNA interference, then incubating mouse macrophages with OX-LDL, cell migration and cell spreading of mouse macrophages were analyzed. Results At 24-72h after macrophages transfected CIB1 siRNA, the express of CIB1 protein was restrained obviously. To silence CIB1 express could increase migration and spreading of mouse macrophages significantly. Conclusions CIB1 plays the important role in intracellular modulating mechanism of OX-LDL inhibiting mouse macrophages migration.
ObjectiveTo observe the influence of down-regulation of HtrA1 expression by small interfering RNA on light-injured human retinal pigment epithelium (RPE) cells. MethodsCultured human RPE cells(8th-12th generations)were exposed to the blue light at the intensity of (2000±500) Lux for 6 hours to establish the light injured model. Light injured cells were divided into HtrA1 siRNA group, negative control group and blank control group. HtrA1 siRNA group and negative control group were transfected with HtrA1 siRNA and control siRNA respectively. The proliferation of cells was assayed by CCK-8 method. Transwell test was used to detect the invasion ability of these three groups. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of HtrA1 and vascular endothelial growth factor (VEGF)-A was detected by real time-polymerase chain reaction and Western blot respectively. ResultsThe mRNA and protein level of HtrA1 in the light injured cells increased significantly compared to that in normal RPE cells (t=17.62, 15.09; P<0.05). Compared with negative control group and blank control group, the knockdown of HtrA1 in HtrA1 siRNA group was associated with reduced cellular proliferation (t=6.37, 4.52), migration (t=9.56, 12.13), apoptosis (t=23.37, 29.08) and decreased mRNA (t=17.36, 11.32, 7.29, 4.05) and protein levels (t=12.02, 15.28, 4.98, 6.24) of HtrA1 and VEGF-A. Cells of HtrA1 siRNA group mainly remained in G0/G1 phase, the difference was statistically significant (t=6.24, 4.93; P<0.05). ConclusionKnockdown of HtrA1 gene may reduce the proliferation, migration capability and apoptosis of light-injured RPE cells, and decrease the expression of VEGF-A.
Objective To explore the influence on the expressions of vascular endothelial growth factor (VEGF) gene and matrix metalloproteinase-2 (MMP-2) gene in hepatocellular carcinoma of SMMC-7721 cells with RNA interference (RNAi) silencing the expression of hypoxia inducible factor-1α (HIF-1α) gene. Methods Firstly, constructed short hairpin RNA (shRNA) targeting for HIF-1α gene, and then transfected it to SMMC-7721 cells after combining with plasmid. The SMMC-7721 cells were divided into three groups, silencing group, negative control group, and blank control group, which were transfected with HIF-1α-shRNA-pGenesil-1 recombinant vector, shRNA-HK-pGenesil-1 recombinant vector, and pGenesil-1 vector respectively. Transfection cells were screened by the concentration of 500 μg/mL G418, and then positive and negative cell clones with transfection recombination carrier were obtained. Detected the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups with real time PCR (RT-PCR) technology, under the condition of hypoxic training 6 h, 12 h, and 24 h, as well as conventional oxygen training. Results There was no expression of HIF-1α mRNA at conventional oxygen condition in the 3 groups, and there was no significant difference in expressions of VEGF mRNA and MMP-2 mRNA among the 3 groups (P>0.05) at the condition of conventional oxygen training. The expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the silencing group, compared with the the negative control group and the blank control group, were obviously decreased (P<0.05) under the condition of hypoxic training (6, 12, and 24 h), while there was no significant difference between the negative control group and the blank control group at each time point (P>0.05), but the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups under every condition of hypoxic training were all higher than those of conventional oxygen condition (P<0.05). Under the condition of hypoxic training, the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups decreased over time, and there was significant difference between any 2 time points in each group (P<0.05). Conclusion RNAi technique can effectively silence the expression of HIF-1α mRNA of SMMC-7721 cells, and then silence the expressions of VEGF and MMP-2 mRNA, to inhibit the invasion and metastasis of hepatocellular carcinoma.
ObjectiveTo establish MCF-7 cell lines with different ERα/ERβ expression level and observe their biological behaviors. MethodsERα or ERβ gene were silenced by RNA interference, and the cell lines with different ERα or ERβ expression level were obtained in MCF cell lines. MTT assay, flow cytometry, RT-PCR, double layer softagar clony formation test, and Matrigel adhesion assay were used to detect the abilities of cell proliferation, apoptosis, tumorigenesis, and adhesion. ResultsThe stable expression cell lines with ERαlow/ERβhigh or ERαhigh/ERβlow were established successfully. After ERα gene knockdown, MCF-7 grew slowly and was arrested at phase G0-G1. Apoptosis of MCF-7 was induced and the capacity of tumorigenesis and adhesion in vitro were weakened. However, the characteristics mentioned above except for adhesion changed to the opposite sides after ERβ gene knockdown. ConclusionsThe ERα gene silence can inhibit the formation of tumor, however the ERβ gene silence can promote tumor growth, invasion, and metastasis. Therefore, may be a useful approach on the breast cancer therapy.