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.
【Abstract】Objective To explore the application of RNA interference (RNAi) in colorectal cancer gene therapy. Methods The related literatures in recent years were reviewed. Results RNAi causes a high effective and distinctive degradation of mRNA homologous in sequence to the dsRNA. This new technology has been successfully applied to research the genesis and the growth of colorectal cancer.Conclusion RNAi has been a new focus in gene therapy for colorectal cancer.
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.
ObjectiveTo explore the effect of DDX46 silencing on growth and apoptosis in esophageal squamous cell carcinoma cell TE-1 by the shRNA. MethodsThe relative expression of DDX46 mRNA in TE-1 cells was detected by real-time quantitative polymerase chain reaction (qRT-PCR) and compared with immortalized human esophageal squamous cell Het-1A. DDX46 shRNA-expressing lentivirus was applied to silence DDX46 (experimental group), and non-silencing control lentivirus was added (control group) with a multiplicity of infection of 5 in TE-1 cells. In both groups, cell growth was monitored using high content screening, cell colony-forming capacity was measured by colony formation assay, cell apoptosis were determined by flow cytometry. Further, the Stress and Apoptosis Signaling Antibody Array Kit was used to detect the changes of signaling molecules in TE-1 cells after DDX46 knockdown. ResultsCompared with the control group, cell counting after DDX46 silencing showed that TE-1 cell growth was significantly inhibited (P<0.001). Colony formation assay showed that cell colony-forming capacity was significantly inhibited (P<0.01). Annexin V-APC flow cytometry showed a significant increase in apoptosis (P<0.001). In PathScan® Antibody Array, the expression levels of Akt (Ser473, phosphorylation) and IκBα (Total, N/A) significantly decreased (P<0.01), and the expression of Caspase-3 (Asp175, cleaved) increased (P<0.05). ConclusionDDX46 is overexpressed in TE-1 cells. Targeted gene silencing of DDX46 inhibits cell growth, and induces cell apoptosis. DDX46 silencing probably by negative regulation of Akt/NF-κB signaling pathway, to play a role in inhibiting TE-1 cells growth and inducing apoptosis.
Objective To study the interferencing and anti-tumor effects of lentiviral vector of siRNA targeting IGF1R and EGFR gene of the liver cancer cell. Methods The complementary DNA containing both sense and antisense Oligo DNA of the targeting sequence was designed, synthesized and connected to the pLVTHM vector, named pLVTHM-IGF1R, into whom the EGFR-siRNA expression frame containing H1 promotor synthesized by RT-PCR was cloned to generate pLVTHM-IGF1R-EGFR-siRNA. The 293T cells were cotransfected by 3 plasmids of pLVTHM-IGF1R-EGFR-siRNA, psPAX2 and pMD2G to enclose LVTHM-IGF1R-EGFR-siRNA, which was amplified in large amount and purified by caesium chloride density gradient centrifugation for measurement of virus titer. SMMC7721 cells infected by LVTHM-IGF1R-EGFR-siRNA were infection group, the untreated SMMC7721 cells and blank vector plasmid LVTHM were two control groups (SMMC7721 cell group and blank vector group). The effect of LVTHM-IGF1R-EGFR-siRNA on IGF1R and EGFR expressions of SMMC7721 cells were detected by RT-PCR and Western blot. The antitumor potential of LVTHM-IGF1R-EGFR-siRNA to SMMC7721 cells was evaluated by Cell Counting Kit-8 assay for cell growth and TUNEL for apoptosis respectively. Results LVTHM-IGF1R-EGFR-siRNA was constructed successfully. Functional pfu titers of LVTHM-IGF1R-EGFR-siRNA was 4.58×109 pfu/ml. Protein and mRNA expression of IGF1R and EGFR of infection group were less than those of blank vector group and SMMC7721 cell group （P＜0.05）, LVTHM-IGF1R-EGFR-siRNA was more effective to inhibit the proliferation and promote apoptosis of SMMC7721 cells （P＜0.05）. Conclusion LVTHM-IGF1R-EGFR-siRNA expressing IGF1R-EGFR-siRNA can inhibit the expression of IGF1R and EGFR, and may be used for further investigation of gene therapy of liver cancer.
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 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.
【Abstract】 Objective The seed cells source is a research focus in tissue engineered cartilage. To observe whether the post-RNA interference (RNAi) chondrocytes could be used as the seed cells of tissue engineered cartilage. Methods Chondrocytes were separated from Sprague Dawley rats. The first passage chondrocytes were used and divided into 2 groups: normal chondrocytes (control group) and post-RNAi (experimental group). Normal and post-RNAi chondrocytes were seeded into chitosan/gelatin material and cultured in vitro to prepare tissue engineered cartilage. The contents of Aggrecan and Aggrecanase-1, 2 were measured by HE and Masson staining, scanning electron microscope (SEM), and RT-PCR. Results The histological results: no obvious difference was observed in cell number and extracellular matrix (ECM) between 2 groups at 2 weeks; when compared with control group, the secretion of ECM and the cell number increased in experimental group with time. The RT-PCR results: the expression of Aggrecan mRNA in experimental group was significantly higher than that in control group (P lt; 0.05); but the expressions of Aggrecanase-1, 2 mRNA in experimental group were significantly lower than those in control group (P lt; 0.05). The SEM results: the cell number in experimental group was obviously more than that in control group, and the cells in experimental group were conjugated closely. Conclusion The post-RNAi chondrocytes can be used as the seed cells for tissue engineered cartilage, which can secrete more Aggrecan than normal chondrocytes. But their biological activities need studying further.
Objective To establish a cell culture model in vitro of acute lung injury and investigate the effects of NF-κB p65 on the inflammation and oxidative stress in TNF-α-activated type Ⅱ alveolar epithelial cells. Methods A549 cells were treated with TNF-α ( 10 ng/mL, 24 h) in the absence or presence of NF-κB p65 siRNA ( 50 nmol /L) . RT-PCR and Western blot were performed to analyze the silence efficiency of RNAi targeting NF-κB p65. The contents of IL-1β, IL-4, and IL-6 in the culture supernatant were measured by ELISA. The concentration of MDA and SOD were detected by colorimetric method. The survival rate of cell was assessed by the methyl thiazolyl tetrazolium ( MTT) assay. Results P65 RNAi significantly decreased the transcription and translation of NF-κB p65 induced by TNF-α( P lt; 0. 05) . The levels of IL-1β, IL-4, and IL-6 were significantly lower in the supernatants of A549 cells pretransfected with NF-κB p65 siRNA ( P lt;0. 05) , while the concentration of MDA markedly decreased ( P lt; 0. 05) , and the activation of SOD increased dramatically ( P lt; 0. 05) . Consequently, the survival rate of A549 in the p65 siRNA group improved( P lt; 0. 05) . Conclusions NF-κB p65 plays a key role in the oxidative stress induced by TNF-α. NF-κB p65 silencing can down-regulate the inflammation and oxidative stress induced by TNF-αand enhance the proliferation of alveolar epithelial cells.
Objective To investigate the effect of TNF-related weak inducer of apoptosis/fibroblast growth Factor-inducible 14 (TWEAK/Fn14) on the cell proliferation by transfecting Fn14 shRNA to PANC-1 cells. Methods The shRNA gene targeting Fn14 gene was constructed and transfected into pancreatic cancer cell line PANC-1 to specifically silence the expression of Fn14 gene. The effect of shRNA interference sequence on the expression of Fn14 was detected by flow cytometry and immunofluorescence. CCK-8 was used to detect the cell proliferation of PANC-1 after blocking TWEAK-induced signal pathway. Western blotting method was used to detect the expressions of downstream factors such as nuclear factor-kappa B (NF-κB), TWEAK and caspase-3 to explore the pathway mechanism of TWEAK/Fn14. Results The absorbance value (A value) in the Fn14 shRNA group was significantly lower than the control groups in 24 hours after transfected (P<0.000 1). After the specific shRNA sequences transfected PANC-1 cells, NF-κB, TWEAK and caspase-3 protein expressions were also significantly lower than the control group (P<0.05), and the apoptosis of PANC-1 cells increased after inhibition of TWEAK/Fn14 signaling pathway. Conclusions TWEAK/Fn14 involved in the progression of pancreatic cancer. The Fn14 expression could influence the process of cell apoptosis.