Objective To construct small interfering RNA（siRNA） eukaryotic expression vector specific for human hnRNP K gene，and to observe its silencing effects on hnRNP K gene in A549 cells.Methods The expression vectors of pSUPER/hnRNP K siRNAa，pSUPER/hnRNP K siRNAc and pSUPER/siRNAn were constructed by gene recombination and then transfected into the A549 lung carcinoma cell line by using Lipofectamine2000（a and c respectively represented A and C fragments in hnRNP K coding sequence contained 19 nts，n represented nonsense fragment as control）.The mRNA and protein were harvested after 24 h and analyzed for the expression of hnRNP K by RT-PCR and Western blotting respectively.Results The siRNA vector targeted to hnRNP K successfully decreased hnRNP K mRNA and protein levels 24 h after transfection in A549 cells.Relative expressed doses of hnRNP K mRNA in lung cancer cells transfected by hnRNP K siRNAa and hnRNP K siRNAc respectively were 0.24±0.53 and 0.28±0.57 after 24 h，which were significantly lower than that in the control group（both Plt;0.01）.The gray scale values of hnRNP K protein were 0.23±0.11 and 0.28±0.09 respectively，which were also significantly lower than those in the control group（both Plt;0.05）.And pSUPER/hnRNP K siRNAa was the most effective one.Conclusion Eukaryotic expression vector of siRNA specific for hnRNP K is successfully constructed，which lays the basis for the function study of hnRNP K gene and its application in the treatment of lung carcinoma.
Abstract: Objective To generate a eukaryotic expression plasmid-pcDNA3.1/human tissue inhibitor of metalloproteinase-1(hTIMP-1)enhanced green fluorescent protein (EGFP), carrying hTIMP-1 and labeled with EGFP, and to examine the expression of hTIMP-1 in vascular smooth muscle cells (SMCs) transferred with hTIMP. Methods The recombinant plasmids of pcDNA3.1/hTIMP-1-EGFP were obtained bypolymerase chain reaction (PCR) amplification, splicing, and insertion of complementary deoxyribonucleic acid (cDNA) fragments of hTIMP-1 and EGFP. The target gene was transferred to the primarily cultured SMCs (pcDNA3.1/hTIMP-1-EGFP transferred group) by using cationic liposome mediated gene transfection technique. EGFP expression was detected by fluorescence microscopy, and the transfection rate was determined by flow cytometry. Reverse transcriptase polymerase chain reaction (RTPCR), Western blotting, and other techniques were used to detect the expression of hTIMP-1 gene. The biological activity of matrix metalloproteinase-2(MMP-2) and matrix metalloproteinase-9(MMP-9) were studied by zymographic analysis of gelatinases. Blank plasmidpcDNA3.1 transferred SMCs (blank plasmid pcDNA3.1 transferred group) and untransferred SMCs (untransferred group) were used as control. Results In cDNA3.1/hTIMP-1-EGFP transferred group,the growth ability of SMCs was profoundly inhibited, bright green fluorescence was observed by fluorescence microscopy 24 hours after transfection in SMCs,the rate of transfection analyzed with flow cytometry was 15%,RT-PCR results showed that the genome of hTIMP-1 transferred SMCs contained a 646 bp specific fragment of hTIMP-1 gene, Western blotting results proved hTIMP-1 protein expression in SMCs transferred by hTIMP-1, zymographic analysis of elatinases showed decreased activity of MMP-2 and MMP-9, compared to those in blank plasmidpcDNA3.1 transferred group and untransferred group, significant differences were observed (Plt;0.05). Conclusion The generation of a eukaryotic expression plasmid carrying TIMP-1 gene and its expression in SMCs provide a sound basis for hTIMP-1 gene therapy.
Objective To clone human bone morphogenetic protein 2 ( BMP-2) gene and construct the gene’s eukaryotic expression vector. Methods The total RNA was extracted from human osteosarcoma cells, the human BMP-2 cDNA was amplified by RT-PCR and inserted into pGEM-T vector. The positive clones were screened out, and the n the recombinant plasmid was confirmed by restriction enzyme digestion, PCR and the analysis of nucleotide sequence. The BMP-2 cDNA in the pGEM-T cloning vec tor was inserted into the pcDNA3.1(+) eukaryotic expression vector. Results The agarose electrophoresis showed that the fragments of BMP-2, pGEMT and pcDNA3.1(+) were 1.2 kbp, 4.0 kbp and 5.0 kbp, respectively. The result of nucleotide sequence confirmed that the cDNA sequence, which was inserted into pGEM-T and pcDNA3.1(+) plasmid was human BMP-2. Conclusion The pcDNA3.1(+)-hBMP-2 eukaryotic vector can be successfully constructed.
Objective To establish a kind of gene therapy method of rheumatoid arthritis, to construct the interleukin-18-PE38 fusion gene expression vectorand to explore the expression of the fusion gene in the chondrocytes and 3T3 cells. Methods Interleukin-18-PE38 fusion gene was cleaved from plasmid PRKL459k-IL-18-PE38 by restriction enzyme digestion,then linked with vectors PsecTag2B and transformed into competence bacteria, positive clones were selected and confimed by restrictive enzyme(EcoRI) digestion assay. The rearrangement plasmid PsecTag2B-IL-18-PE38 was transfected into 3T3 cells and mouse chondrocytes by liposome protocol(experimental group),null vector was used as negative control, and the transient expression was identified by fluorescence immunocytochemical assay. Results Restrictive enzymes digestion analysis revealed thatthe length of theinterleukin-18-PE38 fusion gene was 6 000 bp. Fluorescence immunocytochemical method showed that fluorescence intensity of the experimental group is b,whilefluorescence intensity of the control group is weak. Conclusion the eukaryoticexpression vector PsecTag2B-IL-18-PE38 is established successfully which canbeexpressed in the 3T3 cells and mouse chodrocytes. Our results lay a foundationfor the further investigation for rheumatoid arthritis therapy.
OBJECTIVE: To construct eukaryotic expression vector of rat myogenin gene for further study on its functions in skeletal muscle denervated atrophy and repair. METHODS: The cloning vectors (containing full length of myogenin cDNA and two restriction sites: Hind III and Xho I) were first cut by two restriction endonuclease: Hind III and Xho I, and the same as the eukaryotic expression vector; then, the myogenin cDNA and the digested vector were ligated by T4 DNA ligase, and recombinant eukaryotic expression vector was formed. Its length was certificated by agarose gel electrophoresis analysis, digestion with Hind III and Xho I, PCR; and the rightness of the myogenin cDNA sequence was confirmed by sequencing. RESULTS: The results of agarose gel electrophoresis analysis, digestion, and PCR confirmed the right length of inserted DNA, which was the same as the myogenin cDNA, and the sequencing result of pcDNA3-myogenin was identical with the reported. CONCLUSION: pcDNA3-myogenin a eukaryotic expression vector, is successfully constructed.
ObjectiveTo construct eukaryotic expression vector of pEGFP-N3-TFPI-2, and to provide the base of studying the function of TFPI-2 gene. MethodsExtraction of total RNA from placental tissue was extracted at first, and then reverse transcriptase synthesis of cDNA was carried out. The cDNA fragment of TFPI-2 gene which was obtained by real time PCR (RT-PCR) was inserted into eukaryotic expression vector of pEGFP-N3. After double digestion with XhoⅠand KpnⅠ, the recombinant vector of pEGFP-N3-TFPI-2 was identified in 1% agarose gel electrophoresis and was tested by the sequence analysis. Then, the recombinant vector of pEGFP-N3-TFPI-2 (transfection group) and vector of pEGFP-N3 (blank control group) were transfected into Top10 competent cells with LipofectamineTM 2000, but no transfection-related treatment was performed in cells of untransfection group. Western blot method was used to test the expression of TFPI-2 protein in cells of 3 groups. ResultsThe purity of total RNA which were analysis by agarose gel electrophoresis and spectrophotometry were fit for PCR. After coding of TFPI-2 gene fragment and eukaryotic expression vector of pEGFP-N3, the recombinant plasmid of pEGFP-N3-TFPI-2 were got double digestion with XhoⅠand KpnⅠ, and was identified in 1% agarose gel electrophoresis, of which showing that there were 2 specific amplification of strips at 708 bp and 4 700 bp. Result of sequence analysis confirmed that the size of recombinant vector was consistent with the theoretical value. Results of Western blot showed that the expression of TFPI-2 protein in transfection group (0.657 3±0.032 5) was higher than those of blank control group (0.301 7±0.028 7) and untransfection group (0.314 3±0.026 6), P < 0.01. ConclusionsThe eukaryotic expression vector of pEGFP-N3-TFPI-2 has been constructed successfully, which laiding the foundation for the analysis about function of TFPI-2 gene.
ObjectiveTo establish a cell inflammation model induced by tumor necrosis factor-α (TNF-α) in human bronchus epithelial cells, and investigate the effects of glutathione S-transferase mu 5 (GSTM5) on the inflammation and oxidative stress. Methods16HBE cells were treated with TNF-α (10 ng/mL, 24 h) in the absence or presence of the constructed GSTM5 eukaryotic expression vector (1 μg/mL). The concentration of malondialdehyde (MDA) and total antioxidation capacity (T-AOC) were detected by colorimetric method. The survival rate of cells was assessed by the methyl thiazolyl tetrazolium (MTT) assay. The transcription level of NADPH oxidase-1 (NOX1), NOX2, NOX3, NOX4, NOX5, dual oxidase-1 (DUOX1) and DUOX2 were evaluated by RT-PCR. Western blot was performed to investigate the protein levels of NOX1 and NOX2. ResultsTNF-α simulation significantly increased the level of MDA in cells, and decreased the level of T-AOC and survival rate of 16HBE. When transfected with the GSTM5 eukaryotic expression vector, the concentration of MDA significantly decreased (P < 0.05), and the activation of T-AOC increased dramatically (P < 0.05). Consequently, the survival rate of 16HBE in the GSTM5 group improved (P < 0.05). The 16HBE cells transfected with the constructed GSTM5 eukaryotic expression vector had a lower transcription and protein levels of NOX1 and NOX2 (all P < 0.01). There were no significant changes in the mRNA expressions of NOX3, NOX4, NOX5, DUOX1 or DUOX2. ConclusionGSTM5 may down-regulate the transcription level of NOX1 and NOX2 to reduce the inflammation and oxidative stress induced by TNF-α.