共查询到20条相似文献，搜索用时 31 毫秒
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AIM:To study the expression of telomerase inhibitor Pinx1 in acute leukemia cells and during the differentiation of acute promyelocytic leukemia cells,and to realize its effect on telomerase activity.METHODS:Realtime quantitative PCR with fluorescence probe hybridization was used to measure the expression of Pinx1 and hTERT mRNA in acute leukemia cells and during differentiation of NB4 cells induced by ATRA.The correlations between Pinx1 and hTERT expression were also analyzed.RESULTS:Pinx1 mRNA expression in acute leukemia samples (0.00312,5.42×10-4-0.024) was significantly higher than that in normal bone marrow mononuclear cells (7.89×10-4,0-0.00863,P<0.01).The expression of Pinx1 mRNA had significant positive correlation with hTERT mRNA expression (r=0.296,P<0.05).Pinx1 mRNA expression decreased during differentiation,its expression was positive correlated with hTERT mRNA expression (r=0.900,P<0.05).CONCLUSIONS:As an inhibitor of telomerase,however,Pinx1 also had the same direction of regulation with telomerase activity in acute leukemia cells,suggesting its expression variation may be a subsequent reaction induced by that of hTERT to stabilize telomerase activity.The exact mechanisms remained to be verified. 相似文献
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AIM: To investigate the effect of transfection of hTERT gene into human mesenchymal stem cells (MSCs) on their telomerase activity and life-span.METHODS: Human MSCs were transfected with a pEGFP-hTERT plasmid by liposome-mediated transfection. Then the hTERT mRNA expression in MSCs was detected by RT-PCR. The activity of telomerase in transfected MSCs was detected by PCR and ELISA. The telomerase-positive MSCs was cultured in vitro and induced into neuron-like cells with EGF and bFGF. Neuron-specific markers (NF-M, MAP2) were detected by RT-PCR.RESULTS: hTERT fragment was identified in the hTERT-transfeced cells but not in the untransfected human bone marrow MSCs. The untransfected human MSCs remained telomerase-negative but the hTERT-transfected cells showed robust telomerase activity. The telomerase-negative MSCs entered a nondividing state and senesced after about 20 to 25 passages. In test group, however, telomerase-positive MSCs to date had undergone 35 passages. RT-PCR analysis showed that telomerase-positive MSCs expressed neuron-specific markers, such as NF-M or MAP2 after induced with EGF and bFGF in vitro. CONCLUSION: Ectopic expression of the hTERT gene in human MSCs reconstitutes telomerase activity. The transfection of hTERT gene into human MSCs extends their replicative life span and maintains their multipotent differentiation capacity. 相似文献
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AIM: To study the inhibitory effect and its mechanisms of the extract of Oratosquilla oratoria (EOS) on the activity of telomerase in human nasopharyngeal carcinoma cell line CNE-2Z. METHODS: MTT assay was used to determine the effect of different doses of EOS on the proliferation of CNE-2Z cells. The activity of telomerase was analyzed by TRAP-ELISA. The mRNA expression of hTERT was determined by RT-PCR, and the protein expression of c-Myc was detected by Western blotting. RESULTS: EOS inhibited the proliferation of CNE-2Z cells in a dose-dependent manner (P<0.01). Telomerase activity was decreased, the mRNA expression of hTERT and c-Myc in CNE-2Z cells was also decreased (P<0.01) by the treatment of EOS. The correlation between the down-regulatory expression of hTERT mRNA and inhibitory expression of c-Myc protein (P<0.05) under the condition of EOS exposure was observed. CONCLUSION: EOS inhibits the proliferation of CNE-2Z cells by reducing the activity of telomerase, which is related with the inhibitory expression of hTERT mRNA caused by the decrease in c-Myc production. 相似文献
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BO Yun DU Yi-peng LUO Xiao-feng MI Yang YUAN Guang-qing HE Xia CHEN Zhan-hui ZHOU Jun-yi 《园艺学报》2008,24(3):537-542
AIM: To construct a tetracycline-inducible H1 RNAi system of hTERT and to study the apoptosis rates and survival rates of tetracycline-inducible hTERT RNAi cell line. METHODS: The tetracycline-inducible H1 RNAi system for hTERT was constructed and transfected into TREx-HeLa cell line. The inhibitory effects were determined by RT-PCR and TRAP. The proliferation of the cell line in two groups was assayed by MTT test. The apoptotic rates were estimated by using Hoechst33342 and FACS. RESULTS: Tetracycline-inducible H1 RNAi system of hTERT was constructed successfully and TREx-HeLa cell induciblely interfered with hTERT was cultured successfully. As to the different cell lines, different influences after telomerase activity were declined. For TREx-HeLa cell, declined telomerase activity reduced proliferation but had no remarkable influence in apoptosis during short time. CONCLUSION: Tetracycline-inducible H1 RNAi system of hTERT and the assay of the proliferation and apoptosis of the TREx-HeLa cell provide the basis for further research. 相似文献
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MA Jin-ping CHEN Chuang-qi CAI Shi-rong ZHANG Xin-hua YANG Dong-jie WU Hui HE Yu-long ZHAN Wen-hua 《园艺学报》2010,26(12):2332-2336
AIM: To investigate the effect of specific hTERT RNA interference on biological characteristics of colon carcinoma in vivo and in vitro. METHODS: A small interference RNA (siRNA) targeting to hTERT mRNA (pU6-hTERT-siRNA) was constructed. The siRNA was transfected into LoVo colon cancer cells in vivo and in vitro with LipofectamineTM2000. The groups of non-specific siRNA (pU6-hTERT) and non-treatment were designed as negative control and blank control,respectively. The cell growth in vitro was detected by MTT method. The effect of pU6-hTERT-siRNA on xenografts in nude mice was observed by determining the tumor size. The mRNA expression of hTERT in vitro and in vivo was detected by FQ-PCR quantitatively. The protein level of hTERT was determined by Western blotting. RESULTS: The inhibition rate of cell growth in vitro 72 h after transfection with recombinant plasmids containing hTERT-target sequences was 42.1%, significantly higher than that in control group (3.2%, P<0.01). The size of xenografts in pU6-hTERT-siRNA group was (85.9±18.7)mm3, significantly smaller than that in control group and blank group , P<0.01. The mRNA expression and the protein level of hTERT were both specifically inhibited by pU6-hTERT-siRNAs in LoVo colon cancer cells and xenografts (P<0.01). No difference between control group and blank group was observed (P>0.05).CONCLUSION: hTERT expression in LoVo colon cancer cells is inhibited significantly in vivo and in vitro by using plasmid-based siRNA. Down-regulation of hTERT expression distinctly inhibits the growth of LoVo colon cancer cells in vitro or subcutaneously transplanted in athymic mice. 相似文献
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LI Na ZHOU Hong YU Ying WANG Ting HUANG Hong-liang SHI Wen-xia WANG Hai-bo 《园艺学报》2009,25(12):2447-2453
AIM: To construct a lentiviral vector harboring RNAi sequence targeting human annexin A2 (ANX A2) and to investigate the functions of ANX A2 in antiphospholipid antibody (APL)-induced tissue factor (TF) expression in monocytes. METHODS: Four different short hairpin RNAs (shRNA) targeting ANX A2 gene were constructed and cloned into the pGCSIL-GFP vector. After identification with PCR and sequencing, the effective interference sequence was further determined by Western blotting analysis. The recombinant lentivirus LV-RNAi-ANX A2 harvested from 293T cells was transferred into THP-1 cells and the ANX A2 mRNA and protein expression on THP-1 cells were examined. The transferred-THP-1 cells were stimulated by APL/β2GPI compound, and the TF mRNA and TF activity was assayed. RESULTS: The RNAi sequences targeting the human ANX A2 gene were successfully inserted into the lentiviral vector and the high-performance RNA interference sequence was sieved out. The recombinant lentivirus was harvested from 293T cells with a viral titer of 3×1012 TU/L. THP-1 cells infected with LV-RNAi-ANX A2 showed almost lockout of ANX A2 both at mRNA and protein levels. The TF expression was also significantly decreased in the transferred-THP-1 cells induced by APL/β2GPI compound. CONCLUSION: The lentiviral vector constructed in the present study blocks the ANX A2 expression in THP-1 cells and further inhibits the TF expression induced by APL/β2GPI compound, which indicates that ANX A2 do play an important role in APL-induced TF expression on monocytes. 相似文献
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AIM:To construct a eukaryotic expression vector expressing outer membrane lipoprotein LipL41 of Leptospira lai and express it in mammalian cell. METHODS:LipL41 gene was amplified by PCR from genome of Leptospira lai 017 strain, and was subcloned into vector pGEX-4T-1. After sequencing, LipL41 gene digested by restriction endonuclease and cloned into vector pcDNA3. After confirming the correctness of the eukaryotic recombinant vector by restrication enzyme digestion, it was transfected into COS7 cells by liposome. Its expression was analyzed by RT-PCR. RESULTS:A fragment of 1 011 bp was amplified, and sequence analysis showed it had a 98% homology with Leptospira kirschneri. The analysis of restriction enzyme indicated that the eukaryotic recombinant vector was correctly constructed. A specific amplified fragment was showed in the cells transfected with recombinant plasmid by RT-PCR, but the cell transfected with blank plasmid did not show this band. CONCLUSIONS:The LipL41 gene of Leptospira lai was successfully inserted into eukaryotic expression plasmid and the recombinant plasmid expressed the LipL41 mRNA. 相似文献
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AIM: To establish recombination plasmid pEGFP-NGB and to investigate the expression of pEGFP-NGB in culture neuroglia cells. METHODS: The NGB cds was isolated by using RT-PCR method with total RNA extracted from fetal Kunming mouse brain, then the NGB cds was cloned into the eukaryotic expression vector pEGFP-C1 of EGFP reported green fluorescence protein. The expression vector of recombinant plasmid pEGFP-NGB was successfully constructed. GeneJamer transfection reagent was used to transfer recombinant plasmid pEGFP-NGB into culture neuroglial cells. The mRNA and protein expression of pEGFP-NGB in culture neuroglial cells were investigated. RESULTS: The positive clone sequencing was consistent with the sequence of Genbank. The NGB mRNA and protein expression of pEGFP-NGB in culture neuroglial cells were detected at high levels. The high expression of green fluorescence protein was observed by fluorescence microscope in culture neuroglial cells. CONCLUSION: The expression vector of recombinant plasmid pEGFP-NGB was successfully constructed and green fluorescence protein was expressed in cultured neuroglial cells. 相似文献
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AIM: To investigate the role of B7 homologue 6 (B7-H6) over-expression in natural killer (NK) cell-mediated hepatocyte apoptosis. METHODS: The full-length fragment of B7-H6 gene was amplified by PCR and subcloned into linearized eukaryotic expression vector pIRES2-EGFP to construct recombinant B7-H6 over-expression vector pIRES2-EGFP-B7-H6. The recombinant plasmid was identified by double digestion, PCR and sequencing, and was then transfected into L02 cells. The expression of EGFP was observed by fluorescence microscopy and the transfection efficiency was evaluated by flow cytometry. B7-H6 expression was confirmed by qRT-PCR and Western blot. The L02 cells transfected with pIRES2-EGFP-B7-H6 recombinant plasmid were co-cultured with NK-92 cells at different effector/target ratios, and the cytotoxicity of NK-92 cells was evaluated by CCK-8 assay.RESULTS: The strong green fluorescence in the L02 cells was observed under fluorescence microscope 48 h after transfection. The transfection efficiency reached 92.6%. The expression of B7-H6 at mRNA and protein levels was remarkably increased 48 h after transfection. The cytotoxicity of NK-92 cells against L02 cells transfected with pIRES2-EGFP-B7-H6 plasmid was significantly higher than that of the null vector transfection group (P<0.05).CONCLUSION: The recombinant eukaryotic expression vector pIRES2-EGFP-B7-H6 was constructed successfully. The cytotoxic effect of NK-92 cells against L02 cells can be enhanced by transfecting L02 cells with pIRES2-EGFP-B7-H6 plasmid. 相似文献
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LI Long-guang LI Shu-hua WANG Hong-yan LONG Jie XIE Xiao-bin ZHANG Ya-jie 《园艺学报》2015,31(7):1203-1208
AIM: To construct a conditionally replicating adenovirus vector activated by CXCR4 promoter and to evaluate its ability of lysing the lung cancer cells specifically. METHODS: Human CXCR4-E1A gene amplified by PCR was cloned into the shuttle plasmid pDC316-GFP to construct the recombinant shuttle plasmid pDC316-CXCR4-GFP. The recombinat shuttle plasmid and adenovirus genomic plasmid pBHG-lox-E1, 3Cre were transfected into 293 cells to construct the recombinant adenovirus CRAd-CXCR4-GFP. PCR was used to detect the target gene fragments, and the viral titer was determined. A549 cells with the highest mRNA expression of CXCR4 were screened out from 5 kinds of lung cancer cell lines by real-time PCR. CXCR4 promoter activity and adenovirus replication numbers were detected in A549 cells after transfection of CRAd-CXCR4-GFP and Ad-NULL. CRAd-CXCR4-GFP and Ad-NULL were transfected into A549 cells and 16HBE cells, the apoptotic rates were detected by flow cytometry and the viability was analyzed by CCK-8 assay. RESULTS: The recombinant plasmid pDC316-CXCR4-GFP was constructed successfully. Green fluorescence was observed in 293 cells under fluorescent microscope after co-transfection of pDC316-CXCR4-GFP and pBHG-lox-E1, 3Cre at 11 d. Green fluorescence was observed in 293 cells after infection of amplified 3rd generational adenovirus. PCR showed that the purpose gene was successfully integrated in recombinant adenovirus genome. The virus in the supernatant reached a titer of 1×1013 PFU/L. The mRNA expression of E1A and E4 in the A549 cells after transfection of CRAd-CXCR4-GFP was markedly increased compared with Ad-NULL group. Compared with Ad-NULL group and empty control group, the apoptotic rate and the viability of A549 cells in CRAd-CXCR4-GFP group had no significant difference in the first 4 d, the apoptotic rate increased significantly at 5 d, and the cell viability declined significantly at 5 d, but the apoptotic rate and the viability of 16HBE cells in each group had no significant difference within 5 days. CONCLUSION: The conditionally replicating adenovirus vector CRAd-CXCR4-GFP has been successfully constructed, which has the ability of lysing lung cancer cells specifically. 相似文献
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ZHANG Wen-feng ZHANG Ju-feng SHAO Hong-wei WANG Jun-wei MOU Yan-fang HUANG Shu-lin 《园艺学报》2008,24(3):527-531
AIM: To construct the recombinant dicistronic eukaryotic expression vector pDC315-TCA-12-2-TCB-7.1, which containing T cell antigen receptor (TCR) genes TCA-12-2 and TCB-7.1, and to transfer this recombinant vector into 293 cells to investigate the expression of TCA-12-2 and TCB-7.1. METHODS: The TCA-12-2 was obtained by RT-PCR from the T cells and the TCB-7.1 was amplified by PCR from plamid pcDNA3.1-TCB-7.1 that we constructed before. TCA-12-2 and TCB-7.1 was cloned into vector pIRES2-AcGFP1 firstly, then subcloned into vector pDC315. The recombinant plasmid pDC315-TCA-12-2-TCB-7.1 was verified by restriction enzyme digestion and sequencing, the positive recombinant plasmid was transferred into 293 cells using Lipofectamine 2000. The expressions of gene TCA-12-2 and TCB-7.1 were identified by RT-PCR and flow cytometry. RESULTS: Both TCA-12-2 and TCB-7.1 genes were constructed into eukaryotic expression vector pDC315 and the expressions of genes in 293 cells were detected successfully with RT-PCR and flow cytometry. CONCLUSION: The dicistronic expression vector pDC315-TCA-12-2-TCB-7.1 is successfully constructed and expressed. 相似文献
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HAN Li-hui SUN Wen-sheng LIU Su-xia JIA Xiao-qing WANG Xiao-yan MA Chun-hong GAO Li-fen ZHANG Li-ning CAO Ying-lin 《园艺学报》2005,21(8):1486-1490
AIM: To explore the effect of TNF-related apoptosis inducing ligand (TRAIL), a new apoptotic inducing molecule on the biological activity of hepatocarcinoma cell line. METHODS: The expression of membrane binding TRAIL on HepG2 cells was detected by immuno-cytochemistry. Quantity of secretory TRAIL was assayed by ELISA method. The cytotoxicity and apoptosis induced by TRAIL was detected by MTT and TUNEL method, respectively. The telomerase activity of HepG2 cells was detected by TRAP-PCR assay kit. The expression of hTERT, the catalytic subunit of telomerase, was detected by FCM. RESULTS: TRAIL was constitutively expressed on the membrane of HepG2 cell line. Soluble TRAIL was also expressed to a certain degree. Cytotoxicity assay showed that TRAIL significantly inhibited the growth of hepatocarcinoma cells. TUNEL assay indicated that TRAIL induced apoptosis in hepatocarcinoma cells. Detection of telomerase activity showed that TRAIL inhibited telomerase activity and the expression of telomerase catalytic subunit. CONCLUSION: TRAIL is an effective molecule to inhibit the growth of hepatocarcinoma through multiple pathways, such as inducing apoptosis and inhibiting the activity of telomerase. 相似文献