Objective. To investigate the anti- tumor effects of human single chain interleukin- 12 (hscIL- 12). Method. pcDNA/ hscIL- 12 recombinant was transfected into human hepatic carcinoma cells (7721 cells) by lipofectin m...Objective. To investigate the anti- tumor effects of human single chain interleukin- 12 (hscIL- 12). Method. pcDNA/ hscIL- 12 recombinant was transfected into human hepatic carcinoma cells (7721 cells) by lipofectin method. The 7721/hscIL- 12 cells which secrete hscIL- 12 stably, were obtained via G418 selection, and in vitro the influence of hscIL- 12 gene transduction on the growth of tumor cells was evaluated by cell cycle analysis. In vivo, genetically engineered 7721 cells (7721/hscIL- 12, 7721/pcDNA) and parental cells were implanted into BALB/c nude mice,respectively. 7721/pcDNA and 7721/hscIL- 12 groups were divided into two sub- groups on day 8: one was administered with hPBL twice, 6 days at interval; the other was given equal volume of PBS. Mice were sacrificed on day 26, and spleens and tumors were taken out for histologic assay. Results. hscIL- 12 produced stably by 7721/hscIL- 12 cells had bioactivity, and it was proved by Western blot, immunocytochemistry, and in situ hybridization. In vitro, compared with 7721 and 7721/pcDNA, the 7721/hscIL- 12 grew much more slowly. FACS assay showed apparent G1 arrest of 7721/hscIL- 12 cells. In animal experiment, on day 8 after inoculation, the tumors of 7721 and 7721/pcDNA group were up to 5~ 7mm,while those of 7721/hscIL- 12 group were 2~ 4mm.When treated with hPBL, the tumor of 7721/hscIL- 12 group disappeared completely. Histologically, the tumors from 7721/hscIL- 12 without hPBL treatment had numerous lymphocyte infiltration, the tumor cells displayed depression looking, atrophy, focal necrosis and apoptosis , whereas the tumors of 7721 and 7721/pcDNA groups grew thrivingly. Conclusion. hscIL- 12 transduced 7721 cells could induced significant antitumor immune response which resulted in tumor regression totally when the hPBL was inoculated, and also hscIL- 12 has certain effects on mice immune system. These findings suggest that hscIL- 12 and hscIL- 12 gene therapy might have promising prospects in clinical application.展开更多
To investigate the role of bax in a vincristine (VCR) induced multidrug resistant (MDR) human gastric cancer cell line, SGC7901/VCR, in which the Bax protein expression level was significantly lower compared with th...To investigate the role of bax in a vincristine (VCR) induced multidrug resistant (MDR) human gastric cancer cell line, SGC7901/VCR, in which the Bax protein expression level was significantly lower compared with that in parent cells Methods A bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells by lipofectamine, and resistant clones were selected by G418 Western blotting detected Bax expression in transfectants Tetrazolium blue (MTT) assay evaluated the differences in drug sensitivity and cell cycle changes of transfectants were analyzed using flowcytometry (FCM) Results The bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells Through G418 selection, resistant clones were obtained Western blotting demonstrated that the expression of Bax protein was markedly increased in bax transduced cells These cells were more sensitive to adriamycin (ADR) and VCR than mock vector transducted cells Moreover, bax transfection enhanced ADR induced apoptosis and VCR induced G 2/M phase arrest of SGC7901/VCR cells Conclusion Bax was involved in the MDR of SGC7901/VCR cells展开更多
Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA...Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA795 cell lines). Two IL15 highly expressed cell clones PG1 and LA795A were used to inoculate the nude mice and the T739 syngeneic mice respectively. PG1 cell express higher level of class ⅠMHC molecule on their surface than PG cells. It was shown that the modified LA795A tumor cells grew slowly in T739 mice and induced high levels of CTL/NK/LAK activity in vivo as well, compared with the case of inoculation with LA795 or LA795neo. No significant difference in the tumor growth was observed in groups of the nude mice inoculated by PG1, PG and PGneo cells respectively, except the gene modified cells could not show the lung metastasis of tumors. The supernatants derived from the LA795A cell culture could promote CTL/NK/LAK activity from the whole splenocytes and the CD4/CD8deleted splenic cells in vitro. The results indicated that the IL15 gene transfected tumor cells play important roles in the process of antitumor or antitumor metastasis.展开更多
BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immuno...BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction. OBJECTIVE: To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid (shRNA) into Neuro 2a cells using a lentiviral vector.DESIGN: TiME-AND SETTING: An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008. MATERIALS: PLL3.7, PCMV-VSV-G, and PH'8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.METHODS: Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.MAIN OUTCOME MEASURES: Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS: The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION: Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.展开更多
Objective To determine over-expression of a truncated type ⅡTGF-β receptor in down-regulating TGF-β1 auto production in normal dermal fibroblasts. Methods In vitro cultured dermal fibroblasts were treated with rhT...Objective To determine over-expression of a truncated type ⅡTGF-β receptor in down-regulating TGF-β1 auto production in normal dermal fibroblasts. Methods In vitro cultured dermal fibroblasts were treated with rhTGF-β1 (5ng/ml) or recombinant adenovirus containing α truncated type Ⅱ TGF-β receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-β1 were observed with Northern Blot. Results rh TGF-β1 up-regulated the gene expression of TGF-β1, (34 %-150%) and type Ⅰ pro-collagen( 13 %- 190%). Overexpression of a truncated receptor Ⅱ decreased the gene expression of TGF-β1 (53%-66%). Conclusion Over-expression of the truncated TGF-β receptor Ⅱdown-regulated TGF-β1 autoproduction via blocking signal transduction of TGF-β. This study may provide a new strategy for scar gene therapy.展开更多
Horizontal gene transfer(HGT)in the microbiome has profound consequences for human health and disease.The spread of antibiotic resistance genes,virulence,and pathogenicity determinants predominantly occurs by way of H...Horizontal gene transfer(HGT)in the microbiome has profound consequences for human health and disease.The spread of antibiotic resistance genes,virulence,and pathogenicity determinants predominantly occurs by way of HGT.Evidence exists of extensive horizontal transfer in the human gut microbiome.Phage transduction is a type of HGT event in which a bacteriophage transfers non-viral DNA from one bacterial host cell to another.The abundance of tailed bacteriophages in the human gut suggests that transduction could act as a significant mode of HGT in the gut microbiome.Here we review in detail the known mechanisms of phage-mediated HGT,namely specialized and generalized transduction,lateral transduction,gene-transfer agents,and molecular piracy,as well as methods used to detect phage-mediated HGT,and discuss its potential implications for the human gut microbiome.展开更多
文摘Objective. To investigate the anti- tumor effects of human single chain interleukin- 12 (hscIL- 12). Method. pcDNA/ hscIL- 12 recombinant was transfected into human hepatic carcinoma cells (7721 cells) by lipofectin method. The 7721/hscIL- 12 cells which secrete hscIL- 12 stably, were obtained via G418 selection, and in vitro the influence of hscIL- 12 gene transduction on the growth of tumor cells was evaluated by cell cycle analysis. In vivo, genetically engineered 7721 cells (7721/hscIL- 12, 7721/pcDNA) and parental cells were implanted into BALB/c nude mice,respectively. 7721/pcDNA and 7721/hscIL- 12 groups were divided into two sub- groups on day 8: one was administered with hPBL twice, 6 days at interval; the other was given equal volume of PBS. Mice were sacrificed on day 26, and spleens and tumors were taken out for histologic assay. Results. hscIL- 12 produced stably by 7721/hscIL- 12 cells had bioactivity, and it was proved by Western blot, immunocytochemistry, and in situ hybridization. In vitro, compared with 7721 and 7721/pcDNA, the 7721/hscIL- 12 grew much more slowly. FACS assay showed apparent G1 arrest of 7721/hscIL- 12 cells. In animal experiment, on day 8 after inoculation, the tumors of 7721 and 7721/pcDNA group were up to 5~ 7mm,while those of 7721/hscIL- 12 group were 2~ 4mm.When treated with hPBL, the tumor of 7721/hscIL- 12 group disappeared completely. Histologically, the tumors from 7721/hscIL- 12 without hPBL treatment had numerous lymphocyte infiltration, the tumor cells displayed depression looking, atrophy, focal necrosis and apoptosis , whereas the tumors of 7721 and 7721/pcDNA groups grew thrivingly. Conclusion. hscIL- 12 transduced 7721 cells could induced significant antitumor immune response which resulted in tumor regression totally when the hPBL was inoculated, and also hscIL- 12 has certain effects on mice immune system. These findings suggest that hscIL- 12 and hscIL- 12 gene therapy might have promising prospects in clinical application.
文摘To investigate the role of bax in a vincristine (VCR) induced multidrug resistant (MDR) human gastric cancer cell line, SGC7901/VCR, in which the Bax protein expression level was significantly lower compared with that in parent cells Methods A bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells by lipofectamine, and resistant clones were selected by G418 Western blotting detected Bax expression in transfectants Tetrazolium blue (MTT) assay evaluated the differences in drug sensitivity and cell cycle changes of transfectants were analyzed using flowcytometry (FCM) Results The bax eukaryotic expression vector was constructed and transfected into SGC7901/VCR cells Through G418 selection, resistant clones were obtained Western blotting demonstrated that the expression of Bax protein was markedly increased in bax transduced cells These cells were more sensitive to adriamycin (ADR) and VCR than mock vector transducted cells Moreover, bax transfection enhanced ADR induced apoptosis and VCR induced G 2/M phase arrest of SGC7901/VCR cells Conclusion Bax was involved in the MDR of SGC7901/VCR cells
文摘Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA795 cell lines). Two IL15 highly expressed cell clones PG1 and LA795A were used to inoculate the nude mice and the T739 syngeneic mice respectively. PG1 cell express higher level of class ⅠMHC molecule on their surface than PG cells. It was shown that the modified LA795A tumor cells grew slowly in T739 mice and induced high levels of CTL/NK/LAK activity in vivo as well, compared with the case of inoculation with LA795 or LA795neo. No significant difference in the tumor growth was observed in groups of the nude mice inoculated by PG1, PG and PGneo cells respectively, except the gene modified cells could not show the lung metastasis of tumors. The supernatants derived from the LA795A cell culture could promote CTL/NK/LAK activity from the whole splenocytes and the CD4/CD8deleted splenic cells in vitro. The results indicated that the IL15 gene transfected tumor cells play important roles in the process of antitumor or antitumor metastasis.
基金Open Foundation of Key Laboratory of Biomedical Engineering,Guangdong Province,No.21030400Key Project of Guangzhou Medical and Health Care Foundation,No. 2006-ZDi-04
文摘BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction. OBJECTIVE: To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid (shRNA) into Neuro 2a cells using a lentiviral vector.DESIGN: TiME-AND SETTING: An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008. MATERIALS: PLL3.7, PCMV-VSV-G, and PH'8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.METHODS: Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.MAIN OUTCOME MEASURES: Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS: The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION: Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.
基金Supported by Shanghai Science and Technology Development Foundation(00JC14032)
文摘Objective To determine over-expression of a truncated type ⅡTGF-β receptor in down-regulating TGF-β1 auto production in normal dermal fibroblasts. Methods In vitro cultured dermal fibroblasts were treated with rhTGF-β1 (5ng/ml) or recombinant adenovirus containing α truncated type Ⅱ TGF-β receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-β1 were observed with Northern Blot. Results rh TGF-β1 up-regulated the gene expression of TGF-β1, (34 %-150%) and type Ⅰ pro-collagen( 13 %- 190%). Overexpression of a truncated receptor Ⅱ decreased the gene expression of TGF-β1 (53%-66%). Conclusion Over-expression of the truncated TGF-β receptor Ⅱdown-regulated TGF-β1 autoproduction via blocking signal transduction of TGF-β. This study may provide a new strategy for scar gene therapy.
基金financial support from Science Foundation Ireland[grant number SFI/12/RC/2273_P2]and Wellcome Trust under a Wellcome Trust Research Career Development Fellowship[220646/Z/20/Z](A.N.S.)whole,or in part,by the Wellcome Trust[220646/Z/20/Z].
文摘Horizontal gene transfer(HGT)in the microbiome has profound consequences for human health and disease.The spread of antibiotic resistance genes,virulence,and pathogenicity determinants predominantly occurs by way of HGT.Evidence exists of extensive horizontal transfer in the human gut microbiome.Phage transduction is a type of HGT event in which a bacteriophage transfers non-viral DNA from one bacterial host cell to another.The abundance of tailed bacteriophages in the human gut suggests that transduction could act as a significant mode of HGT in the gut microbiome.Here we review in detail the known mechanisms of phage-mediated HGT,namely specialized and generalized transduction,lateral transduction,gene-transfer agents,and molecular piracy,as well as methods used to detect phage-mediated HGT,and discuss its potential implications for the human gut microbiome.