Background Bcl-2, the anti-apoptotic protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of Bcl-2, RNA interference （RNAi） was used t...Background Bcl-2, the anti-apoptotic protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of Bcl-2, RNA interference （RNAi） was used to inhibit Bcl-2 expression in the human gastric cancer cells in vitro and in vivo. Methods Bcl-2 small interfering RNA （siRNA） was transfected into human gastric cancer cells $GC-7901, and Bcl-2 expression was monitored by real-time polymerase chain reaction （PCR） and Western blot. Cell proliferation, apoptosis, and telomerase activity were examined by MTT, flow cytometry, and TRAP assay, respectively. Gastric cancer cells treated with 100 nmol/L Bcl-2 siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. Results Bcl-2 siRNA significantly inhibited the expression of Bcl-2 in human gastric cancer cells at both mRNA and protein levels in a time- and dose-dependent manner. Bcl-2 siRNA also decreased telomerase activity （by 78.76%） and increased the rate of apoptosis （by 37.47%）. SGC-7901 cell growth was also significantly suppressed in vivo and in vitro. Conclusions Bcl-2 expression knockdown suppressed the growth of gastric cancer cells. Thus, Bcl-2 may play a very important role in carcinogenesis of gastric cancer and its knockdown may offer a new potential gene therapy approach for human gastric cancer in future.展开更多
Objective The aim of this review was to assess RNA interference (RNAi) and its possibility as a potential and powerful tool to develop highly specific double-stranded RNA ( dsRNA) or small interfering RNA (siRNA) base...Objective The aim of this review was to assess RNA interference (RNAi) and its possibility as a potential and powerful tool to develop highly specific double-stranded RNA ( dsRNA) or small interfering RNA (siRNA) based gene-silencing therapeutics. Data sources The data used in this review were obtained from the current RNAi-related research reports. Study selection dsRNA-mediated RNAi has recently emerged as a powerful reverse genetic tool to silence, gene expression in multiple organisms. The discovery that synthetic duplexes of 21 nucleotides siRNAs trigger gene-specific silencing in mammalian cells has further expanded the utility of RNAi in to the mammalian system. Data extraction The currently published papers reporting the discovery and mechanism of RNAi phenomena and application of RNAi on gene function in mammalian cells were included. Data synthesis Since the recent development of RNAi technology in the mammalian system, investigators have used RNAi to elucidate gene function, and to develop gene-based therapeutics by delivery exogenous siRNA or siRNA expressing vector. The general and sequence-specific inhibitory effects of RNAi that will be selective, long-term, and systemic to modulate gene targets mentioned in similar reports have caused much concern about its effectiveness in mammals and its eventual use as a therapeutic mordality. Conclusions It is certain that the ability of RNAi in mammals to silence specific genes, either when transfected directly as siRNAs or when generated from DNA vectors, will undoubtedly accelerate the study of gene function and might also be used as a potentially useful method to develop highly gene-specific therapeutic methods. It is also expected that RNAi might one day be used to treat human diseases.展开更多
To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 pL shRNA- aquapo...To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 pL shRNA- aquaporin-4 （control group） or siRNA- aquaporin-4 solution （1：800） （RNA interference group） into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25- 6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5 4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson＇s correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient （r = -0.806, P 〈 0.01）. These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracelfular edema with time-effectiveness. Moreover, diffusion-wei展开更多
CD59, belonging to membrane complement regulatory proteins （mCRPs）, inhibits the cytolytic activity of complement and is over-expressed in solid cancers, including ovary cancer. The aim of the present study was to c...CD59, belonging to membrane complement regulatory proteins （mCRPs）, inhibits the cytolytic activity of complement and is over-expressed in solid cancers, including ovary cancer. The aim of the present study was to construct recombinant retrovirus encoding shRNA targeted human CD59 and infect A2780 cells in order to investigate the relationship between decreased CD59 expression and tumorigenesis of ovary cancer, siCD59 and siCD59-C were successfully constructed and identified by PCR, restriction endonuclease analyses and DNA sequencing, respectively. The siCD59 was able to efficiently infect A2780 cells, which was confirmed by Western blotting. When incubated with fresh normal human serum （8%, v/v） for 1 h at 37℃, the cell viability was decreased and cell damage was increased in siCD59 infected A2780 cells compared to siCD59-C infected cells. This led to the activation of caspase-3. The apoptosis in siCD59 infected cells was shown with hypercondensed nuclei using Hoechst staining. Meanwhile, the weight of ovary tumor graft in nude mice was significantly decreased in siCD59 group compared to that of siCD59-C group. And the expression of CD59 protein in tumor tissue in siCD59 group was significantly decreased. These results suggested that CD59 silencing in ovary cancer cells v/a retrovirusmediated RNAi can enhance complement-mediated cell damage, inhibiting growth of ovary cancer. CD59 might be a potential target for gene therapy in ovary cancer. Cellular ＆ Molecular Immunology.展开更多
RNA interference （RNAi） suppresses the expression of target genes by post- transcriptional regulation. Because double-stranded RNA （dsRNA） mediated gene silenc- ing is a conserved mechanism in many eukaryotes, RNA...RNA interference （RNAi） suppresses the expression of target genes by post- transcriptional regulation. Because double-stranded RNA （dsRNA） mediated gene silenc- ing is a conserved mechanism in many eukaryotes, RNAi has become a valuable tool for unveiling gene function in many model insects. Recent research has also shown that RNAi can also be effective in the downregulation of target genes in Hemiptera. In this review, we discuss the use of the RNAi technique in gene functional analysis in hemipterans, highlighting the methods of dsRNA uptake by these insects and discuss the knock-down efficiency of these techniques. Although the RNAi technique has disadvantages, our pri- mary goal here is to determine whether it can be exploited further in the discovery of new ~ene functions, and as a oest control strategy, in some important HemiDteran oests.展开更多
基金the grants from Shanghai Medical Key Discipline (No.05Ⅲ005)the National High Technology and Development Program of China(863 Program,No.2002BA7111A06).
文摘Background Bcl-2, the anti-apoptotic protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of Bcl-2, RNA interference （RNAi） was used to inhibit Bcl-2 expression in the human gastric cancer cells in vitro and in vivo. Methods Bcl-2 small interfering RNA （siRNA） was transfected into human gastric cancer cells $GC-7901, and Bcl-2 expression was monitored by real-time polymerase chain reaction （PCR） and Western blot. Cell proliferation, apoptosis, and telomerase activity were examined by MTT, flow cytometry, and TRAP assay, respectively. Gastric cancer cells treated with 100 nmol/L Bcl-2 siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. Results Bcl-2 siRNA significantly inhibited the expression of Bcl-2 in human gastric cancer cells at both mRNA and protein levels in a time- and dose-dependent manner. Bcl-2 siRNA also decreased telomerase activity （by 78.76%） and increased the rate of apoptosis （by 37.47%）. SGC-7901 cell growth was also significantly suppressed in vivo and in vitro. Conclusions Bcl-2 expression knockdown suppressed the growth of gastric cancer cells. Thus, Bcl-2 may play a very important role in carcinogenesis of gastric cancer and its knockdown may offer a new potential gene therapy approach for human gastric cancer in future.
文摘Objective The aim of this review was to assess RNA interference (RNAi) and its possibility as a potential and powerful tool to develop highly specific double-stranded RNA ( dsRNA) or small interfering RNA (siRNA) based gene-silencing therapeutics. Data sources The data used in this review were obtained from the current RNAi-related research reports. Study selection dsRNA-mediated RNAi has recently emerged as a powerful reverse genetic tool to silence, gene expression in multiple organisms. The discovery that synthetic duplexes of 21 nucleotides siRNAs trigger gene-specific silencing in mammalian cells has further expanded the utility of RNAi in to the mammalian system. Data extraction The currently published papers reporting the discovery and mechanism of RNAi phenomena and application of RNAi on gene function in mammalian cells were included. Data synthesis Since the recent development of RNAi technology in the mammalian system, investigators have used RNAi to elucidate gene function, and to develop gene-based therapeutics by delivery exogenous siRNA or siRNA expressing vector. The general and sequence-specific inhibitory effects of RNAi that will be selective, long-term, and systemic to modulate gene targets mentioned in similar reports have caused much concern about its effectiveness in mammals and its eventual use as a therapeutic mordality. Conclusions It is certain that the ability of RNAi in mammals to silence specific genes, either when transfected directly as siRNAs or when generated from DNA vectors, will undoubtedly accelerate the study of gene function and might also be used as a potentially useful method to develop highly gene-specific therapeutic methods. It is also expected that RNAi might one day be used to treat human diseases.
基金supported by the National Natural Science Foundation of China, No. 30960399, 81160181
文摘To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 pL shRNA- aquaporin-4 （control group） or siRNA- aquaporin-4 solution （1：800） （RNA interference group） into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25- 6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5 4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson＇s correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient （r = -0.806, P 〈 0.01）. These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracelfular edema with time-effectiveness. Moreover, diffusion-wei
基金supported by grants from the National Natural Science Foundation of China (No. 30671936).
文摘CD59, belonging to membrane complement regulatory proteins （mCRPs）, inhibits the cytolytic activity of complement and is over-expressed in solid cancers, including ovary cancer. The aim of the present study was to construct recombinant retrovirus encoding shRNA targeted human CD59 and infect A2780 cells in order to investigate the relationship between decreased CD59 expression and tumorigenesis of ovary cancer, siCD59 and siCD59-C were successfully constructed and identified by PCR, restriction endonuclease analyses and DNA sequencing, respectively. The siCD59 was able to efficiently infect A2780 cells, which was confirmed by Western blotting. When incubated with fresh normal human serum （8%, v/v） for 1 h at 37℃, the cell viability was decreased and cell damage was increased in siCD59 infected A2780 cells compared to siCD59-C infected cells. This led to the activation of caspase-3. The apoptosis in siCD59 infected cells was shown with hypercondensed nuclei using Hoechst staining. Meanwhile, the weight of ovary tumor graft in nude mice was significantly decreased in siCD59 group compared to that of siCD59-C group. And the expression of CD59 protein in tumor tissue in siCD59 group was significantly decreased. These results suggested that CD59 silencing in ovary cancer cells v/a retrovirusmediated RNAi can enhance complement-mediated cell damage, inhibiting growth of ovary cancer. CD59 might be a potential target for gene therapy in ovary cancer. Cellular ＆ Molecular Immunology.
文摘RNA interference （RNAi） suppresses the expression of target genes by post- transcriptional regulation. Because double-stranded RNA （dsRNA） mediated gene silenc- ing is a conserved mechanism in many eukaryotes, RNAi has become a valuable tool for unveiling gene function in many model insects. Recent research has also shown that RNAi can also be effective in the downregulation of target genes in Hemiptera. In this review, we discuss the use of the RNAi technique in gene functional analysis in hemipterans, highlighting the methods of dsRNA uptake by these insects and discuss the knock-down efficiency of these techniques. Although the RNAi technique has disadvantages, our pri- mary goal here is to determine whether it can be exploited further in the discovery of new ~ene functions, and as a oest control strategy, in some important HemiDteran oests.
