The cytosolic liver-specific growth factor-hepatic stimulator substance (HSS) has been shown to be able to amplify the rat hepatocyte proliferation responded to EGF. In order to get more insight into the mechanism, th...The cytosolic liver-specific growth factor-hepatic stimulator substance (HSS) has been shown to be able to amplify the rat hepatocyte proliferation responded to EGF. In order to get more insight into the mechanism, the regulatory effect of HSS on EGF-receptor(EGF-R) and the receptor phosphorylation at molecular level was studied. HSS partially purified from weanling rat liver was given to cultured hepatocytes and its influence on EGF-R specific binding and internalization as well as mRNA expression were investigated. The results showed that preincubation of hepatocytes with HSS could lead to an increase in [125I]-EGF binding to its receptors and inhibit EGFinduced receptor down-regulation. Furthermore, the overexpression of EGF-R mRNA stimulated by HSS was seen during 2-12 h after the incubation. Additionally, it was demonstrated with human hepatoma sMMC-7721 cells in Western blot that the EGF-R expression and the receptor autophosphorylation were increased with dose/timedependency after HSS treatment. These results strongly suggest that the mechanism of HSS action on hepatocyte growth might be related to its modulation on EGF-R and receptor-mediated signaling transduction.展开更多
AIM： To evaluate whether the combination of recom- binant chicken fibroblast growth factor receptor -1 （FGFR-1） protein vaccine （cFR-I） combined with low- dose gemcitabine would improve anti-tumor efficacy in a m...AIM： To evaluate whether the combination of recom- binant chicken fibroblast growth factor receptor -1 （FGFR-1） protein vaccine （cFR-I） combined with low- dose gemcitabine would improve anti-tumor efficacy in a mouse CT26 colon adenocarcinoma （CT26） model.METHODS： The CT26 model was established in BABL/c mice. Seven days after tumor ceil injection, mice were randomly divided into four groups： combination therapy, cFR-1 alone, gemcitabine alone, and normal saline groups. Tumor growth, survival rate of tumor-bearing mice, and systemic toxicity were observed. The presence of anti-tumor auto-antibodies was detected by Western blot analysis and enzyme-linked immunospot assay, microvessel density （MVD） of the tumors and tumor cell proliferation were detected by Immunohistochemistry staining, and tumor cell apoptosis was detected by TdT- mediated biotinylated-dUTP nick end label staining.RESULTS： The combination therapy results in apparent decreases in tumor volume, microvessel density and tumor cell proliferation, and an increase in apoptosis without obvious side-effects as compared with either therapy alone or normal control groups. Also, both auto- antibodies and the antibody-producing B cells against mouse FGFR-1 were detected in mice immunized with cFR-1 vaccine alone or with combination therapy, but not in non-immunized mice. In addition, the deposition of auto-antibodies on endothelial cells from mice immunized with cFR-1 was observed by immunofluorescent stain- ing, but not on endothelial cells from control groups. Synergistic indexes of tumor volume, MVD, cell apoptosis and proliferation in the combination therapy group were 1.71 vs 1.15 vs 1.11 and 1.04, respectively, 31 d after tumor cell injection.CONCLUSION： The combination of cFR-l-mediated antiangiogenesis and low-dose gemcitabine synergistically enhances the anti-tumor activity without overt toxicity in mice.展开更多
OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was ins...OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was inserted intopGenesil-1-U6 to construct the recombinant plasmid pGenesil-1-U6-cyclinE1. The identified recombinant plasmid was introducedinto ACHN cells with lipofectamine 2000. The inhibition ofcyclinE1 mRNA and protein expression were analyzed by RT-PCRand western-blotting. MTT method was used for observing cellproliferation and drawing growth curve. The cell cycle and ratiosof apoptotic cell were assessed by flow cytometric detection. Theability of invasion and speed of cell migration were detected bytranswell chamber invasive models and cell scratch method.RESULTS The inhibition of expression of cyclinE1 in ACHN cellsmediated by recombinant vector (0.0933 ± 0.05) was significantlylower than that in the group of transfected with empty vector(0.8827 ± 0.04) and the control group (0.9021 ± 0.03) (P < 0.05).Flow cytometry showed that recombinant cells were blocked inthe G_1 phase and the apoptotic ratio was increased significantly(11.15 ± 4.00)% (P < 0.05). The curves of cell growth indicated thatthe proliferation of cell transfected with recombinant plasmid wasinhibited significantly compared with that in control group (P <0.05). The results of transwell and cell scratch suggested that theabilities of invasion and migration of the cells transfected withrecombinant plasmid were decreased conspicuously (P < 0.05).CONCLUSION The expression of cyclinE1 could be inhibitedsuccessfully by RNA interference induced by shRNA expressionvector. This consequently inhibits the cell growth and inducesapoptosis. Our study provided a preliminary result in searching ofRNA interference (RNAi) therapy for renal cell carcinoma.展开更多
Interleukin-3 （IL-3） deprivation of the mouse pro-B cell line Ba/F3 induces cell death that is abrogated by B-cell lymphoma 2 （Bcl-2） overexpression, but remains unaffected by the pan-caspase inhibitor carbobenzox...Interleukin-3 （IL-3） deprivation of the mouse pro-B cell line Ba/F3 induces cell death that is abrogated by B-cell lymphoma 2 （Bcl-2） overexpression, but remains unaffected by the pan-caspase inhibitor carbobenzoxy-valyl-analyl- aspartyl-[O-methyl]-fluoromethylketone （zVAD-fmk）. IL-3 withdrawal causes receptor-interacting protein （RIP）I cleavage into C-terminal fragments of 30 and 25 kDa, and only cleavage leading to the former was prevented by zVAD-fmk, siRNA experiments demonstrated that generation of the 25-kDa fragment was due to a Bcl-2-modulated release of the mitochondrial serine protease high temperature requirement protein A2 （HtrA2）/Omi. Accordingly, recombinant HtrA2/Omi efficiently cleaved mouse RIP1 in vitro, generating fragments matching those observed in IL-3-deprived Ba/F3 cells. The HtrA2/Omi cleavage site in mouse RIP1 was mapped to the intermediate domain and the corresponding N- and C-terminal fragments were impaired in their ability to activate nuclear factor-r,B, c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Interestingly, knockdown of HtrA2/Omi afforded pro- tection against IL-3 withdrawal-induced death in the presence of zVAD-fmk, demonstrating a role for HtrA2/Omi in caspase-independent cell death during growth factor withdrawal by cleaving RIP1.展开更多
文摘The cytosolic liver-specific growth factor-hepatic stimulator substance (HSS) has been shown to be able to amplify the rat hepatocyte proliferation responded to EGF. In order to get more insight into the mechanism, the regulatory effect of HSS on EGF-receptor(EGF-R) and the receptor phosphorylation at molecular level was studied. HSS partially purified from weanling rat liver was given to cultured hepatocytes and its influence on EGF-R specific binding and internalization as well as mRNA expression were investigated. The results showed that preincubation of hepatocytes with HSS could lead to an increase in [125I]-EGF binding to its receptors and inhibit EGFinduced receptor down-regulation. Furthermore, the overexpression of EGF-R mRNA stimulated by HSS was seen during 2-12 h after the incubation. Additionally, it was demonstrated with human hepatoma sMMC-7721 cells in Western blot that the EGF-R expression and the receptor autophosphorylation were increased with dose/timedependency after HSS treatment. These results strongly suggest that the mechanism of HSS action on hepatocyte growth might be related to its modulation on EGF-R and receptor-mediated signaling transduction.
基金Supported by the Natural Sciences Foundation of Hainan Province, No. 30321partly supported by the National Natural Sciences Foundation of China, No. 30660055
文摘AIM： To evaluate whether the combination of recom- binant chicken fibroblast growth factor receptor -1 （FGFR-1） protein vaccine （cFR-I） combined with low- dose gemcitabine would improve anti-tumor efficacy in a mouse CT26 colon adenocarcinoma （CT26） model.METHODS： The CT26 model was established in BABL/c mice. Seven days after tumor ceil injection, mice were randomly divided into four groups： combination therapy, cFR-1 alone, gemcitabine alone, and normal saline groups. Tumor growth, survival rate of tumor-bearing mice, and systemic toxicity were observed. The presence of anti-tumor auto-antibodies was detected by Western blot analysis and enzyme-linked immunospot assay, microvessel density （MVD） of the tumors and tumor cell proliferation were detected by Immunohistochemistry staining, and tumor cell apoptosis was detected by TdT- mediated biotinylated-dUTP nick end label staining.RESULTS： The combination therapy results in apparent decreases in tumor volume, microvessel density and tumor cell proliferation, and an increase in apoptosis without obvious side-effects as compared with either therapy alone or normal control groups. Also, both auto- antibodies and the antibody-producing B cells against mouse FGFR-1 were detected in mice immunized with cFR-1 vaccine alone or with combination therapy, but not in non-immunized mice. In addition, the deposition of auto-antibodies on endothelial cells from mice immunized with cFR-1 was observed by immunofluorescent stain- ing, but not on endothelial cells from control groups. Synergistic indexes of tumor volume, MVD, cell apoptosis and proliferation in the combination therapy group were 1.71 vs 1.15 vs 1.11 and 1.04, respectively, 31 d after tumor cell injection.CONCLUSION： The combination of cFR-l-mediated antiangiogenesis and low-dose gemcitabine synergistically enhances the anti-tumor activity without overt toxicity in mice.
基金supported by a grant from Major State Basic Research Development Program,China(No.2002CB513107).
文摘OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was inserted intopGenesil-1-U6 to construct the recombinant plasmid pGenesil-1-U6-cyclinE1. The identified recombinant plasmid was introducedinto ACHN cells with lipofectamine 2000. The inhibition ofcyclinE1 mRNA and protein expression were analyzed by RT-PCRand western-blotting. MTT method was used for observing cellproliferation and drawing growth curve. The cell cycle and ratiosof apoptotic cell were assessed by flow cytometric detection. Theability of invasion and speed of cell migration were detected bytranswell chamber invasive models and cell scratch method.RESULTS The inhibition of expression of cyclinE1 in ACHN cellsmediated by recombinant vector (0.0933 ± 0.05) was significantlylower than that in the group of transfected with empty vector(0.8827 ± 0.04) and the control group (0.9021 ± 0.03) (P < 0.05).Flow cytometry showed that recombinant cells were blocked inthe G_1 phase and the apoptotic ratio was increased significantly(11.15 ± 4.00)% (P < 0.05). The curves of cell growth indicated thatthe proliferation of cell transfected with recombinant plasmid wasinhibited significantly compared with that in control group (P <0.05). The results of transwell and cell scratch suggested that theabilities of invasion and migration of the cells transfected withrecombinant plasmid were decreased conspicuously (P < 0.05).CONCLUSION The expression of cyclinE1 could be inhibitedsuccessfully by RNA interference induced by shRNA expressionvector. This consequently inhibits the cell growth and inducesapoptosis. Our study provided a preliminary result in searching ofRNA interference (RNAi) therapy for renal cell carcinoma.
文摘Interleukin-3 （IL-3） deprivation of the mouse pro-B cell line Ba/F3 induces cell death that is abrogated by B-cell lymphoma 2 （Bcl-2） overexpression, but remains unaffected by the pan-caspase inhibitor carbobenzoxy-valyl-analyl- aspartyl-[O-methyl]-fluoromethylketone （zVAD-fmk）. IL-3 withdrawal causes receptor-interacting protein （RIP）I cleavage into C-terminal fragments of 30 and 25 kDa, and only cleavage leading to the former was prevented by zVAD-fmk, siRNA experiments demonstrated that generation of the 25-kDa fragment was due to a Bcl-2-modulated release of the mitochondrial serine protease high temperature requirement protein A2 （HtrA2）/Omi. Accordingly, recombinant HtrA2/Omi efficiently cleaved mouse RIP1 in vitro, generating fragments matching those observed in IL-3-deprived Ba/F3 cells. The HtrA2/Omi cleavage site in mouse RIP1 was mapped to the intermediate domain and the corresponding N- and C-terminal fragments were impaired in their ability to activate nuclear factor-r,B, c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Interestingly, knockdown of HtrA2/Omi afforded pro- tection against IL-3 withdrawal-induced death in the presence of zVAD-fmk, demonstrating a role for HtrA2/Omi in caspase-independent cell death during growth factor withdrawal by cleaving RIP1.
