目的测定中药柴胡(Bupleurun Chinese DC, BCDC)提取物对人肝癌细胞BEL-7402细胞内游离钙离子浓度([Ca2+]i)的影响,以探索柴胡逆转BEL-7402细胞多药耐药的机制.方法以Fura-2/AM为细胞内钙离子的荧光指示剂,用双波长荧光分光光度计分别...目的测定中药柴胡(Bupleurun Chinese DC, BCDC)提取物对人肝癌细胞BEL-7402细胞内游离钙离子浓度([Ca2+]i)的影响,以探索柴胡逆转BEL-7402细胞多药耐药的机制.方法以Fura-2/AM为细胞内钙离子的荧光指示剂,用双波长荧光分光光度计分别测定不同条件下的BEL-7402细胞内[Ca2+]i.结果柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降(P<0.001).结论柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降,为一种钙离子通道阻滞剂(Calcium channel blocker, CCB),提示钙离子通道阻滞作用为柴胡逆转BEL-7402细胞多药耐药的机制之一.展开更多
AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 prot...AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 proteins. METHODS BEL 7404 human hepatoma cells were maintained in RPMI 1640 medium supplemented with 10% new born calf serum. Cells adhered to coverslips were used to detect Fas and Bcl 2 protein expression by the avidin biotin complex (ABC) immunocytochemical assay. RESULTS Immunocytochemical study showed that essentially all the BEL 7404 human hepatoma cells could express Fas and Bcl 2 proteins, although in various amounts. No positive staining for Fas and Bcl 2 proteins was observed when cells were incubated with non relevant sera to establish the specificity. CONCLUSION Fas apoptosis signals and Bcl 2 rescue/survival signals from apoptosis are expressed in BEL 7404 human hepatoma cells. The finding strongly implys that AFP mediated cell apoptosis and growth enhancement are potentially associated with Fas and Bcl 2 proteins present in those cells.展开更多
Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulat...Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of "Death factor" family, the transfection experiments with expression vectors pcDNA3-fl and pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl-2. The data showed that the expression of FasL in pcDNA3-fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3-bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fl transient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hepatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.展开更多
AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth in...AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis. METHODS： Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization （ISH） and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-（4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium （MTT） bromide colorimetric assay. Celecoxib- induced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） and flow cytometry （FCM）. The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis. RESULTS： Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTT assays and morphological changes. The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 μmol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402 and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%,and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3 and dephosphorylation of Akt （Thr^308）. Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt （Thr^308） after treatment with celecoxib. CONCLUSION： COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner.展开更多
文摘AIM To study the expression of Fas and Bcl 2 proteins in BEL 7404 human hepatoma cells in order to analyze the possible relationship between cell growth regulation by alpha fetoprotein(AFP) and Fas/Bcl 2 proteins. METHODS BEL 7404 human hepatoma cells were maintained in RPMI 1640 medium supplemented with 10% new born calf serum. Cells adhered to coverslips were used to detect Fas and Bcl 2 protein expression by the avidin biotin complex (ABC) immunocytochemical assay. RESULTS Immunocytochemical study showed that essentially all the BEL 7404 human hepatoma cells could express Fas and Bcl 2 proteins, although in various amounts. No positive staining for Fas and Bcl 2 proteins was observed when cells were incubated with non relevant sera to establish the specificity. CONCLUSION Fas apoptosis signals and Bcl 2 rescue/survival signals from apoptosis are expressed in BEL 7404 human hepatoma cells. The finding strongly implys that AFP mediated cell apoptosis and growth enhancement are potentially associated with Fas and Bcl 2 proteins present in those cells.
基金Major State Basic Reaearch (973) Program of China.
文摘Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of "Death factor" family, the transfection experiments with expression vectors pcDNA3-fl and pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl-2. The data showed that the expression of FasL in pcDNA3-fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3-bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fl transient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hepatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.
基金Supported by Medical Science Research Foundation of Jiangsu Health Bureau Grant Z200314 (to JL)Medical Science Research Foundation of Nanjing Medical University Grant NY1999023 (to NBL) and CX2003012 (to JL)
文摘AIM： To investigate the cyclooxygenase-2 （COX-2） expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis. METHODS： Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization （ISH） and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-（4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium （MTT） bromide colorimetric assay. Celecoxib- induced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） and flow cytometry （FCM）. The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis. RESULTS： Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTT assays and morphological changes. The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 μmol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402 and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%,and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3 and dephosphorylation of Akt （Thr^308）. Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt （Thr^308） after treatment with celecoxib. CONCLUSION： COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner.
