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 action of apoptosis in occurrence ofliver cacinornas in vivo and the biological effect of Solanumlyratum Thumb on BEL-7404 cell line inducing apoptosis invitro.METHODS: The apoptosis in the liv...AIM: To investigate the action of apoptosis in occurrence ofliver cacinornas in vivo and the biological effect of Solanumlyratum Thumb on BEL-7404 cell line inducing apoptosis invitro.METHODS: The apoptosis in the liver carcinoma wasdetected with terminal deoxynucl neotidyl transferasemediated dUTP nick end labelling (TUNEL); the cancer cellscultured in DMED medium were treated with extract ofSolanum lyratum Thumb and observed under microscope,and their DNA was assayed by gel electrophoresis.RESULTS: In vivo apoptotic cells in the cancer adjacenttissues inceased; in vitro treatment of liver cancers withextract of Solanum lyratum Thumb could induce the cells tomanifest a typical apoptotic morphology. Their DNA wasfractured and a characteristic ladder pattem could be foundusing electrophoresis.CONCLUSION: In vivo the apoptosis of carcinomas waslower; maybe the cells divided quickly and then the cancersoccurred. In the cancer adjacent tissues, the apoptosispricked up, and in vitro Solarium lyratum Thumb couldinduce the apoptosis of BEL-7404 cells.展开更多
Effects of thapsigargin, an inhibitor of Ca2+-ATPase in surface of endoplasmic reticulum, on apoptotic cell death were studied in human hepatoma cells of BEL-7404 cell line by using both flow cytometry and electron mi...Effects of thapsigargin, an inhibitor of Ca2+-ATPase in surface of endoplasmic reticulum, on apoptotic cell death were studied in human hepatoma cells of BEL-7404 cell line by using both flow cytometry and electron mi-croscopy Propidium iodide staining and flow cytome- try revealed that in the serum-free condition, thapsigar-gin increased the rate of apoptosis of BEL- 7404 cells in a dose-dependent manner. Prolongation of the period of serum-free condition enhanced the apoptosis induced by thapsigargin treatment. Morphological observation with electron microscope further demonstrated that chromatin condensation and fragmentation, apoptotic bodies existed in TG-treated cells, supporting that thapsigargin is a po-tent activator of apoptosis in the cells.展开更多
Epidermal growth factor （EGF） induced intracellular free calcium ([Ca2+]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line. Single cell [Ca2+]i analysis and [Ca2+], measur...Epidermal growth factor （EGF） induced intracellular free calcium ([Ca2+]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line. Single cell [Ca2+]i analysis and [Ca2+], measurement in cell populations revealed that EGF triggered a rapid [Ca2+]iincrease in the dose-dependent and time- dependent manner. Pretreatment of cells with an endoplasmic reticulum （ER） Ca2+-ATPase inhibitor, thapsigargin （TG） at 100 nM concentration for 20 min, completely abolished EGF-induced [Ca2+]i increase, and chelating extracellular calcium by excess EGTA partially inhibited the increase.Furthermore, the expression of antisense EGF receptor sequence in BEL-7404 cells suppressed the [Ca2+]i response to EGF. The results suggest that EGF receptor-mediated [Ca2+]i increase in the human hepatoma cells is essentially dependent on the Ca2+ storage in ER.展开更多
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.
文摘AIM: To investigate the action of apoptosis in occurrence ofliver cacinornas in vivo and the biological effect of Solanumlyratum Thumb on BEL-7404 cell line inducing apoptosis invitro.METHODS: The apoptosis in the liver carcinoma wasdetected with terminal deoxynucl neotidyl transferasemediated dUTP nick end labelling (TUNEL); the cancer cellscultured in DMED medium were treated with extract ofSolanum lyratum Thumb and observed under microscope,and their DNA was assayed by gel electrophoresis.RESULTS: In vivo apoptotic cells in the cancer adjacenttissues inceased; in vitro treatment of liver cancers withextract of Solanum lyratum Thumb could induce the cells tomanifest a typical apoptotic morphology. Their DNA wasfractured and a characteristic ladder pattem could be foundusing electrophoresis.CONCLUSION: In vivo the apoptosis of carcinomas waslower; maybe the cells divided quickly and then the cancersoccurred. In the cancer adjacent tissues, the apoptosispricked up, and in vitro Solarium lyratum Thumb couldinduce the apoptosis of BEL-7404 cells.
文摘Effects of thapsigargin, an inhibitor of Ca2+-ATPase in surface of endoplasmic reticulum, on apoptotic cell death were studied in human hepatoma cells of BEL-7404 cell line by using both flow cytometry and electron mi-croscopy Propidium iodide staining and flow cytome- try revealed that in the serum-free condition, thapsigar-gin increased the rate of apoptosis of BEL- 7404 cells in a dose-dependent manner. Prolongation of the period of serum-free condition enhanced the apoptosis induced by thapsigargin treatment. Morphological observation with electron microscope further demonstrated that chromatin condensation and fragmentation, apoptotic bodies existed in TG-treated cells, supporting that thapsigargin is a po-tent activator of apoptosis in the cells.
文摘Epidermal growth factor （EGF） induced intracellular free calcium ([Ca2+]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line. Single cell [Ca2+]i analysis and [Ca2+], measurement in cell populations revealed that EGF triggered a rapid [Ca2+]iincrease in the dose-dependent and time- dependent manner. Pretreatment of cells with an endoplasmic reticulum （ER） Ca2+-ATPase inhibitor, thapsigargin （TG） at 100 nM concentration for 20 min, completely abolished EGF-induced [Ca2+]i increase, and chelating extracellular calcium by excess EGTA partially inhibited the increase.Furthermore, the expression of antisense EGF receptor sequence in BEL-7404 cells suppressed the [Ca2+]i response to EGF. The results suggest that EGF receptor-mediated [Ca2+]i increase in the human hepatoma cells is essentially dependent on the Ca2+ storage in ER.
