Death ligand mediated apoptotic activation is a mode of cell death that is widely used in cellular and physiological situations. Interest in studying death ligand induced apoptosis has increased due to the promising r...Death ligand mediated apoptotic activation is a mode of cell death that is widely used in cellular and physiological situations. Interest in studying death ligand induced apoptosis has increased due to the promising role of recombinant soluble forms of death ligands (mainly recombinant TRAIL) in anti-cancer therapy. A clear elucidation of how death ligands activate the type 1 and type 2 apoptotic pathways in healthy and cancer cells may help develop better chemotherapeutic strategies. In this work, we use kinetic Monte Carlo simulations to address the problem of type 1/ type 2 choice in death ligand mediated apoptosis of cancer cells. Our study provides insights into the activation of membrane proximal death module that results from complex interplay between death and decoy receptors. Relative abundance of death and decoy receptors was shown to be a key parameter for activation of the initiator caspases in the membrane module. Increased concentration of death ligands frequently increased the type 1 activation fraction in cancer cells, and, in certain cases changed the signaling phenotype from type 2 to type 1. Results of this study also indicate that inherent differences between cancer and healthy cells, such as in the membrane module, may allow robust activation of cancer cell apoptosis by death ligand induction. At the same time, large cell-to-cell variability through the type 2 pathway was shown to provide protection for healthy cells. Such elucidation of selective activation of apoptosis in cancer cells addresses a key question in cancer biology and cancer therapy.展开更多
Objective： To investigate the effects of xanthotoxin from Apiaceae medicinal plants on cell proliferation and apoptosis, and explore its mechanism of action against human gastric carcinoma SGC-7901 cells in vitro.Met...Objective： To investigate the effects of xanthotoxin from Apiaceae medicinal plants on cell proliferation and apoptosis, and explore its mechanism of action against human gastric carcinoma SGC-7901 cells in vitro.Methods： SGC-7901, HepG-2, MCF-7, and A549 cells were treated with different concentrations of xanthotoxin（10, 20, 60, 80, 100, 120, 140, and 160 μg/mL） for 48 h, and the cell viability（IC50） was determined by MTT assay; Xanthotoxin-induced apoptosis in cells was observed by using Hoechst 33258 Staining Kit and Annexin V-FITC Apoptosis Detection Kit; Flow cytometry was used to detect apoptosis related proteins of Fas/FasL, Bid, and DR5/TRAIL proteins in human gastric carcinoma SGC-7901 cells after being treated by xanthotoxin; The influence of xanthotoxin on Caspase-8 protein expression in the cells was determined by Flouormetric Assay Kit.Results： Xanthotoxin obviously inhibited SGC-7901, HepG-2, MCF-7, and A549 cells proliferation, and its inhibition was in a concentration-dependent manner; flow cytometry results showed that in a certain concentration range, xanthotoxin can increase the expression levels of Fas/FasL and DR5/TRAIL proteins in a concentration-dependence manner. The content of Bid protein in cells was increased, and it showed concentration-dependence.Conclusion： Xanthotoxin may induce SGC-7901 cells apoptosis in a certain concentration range through the Fas/FasL protein mediated death receptor pathway, or by DR5/TRAIL mediated death receptor pathway, and increase the expression level of death receptor protein, activation Caspase-8, activating downstream effect factor, inducing cell apoptosis, or activate Caspase-8 cutting activate protein Bid, and then enter the mitochondrial pathway, induction of apoptosis.展开更多
The apoptosis inducing effects on tumor cell lines MGC803, BEL7402 and HL60 by Fas ligand and anti-human DR5 monoclonal antibodies （anti-DR5 mAb） and the underlying mechanism was studied. Fas/DR5 mRNA was detected b...The apoptosis inducing effects on tumor cell lines MGC803, BEL7402 and HL60 by Fas ligand and anti-human DR5 monoclonal antibodies （anti-DR5 mAb） and the underlying mechanism was studied. Fas/DR5 mRNA was detected by RT-PCR. Cytotoxicity exerted by FasL/anti-DR5 mAb on tumor cell lines was measured by MTT assay and the induced apoptosis was determined by agarose gel electrophoresis. Flow cytometry was employed to analyze the mode of cell death. The mRNA expression of DR5 in MGC803 and BEL7402 cells after giving anti-DR5 mAb was up-regulated compared with control group, while it was down-regulated in HL60 cells in the same condition. The mRNA expression of Fas in HL60 was higher after giving FasL compared with control group, while it was lower in MGC803 and BEL7402. MGC803 and BEL7402 were sensitive to anti-DR5 mAb but partially to FasL, and HL60 was sensitive to FasL but less sensitive to anti-DR5 mAb. Apoptosis induced by Fas ligand and anti-DR5 mAb vary among tumor cell lines. The underlying mechanism may be relevant to Fas/DR5 mRNA expression, which was presented as the release of caspase-8 and Bcl-2.展开更多
文摘Death ligand mediated apoptotic activation is a mode of cell death that is widely used in cellular and physiological situations. Interest in studying death ligand induced apoptosis has increased due to the promising role of recombinant soluble forms of death ligands (mainly recombinant TRAIL) in anti-cancer therapy. A clear elucidation of how death ligands activate the type 1 and type 2 apoptotic pathways in healthy and cancer cells may help develop better chemotherapeutic strategies. In this work, we use kinetic Monte Carlo simulations to address the problem of type 1/ type 2 choice in death ligand mediated apoptosis of cancer cells. Our study provides insights into the activation of membrane proximal death module that results from complex interplay between death and decoy receptors. Relative abundance of death and decoy receptors was shown to be a key parameter for activation of the initiator caspases in the membrane module. Increased concentration of death ligands frequently increased the type 1 activation fraction in cancer cells, and, in certain cases changed the signaling phenotype from type 2 to type 1. Results of this study also indicate that inherent differences between cancer and healthy cells, such as in the membrane module, may allow robust activation of cancer cell apoptosis by death ligand induction. At the same time, large cell-to-cell variability through the type 2 pathway was shown to provide protection for healthy cells. Such elucidation of selective activation of apoptosis in cancer cells addresses a key question in cancer biology and cancer therapy.
基金supported by Harbin University of Commerce Research Funding(17x072)
文摘Objective： To investigate the effects of xanthotoxin from Apiaceae medicinal plants on cell proliferation and apoptosis, and explore its mechanism of action against human gastric carcinoma SGC-7901 cells in vitro.Methods： SGC-7901, HepG-2, MCF-7, and A549 cells were treated with different concentrations of xanthotoxin（10, 20, 60, 80, 100, 120, 140, and 160 μg/mL） for 48 h, and the cell viability（IC50） was determined by MTT assay; Xanthotoxin-induced apoptosis in cells was observed by using Hoechst 33258 Staining Kit and Annexin V-FITC Apoptosis Detection Kit; Flow cytometry was used to detect apoptosis related proteins of Fas/FasL, Bid, and DR5/TRAIL proteins in human gastric carcinoma SGC-7901 cells after being treated by xanthotoxin; The influence of xanthotoxin on Caspase-8 protein expression in the cells was determined by Flouormetric Assay Kit.Results： Xanthotoxin obviously inhibited SGC-7901, HepG-2, MCF-7, and A549 cells proliferation, and its inhibition was in a concentration-dependent manner; flow cytometry results showed that in a certain concentration range, xanthotoxin can increase the expression levels of Fas/FasL and DR5/TRAIL proteins in a concentration-dependence manner. The content of Bid protein in cells was increased, and it showed concentration-dependence.Conclusion： Xanthotoxin may induce SGC-7901 cells apoptosis in a certain concentration range through the Fas/FasL protein mediated death receptor pathway, or by DR5/TRAIL mediated death receptor pathway, and increase the expression level of death receptor protein, activation Caspase-8, activating downstream effect factor, inducing cell apoptosis, or activate Caspase-8 cutting activate protein Bid, and then enter the mitochondrial pathway, induction of apoptosis.
文摘The apoptosis inducing effects on tumor cell lines MGC803, BEL7402 and HL60 by Fas ligand and anti-human DR5 monoclonal antibodies （anti-DR5 mAb） and the underlying mechanism was studied. Fas/DR5 mRNA was detected by RT-PCR. Cytotoxicity exerted by FasL/anti-DR5 mAb on tumor cell lines was measured by MTT assay and the induced apoptosis was determined by agarose gel electrophoresis. Flow cytometry was employed to analyze the mode of cell death. The mRNA expression of DR5 in MGC803 and BEL7402 cells after giving anti-DR5 mAb was up-regulated compared with control group, while it was down-regulated in HL60 cells in the same condition. The mRNA expression of Fas in HL60 was higher after giving FasL compared with control group, while it was lower in MGC803 and BEL7402. MGC803 and BEL7402 were sensitive to anti-DR5 mAb but partially to FasL, and HL60 was sensitive to FasL but less sensitive to anti-DR5 mAb. Apoptosis induced by Fas ligand and anti-DR5 mAb vary among tumor cell lines. The underlying mechanism may be relevant to Fas/DR5 mRNA expression, which was presented as the release of caspase-8 and Bcl-2.
