Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a new member of TNF family. It was reported that TRAIL could induce apoptosis of tumor cells but not normal cells in tissue culture system. To f...Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a new member of TNF family. It was reported that TRAIL could induce apoptosis of tumor cells but not normal cells in tissue culture system. To further study the biological activity and potential clinical significance, a recombinant soluble TRAIL (rsTRAIL) has been expressed stably in E. coli after transformation of pET28b vector containing the extracellular domain of TRAIL. The yield of rsTRAIL is approximately as high as 60% of whole bacterial proteins. The rsTRAIL, purified by Ni^+ -agarose affinity chromatography, could remarkably trigger apoptosis at the concentrations of 0.1—1 μg/mL in all 7 tumor cell lines tested in vitro. However, this killing activity has not been observed in mouse fibroblast cell line (NIH3T3) as normal control. Further investigation shows that the rsTRAIL could also kill primary tumor cells isolated freshly from patients with cardiac cancer, breast cancer and malignant thymoma, while the normal human展开更多
To unravel the pharmacological actions of garlic, a simple thiocompound, zajoene, was purified from the fresh cloves. Three tumor cell lines were subjected to treatment with zajoene at different concentrations in vitr...To unravel the pharmacological actions of garlic, a simple thiocompound, zajoene, was purified from the fresh cloves. Three tumor cell lines were subjected to treatment with zajoene at different concentrations in vitro and the morphological changes, DNA content of the cells and chromosome DNA fragmentation were observed by light microscopy, flow cytometry and agarose gel electrophoresis respectively. It was found that zajoene induced cell death by apoptosis in human HL60 promyelocytic leukemia cells, MGc803 gastric mucoid adenocarcinoma cells and Molt4 T lymphocyte leukemia cells. Western blot assay showed that z ajoene inhibited protooncogene bcl2 expression in the three different kinds of tumor cells, suggesting that zajoene may be a potential agent for tumor chemotherapy.展开更多
In the present study, actions of phenothiazines(PTZ) in reversing multidrug resistance(MDR) and inhibiting PKC activity were investigated. It was found that the three PTZs caused 2.49, 36.58 and 75.78 fold reversal of...In the present study, actions of phenothiazines(PTZ) in reversing multidrug resistance(MDR) and inhibiting PKC activity were investigated. It was found that the three PTZs caused 2.49, 36.58 and 75.78 fold reversal of K562/AO2 MDR cells resistant to adriamycin, respectively, while the chemosensitizer verapamil caused 40 fold reversal in the same condition, indicating that PTZ11 is a novel reversal agent of MDR and a potential chemotherapeutic reagent for tumor therapy. PKC activity analysis in the presence of PTZs showd that PTZ6 and PTZ11 inhibited rat brain protein kinase C activity in a manner of dose_dependent. The IC 50 values were (489.77±31.4) and (113±9.64) μmol/L, respectively. PTZ7 had no inhibition on PKC activity. Further study showed that PTZ11 could reduce PMA_mediated activation of PKC in a manner of dose_dependent, suggesting that PTZ11 might compete for the high_affinity phorbol ester binding site within PKC molecule. Recently, an X_ray structure of PMA in complex with PKC Cys2 activator_binding domain was solved. We therefore decided to explore the possible binding model of PTZ11 with PKC molecule using SYBYL 6.02 program. It was shown that the binding site of PTZ11 with PKC molecule partially overlapped with that of PMA, providing for the first time new data for designing PKC inhibitors and MDR reversal drugs.展开更多
基金This work was partially supported by Natural Science Foundation of China （No. 30571687）；and National Basic Research Program of China （No. 2007CB507404）.
文摘Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a new member of TNF family. It was reported that TRAIL could induce apoptosis of tumor cells but not normal cells in tissue culture system. To further study the biological activity and potential clinical significance, a recombinant soluble TRAIL (rsTRAIL) has been expressed stably in E. coli after transformation of pET28b vector containing the extracellular domain of TRAIL. The yield of rsTRAIL is approximately as high as 60% of whole bacterial proteins. The rsTRAIL, purified by Ni^+ -agarose affinity chromatography, could remarkably trigger apoptosis at the concentrations of 0.1—1 μg/mL in all 7 tumor cell lines tested in vitro. However, this killing activity has not been observed in mouse fibroblast cell line (NIH3T3) as normal control. Further investigation shows that the rsTRAIL could also kill primary tumor cells isolated freshly from patients with cardiac cancer, breast cancer and malignant thymoma, while the normal human
文摘To unravel the pharmacological actions of garlic, a simple thiocompound, zajoene, was purified from the fresh cloves. Three tumor cell lines were subjected to treatment with zajoene at different concentrations in vitro and the morphological changes, DNA content of the cells and chromosome DNA fragmentation were observed by light microscopy, flow cytometry and agarose gel electrophoresis respectively. It was found that zajoene induced cell death by apoptosis in human HL60 promyelocytic leukemia cells, MGc803 gastric mucoid adenocarcinoma cells and Molt4 T lymphocyte leukemia cells. Western blot assay showed that z ajoene inhibited protooncogene bcl2 expression in the three different kinds of tumor cells, suggesting that zajoene may be a potential agent for tumor chemotherapy.
文摘In the present study, actions of phenothiazines(PTZ) in reversing multidrug resistance(MDR) and inhibiting PKC activity were investigated. It was found that the three PTZs caused 2.49, 36.58 and 75.78 fold reversal of K562/AO2 MDR cells resistant to adriamycin, respectively, while the chemosensitizer verapamil caused 40 fold reversal in the same condition, indicating that PTZ11 is a novel reversal agent of MDR and a potential chemotherapeutic reagent for tumor therapy. PKC activity analysis in the presence of PTZs showd that PTZ6 and PTZ11 inhibited rat brain protein kinase C activity in a manner of dose_dependent. The IC 50 values were (489.77±31.4) and (113±9.64) μmol/L, respectively. PTZ7 had no inhibition on PKC activity. Further study showed that PTZ11 could reduce PMA_mediated activation of PKC in a manner of dose_dependent, suggesting that PTZ11 might compete for the high_affinity phorbol ester binding site within PKC molecule. Recently, an X_ray structure of PMA in complex with PKC Cys2 activator_binding domain was solved. We therefore decided to explore the possible binding model of PTZ11 with PKC molecule using SYBYL 6.02 program. It was shown that the binding site of PTZ11 with PKC molecule partially overlapped with that of PMA, providing for the first time new data for designing PKC inhibitors and MDR reversal drugs.
