Glioblastoma is the deadliest neoplasm with the worst 5-year survival rate among all human cancers.Autophagy promotes autophagic cell death or blocks the induction of apoptosis in eukaryotic cells.Here,we investigated...Glioblastoma is the deadliest neoplasm with the worst 5-year survival rate among all human cancers.Autophagy promotes autophagic cell death or blocks the induction of apoptosis in eukaryotic cells.Here,we investigated whether varying levels of autophagic flux in glioblastoma lead to different efficacies of curcumin treatment using U87 MG and A172 human glioblastoma cells.The number of LC3 puncta,the number of cells with LC3 puncta and the level of LC3 Ⅱ,Atg5 and Atg7 protein were higher in U87 MG cells compared with A172 cells.When the cells were incubated with curcumin for 24 or 48 h,the percentage of cell death was higher in A172 cells compared with U87 MG cells.Although the level of LC3 was lower,that of curcumin-induced LC3 was higher,in A172 cells than in U87 MG cells.The relative increases in cell death and LC3-mediated autophagy were greater under serum starvation in A172 cells compared with U87 MG cells.Curcumin-induced A172 cell death was reduced by serum starvation.When both types of cells were transfected with LC3-GFP,the percentage of cell death was higher in A172 cells than that in U87 MG cells.Taken together,the data demonstrate that curcumin-mediated tumor cell death is regulated by the basal level of autophagic flux in different glioblastoma cells.This suggests that prior to the use of various curcumin therapeutics,the level of basal or induced autophagic flux should be carefully examined in tumor cells for the best efficacy.展开更多
To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxi...To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA172), were irradiated by 12C6+ ions to 0, 1 or 2Gy. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G2/M stage arrest induced by the 12C6+ ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.展开更多
基金This work was supported by the R&D program for Society of the National Research Foundation(NRF)funded by the Ministry of Science,ICT&Future Planning(Grant from Mid-career Researcher Program:No.2018R1A2A3075602),Republic of Korea.
文摘Glioblastoma is the deadliest neoplasm with the worst 5-year survival rate among all human cancers.Autophagy promotes autophagic cell death or blocks the induction of apoptosis in eukaryotic cells.Here,we investigated whether varying levels of autophagic flux in glioblastoma lead to different efficacies of curcumin treatment using U87 MG and A172 human glioblastoma cells.The number of LC3 puncta,the number of cells with LC3 puncta and the level of LC3 Ⅱ,Atg5 and Atg7 protein were higher in U87 MG cells compared with A172 cells.When the cells were incubated with curcumin for 24 or 48 h,the percentage of cell death was higher in A172 cells compared with U87 MG cells.Although the level of LC3 was lower,that of curcumin-induced LC3 was higher,in A172 cells than in U87 MG cells.The relative increases in cell death and LC3-mediated autophagy were greater under serum starvation in A172 cells compared with U87 MG cells.Curcumin-induced A172 cell death was reduced by serum starvation.When both types of cells were transfected with LC3-GFP,the percentage of cell death was higher in A172 cells than that in U87 MG cells.Taken together,the data demonstrate that curcumin-mediated tumor cell death is regulated by the basal level of autophagic flux in different glioblastoma cells.This suggests that prior to the use of various curcumin therapeutics,the level of basal or induced autophagic flux should be carefully examined in tumor cells for the best efficacy.
基金grants from the National Natural Science Foundation of China (10675151)the Key Scientific Technology Research Projects of Gansu Prov-ince (2GS052-A43-00 8-02, 2GS063-A43-012)the Scientific Technology Research Project of Lanzhou-Chinese Academy of Sciences (06-2-58).
文摘To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA172), were irradiated by 12C6+ ions to 0, 1 or 2Gy. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G2/M stage arrest induced by the 12C6+ ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.
