Objective To investigate the potential mechanisms of cell death after the treatment with ceramide. Methods MTT assay, DNA ladder, reporter assay, FACS and Western blot assay were employed to investigate the potential ...Objective To investigate the potential mechanisms of cell death after the treatment with ceramide. Methods MTT assay, DNA ladder, reporter assay, FACS and Western blot assay were employed to investigate the potential mechanisms of cell death after the treatment with C2-ceramide. Results A short-time treatment with C2-ceramide induced cell death, which was associated with p38 MAP kinase activation, but had no links with typical caspase activation or PARP degradation. Rather than caspase inhibitor, Inhibitor of p38 MAP kinase blocked cell death induced by a short-time treatment with ceramide （〈12 h）. However, inhibition of p38 MAP kinase could not block cell death induced by a prolonged treatment with ceramide （〉12 h）. Moreover, incubation of cells with ceramide for a long time （〉12 h） increased subG1, but reduced S phase accompanied by caspase-dependent and caspase-independent changes including NFr, B activation. Conclusion Ceramide-induced cell apoptosis involves both caspase-dependent and -independent signaling pathway. Caspase-independent cell death occurring in a relatively early stage, which is mediated via p38 MAP kinase, can progress into a stage involving both caspase-dependent and -independent mechanisms accompanied by cell signaling of MAPKs and NFκB.展开更多
Objective:To investigate the cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines(HT29).Methods:The cytotoxic activity of the hexane...Objective:To investigate the cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines(HT29).Methods:The cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines(HT29) was determined by using the SRB assay.Results:The ethyl acetate extract showed a higher cytotoxic effect compared to the hexane extract.Morphological changes of the HT29 cells such as cell shrinkage,membrane blebbling and formation of apoptotic bodies while changes in nuclear morphology like chromatin condensation and nuclear fragmentation were observed.Further evidence of apoptosis in HT29 cells was further supported by the externalization of phosphatidylserine which indicate early sign of apoptosis.Conclusions:The early sign of apoptosis is consistent with the cell cycle arrest at the G_0/G_1 checkpoint which suggests that the changes on the cell cycle lead to the induction of apoptosis in HT29.展开更多
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(RCEES-QN-200712)the Special Funds for Young Scholars of RCEES,CAS.
文摘Objective To investigate the potential mechanisms of cell death after the treatment with ceramide. Methods MTT assay, DNA ladder, reporter assay, FACS and Western blot assay were employed to investigate the potential mechanisms of cell death after the treatment with C2-ceramide. Results A short-time treatment with C2-ceramide induced cell death, which was associated with p38 MAP kinase activation, but had no links with typical caspase activation or PARP degradation. Rather than caspase inhibitor, Inhibitor of p38 MAP kinase blocked cell death induced by a short-time treatment with ceramide （〈12 h）. However, inhibition of p38 MAP kinase could not block cell death induced by a prolonged treatment with ceramide （〉12 h）. Moreover, incubation of cells with ceramide for a long time （〉12 h） increased subG1, but reduced S phase accompanied by caspase-dependent and caspase-independent changes including NFr, B activation. Conclusion Ceramide-induced cell apoptosis involves both caspase-dependent and -independent signaling pathway. Caspase-independent cell death occurring in a relatively early stage, which is mediated via p38 MAP kinase, can progress into a stage involving both caspase-dependent and -independent mechanisms accompanied by cell signaling of MAPKs and NFκB.
基金financially supported by UM High Impact Research Grant UM-MOHE UM.C/625/1/HIR/MOHE/SC/02 from Ministry of Higher Education Malaysia
文摘Objective:To investigate the cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines(HT29).Methods:The cytotoxic activity of the hexane and ethyl acetate extracts of Curcuma mangga rhizomes against human colorectal adenocarcinoma cell lines(HT29) was determined by using the SRB assay.Results:The ethyl acetate extract showed a higher cytotoxic effect compared to the hexane extract.Morphological changes of the HT29 cells such as cell shrinkage,membrane blebbling and formation of apoptotic bodies while changes in nuclear morphology like chromatin condensation and nuclear fragmentation were observed.Further evidence of apoptosis in HT29 cells was further supported by the externalization of phosphatidylserine which indicate early sign of apoptosis.Conclusions:The early sign of apoptosis is consistent with the cell cycle arrest at the G_0/G_1 checkpoint which suggests that the changes on the cell cycle lead to the induction of apoptosis in HT29.
