AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated wi...AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated with various concentrations (20-200 μg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis,and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.RESULTS: PMBE (20-200 μg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 μg/mL PMBE for 24, 48, or 72 h, a typical apoptotic 'DNA ladder'was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy.Sub-G1 curves were displayed by flow cytometry analysis.PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 μg/mL PMBE.CONCLUSION: PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.展开更多
Objective To observe in vitro effects and morphological changes of human peripheral blood dendritic cells (DCs) on the ability of lymphokine and phytohaemagglutininum (PHA) activated killer (LPAK) cells to induce apo...Objective To observe in vitro effects and morphological changes of human peripheral blood dendritic cells (DCs) on the ability of lymphokine and phytohaemagglutininum (PHA) activated killer (LPAK) cells to induce apoptosis of the human hepatoma cell line (BEL-7402， B).Methods Experimental groups were divided into LD group (DCs+L+B), L group (L+B)， D group (DCs+B) and B group. The methods of neutral red uptake, ordinary light microscopy, electron microscopy, TDT mediated X-dUTP nick end labeling (TUNEL) were used. Results The difference between the D group and the B group was not distinct (P>0.05). The difference between the LD group and the L group was distinct， with DCs+LPAK >LPAK (P<0.01) in cytotoxity. Apoptotic cells were TUNEL positive in light microscopy, and apoptotic nuclei were stained yellow brown and dark brown, with size and shape varying from cell to cell. Ultrastructural change in apoptotic tumor cells comprised of compaction and condensation of nuclear chromatin， and condensation of cytoplasm and apoptotic bodies. At the same time, LPAK cells manifested the characteristics of autophagic apoptosis, and there were some autophagic bodies in it. Conclusions The combination of human blood DCs and LPAK cells could induce apoptosis of BEL-7402 cells effectively, with some LPAK cells manifesting the characteristics of autophagic apoptosis.展开更多
文摘AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.METHODS: BEL-7402 cells were incubated with various concentrations (20-200 μg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis,and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.RESULTS: PMBE (20-200 μg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 μg/mL PMBE for 24, 48, or 72 h, a typical apoptotic 'DNA ladder'was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy.Sub-G1 curves were displayed by flow cytometry analysis.PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 μg/mL PMBE.CONCLUSION: PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.
基金fundingfromtheNaturalScience FoundationofGuangdongProvince (No 1995 0 1)andtheScientific ResearchFoundationoftheRailwayMinistr
文摘Objective To observe in vitro effects and morphological changes of human peripheral blood dendritic cells (DCs) on the ability of lymphokine and phytohaemagglutininum (PHA) activated killer (LPAK) cells to induce apoptosis of the human hepatoma cell line (BEL-7402， B).Methods Experimental groups were divided into LD group (DCs+L+B), L group (L+B)， D group (DCs+B) and B group. The methods of neutral red uptake, ordinary light microscopy, electron microscopy, TDT mediated X-dUTP nick end labeling (TUNEL) were used. Results The difference between the D group and the B group was not distinct (P>0.05). The difference between the LD group and the L group was distinct， with DCs+LPAK >LPAK (P<0.01) in cytotoxity. Apoptotic cells were TUNEL positive in light microscopy, and apoptotic nuclei were stained yellow brown and dark brown, with size and shape varying from cell to cell. Ultrastructural change in apoptotic tumor cells comprised of compaction and condensation of nuclear chromatin， and condensation of cytoplasm and apoptotic bodies. At the same time, LPAK cells manifested the characteristics of autophagic apoptosis, and there were some autophagic bodies in it. Conclusions The combination of human blood DCs and LPAK cells could induce apoptosis of BEL-7402 cells effectively, with some LPAK cells manifesting the characteristics of autophagic apoptosis.
