OBJECTIVE To investigate the effects of survivin antisense oligodeoxy-nucleotid (ASODN) on proliferation and apoptosis in the chronic myeloid leukemia cell line K562. METHODS Different concentrations of an antisense o...OBJECTIVE To investigate the effects of survivin antisense oligodeoxy-nucleotid (ASODN) on proliferation and apoptosis in the chronic myeloid leukemia cell line K562. METHODS Different concentrations of an antisense oligodeoxy-nucleotid and control sequence (scrambled ODN) targeting the survivin gene were transferred into K562 by a lipofectin reagent. The MTT assay was used to measure the growth inhibitory rate, IC50, and to observe the cytotoxicity of survivin ASODN in the K562 cells. The morphologic changes in the nucleus and the apoptotic rate were observed by Hoechst33342/PI staining. Caspase-3 activity was evaluated by a kinase activity assay. The changes of survivin protein expression after transfection were detected by Western blots. RESULTS Eight hours after transfection, fluorescence in the K562 cells was well distributed. Treatment of the cells for 44 h with different concentrations of survivin ASODN produced a IC50 of 800 nmol/L. The growth inhibitory rate with 200, 400, 600 and 1000 nmol/L of survivin ASODN was 15.8±1.6%, 23.8±5.9%, 37.1±5.6% and 77.3±2.5% respectively. After 36 h of of survivin ASODN treatment, distinct morphologic changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst33342/PI staining. Caspase-3 activity increased significantly after treatment of the cells with different concentrations of survivin ASODN(P<0.01)and following treatment with 800 nmol/L survivin ASODN, survivin expression decreased significantly. CONCLUSION Survivin ASODN exerts an anti-cancer effect by inducing apoptosis in K562 leukaemia cells. Up-regulated expression of caspase-3 may play a role in this process.展开更多
It is first demonstrated that dipyridamole (DP) and radiation were capable of significantly inhibiting, independently and synerglcally, clonogenlc growth in the two kinds of K562 cell lines, adriamycin (ADM) -sensitiv...It is first demonstrated that dipyridamole (DP) and radiation were capable of significantly inhibiting, independently and synerglcally, clonogenlc growth in the two kinds of K562 cell lines, adriamycin (ADM) -sensitive and ADM- resistant. DP or radiation alone Increased clonogenlc Inhibition rate (CIR) in the two kinds of cell lines in a dose- dependent fashion. DP potentiated radiosensitivity and radiation increased inhibition of DP in the two kinds of cell lines. K562/ ADM cell lines were higher sensitive to DP. radiation and combination of them than K562 cell lines (P<0. 01). There was stronger synergic inhibition of clonogenlc growth in the two kinds of cell lines when pretreated with DP than when posttreated with DP (P<0. 01).展开更多
It was first reported here that verupamil(VP) and electric beam radiation(EBR) were capable of inhibiting,independently or synergically,clonogenic growth in two kinds of K562 cell lines, adriamycin(ADM)-sensitive and ...It was first reported here that verupamil(VP) and electric beam radiation(EBR) were capable of inhibiting,independently or synergically,clonogenic growth in two kinds of K562 cell lines, adriamycin(ADM)-sensitive and ADM-resistant(K562/S and K562/ADM).Results showed that clonogenic rate(CGR) decreased by 3%-99.9% in the prasence of dependent dose-ADM(3.8μg/ml) in K562/ADM cell lines,while treated with 0.5μM-6μM of VP.VP was capable of potentiating radiosensitivity in K562/S and K562/ADM cell lines,whether before or after exposure of them to electric beam radiation,and significantly reduced CGR in these kinds of cell lines(P<0.01).展开更多
OBJECTIVE To explore the anticancer mechanism of triptolide in human leukemia K562 cells,and to further determine whether the proteasomal inhibitor,MG132,can potentiate apoptosis in triptolide-treated K562 cells.METHO...OBJECTIVE To explore the anticancer mechanism of triptolide in human leukemia K562 cells,and to further determine whether the proteasomal inhibitor,MG132,can potentiate apoptosis in triptolide-treated K562 cells.METHODS Apoptosis was assessed via annexin V/PI double-labeled cytometry.The expressions of the IκBα and NF-κB/p65 proteins in K562 cells was investigated using Western blo ing.RESULTS The inhibitory rates of K562 cells treated by triptolide gradually increased in a dose-and time-dependent manner,and treatment with triptolide plus MG132 potentiated the apoptotic rate.Triptolide inhibited the degradation of the IκBα protein and the nuclear localization of NF-κB/p65 proteins induced by TNF-α,and MG132 potentiated the effect of triptolide.Triptolide plus MG132 almost completely blocked the NF-κB activation induced by TNF-α.CONCLUSION The anti-proliferative activities of triptolide and MG132 were related to the NF-κB signal pathway.展开更多
Objective: To explore the effects of Taxol in inhibiting human leukemia k562 cell proliferation and inducing apoptosis in vitro. Methods: Human leukemia K562 cells were treated with Taxol of different concentrations f...Objective: To explore the effects of Taxol in inhibiting human leukemia k562 cell proliferation and inducing apoptosis in vitro. Methods: Human leukemia K562 cells were treated with Taxol of different concentrations for 12-72 hrs. Cell proliferation was evaluated by MTT assay and morphological changes of apoptosis were examined by microscopy. Cell apoptosis was determined by flow cytometry (FCM) and DNA gel electrophoresis. Results: Growth of K562 cells was inhibited by Taxol with an IC50 value of 0. 84μg/ml. Typical nuclear condensation and apoptosis bodies were observed as early as 24 hrs after a 0.5μg/ml Taxol treatment; Apoptotic rate of the Taxol-treated K562 cells increased from 3.7% to 24.0% in 24 hrs. No DNA ladder was observed by DNA gel electrophoresis. Conclusion: Taxol could inhibit K562 cell growth and induce apoptosis in vitro.展开更多
It is well accepted in China that elder ginsengs have more bioactivity and value than younger ones. However, there is little research about the comparison of beneficial effects of ginsengs with different ages. In this...It is well accepted in China that elder ginsengs have more bioactivity and value than younger ones. However, there is little research about the comparison of beneficial effects of ginsengs with different ages. In this study, ginseng root extracts (GRE) were extracted from ginsengs of 5, 8, 12, 14, and 16 years old, respectively, using 55% ethanol and their effects on human leukemic K562 cells within 48 hours were tested by using Cell Counting Kit-8. The results show that there are significant increases in the cell viability of all the GRE groups compared with Control group within 32 hours. Furthermore, the growth curves of GRE groups were obviously distinct from each other. The cell viability of 5-year-old and 8-year-old GRE groups kept a rapid increase while that of 16-year-old GRE group showed a strong fluctuation within 28 hours. Our results demonstrate that root extracts from ginsengs of different ages contain different bioactivity constituents and have different effects on cell.展开更多
The nucleax mains attachment regions(MARs) and the binding nuclear matrix proteins in the 5’-flalildng cisacting elements of the humanε-globin gene have been examined. Using in vitro DNA-matrix binding assay,it has ...The nucleax mains attachment regions(MARs) and the binding nuclear matrix proteins in the 5’-flalildng cisacting elements of the humanε-globin gene have been examined. Using in vitro DNA-matrix binding assay,it has been shown that the positive stage-specific regulatory element (ε-PREII, -446bp-419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells, indicating thatε-PREII mad be an erythroidspecilic facultstive MAR. In gel mobility shift assay and Southwestern blotting assal an eothroid-specific nuclear matrix protein (ε-NMPk) in K562 cells has been revealed to bind to this positive regulatory element (E-PREII). Furthermore, we demonstrated that the silencer (-392hp -177bp) uP8tream of the humanε-globin gene could associate with the nuclear matrices from K562, HEL and Raji cells. In addition, the nucleax matrix proteins prepared from these three cell lines could also bind to this silencer, suggesting that this silencer element linght be a constitutive nuclear mains attachment region (constitutive MAR). Our results demonstrated that the nucleax madrid and nuclear mains proteins lxilght play an important role in the regulation of the human 5-globin gene expression.展开更多
OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI)...OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.展开更多
By applying the technique of cybridization between reticulocytes and myeloma cells, we reported that the erythroid cell cytoplasms had some regulatory effects upon the malignancy of the myeloma. Though such a method p...By applying the technique of cybridization between reticulocytes and myeloma cells, we reported that the erythroid cell cytoplasms had some regulatory effects upon the malignancy of the myeloma. Though such a method produces reliable results, to establish inducible cytogenetic mutations in myeloma cells, to select the HGPRT^- mutants and finally to select the cybrids through HAT medium, however, still need a lot of time. Recently, by using gene transfer techniques, new selectable genetic markers could be introduced into cells directly, this provides an alternative new way to make cellular hybrids. Yet up to now, the host cells for gene transfer are all the kind of cells with nuclei. Here, by展开更多
文摘OBJECTIVE To investigate the effects of survivin antisense oligodeoxy-nucleotid (ASODN) on proliferation and apoptosis in the chronic myeloid leukemia cell line K562. METHODS Different concentrations of an antisense oligodeoxy-nucleotid and control sequence (scrambled ODN) targeting the survivin gene were transferred into K562 by a lipofectin reagent. The MTT assay was used to measure the growth inhibitory rate, IC50, and to observe the cytotoxicity of survivin ASODN in the K562 cells. The morphologic changes in the nucleus and the apoptotic rate were observed by Hoechst33342/PI staining. Caspase-3 activity was evaluated by a kinase activity assay. The changes of survivin protein expression after transfection were detected by Western blots. RESULTS Eight hours after transfection, fluorescence in the K562 cells was well distributed. Treatment of the cells for 44 h with different concentrations of survivin ASODN produced a IC50 of 800 nmol/L. The growth inhibitory rate with 200, 400, 600 and 1000 nmol/L of survivin ASODN was 15.8±1.6%, 23.8±5.9%, 37.1±5.6% and 77.3±2.5% respectively. After 36 h of of survivin ASODN treatment, distinct morphologic changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst33342/PI staining. Caspase-3 activity increased significantly after treatment of the cells with different concentrations of survivin ASODN(P<0.01)and following treatment with 800 nmol/L survivin ASODN, survivin expression decreased significantly. CONCLUSION Survivin ASODN exerts an anti-cancer effect by inducing apoptosis in K562 leukaemia cells. Up-regulated expression of caspase-3 may play a role in this process.
文摘It is first demonstrated that dipyridamole (DP) and radiation were capable of significantly inhibiting, independently and synerglcally, clonogenlc growth in the two kinds of K562 cell lines, adriamycin (ADM) -sensitive and ADM- resistant. DP or radiation alone Increased clonogenlc Inhibition rate (CIR) in the two kinds of cell lines in a dose- dependent fashion. DP potentiated radiosensitivity and radiation increased inhibition of DP in the two kinds of cell lines. K562/ ADM cell lines were higher sensitive to DP. radiation and combination of them than K562 cell lines (P<0. 01). There was stronger synergic inhibition of clonogenlc growth in the two kinds of cell lines when pretreated with DP than when posttreated with DP (P<0. 01).
文摘It was first reported here that verupamil(VP) and electric beam radiation(EBR) were capable of inhibiting,independently or synergically,clonogenic growth in two kinds of K562 cell lines, adriamycin(ADM)-sensitive and ADM-resistant(K562/S and K562/ADM).Results showed that clonogenic rate(CGR) decreased by 3%-99.9% in the prasence of dependent dose-ADM(3.8μg/ml) in K562/ADM cell lines,while treated with 0.5μM-6μM of VP.VP was capable of potentiating radiosensitivity in K562/S and K562/ADM cell lines,whether before or after exposure of them to electric beam radiation,and significantly reduced CGR in these kinds of cell lines(P<0.01).
基金a grant from the National Natural Science Foundation of China(No.30570776)
文摘OBJECTIVE To explore the anticancer mechanism of triptolide in human leukemia K562 cells,and to further determine whether the proteasomal inhibitor,MG132,can potentiate apoptosis in triptolide-treated K562 cells.METHODS Apoptosis was assessed via annexin V/PI double-labeled cytometry.The expressions of the IκBα and NF-κB/p65 proteins in K562 cells was investigated using Western blo ing.RESULTS The inhibitory rates of K562 cells treated by triptolide gradually increased in a dose-and time-dependent manner,and treatment with triptolide plus MG132 potentiated the apoptotic rate.Triptolide inhibited the degradation of the IκBα protein and the nuclear localization of NF-κB/p65 proteins induced by TNF-α,and MG132 potentiated the effect of triptolide.Triptolide plus MG132 almost completely blocked the NF-κB activation induced by TNF-α.CONCLUSION The anti-proliferative activities of triptolide and MG132 were related to the NF-κB signal pathway.
文摘Objective: To explore the effects of Taxol in inhibiting human leukemia k562 cell proliferation and inducing apoptosis in vitro. Methods: Human leukemia K562 cells were treated with Taxol of different concentrations for 12-72 hrs. Cell proliferation was evaluated by MTT assay and morphological changes of apoptosis were examined by microscopy. Cell apoptosis was determined by flow cytometry (FCM) and DNA gel electrophoresis. Results: Growth of K562 cells was inhibited by Taxol with an IC50 value of 0. 84μg/ml. Typical nuclear condensation and apoptosis bodies were observed as early as 24 hrs after a 0.5μg/ml Taxol treatment; Apoptotic rate of the Taxol-treated K562 cells increased from 3.7% to 24.0% in 24 hrs. No DNA ladder was observed by DNA gel electrophoresis. Conclusion: Taxol could inhibit K562 cell growth and induce apoptosis in vitro.
文摘It is well accepted in China that elder ginsengs have more bioactivity and value than younger ones. However, there is little research about the comparison of beneficial effects of ginsengs with different ages. In this study, ginseng root extracts (GRE) were extracted from ginsengs of 5, 8, 12, 14, and 16 years old, respectively, using 55% ethanol and their effects on human leukemic K562 cells within 48 hours were tested by using Cell Counting Kit-8. The results show that there are significant increases in the cell viability of all the GRE groups compared with Control group within 32 hours. Furthermore, the growth curves of GRE groups were obviously distinct from each other. The cell viability of 5-year-old and 8-year-old GRE groups kept a rapid increase while that of 16-year-old GRE group showed a strong fluctuation within 28 hours. Our results demonstrate that root extracts from ginsengs of different ages contain different bioactivity constituents and have different effects on cell.
文摘The nucleax mains attachment regions(MARs) and the binding nuclear matrix proteins in the 5’-flalildng cisacting elements of the humanε-globin gene have been examined. Using in vitro DNA-matrix binding assay,it has been shown that the positive stage-specific regulatory element (ε-PREII, -446bp-419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells, indicating thatε-PREII mad be an erythroidspecilic facultstive MAR. In gel mobility shift assay and Southwestern blotting assal an eothroid-specific nuclear matrix protein (ε-NMPk) in K562 cells has been revealed to bind to this positive regulatory element (E-PREII). Furthermore, we demonstrated that the silencer (-392hp -177bp) uP8tream of the humanε-globin gene could associate with the nuclear matrices from K562, HEL and Raji cells. In addition, the nucleax matrix proteins prepared from these three cell lines could also bind to this silencer, suggesting that this silencer element linght be a constitutive nuclear mains attachment region (constitutive MAR). Our results demonstrated that the nucleax madrid and nuclear mains proteins lxilght play an important role in the regulation of the human 5-globin gene expression.
基金Shanghai Municipal Health Bureau:Traditional Chinese Medicine in Treating with Advanced Hepatocellular Carcinoma(No.ZYSNXD-CC-ZDYJ032)
文摘OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.
文摘By applying the technique of cybridization between reticulocytes and myeloma cells, we reported that the erythroid cell cytoplasms had some regulatory effects upon the malignancy of the myeloma. Though such a method produces reliable results, to establish inducible cytogenetic mutations in myeloma cells, to select the HGPRT^- mutants and finally to select the cybrids through HAT medium, however, still need a lot of time. Recently, by using gene transfer techniques, new selectable genetic markers could be introduced into cells directly, this provides an alternative new way to make cellular hybrids. Yet up to now, the host cells for gene transfer are all the kind of cells with nuclei. Here, by
