Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The e...Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The expression levels of protein were assayed by immunofluorescence using fluoresce isothiocyanate label. The morphological changes in apoptotic cells were observed. Flow cytometric analysis of DNA fragmentation was also performed. Results Antisense peptide nucleic acid (PNA) targeting the coding region of the Bcl-2 mRNA could effectively inhibit the growth of HL60 cells, down-regulate the synthesis of Bcl-2 protein and induce apoptosis. After HL60 cells were treated with 10 μmol/L Bcl-2 antisense PNA or antisense oligonucleotide for 72 h respectively, apoptotic rates of HL60 cells were 17.80±1.53 and 13.17±1.12, respectively( P <0.05). Conclusion Antisense PNA targeting the coding region of Bcl-2 mRNA may have stronger antisense effects than the antisense oligonucleotides and could induce apoptosis of HL60 cells.展开更多
Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: ...Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: Apoptosis was detected by morphological observation and flow cytomertric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label, respectively. Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Results: Treatment of 2 μmol/L at As2O3 could induce apoptosis of HL-60 cells. hTERT was decreased at both mRNA and protein levels during apoptosis of HL-60 cells. Telomerase activity of HL-60 cells was significantly inhibited. Conclusion: It is suggested that telomerase activity of HL-60 cells might be specifically inhibited by AS2O3 through the downregulation of hTERT gene expression.展开更多
The mechanisms of curcumin inhibiting the proliferation of HL-60 cells were investigated. Acute myeloid leukemic cell line HL-60 was studied by using cell culture, NBT reduction, SABC method measuring BrdU incorporati...The mechanisms of curcumin inhibiting the proliferation of HL-60 cells were investigated. Acute myeloid leukemic cell line HL-60 was studied by using cell culture, NBT reduction, SABC method measuring BrdU incorporation rate, FCM measuring DNA contents and TUNEL method determining apoptotic cell percentage. Curcumin inhibited proliferation of HL-60 cells in a dose- and time-dependent manner. When the HL-60 cells were treated with 25 μmol/L curcumin for 48 h, the inhibitory rate was 60. 71 % ± 1. 20 %. The study on BrdU incorporation rate and the distribution of DNA content and NBT reduction indicated that curcumin arrested. the cells in G2/M phase of cell cy cle at first, then in G0/G1 phase, the whole cell cycle progression was slowed down and DNA synthesis activities was halted. The arrested cells went to apoptosis instead of differentiation. The comparative study indicated that the ability of curcumin regulating the cell cycle of HL-60 cells was stronger than As2O3 and the acting points of curcumin were not completely consistent with those of VP-16. It was suggested that curcumin was able to regulate, to some extent, the G1/S and G2/M transmit checkpoints and disturb the HL-60 cell cycle to induce apoptosis.展开更多
Studies have indicated that flavonoid luteolin is a potential inhibitor of tumor cell proliferation and may function as an anticarcinogenic agent. Pyrrolidine dithiocarbamate (PDTC), a synthetic compound, may exhibit ...Studies have indicated that flavonoid luteolin is a potential inhibitor of tumor cell proliferation and may function as an anticarcinogenic agent. Pyrrolidine dithiocarbamate (PDTC), a synthetic compound, may exhibit biphasic effects on apoptosis depending on the experimental context. Previously, we found that luteolin induced the activation of the proapoptotic proteins, such as Bad, Bid, and Bax, in HL-60 human leukemia cells. We also explored the modulatory effects and molecular mechanisms of PDTC on the cytotoxicity of luteolin in HL-60 cells;PDTC could interfere with luteolin’s ability to cleave poly(ADP-ribose)-polymerase (PARP) and DNA fragmentation of factor-45 (DFF-45). In the current study, we further investigated the effect of PDTC on the luteolin-induced death-receptor pathway and the cleavage of the Bcl-2 family members. We found that the combination of luteolin and PDTC increased the survival of the HL-60 cells such that PDTC inhibited both extrinsic and intrinsic pathways in luteolin-induced apoptosis.展开更多
The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was i...The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was inhibited by S86019 in vitro. Under the action of S86019 the HL-60 cells were induced to differentiate into metamyelocytes, myelocytes and much matured cells with banded or segmented nucleus. Flow cytometry demonstrated that the cell population of HL-60 cells was blocked at G1 phase which resulted in the elevation of percentage of G1 cells and decrease of percentage of cells in S phase. Experimental results demonstrated that S86019 is an active inducer of cell differentiation in HL-60 cells.展开更多
To understand the effect of rh-IFN-γ on the ability of curcumin to kill HL-60 cells in vitro, the myeloid leukemic cell line HL-60 was studied by using cell culture. BrdU incorporation rate was examined by SABC, DNA ...To understand the effect of rh-IFN-γ on the ability of curcumin to kill HL-60 cells in vitro, the myeloid leukemic cell line HL-60 was studied by using cell culture. BrdU incorporation rate was examined by SABC, DNA content was determined by flow cytometry and apoptotic cell percentage was determined by TUNEL method. The results showed that curcumin inhibited proliferation of leukemic cells in a dose-dependent manner. When HL-60 cells were treated with 25 μmol curcumin for 24 h, the proliferative inhibitory rate was 43. 75±2. 00 %.This effect could be enhanced obviously by IFN-γ, the combined proliferative inhibitory rate increased to over 80 %. The 5-BrdU incorportion rate and the distribution of DNA content indicated that curcumin could arrest cells in the G1/G0 and G2/M phase of cell cycle. At the same time, the sub-G1 peak (apoptotic peak) appeared. After IFN-γ combined with curcumin, DNA synthesis rate decreased further. It showed a significant difference when compared with single drug group (Pr< 0. 05). Meanwhile, sub-G1 peak also increased. The percentage of TUNEL positive cells was aslo increased. It is concluded that IFN-γ can enhance the antiproliferative ability of curcumin against HL-60 cells.展开更多
Summary: In order to examine the strong anticancer action and low toxicity of Trichostatin A (TSA), the effect of TSA was examined on the growth inhibition, acetylation of histone H_3 and apoptosis in HL-60 cells by e...Summary: In order to examine the strong anticancer action and low toxicity of Trichostatin A (TSA), the effect of TSA was examined on the growth inhibition, acetylation of histone H_3 and apoptosis in HL-60 cells by employing MTT, immunocytochemical techniques, and Annexin-V-FITC/PI assay. Our results showed that TSA could inhibit proliferation of HL-60 cells in a time-and dose-dependent manner, and the IC_~50 at the 36th h was 100 ng/ml. The apoptosis-inducing effect of TSA on HL-60 cells was also time-and dose-dependent. But it didn't demonstrate apparent apoptosis induction in NPBMNCs within specific dose and time range. Both of the acetylation of histone H_3 in HL-60 cells and NPBMNCs increased significantly (P<0.05) after treated with 100 ng/ml TSA for 4 h. However, there was no significant differences between the two groups (P>0.05). It is concluded that TSA can inhibit growth and induce apoptosis of HL-60 cells in a time-and dose-dependent manner, and is able to selectively induce apoptosis in HL-60 cells but does not respond in NPBMNCs under the same conditions. The difference of TSA between HL-60 cells and NPBMNCs can't be explained by the regulation of histone acetylation.展开更多
Objective To understand the mechanism of the hyperthermia and harringtonine in purging of leukemia cells In Vitro. telomerase activity of HL-60 cells treated by hyperthermia ( 42℃ for one hour) and different concen...Objective To understand the mechanism of the hyperthermia and harringtonine in purging of leukemia cells In Vitro. telomerase activity of HL-60 cells treated by hyperthermia ( 42℃ for one hour) and different concentrations of Harringtonine were investigated.Methods Using Telomeric Repeats Amplification Protocol (TRAP) and ELISA techniques to analyze the telomerase activity of HL-60 cells. Results Our results showed that harringtonine inhibited the telomerase activity of HL-60 cells in a dosage related manner. Moreover, the telomerase activity of HL-60 cells was significantly decreased after the hyperthermia treatment as compared with untreated cells.Conclusion The effect of the hyperthermia and Harringtonine on purging leukemia cells In Vitro may be mediated by down regulation of telomerase activity of tumor cells.展开更多
Objective To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODN) on expressions of caspase-3 and it's mRNA in γ-radiation induced apoptotic HL-60 cells, and screen the effective...Objective To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODN) on expressions of caspase-3 and it's mRNA in γ-radiation induced apoptotic HL-60 cells, and screen the effective ASODN. Methods ASODN-1 and ASODN-2 targeting 5′-noncoding region and initial translation region of caspase-3 mRNA were respectively designed, synthesized and introduced into HL-60 cells by means of liposome-mediated transfection followed by 10Gy γ-radiation exposures. TUNEL assay was conducted to investigate the morphologic change and apoptotic percentage of HL-60 cells 18 h later. Immunocytochemical staining and one step RT-PCR were respectively performed to detect the expressions of caspase-3 and it's mRNA. Mismatched oligodeoxynucleotide (MODN) transfected and un-transfected HL-60 cells were taken as control. Results TUNEL assay found that the apoptotic percentages in ASODN-1 and ASODN-2 groups were significantly reduced compared with the control groups (P<0.01) when the final concentration of both ASODNs was ≥3μmol/L. Immunocytochemistry showed that caspase-3 positive cell percentages were reduced but the average gray values increased significantly compared with the control groups (P<0.01). RT-PCR showed expressions of caspase-3 mRNA was decreased after ASODN transfection. Furthermore, ASODN-1 proved more effective in inhibiting HL-60 cell apoptosis than ASODN-2 (P<0.01). Conclusion Caspase-3 mRNA ASODNs can prevent HL-60 cells from apoptosis induced by γ-radiation and reduce expression of caspase-3 and its mRNA. These effects are dose dependent in a certain range.展开更多
The myeloid leukemic cell line HL-60 was studied by using DNA gel electrophoresis, flow cytomery, McAb C-myc, McAb Bc1-2 and CFU-L. From zero to 36 h,the apoptosis rates of 8 different phases and other indexes were ob...The myeloid leukemic cell line HL-60 was studied by using DNA gel electrophoresis, flow cytomery, McAb C-myc, McAb Bc1-2 and CFU-L. From zero to 36 h,the apoptosis rates of 8 different phases and other indexes were observed. The results showed that with the prolonged time of drug incubation,apoptosis of HL-60 cells increased progressively. This effect can be enhanced obviously by rh-IL-3 and rh-GM-CSF. At the same time,the killed rate of leukemic cells by Ara-C induction was increased. C-myc expression was decreased and Bc1-2 expression did not display apparent change. Interestingly, the normal hemopoietic cells were not affected by these two kinds of cytokine. The theoretical basis was provided for concurrent use of rh-IL-3, rh-GM-CSF and cytotoxic drugs whose purpose is to elevate remission rate during the phase of induced remission of leukemia.展开更多
Acute promyelocytic leukemia (APL) is a severe type of acute leukemia and the prognosis of patients was poor. Indirubin is the active constituent of the traditional Chinese medicine qingdai and an indoline anti-tumor ...Acute promyelocytic leukemia (APL) is a severe type of acute leukemia and the prognosis of patients was poor. Indirubin is the active constituent of the traditional Chinese medicine qingdai and an indoline anti-tumor drug. N’-Acetylindirubin is a novel indirubin derivative with better curative effect and less side effect. In this study, the effects of N’-Acetylindirubin on proliferation, apoptosis and cell cycle of acute myeloid leukemia cell line HL-60 was examined. The results demonstrated that N’-Acetylindirubin significantly induced apoptotic cell death in a dose and time-dependent manner and arrested cell cycle in G2/M in HL-60 cells. N’-Acetylindirubin also suppressed cyclin D1. This study suggests that N’-Acetylindirubin may serves as a potential chemopreventive agent for acute promyelocytic leukemia.展开更多
The cytotoxic effects of Paraquat, an herbicide refractory to treatment after intentional or accidental contact, were investigated on the human leukemia HL-60 cells. With the establishment of Paraquat injury model of ...The cytotoxic effects of Paraquat, an herbicide refractory to treatment after intentional or accidental contact, were investigated on the human leukemia HL-60 cells. With the establishment of Paraquat injury model of HL-60 cells, trypan blue exclusion assaying was performed to have determined the effects of Paraquat-induced cytotoxicity on HL-60 cells in a concentration- dependent manner. Upon treatment with various concentrations of Paraquat, pronounced increase on the levels of intracellular production of O2?- and H2O2 was detected with employment of fluorescent probes. Indicative of the oxidative stress, levels of MDA and T-AOC were quantitated to have determined the causal role for Paraquat in subjecting HL-60 cells to oxidative damage. Based on this finding, effects of antioxidant enzymes including GSH, NAC, CAT and SOD on attenuating the Paraquat-induced oxidative damage on HL-60 cells were examined, aiming to identify the most effective antioxidant enzyme for alleviating the cytotoxicity induced by Paraquat. In conjunction with the determination of cytotoxicity exerted by all the antioxidant enzymes on HL-60 cells, GSH-with its least inherent cytotoxicity on HL-60 cells-was identified as a promising candidate ingredient for extenuating the Paraquat-induced cytotoxicity.展开更多
Tetrahydroisoquinolines are known to have various biological effects, including antitumor activity. This study investigated the effect of 1-chloromethyl-6, 7-dimethoxy-3, 4-dihydro-1H-isoquinoline-2-sulfonic acid amid...Tetrahydroisoquinolines are known to have various biological effects, including antitumor activity. This study investigated the effect of 1-chloromethyl-6, 7-dimethoxy-3, 4-dihydro-1H-isoquinoline-2-sulfonic acid amide (CDST), a newly synthesized anticancer agent, on cellular differentiation and proliferation in HL-60 cells. Differentiation and proliferation of HL-60 cells were determined through expression of CD11b and CD14 surface antigens using flow cytometry and nitroblue tetrazolium (NBT) assay, and through analysis of cell cycle using propidium iodide staining, western blot analysis and immunoprecipitation, respectively. CDST induced the differentiation of HL-60, as shown by increased expression of differentiation surface antigen CD11b (but no significant change in CD14 expression) and increased NBT-reducing functional activity. DNA flow cytometry analysis indicated that CDST markedly induced a G0/G1 phase arrest of HL-60 cells. Subsequently, we examined the expre-ssion of G0/G1 phase cell cycle-related proteins, including cyclin-dependent kinases (CDKs), cyclins and cyclin dependent kinase inhibitors (CKIs), during the differentiation of HL-60. The levels of CDK2, CDK6, cyclin E and cyclin A were decreased, whereas steady-state levels of CDK4 and cyclin D1 were unaffected. The expression of the p27Kip1 was markedly increased by CDST, but not p21WAF1/Cip1. Moreover, CDST markedly enhanced the binding of p27Kip1 with CDK2 and CDK6, resulting in the reduced activity of both kinases. Taken together, these results demonstrate that CDST is capable of inducing cellular differentiation and growth inhibition through p27Kip1 protein-related G0/G1 phase arrest in HL-60 cells.展开更多
Objective To investigate the effects of quercetin on cell morphology, expression of promye-locytic leukemia (PML) mRNA and PML protein localization of NB4, HL-60 cells. Methods Cells mor-phology assayed by Wright’ s ...Objective To investigate the effects of quercetin on cell morphology, expression of promye-locytic leukemia (PML) mRNA and PML protein localization of NB4, HL-60 cells. Methods Cells mor-phology assayed by Wright’ s stain, fluorescence stain, and PML mRNA expression by RT-PCR, PML protein localization by immuno-fluorescence. Results The typical apoptosis was found in NB4 and HL-60 cells after treatment with quercetin. Immuno-fluorescence analysis showed after treatment with quercetin, the fusion pro-tein disappeared in NB4 cells, PML protein relocated, then degraded, and that also seen in HL-60 cells. The expression of PML mRNA is not changed in quercetin-treated cells. Conclusion PML play the role of apop-tosis inducer in leukemia cells at the translational level, quercetin can inhibit the proliferation of leukemia cells, and induce NB4, HL-60 cells apoptosis.展开更多
文摘Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The expression levels of protein were assayed by immunofluorescence using fluoresce isothiocyanate label. The morphological changes in apoptotic cells were observed. Flow cytometric analysis of DNA fragmentation was also performed. Results Antisense peptide nucleic acid (PNA) targeting the coding region of the Bcl-2 mRNA could effectively inhibit the growth of HL60 cells, down-regulate the synthesis of Bcl-2 protein and induce apoptosis. After HL60 cells were treated with 10 μmol/L Bcl-2 antisense PNA or antisense oligonucleotide for 72 h respectively, apoptotic rates of HL60 cells were 17.80±1.53 and 13.17±1.12, respectively( P <0.05). Conclusion Antisense PNA targeting the coding region of Bcl-2 mRNA may have stronger antisense effects than the antisense oligonucleotides and could induce apoptosis of HL60 cells.
基金This work was supported by the Guangdong Provincial Key Foundation of Science and Technology Program (99M01204G) and the Guangzhou City Key Foundation of Science and Technology Program (2001-Z-037-01).
文摘Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: Apoptosis was detected by morphological observation and flow cytomertric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label, respectively. Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Results: Treatment of 2 μmol/L at As2O3 could induce apoptosis of HL-60 cells. hTERT was decreased at both mRNA and protein levels during apoptosis of HL-60 cells. Telomerase activity of HL-60 cells was significantly inhibited. Conclusion: It is suggested that telomerase activity of HL-60 cells might be specifically inhibited by AS2O3 through the downregulation of hTERT gene expression.
基金a grant from National Natural Science Foundation of China (No. 39770934).
文摘The mechanisms of curcumin inhibiting the proliferation of HL-60 cells were investigated. Acute myeloid leukemic cell line HL-60 was studied by using cell culture, NBT reduction, SABC method measuring BrdU incorporation rate, FCM measuring DNA contents and TUNEL method determining apoptotic cell percentage. Curcumin inhibited proliferation of HL-60 cells in a dose- and time-dependent manner. When the HL-60 cells were treated with 25 μmol/L curcumin for 48 h, the inhibitory rate was 60. 71 % ± 1. 20 %. The study on BrdU incorporation rate and the distribution of DNA content and NBT reduction indicated that curcumin arrested. the cells in G2/M phase of cell cy cle at first, then in G0/G1 phase, the whole cell cycle progression was slowed down and DNA synthesis activities was halted. The arrested cells went to apoptosis instead of differentiation. The comparative study indicated that the ability of curcumin regulating the cell cycle of HL-60 cells was stronger than As2O3 and the acting points of curcumin were not completely consistent with those of VP-16. It was suggested that curcumin was able to regulate, to some extent, the G1/S and G2/M transmit checkpoints and disturb the HL-60 cell cycle to induce apoptosis.
文摘Studies have indicated that flavonoid luteolin is a potential inhibitor of tumor cell proliferation and may function as an anticarcinogenic agent. Pyrrolidine dithiocarbamate (PDTC), a synthetic compound, may exhibit biphasic effects on apoptosis depending on the experimental context. Previously, we found that luteolin induced the activation of the proapoptotic proteins, such as Bad, Bid, and Bax, in HL-60 human leukemia cells. We also explored the modulatory effects and molecular mechanisms of PDTC on the cytotoxicity of luteolin in HL-60 cells;PDTC could interfere with luteolin’s ability to cleave poly(ADP-ribose)-polymerase (PARP) and DNA fragmentation of factor-45 (DFF-45). In the current study, we further investigated the effect of PDTC on the luteolin-induced death-receptor pathway and the cleavage of the Bcl-2 family members. We found that the combination of luteolin and PDTC increased the survival of the HL-60 cells such that PDTC inhibited both extrinsic and intrinsic pathways in luteolin-induced apoptosis.
文摘The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was inhibited by S86019 in vitro. Under the action of S86019 the HL-60 cells were induced to differentiate into metamyelocytes, myelocytes and much matured cells with banded or segmented nucleus. Flow cytometry demonstrated that the cell population of HL-60 cells was blocked at G1 phase which resulted in the elevation of percentage of G1 cells and decrease of percentage of cells in S phase. Experimental results demonstrated that S86019 is an active inducer of cell differentiation in HL-60 cells.
文摘To understand the effect of rh-IFN-γ on the ability of curcumin to kill HL-60 cells in vitro, the myeloid leukemic cell line HL-60 was studied by using cell culture. BrdU incorporation rate was examined by SABC, DNA content was determined by flow cytometry and apoptotic cell percentage was determined by TUNEL method. The results showed that curcumin inhibited proliferation of leukemic cells in a dose-dependent manner. When HL-60 cells were treated with 25 μmol curcumin for 24 h, the proliferative inhibitory rate was 43. 75±2. 00 %.This effect could be enhanced obviously by IFN-γ, the combined proliferative inhibitory rate increased to over 80 %. The 5-BrdU incorportion rate and the distribution of DNA content indicated that curcumin could arrest cells in the G1/G0 and G2/M phase of cell cycle. At the same time, the sub-G1 peak (apoptotic peak) appeared. After IFN-γ combined with curcumin, DNA synthesis rate decreased further. It showed a significant difference when compared with single drug group (Pr< 0. 05). Meanwhile, sub-G1 peak also increased. The percentage of TUNEL positive cells was aslo increased. It is concluded that IFN-γ can enhance the antiproliferative ability of curcumin against HL-60 cells.
文摘Summary: In order to examine the strong anticancer action and low toxicity of Trichostatin A (TSA), the effect of TSA was examined on the growth inhibition, acetylation of histone H_3 and apoptosis in HL-60 cells by employing MTT, immunocytochemical techniques, and Annexin-V-FITC/PI assay. Our results showed that TSA could inhibit proliferation of HL-60 cells in a time-and dose-dependent manner, and the IC_~50 at the 36th h was 100 ng/ml. The apoptosis-inducing effect of TSA on HL-60 cells was also time-and dose-dependent. But it didn't demonstrate apparent apoptosis induction in NPBMNCs within specific dose and time range. Both of the acetylation of histone H_3 in HL-60 cells and NPBMNCs increased significantly (P<0.05) after treated with 100 ng/ml TSA for 4 h. However, there was no significant differences between the two groups (P>0.05). It is concluded that TSA can inhibit growth and induce apoptosis of HL-60 cells in a time-and dose-dependent manner, and is able to selectively induce apoptosis in HL-60 cells but does not respond in NPBMNCs under the same conditions. The difference of TSA between HL-60 cells and NPBMNCs can't be explained by the regulation of histone acetylation.
文摘Objective To understand the mechanism of the hyperthermia and harringtonine in purging of leukemia cells In Vitro. telomerase activity of HL-60 cells treated by hyperthermia ( 42℃ for one hour) and different concentrations of Harringtonine were investigated.Methods Using Telomeric Repeats Amplification Protocol (TRAP) and ELISA techniques to analyze the telomerase activity of HL-60 cells. Results Our results showed that harringtonine inhibited the telomerase activity of HL-60 cells in a dosage related manner. Moreover, the telomerase activity of HL-60 cells was significantly decreased after the hyperthermia treatment as compared with untreated cells.Conclusion The effect of the hyperthermia and Harringtonine on purging leukemia cells In Vitro may be mediated by down regulation of telomerase activity of tumor cells.
文摘Objective To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODN) on expressions of caspase-3 and it's mRNA in γ-radiation induced apoptotic HL-60 cells, and screen the effective ASODN. Methods ASODN-1 and ASODN-2 targeting 5′-noncoding region and initial translation region of caspase-3 mRNA were respectively designed, synthesized and introduced into HL-60 cells by means of liposome-mediated transfection followed by 10Gy γ-radiation exposures. TUNEL assay was conducted to investigate the morphologic change and apoptotic percentage of HL-60 cells 18 h later. Immunocytochemical staining and one step RT-PCR were respectively performed to detect the expressions of caspase-3 and it's mRNA. Mismatched oligodeoxynucleotide (MODN) transfected and un-transfected HL-60 cells were taken as control. Results TUNEL assay found that the apoptotic percentages in ASODN-1 and ASODN-2 groups were significantly reduced compared with the control groups (P<0.01) when the final concentration of both ASODNs was ≥3μmol/L. Immunocytochemistry showed that caspase-3 positive cell percentages were reduced but the average gray values increased significantly compared with the control groups (P<0.01). RT-PCR showed expressions of caspase-3 mRNA was decreased after ASODN transfection. Furthermore, ASODN-1 proved more effective in inhibiting HL-60 cell apoptosis than ASODN-2 (P<0.01). Conclusion Caspase-3 mRNA ASODNs can prevent HL-60 cells from apoptosis induced by γ-radiation and reduce expression of caspase-3 and its mRNA. These effects are dose dependent in a certain range.
文摘The myeloid leukemic cell line HL-60 was studied by using DNA gel electrophoresis, flow cytomery, McAb C-myc, McAb Bc1-2 and CFU-L. From zero to 36 h,the apoptosis rates of 8 different phases and other indexes were observed. The results showed that with the prolonged time of drug incubation,apoptosis of HL-60 cells increased progressively. This effect can be enhanced obviously by rh-IL-3 and rh-GM-CSF. At the same time,the killed rate of leukemic cells by Ara-C induction was increased. C-myc expression was decreased and Bc1-2 expression did not display apparent change. Interestingly, the normal hemopoietic cells were not affected by these two kinds of cytokine. The theoretical basis was provided for concurrent use of rh-IL-3, rh-GM-CSF and cytotoxic drugs whose purpose is to elevate remission rate during the phase of induced remission of leukemia.
文摘Acute promyelocytic leukemia (APL) is a severe type of acute leukemia and the prognosis of patients was poor. Indirubin is the active constituent of the traditional Chinese medicine qingdai and an indoline anti-tumor drug. N’-Acetylindirubin is a novel indirubin derivative with better curative effect and less side effect. In this study, the effects of N’-Acetylindirubin on proliferation, apoptosis and cell cycle of acute myeloid leukemia cell line HL-60 was examined. The results demonstrated that N’-Acetylindirubin significantly induced apoptotic cell death in a dose and time-dependent manner and arrested cell cycle in G2/M in HL-60 cells. N’-Acetylindirubin also suppressed cyclin D1. This study suggests that N’-Acetylindirubin may serves as a potential chemopreventive agent for acute promyelocytic leukemia.
文摘The cytotoxic effects of Paraquat, an herbicide refractory to treatment after intentional or accidental contact, were investigated on the human leukemia HL-60 cells. With the establishment of Paraquat injury model of HL-60 cells, trypan blue exclusion assaying was performed to have determined the effects of Paraquat-induced cytotoxicity on HL-60 cells in a concentration- dependent manner. Upon treatment with various concentrations of Paraquat, pronounced increase on the levels of intracellular production of O2?- and H2O2 was detected with employment of fluorescent probes. Indicative of the oxidative stress, levels of MDA and T-AOC were quantitated to have determined the causal role for Paraquat in subjecting HL-60 cells to oxidative damage. Based on this finding, effects of antioxidant enzymes including GSH, NAC, CAT and SOD on attenuating the Paraquat-induced oxidative damage on HL-60 cells were examined, aiming to identify the most effective antioxidant enzyme for alleviating the cytotoxicity induced by Paraquat. In conjunction with the determination of cytotoxicity exerted by all the antioxidant enzymes on HL-60 cells, GSH-with its least inherent cytotoxicity on HL-60 cells-was identified as a promising candidate ingredient for extenuating the Paraquat-induced cytotoxicity.
文摘Tetrahydroisoquinolines are known to have various biological effects, including antitumor activity. This study investigated the effect of 1-chloromethyl-6, 7-dimethoxy-3, 4-dihydro-1H-isoquinoline-2-sulfonic acid amide (CDST), a newly synthesized anticancer agent, on cellular differentiation and proliferation in HL-60 cells. Differentiation and proliferation of HL-60 cells were determined through expression of CD11b and CD14 surface antigens using flow cytometry and nitroblue tetrazolium (NBT) assay, and through analysis of cell cycle using propidium iodide staining, western blot analysis and immunoprecipitation, respectively. CDST induced the differentiation of HL-60, as shown by increased expression of differentiation surface antigen CD11b (but no significant change in CD14 expression) and increased NBT-reducing functional activity. DNA flow cytometry analysis indicated that CDST markedly induced a G0/G1 phase arrest of HL-60 cells. Subsequently, we examined the expre-ssion of G0/G1 phase cell cycle-related proteins, including cyclin-dependent kinases (CDKs), cyclins and cyclin dependent kinase inhibitors (CKIs), during the differentiation of HL-60. The levels of CDK2, CDK6, cyclin E and cyclin A were decreased, whereas steady-state levels of CDK4 and cyclin D1 were unaffected. The expression of the p27Kip1 was markedly increased by CDST, but not p21WAF1/Cip1. Moreover, CDST markedly enhanced the binding of p27Kip1 with CDK2 and CDK6, resulting in the reduced activity of both kinases. Taken together, these results demonstrate that CDST is capable of inducing cellular differentiation and growth inhibition through p27Kip1 protein-related G0/G1 phase arrest in HL-60 cells.
基金Partially supported by the National Natural Science Foundation ofchina (36970328)
文摘Objective To investigate the effects of quercetin on cell morphology, expression of promye-locytic leukemia (PML) mRNA and PML protein localization of NB4, HL-60 cells. Methods Cells mor-phology assayed by Wright’ s stain, fluorescence stain, and PML mRNA expression by RT-PCR, PML protein localization by immuno-fluorescence. Results The typical apoptosis was found in NB4 and HL-60 cells after treatment with quercetin. Immuno-fluorescence analysis showed after treatment with quercetin, the fusion pro-tein disappeared in NB4 cells, PML protein relocated, then degraded, and that also seen in HL-60 cells. The expression of PML mRNA is not changed in quercetin-treated cells. Conclusion PML play the role of apop-tosis inducer in leukemia cells at the translational level, quercetin can inhibit the proliferation of leukemia cells, and induce NB4, HL-60 cells apoptosis.