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
Objective: To clone the gene associated with apoptosis induced by an inhibitor of polyamine biosynthesis, a-difluoromethylornithime(DFMO). Methods: The differential sufbtraction sereening was used for gene cloning f...Objective: To clone the gene associated with apoptosis induced by an inhibitor of polyamine biosynthesis, a-difluoromethylornithime(DFMO). Methods: The differential sufbtraction sereening was used for gene cloning from cDNA library of HL60 cells treated by DFMO. Northern blot,morphological observation, FCM assays and ladder map of DNA electrophoresis were performed. Results: The transfectiong gene expression and activity of inducing apoptosis in the cell transfected from recombinant plasmid containing the cloned fragment df4 wasproved. Conclusion: It is suggest that df4 gene cloned in the study coul be a gene regulating apoptosis of HL60 cells.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
To explore the effect of NF κB on bcl x gene transcription in extended drug resistance leukemia cell line HL 60/E6, drug resistant subline HL 60/E6 was derived by intermittently exposing HL 60 cells to 6 ng/ml ...To explore the effect of NF κB on bcl x gene transcription in extended drug resistance leukemia cell line HL 60/E6, drug resistant subline HL 60/E6 was derived by intermittently exposing HL 60 cells to 6 ng/ml epirubicin. Indirect immunofluorescence was used to demonstrate the location of NF κB RelA in HL 60/E6 cells. FCM analysis and RT PCR were used to detect the efficiency of liposome mediated ODN transfection and the change of bcl x L mRNA levels after 5 μmol/L phosphorothioate (PS) derivatized antisense (AS) oligodeoxynucleotide (ODN) directed to RelA was transferred into HL 60/E6 cells. The results showed that RelA remained persistently active and located at the nuclei of HL 60/E6 cells,but in the cytoplasm of HL 60 cells, the efficiency of liposome mediated ODN transfection was significantly higher than that of null ODN ( P <0.01 in 4 h, 6 h, 12 h, 24 h). Exposure of HL 60/E6 cells to 5 μmol/L AS PS ODN directed to RelA led to a maximal 40 % decline of bcl x L mRNA levels within 8 h. The inhibition rate of bcl x L mRNA was (15±1.79) %, (28±2.34) %, (40±3.47) %, (20±1.54) % in 4 h, 6 h, 8 h, 15 h, respectively, but it was less than 15 % in control group. It was concluded that NF κB was involved in regulating bcl x transcription. It was suggested that NF κB was an important factor for drug resistance in leukemia cells.展开更多
The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a ch...The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.展开更多
The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the targe...The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the target cells. The results showed that the transfection rate of oligonucleotide to the HL-60 was about 90 %—95 % and it had no obvious attenuation within 84 h. However, the plasmid transfection rate was only 5 %—25 % and it was decreased significantly within 60 h. It was suggested that the transfection of oligonucleotide with liposomes was better than that of plasmid.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
In present study we studied the effect of all-trans retinoic acid(ATRA) and dimethylsulfoxide (DMSO) on the induction of apoptosis in HL-60 cell line. Based on morphological changes by Hochest 33342 staining and ident...In present study we studied the effect of all-trans retinoic acid(ATRA) and dimethylsulfoxide (DMSO) on the induction of apoptosis in HL-60 cell line. Based on morphological changes by Hochest 33342 staining and identification of internucleosomal DNA cleavage by gel electrophoresis, we observed aberrant nuclear chromatin eondensation and ladder-like pattern of DNA degradation. Using Flow Cytometric method, we found sub-G1 peak in RA-treated HL-60 cells starting 5 to 6 d after the initiation of the treatment. However, such an obvious apoptotic peak was not identified in DMSO-differentiated cells. Combining the research accomplished before, our study approves further that apoptosis could be a common mode of death of terminally differentiated HL-60 cells.展开更多
Aim To study the effect of 8-chloroadenosine (8-CA)on undifferentiatied HL-60 cell line. Methods The IC50 of cancer cell proliferation was determined using a microculture plate reader at 570 nm (MTT) and 540 nm (SRB)....Aim To study the effect of 8-chloroadenosine (8-CA)on undifferentiatied HL-60 cell line. Methods The IC50 of cancer cell proliferation was determined using a microculture plate reader at 570 nm (MTT) and 540 nm (SRB).Morphology of HL-60 cells was observed under a scanning electron microscope and a transmission electron microscope. The differentiation of HL-60 cells was examined by nitro blue tetrazolium reduction (NBT) and acid phosphatase assay. The cycle of HL-60 cells was analyzed by flow cytometry. Results 8-CA inhibited proliferation of eight human cancer cell lines.The IC50 ranked in the following order; KB (0.05 μmol·L^-1 ) < HL-60 (0.25 μmol·L^-1) < Bel-7402 (0.56μmol·L^-1 )< MCF-7 (0.65μmol·L^-1) < HCT (0.79 μmol·L^-1) < HeLa (0.89μmol·L^-1) < BGC-823 ( 1.149μmol·L^-1) <PG (2.50μmol·L^-1). The scanning and transmission electron microscopy showed that the microvilli of HL-60 cell surface shortened, and the shape of HL-60 cells nuclei changed to kidney-shaped, horse shoe-shaped and bilob ated after treatment with 8-CA. Meanwhile, 8-CA promoted NBT reduction and increased activity of acid phosphatase in HL-60 ceils in a time and concentration-dependent manner. Flow cytometry analysis indicated that 8-CA induced an appreciable increase of the cell population in G1 phase with a marked reduction in S phase. Conclusion 8-CA can induce differentiation of HL-60 cells and block the cells at G1 phase, thus inhibiting proliferation of 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
It was confirmed that the damage of HL-60 cells caused by heating (42℃, 60min) was of heterogeueity.The partial recovery of colony survival and 3H-TdR incorporation from inhibited HL-60 cells was acquired through sh...It was confirmed that the damage of HL-60 cells caused by heating (42℃, 60min) was of heterogeueity.The partial recovery of colony survival and 3H-TdR incorporation from inhibited HL-60 cells was acquired through short-term (24h) Iiquid culture. The resultsindicated that inhibition of DNA synthesis and colonyformation of leukemic cells by hyperthermia was partlyreversible. Its clinical significance and pathogenicmechanism were also discussed.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
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
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.
文摘Objective: To clone the gene associated with apoptosis induced by an inhibitor of polyamine biosynthesis, a-difluoromethylornithime(DFMO). Methods: The differential sufbtraction sereening was used for gene cloning from cDNA library of HL60 cells treated by DFMO. Northern blot,morphological observation, FCM assays and ladder map of DNA electrophoresis were performed. Results: The transfectiong gene expression and activity of inducing apoptosis in the cell transfected from recombinant plasmid containing the cloned fragment df4 wasproved. Conclusion: It is suggest that df4 gene cloned in the study coul be a gene regulating apoptosis of HL60 cells.
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To explore the effect of NF κB on bcl x gene transcription in extended drug resistance leukemia cell line HL 60/E6, drug resistant subline HL 60/E6 was derived by intermittently exposing HL 60 cells to 6 ng/ml epirubicin. Indirect immunofluorescence was used to demonstrate the location of NF κB RelA in HL 60/E6 cells. FCM analysis and RT PCR were used to detect the efficiency of liposome mediated ODN transfection and the change of bcl x L mRNA levels after 5 μmol/L phosphorothioate (PS) derivatized antisense (AS) oligodeoxynucleotide (ODN) directed to RelA was transferred into HL 60/E6 cells. The results showed that RelA remained persistently active and located at the nuclei of HL 60/E6 cells,but in the cytoplasm of HL 60 cells, the efficiency of liposome mediated ODN transfection was significantly higher than that of null ODN ( P <0.01 in 4 h, 6 h, 12 h, 24 h). Exposure of HL 60/E6 cells to 5 μmol/L AS PS ODN directed to RelA led to a maximal 40 % decline of bcl x L mRNA levels within 8 h. The inhibition rate of bcl x L mRNA was (15±1.79) %, (28±2.34) %, (40±3.47) %, (20±1.54) % in 4 h, 6 h, 8 h, 15 h, respectively, but it was less than 15 % in control group. It was concluded that NF κB was involved in regulating bcl x transcription. It was suggested that NF κB was an important factor for drug resistance in leukemia cells.
文摘The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.
基金This project was supported by a grant from National Natu ral Sciences Foundation of China (No. 39800149).
文摘The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the target cells. The results showed that the transfection rate of oligonucleotide to the HL-60 was about 90 %—95 % and it had no obvious attenuation within 84 h. However, the plasmid transfection rate was only 5 %—25 % and it was decreased significantly within 60 h. It was suggested that the transfection of oligonucleotide with liposomes was better than that of plasmid.
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In present study we studied the effect of all-trans retinoic acid(ATRA) and dimethylsulfoxide (DMSO) on the induction of apoptosis in HL-60 cell line. Based on morphological changes by Hochest 33342 staining and identification of internucleosomal DNA cleavage by gel electrophoresis, we observed aberrant nuclear chromatin eondensation and ladder-like pattern of DNA degradation. Using Flow Cytometric method, we found sub-G1 peak in RA-treated HL-60 cells starting 5 to 6 d after the initiation of the treatment. However, such an obvious apoptotic peak was not identified in DMSO-differentiated cells. Combining the research accomplished before, our study approves further that apoptosis could be a common mode of death of terminally differentiated HL-60 cells.
文摘Aim To study the effect of 8-chloroadenosine (8-CA)on undifferentiatied HL-60 cell line. Methods The IC50 of cancer cell proliferation was determined using a microculture plate reader at 570 nm (MTT) and 540 nm (SRB).Morphology of HL-60 cells was observed under a scanning electron microscope and a transmission electron microscope. The differentiation of HL-60 cells was examined by nitro blue tetrazolium reduction (NBT) and acid phosphatase assay. The cycle of HL-60 cells was analyzed by flow cytometry. Results 8-CA inhibited proliferation of eight human cancer cell lines.The IC50 ranked in the following order; KB (0.05 μmol·L^-1 ) < HL-60 (0.25 μmol·L^-1) < Bel-7402 (0.56μmol·L^-1 )< MCF-7 (0.65μmol·L^-1) < HCT (0.79 μmol·L^-1) < HeLa (0.89μmol·L^-1) < BGC-823 ( 1.149μmol·L^-1) <PG (2.50μmol·L^-1). The scanning and transmission electron microscopy showed that the microvilli of HL-60 cell surface shortened, and the shape of HL-60 cells nuclei changed to kidney-shaped, horse shoe-shaped and bilob ated after treatment with 8-CA. Meanwhile, 8-CA promoted NBT reduction and increased activity of acid phosphatase in HL-60 ceils in a time and concentration-dependent manner. Flow cytometry analysis indicated that 8-CA induced an appreciable increase of the cell population in G1 phase with a marked reduction in S phase. Conclusion 8-CA can induce differentiation of HL-60 cells and block the cells at G1 phase, thus inhibiting proliferation of 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It was confirmed that the damage of HL-60 cells caused by heating (42℃, 60min) was of heterogeueity.The partial recovery of colony survival and 3H-TdR incorporation from inhibited HL-60 cells was acquired through short-term (24h) Iiquid culture. The resultsindicated that inhibition of DNA synthesis and colonyformation of leukemic cells by hyperthermia was partlyreversible. Its clinical significance and pathogenicmechanism were also discussed.
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.
