OBJECTIVE To study whether an adriamycin-resistant cell line(HL-60/ADR) can be sensitized by adriamycin(ADR) to TRAIL-mediated apoptosis.METHODS The mRNA levels of the TRAIL receptor and apoptosis-related signaling mo...OBJECTIVE To study whether an adriamycin-resistant cell line(HL-60/ADR) can be sensitized by adriamycin(ADR) to TRAIL-mediated apoptosis.METHODS The mRNA levels of the TRAIL receptor and apoptosis-related signaling molecules involved in the TRAIL-mediated apoptotic pathway were measured by RT-PCR.The protein levels of apoptotic-related signaling molecules involved in the TRAIL-mediated apoptotic pathway and processed caspase-3,caspase-9,and caspase-8 were measured by Western blots.Apoptosis was assessed by flow cytometry.Mitochondrial membrane potential was analyzed by DiOC6(3) staining.Cytotoxicity was determined by the colorimetric MTT viability/ proliferation assay.RESULTS Treatment with a combination of TRAIL and subtoxic concentrations of ADR resulted in synergistic cytotoxicity and apoptosis for both the parental HL-60 and the HL-60/ADR cells.For HL-60,there was a 5-fold potentiation and synergy in cytotoxicity for TRAIL and for HL-60/ADR,cytotoxicity to TRAIL was potentiated 6-fold with ADR.Adriamycin treatment modestly up-regulated TRAIL-R2(DR5),but had no effect on the expression of Fas-associated death domain,c-FLIP,Bcl-2,Bcl-xL,Bax,and IAP family members(cIAP-1,cIAP-2,XIAP,and survivin).The protein levels of pro-caspase-8 and pro-caspase-3 were not affected by ADR,whereas pro-caspase-9 and Apaf-1 were up-regulated.Combined treatment with TRAIL and ADR resulted in activation of caspase-9 and caspase-3,but there was no detectable processing of caspase-8 beyond the background levels.There was signif icant depolarization of the mitochondrial membrane by the combined treatment of both cell lines and it was more pronounced in the parental HL-60 cell line.The combined treatment with TRAIL and ADR resulted in 42.6% of the HL-60/ADR cells undergoing DNA fragmentation,whereas treatment with either ADR or TRAIL alone resulted in 5.46% and 21.3% DNA fragmented cells,respectively.Similar results were obtained with the HL-60 cells.CONCLUSION These fi ndings demonstrate that ADR can still signal ADR-resistant tumor cells,resulting in the modifi cation of the TRAIL-mediated signaling pathway and apoptosis.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 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
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
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
Arsenic Trioxide (ATO) is widely acknowledged as the treatment of choice for Acute Promyelocytic Leukemia (APL). It is a “two-sided” drug since it can induce differentiation or kill APL and other tumor cells accordi...Arsenic Trioxide (ATO) is widely acknowledged as the treatment of choice for Acute Promyelocytic Leukemia (APL). It is a “two-sided” drug since it can induce differentiation or kill APL and other tumor cells according to the dosage. Part of the cytotoxic effects of ATO on APL cells is due to its pro-oxidant activity, a characteristic which ATO shares with a number of other compounds, including high doses of ascorbate (ASC). In a comparative investigation on the cytotoxic effects of both ATO and ASC on HL60 (APL) cell lines, in Vitro, we have been able to confirm the known cytotoxic effects of ATO, but, more importantly, we have demonstrated that ASC is significantly more effective than ATO, in killing these cancer cells in Vitro, when the concentrations are maintained within the millimolar (mM) range, i.e. the range of plasma concentrations at which ASC induces oxidative damage to tumor cells. Since these plasma levels can be reached only by the intravenous administration of high doses of ASC, we propose that intravenous high doses of ASC may represent a potentially revolutionary new approach in the management of APL.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
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
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
By using an LKB-2277 Bioactivity Monitor, the effect ofporphyrin-cholesterol esters on cancer cells RL-60 were examined at 25℃.There is a dirrerence in the shape of the thermogenesls curve samong different kinds or ...By using an LKB-2277 Bioactivity Monitor, the effect ofporphyrin-cholesterol esters on cancer cells RL-60 were examined at 25℃.There is a dirrerence in the shape of the thermogenesls curve samong different kinds or Porphyrln-cholesterol esters,and the death rate or HL-60 cells is also different. The results show that porphyrin-chsterol esters can powerfully inhibit their metabolism, the inhibitory sequence is Ⅱ >I >Ⅲ,but the inhibitory way of each ester is different.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
文摘OBJECTIVE To study whether an adriamycin-resistant cell line(HL-60/ADR) can be sensitized by adriamycin(ADR) to TRAIL-mediated apoptosis.METHODS The mRNA levels of the TRAIL receptor and apoptosis-related signaling molecules involved in the TRAIL-mediated apoptotic pathway were measured by RT-PCR.The protein levels of apoptotic-related signaling molecules involved in the TRAIL-mediated apoptotic pathway and processed caspase-3,caspase-9,and caspase-8 were measured by Western blots.Apoptosis was assessed by flow cytometry.Mitochondrial membrane potential was analyzed by DiOC6(3) staining.Cytotoxicity was determined by the colorimetric MTT viability/ proliferation assay.RESULTS Treatment with a combination of TRAIL and subtoxic concentrations of ADR resulted in synergistic cytotoxicity and apoptosis for both the parental HL-60 and the HL-60/ADR cells.For HL-60,there was a 5-fold potentiation and synergy in cytotoxicity for TRAIL and for HL-60/ADR,cytotoxicity to TRAIL was potentiated 6-fold with ADR.Adriamycin treatment modestly up-regulated TRAIL-R2(DR5),but had no effect on the expression of Fas-associated death domain,c-FLIP,Bcl-2,Bcl-xL,Bax,and IAP family members(cIAP-1,cIAP-2,XIAP,and survivin).The protein levels of pro-caspase-8 and pro-caspase-3 were not affected by ADR,whereas pro-caspase-9 and Apaf-1 were up-regulated.Combined treatment with TRAIL and ADR resulted in activation of caspase-9 and caspase-3,but there was no detectable processing of caspase-8 beyond the background levels.There was signif icant depolarization of the mitochondrial membrane by the combined treatment of both cell lines and it was more pronounced in the parental HL-60 cell line.The combined treatment with TRAIL and ADR resulted in 42.6% of the HL-60/ADR cells undergoing DNA fragmentation,whereas treatment with either ADR or TRAIL alone resulted in 5.46% and 21.3% DNA fragmented cells,respectively.Similar results were obtained with the HL-60 cells.CONCLUSION These fi ndings demonstrate that ADR can still signal ADR-resistant tumor cells,resulting in the modifi cation of the TRAIL-mediated signaling pathway and apoptosis.
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 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.
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Arsenic Trioxide (ATO) is widely acknowledged as the treatment of choice for Acute Promyelocytic Leukemia (APL). It is a “two-sided” drug since it can induce differentiation or kill APL and other tumor cells according to the dosage. Part of the cytotoxic effects of ATO on APL cells is due to its pro-oxidant activity, a characteristic which ATO shares with a number of other compounds, including high doses of ascorbate (ASC). In a comparative investigation on the cytotoxic effects of both ATO and ASC on HL60 (APL) cell lines, in Vitro, we have been able to confirm the known cytotoxic effects of ATO, but, more importantly, we have demonstrated that ASC is significantly more effective than ATO, in killing these cancer cells in Vitro, when the concentrations are maintained within the millimolar (mM) range, i.e. the range of plasma concentrations at which ASC induces oxidative damage to tumor cells. Since these plasma levels can be reached only by the intravenous administration of high doses of ASC, we propose that intravenous high doses of ASC may represent a potentially revolutionary new approach in the management of APL.
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By using an LKB-2277 Bioactivity Monitor, the effect ofporphyrin-cholesterol esters on cancer cells RL-60 were examined at 25℃.There is a dirrerence in the shape of the thermogenesls curve samong different kinds or Porphyrln-cholesterol esters,and the death rate or HL-60 cells is also different. The results show that porphyrin-chsterol esters can powerfully inhibit their metabolism, the inhibitory sequence is Ⅱ >I >Ⅲ,but the inhibitory way of each ester is different.
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.