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Objective To evaluate the effect of down-regulating SALL4 on the radiosensitivity of leukemia cells,aiming to provide new ideas for improving radiosensitivity of leukemia patients.Methods Human acute myeloid leukemia cell line HL-60 infected with shRNA SALL4 and shRNA control lentivirus was classified into the Lv-shSALL4 group and Lv-shNC group.The levels of SALL4 mRNA and protein in cells were detected by RT-PCR and Western blot.The infected cells treated with 8 Gy dose irradiation were assigned into the Lv-shSALL4 + radiation and Lv-shNC+radiation groups.The cell apoptosis was detected by flow cytometry.The levels of cleaved Caspase-3,cleaved Caspase-9 and Bax proteins in cells were determined by Western blot.The cells in the Lv-shSALL4 and Lv-shNC groups were exposed to 0,2,4,6 and 8 Gy irradiation.The radiosensitivity ratio was determined by cell clone test.Results The level of SALL4 in the Lv-shSALL4 group was significantly lower than that in the Lv-shNC group (P<0.05).The cell apoptosis rate was significantly increased,the levels of cleaved Caspase-3,cleaved Caspase-9 and Bax proteins were remarkably up-regulated in cells compared with those in the Lv-shNC group (all P< 0.05).The cell proliferation ability in the Lv-shSALL4 + radiation was significantly reduced,the cell apoptosis rate was considerably increased,the levels of cleaved Caspase-3,cleaved Caspase-9 and Bax proteins were significantly up-regulated compared with those in the Lv-shSALL4 and Lv-shNC+ radiation groups (all P<0.05).The cell radiosensitization ratio in the Lv-shSALL4 group was 1.323.Conclusion Down-regulating SALL4 can increase the radiosensitivity of leukemic cells,inhibit the cell proliferation and induce the apoptosis of leukemic cells.
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Objective@#To evaluate the effect of down-regulating SALL4 on the radiosensitivity of leukemia cells, aiming to provide new ideas for improving radiosensitivity of leukemia patients.@*Methods@#Human acute myeloid leukemia cell line HL-60 infected with shRNA SALL4 and shRNA control lentivirus was classified into the Lv-shSALL4 group and Lv-shNC group. The levels of SALL4 mRNA and protein in cells were detected by RT-PCR and Western blot. The infected cells treated with 8 Gy dose irradiation were assigned into the Lv-shSALL4+ radiation and Lv-shNC+ radiation groups. The cell apoptosis was detected by flow cytometry. The levels of cleaved Caspase-3, cleaved Caspase-9 and Bax proteins in cells were determined by Western blot. The cells in the Lv-shSALL4 and Lv-shNC groups were exposed to 0, 2, 4, 6 and 8 Gy irradiation. The radiosensitivity ratio was determined by cell clone test.@*Results@#The level of SALL4 in the Lv-shSALL4 group was significantly lower than that in the Lv-shNC group (P<0.05). The cell apoptosis rate was significantly increased, the levels of cleaved Caspase-3, cleaved Caspase-9 and Bax proteins were remarkably up-regulated in cells compared with those in the Lv-shNC group (all P<0.05). The cell proliferation ability in the Lv-shSALL4+ radiation was significantly reduced, the cell apoptosis rate was considerably increased, the levels of cleaved Caspase-3, cleaved Caspase-9 and Bax proteins were significantly up-regulated compared with those in the Lv-shSALL4 and Lv-shNC+ radiation groups (all P<0.05). The cell radiosensitization ratio in the Lv-shSALL4 group was 1.323.@*Conclusion@#Down-regulating SALL4 can increase the radiosensitivity of leukemic cells, inhibit the cell proliferation and induce the apoptosis of leukemic cells.
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Objective To construct the ICAT gene interference lentivirus expression vector targeting and to establish stable transfected cell line HL60 .Methods The interference sequence targeted at human ICAT gene was designed and synthesized ,after annealing ,which was connected to PGLV3 interference vector and with PG‐p1‐VSVG ,PG‐p1‐REV ,PG‐p1‐RRE were co‐transfected into 293T cells The lentivirus particles were packaged and generated .The virus titer was detected .HL60 cells were transfected for establishing the stable cell line ;RT‐PCR and Western Blot techniques were used to detect ICAT gene and protein expression in sta‐ble HL60 cells ,then the results were compared with those in the control group .Results The lentivirus expression vector targeted at ICAT was successfully constructed and the virus titer was 2 × 108 U/mL .Stable transfected HL60 cell line was established .The effective interference verification revealed that shICAT could significantly reduce the mRNA and protein level of ICAT ( P<0 .001) .Conclusion The shRNA lentiviral expression vector of ICAT gene is successfully constructed and the HL 60 cell line stably interfering ICAT expression is established .
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@#To determine the effects of celastrol on the proliferation and apoptosis of cell lines HL-60 and Jurkat in human leukemia. Human leukemia cell lines were treated with celastrol at different concentrations. The inhibitory rate of cell proliferation was detected by MTT assay; the apoptosis rate was detected by AnnexinV-FITC/PI double staining; cell cycle was observed by PI staining; cell morphology was observed by transmission electron microscope(TEM). Cell proliferation was inhibited by celastrol, with IC50 of(0. 46±1. 05)μmol/L and(0. 88±1. 13)μmol/L at 24 h. Celastrol induced cell apoptosis in a dose-dependent manner. The cell cycle distribution of G1 phase rate increased, S phase rate decreased(P< 0. 05)with typical cell apoptosis-induced morphological changes. Results showed that celastrol could significantly inhibit cell proliferation and induce apoptosis in human leukemia cell lines of HL-60 and Jurkat.
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Objective Nanoparticles are widely investigated and applied in clinical diagnosis and treatment as drug carrier,and their transmembrane process is related to their biological effects.The aim of this study was to investigate the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells via fluorescence tracking.Methods The transmembrane process of nanoparticles was quantitatively analyzed by laser scanning confocal microscopy.Results The analyzing results showed that the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells was strongly temperature-dependent.The receptor-mediated endocytosis mechanism played an important role in the transmembrane process for cellular uptake of nanopaticles.Conclusions This study provides a theoretical basis for design and application of nano-medicines.
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Objective To investigate the therapeutic effects of arsenic trioxide(ATO) plus vitamin K2(VK2) on proliferation of HL-60 cells from acute promyelocytic leukemia cell line and explore the possible mechanism.Methods ①HL-60 cells were exposed to ATO(0.0,0.5,1.0,2.0,4.0 μmol/L),VK2(0.0,2.5,5.0,10.0,20.0μmol/L),or both of different concentrations (0.5 μmol/L ATO + 2.5 μmol/L VK2,1.0 μmol/L ATO + 5.0μmol/L VK2,2.0 μmol/L ATO + 10.0 μmol/L VK2,4.0 μmol/L ATO + 20.0 μmol/L VK2) for 24,48 or 72 h,respectively.The method of CCK-8 was used to assess the proliferation of HL-60 cells and the half inhibitory concentration(IC50) of ATO or VK2 was calculated,respectively.②Combination index (CI) was used to evaluate the combinative effect of the two treatments:CI < 1,=1 or > 1 indicated synergistic,additive,or antagonistic effect,respectively.③After HL-60 cells were treated with 1.0 μmol/L ATO or 5.0 μmol/L VK2 individually or simultaneously for 48 h,Annnexin V/PI staining was performed to identify the apoptosis rate of each group.Untreated cells were used as control group.Results ①ATO or VK2 alone inhibited the proliferation of HL-60 cells in a concentration and time dependent manner.The IC50 of ATO or VK2 at time of 24,48,72 h were (22.86 ± 2.44),(6.66 ± 0.34),(4.14 ± 0.41) and (18.40 ± 1.12),(13.48 ± 0.73),(8.95 ± 0.40) μmol/L,respectively; ②The combination of ATO and VK2 illustrated a synergistic effect with CI < 1.③No statistical difference was found among control group [(4.38 ± 0.56)%],1.0 μmol/L ATO group [(5.76 ± 1.63)%] and 5.0 μmol/L VK2 group [(6.38 ± 1.42)%] in the apoptosis rate(all P > 0.05).However,the apoptosis rate of combined group did rise to (44.18 ± 8.42)%,with a significant improvement to that of VK2 or ATO group alone (all P < 0.01).Conclusions The combination of VK2 and ATO exhibits an enhanced synergistical inhibitive effect on proliferation of HL-60 cells,and apoptosis may be involved in this synergy in part.
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Objective To explore the influence of mitochondrial permeability transition pore opening and cytochrome C (Cyt C) being discharged on the apoptotic mechanism of HL-60 cell induced by desferrioxamine (DFO),so as to provide scientific basis for the clinicians to adopt the strategy of iron deprivation to treat human leukemia.Methods HL-60 cells were co-cultivated with various concentration of DFO for 24-72 hours,then the apoptotic cells and the changes of mitochondrial membrane potential(△Ψm) were examined by means of flow cytometry(FCM),and Cyt C in cytoplasm was detected by way of celluar immunohistochemistry.Results The cell apoptotic rate assumed rising tendency as the highest rate could be up to (44.10 ± 6.3 1) %,and the effect was of time-and-dose dependence (P <0.01).FCM could detect the △Ψm declining(P < 0.05),and the Cyt C positive cell rate was higher than the controls,the differences were of statistical significance(P < 0.05).Conclusions DFO can induce the HL-60 cells apoptosis,and the possible mechanism is that DFO make the mitochondrial permeability transition pore open and get Cyt C discharged from the mitochondria.
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The objective of this study was to evaluate the effects of tetramethylpyrazine (TMP) in combination with arsenic trioxide (As2O3) on the proliferation and differentiation of HL-60 cells. The HL-60 cells were treated with 300 µg/mL TMP, 0.5 µM As2O3, and 300 µg/mL TMP combined with 0.5 µM As2O3, respectively. The proliferative inhibition rates were determined with MTT. Differentiation was detected by the nitroblue tetrazolium (NBT) reduction test, Wright’s staining and the distribution of CD11b and CD14. Flow cytometry was used to analyze cell cycle distribution. RT-PCR and Western blot assays were employed to detect the expressions of c-myc, p27, CDK2, and cyclin E1. Combination treatment had synergistic effects on the proliferative inhibition rates. The rates were increased gradually after the combination treatment, much higher than those treated with the corresponding concentration of As2O3 alone. The cells exhibited characteristics of mature granulocytes and a higher NBT-reducing ability, being a 2.6-fold increase in the rate of NBT-positive ratio of HL-60 cells within the As2O3 treatment versus almost a 13-fold increase in the TMP + As2O3 group. Cells treated with both TMP and As2O3 expressed far more CD11b antigens, almost 2-fold compared with the control group. Small doses of TMP potentiate As2O3-induced differentiation of HL-60 cells, possibly by regulating the expression and activity of G0/G1 phase-arresting molecules. Combination treatment of TMP with As2O3 has significant synergistic effects on the proliferative inhibition of HL-60 cells.
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Humans , Antineoplastic Agents/pharmacology , Arsenicals/pharmacology , /drug effects , Oxides/pharmacology , Pyrazines/pharmacology , Blotting, Western , Cell Cycle/drug effects , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Drug Synergism , Flow Cytometry , /cytology , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Objective To evaluate the enhancement of chemosensitivity of celecoxib, a specific cyclooxygenase-2 (COX-2) inhibitor, on leukemia HL-60 cell line in vitro, and explore the possible mechanisms. Methods MTT assay was used to assess the cytostatic efficacy of doxorubicin in the absent or present of different doses of celecoxib on HL-60 cell. The apoptosis of HL-60 cells was measured by flow cytometry (FCM). Gene expressions of Survivin was examined by reverse transcription-polymerase chain reaction (RT-PCR). Protein of survivin was detected by Western blotting. Results Celecoxib could increase the cytostatic efficacy of doxorubicin on HL-60 cells. HL-60 cells were treated with increasing doses of doxorubicin in absence or presence of celecoxib (5 μmol/L, 10 μmol/L), IC50 were 0.48 μg/ml, 0.25 μg/ml and 0.16 μg/ml, respectively. Doxorubicin combined with low dose of celecoxib could induce the down-regulation of mRNA and protein of Survivin. Apoptosis rate of HL-60 cells treated with both 0.10 μg/ml doxorubicin and celecoxib(5 μmol/L, 10 μmol/L) were (13.07±1.66) % and (22.36±1.84) %, respectively, while it was (5.72±1.25) % in HL-60 cells treated with 0.10 μg/ml doxorubicin alone, with significant difference (P<0.01).Conclusion Celecoxib could enhance the chemosensitivity of doxorubicin on leukemia HL-60 cell, which involves in increasing the apoptosis of HL-60 cells by down-regulation expression of Survivin.
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Objective To filter the noises in the experimental data of parallel plate flow chamber for observing more clearly the events occurring in the process of cell rolling adhesion and develop a new method to measure the elasticity of microvillus on cells based on the flow chamber experiment. Method The experiment of E-selectin regulated HL-60 cell rolling was performed by flow chamber system, and the data were denoised by wavelet analysis so that the high frequency thermal response signals were extracted from the data. Based on the equipartition theorem and equilibrium equations of tethered cell, the relationship between the cell microvillus spring constant and thermal fluctuations was constructed. Results Filtering noises from cell rolling time course by wavelet analysis, the events such as free rolling, slowing down, stopping and speeding up of rolling cell could be observed more easily; almost 80% of fluctuating energy of a rolling cell was involved in its high frequency fluctuation which was regarded as the thermal response of the cell to the Brown movement of water molecules, and the spring constant of microvillus on HL-60 cell was measured to be (13.7±7.4) μN/m at wall shear stress from 0.01~0.06 Pa. Conclusions The wavelet analysis can filter the thermal noises in cell rolling data of flow chamber experiment, and since the rigidity information of cell microvillus is involved in and can be extracted from the high frequency thermal fluctuation of the rolling cell, the parallel plate flow chamber experimental technique can be extended to measure the elasticity of microvillus on cells.
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Objective The effects of TPT on the induction of apoptosis of leukemia cells and the regulation of c-myc in mRNA and protein level. Methods RT-PCR method was adopted to examine the expressions of the genes and immune histochemistry for the proteins of c-myc in HL-60 cells treated with TPT of optimal concentration and time. Results After HL-60 cells by TPT of 0.15 μmol/L for 12 h, the expression of c-myc mRNA decreased markedly assayed by RT-PCR. There was a significant difference between the TPT group and the control group(0.17±0.03 vs 1.11±0.25, P <0.05), expressive c-myc protein decreased assayed by evidently immunohistochemistry. The percentage of positive cells expressing c-myc protein was a significant difference between the TPT treated group and the control group (19.67 % vs 68.33 %, P<0.05). Conclusion TPT down-regulates endogenic c-myc mRNA and c-myc protein in HL-60 cells.
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Objective To explore the mechanisms of apoptosis induced by arsenic trioxide and amifostine in human acute promyelocytic leukemia cell lines HL-60 in vitro.Methods HL-60 cells were treated with different concentrations of arsenic trioxide alone and combined with amifostine.The inhibitory ratio of the ceils were measured by MTT assay.and the expression of Survivin Was detected by semiquantitate RT-PCR.Results Proliferation of HL-60 cells exposed to arsenic trioxide dwpped down with increasing dose of the dmg and this effect Was significantly hisher when arsenic trioxide Was used in combination with amifostine.Furthermore.there was a more significant decrease in Survivin expression in HL-60 cells treated with arsenic trioxide in combination with amifostine as compared to the cells treated only with arsenic trioxide.Conclusion Arsenic trioxide induced HL-60 cells to undergo apoptosis by downregulating the expression of Survivin. Amifostine enhanced the sensitivity of HL-60 cells to arsenic trioxide by downregulating the expression of Survivin,thus promoting apoptosis effect.
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Objective To detect whether trichostatin(TSA) can induce HL-60 differentiation in vitro. Methods MTT method was used to test the effect of TSA on HL-60 cell growth. Cell cycle was tested by flow cytometry. CD11b expression was tested for detecting cell differentiation, RT-PCR was used to detect the mRNA expression of c-myc in the cells treated by TSA. Results Down-regulation of cell proliferation was observed and cells significantly accumulated at the G0 and G1 phase in HL-60 cells treated with TSA( P <0. 01). Dif-ferentiation rate was 15. 24% after being treated by TSA for 48 h. mRNA of c-myc was down regulated in time-dependent manner. Conclusion TSA can inhibit proliferation and induce differentiation in HL-60 cells.
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Objective:To establish the granulocyte-differentiation model of the HL60 cells which are treated with All-trans retinoic acid(ATRA),and to use the modified two-dimensional electrophoresis conditions to analyze the differences of protein expression between treated and untreated HL60 cells.Methods:HL60 cells were induced through treatment with All-trans retinoic acid(ATRA).For selection of the appropriate drug concentration and induction time,MTT and flow cytometry are used to detect the HL60cell proliferation and the expression of differentiation antigens CD11b respectively.Cellular chemical staining was used for the verification of the differentiation of the treated HL60 cells.The protein of HL60 cell lines could be separated by modified two-dimensional electrophoresis(2-DE).PDQuest software was used to analyze the different protein expression between treated and untreated HL60 cells.The protein was analyzed by matrix-assisted laser desorption -time of flight mass spectrometry(MALDI-TOF).Results:ATRA could inhibit HL60 cell proliferation,and with the increase in drug concentration,the effect of inhibiting was more significant.Treated with 2? M ATRA for five days,there were more than 90% of HL60 cells expressing antigenCD11b.Cellular chemical staining also showed that ATRA could induce HL60 cells to granulocyte cells.By the analysis of modified 2-DE and PDQuest software,25 protein spots was detected in untreated cells,while 15 protein spots was promoted Some of them were oncogene protein and suppressor gene protein,while some of others are involved in apoptosis.Conclusion:ATRA could induce HL60 cells to granulocyte cells in selected drug concentration and induction time.Using the modified two-dimensional electrophoresis conditions,different protein expression can be found from the traditional two-dimensional electrophoresis.
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Objective:To investigate the effect and mechanism of total flavonoids of Hedysarum polybotry on induction of differentiation in human leukemia HL-60 cells. Method After the treatment of HL-60 cells with total flavonoids of Hedysarum polybotry, the cell differentiation was detected with NBT reduction method. Cell cycle, CD11b and C-fos were analysed by the flow cytometry. Result The positive rate of NBT reduction and the expression of CD11b were significantly increased. Similar, the expression of C-fos gene was upregulated. The growth of HL-60 cells was arrested at G0/G1 and G2/M phase. Conclusion Total flavonoids of Hedysarum polybotry could induce differentiation of HL-60 cells. Its molecular mechanism might be related to the modulation of gene expressions associated with the proliferation and differentiation, which leads to the inhibition of DNA synthesis.
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Objective To investigate the mechanism of rosiglitazone on human leukemia cell line HL-60 in vitro.Methods Inhibition of HL-60 cell proliferation was shown by MTT array;cell cycle and apoptosis of human leukemia cell line HL-60 was detected by flowcytometry(FCM);expression of PPAR?,p21WAF1,Bax and bcl-2 was examined by SP immnocytochemical and western blotting.Results Rosiglitazone significantly inhibited proliferation of HL-60 cell and the inhibition effects had a dose-and time-dependence.The inhibition fraction of HL-60 cell to 100?mol/L rosiglitazone for 48h was 77%.Flow cytometry analysis revealed that proliferation of HL-60 cell treated with 10~100?mol/L rosiglitazone significantly inhibited.50~100?mol/L Rosiglitazone cold induce apoptosis of HL-60 cell.SP immnocytochemical found the nuclear translocation on PPAR?,and western blotting revealed that the Bax expression was increased,while the bcl-2 and NF-?B expression was decreased.The expression of PPAR?,Bax,bcl-2 and NF-?B had no change by GW9662,a specific inhibitor of PPAR?.Conclusion Rosiglitazone could induce apoptosis in HL-60 cells which may be involved in the activation of PPAR? and down-regulation of Bax and up-regulation of Bcl-2 and NF-?B protein.
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Objective To observe the effects of fluvastatin on proliferation and apoptosis of HL-60 cells,and to offer the theoretical evidence for tumor treatment.Methods HL-60 cells were divided into:fluvastatin groups(0.5,5.0,10.0 and 20.0 ?mol?L-1),HL-60 control group,positive control group(treated with 10.0 ?mol?L-1ATRA).The live cell number was counted for cell proliferation assay.The growth inhibitory rate of HL-60 cells was detected using CCK-8 kit.The cell cycle distribution and apoptotic rate were measured using flow cytometry assay.Results Compared with control group,after HL-60 cells were treated with 0.5,5.0,10.0 and 20.0 ?mol?L-1of fluvastatin for 1-4 d,the number of live cells decreased in different level(P
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Objective To observe the effect of fluvastatin(Flu) on differentiation and induction of human promyelocytic leukemia HL-60 cells and provide the theoretical foundation for treatment of human promyelocytic leukemia.Methods The cultured HL-60 cells were treated with 20 ?mol?L-1 Flu,the morphological changes of the cell differentiation were examined.The NBT reduction capability was detected in HL-60 cells treated with Flu for 72 h.After HL-60 cells were treated with 20 ?mol?L-1 Flu for 5 d,they were stained with non-specific esterase and the percentage of differentiation cells was analyzed.Results The HL-60 cells treated with Flu showed smaller cell body,reducing proportion of nucleus to cytoplasm,the nucleus tortuosity,fold or sublobe.There were specific granules and vacuoles in cytoplasm,displaying that some cells had differentiated to relative mature cells.As compared with control group,the NBT reduction capability in HL-60 cells treated with Flu for 72 h was significantly higher than that in control cells(P
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Objective To study the effect of siRNA targeting bcl-2 gene on the drug-sensitivity of HL-60 cell to homoharringtonin(HT). Methods siRNA, selected by previous experiments and packaged with lipofectamine 2000, was transferred into HL-60 cells. Six hours later, the cells were cultured with homoharringtonin. The cell growth of HL-60 cells was detected by MTT methods at 24, 48, 72 hours respectively. The level of bcl-2 protein and ROS (reactive oxygen species, ROS) as well as membrane potential of mitochondrion was determined by flowcytometry. Results The siRNA could significantly increase the inhibitive effect of homoharringtonin on growth of HL-60 cells. The combination of siRNA with homoharringtonin resulted in the falling of bcl-2 protein level and rising of ROS level as well as descending of membrane potential of mitochondrion of HL-60 significantly (P
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Background and purpose:Ara-C is one of the most effective and common agents in the treatment of acute nonlyphocytic leukemia. Telomerase is a unique complex of ribonucleoprotein. It plays an important role in the pathogenesis and development of cancer. In this study, we investigate the changes of mRNA expression of telomerase subunits in HL-60 cells induced by Ara-c and try to come up with a theory that could help to assess the efficacy of Ara-C. Methods:The combinations of various Ara-C concentration and the incubation time were used to treat HL-60. The ratios of apoptotic cell to necrosis cell were determined by flow cytometry and the expressions of telomerase subunits mRNA were evaluated by RT-PCR.Results:① There was no influence on transcription of telomerase subunits gene after HL-60 cells was cultured with 0~0.2ug/ml Ara-C for 12 hours;② 2ug/ml and 10ug/ml of Ara-C could down regulate the expression of hTERT from 0.80+0.07 to 0.50+0.04 and 0.39+0.03, not hTR and hTP1;③ with longer incubation with 10ug/ml of Ara-C, the percentage of apoptosis could be increased. The maximal induction of apoptosis (18.16+4.25%) could be reached at 12hrs treatment of Ara-C, then gradually decreased later on. The rate of necrosis increased with time, the maximal percentage(57.94+12.03%) of necrosis was observed at 48hrs of incubation time with drug. The mRNA level of hTERT gene also decreased along with the cultured time , the lowest value (0.18+0.03) has been documented at 48hrs time point, but not hTR、TP1.Conclusions:① Ara-C could down-regulate the expression of hTERT mRNA in a dose-and time-dependent manner, but not hTR、hTP1;② There might be no relationship between the percentage of apoptosis induced by Ara-C apoptosis and the expression of telomerase hTERT gene mRNA, but a close relationship between necrosis and the expression of hTERT mRNA has been found.