Study on the mechanism of diterpenoid DP from Euphorbia fischeriana against leukemia / 中国药房

OBJECTIVE To explore whether diterpenoid 12-deoxyphorbol-13-palmitate （DP） from Euphorbia fischeriana can exert anti-leukemia effects through the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signal pathway， and to provide experimental evidence for developing it into a new anti-leukemia drug. METHODS Using LY294002 （PI3K specific inhibitor） as tool drug， the effects of 24 h DP treatment on the proliferation and apoptosis of human myeloid leukemia HL60 cells were detected by MTT method， Annexin Ⅴ-FITC/PI staining and AO-EB staining. ELISA method was used to detect lactic dehydrogenase （LDH） release and the activities of cysteinyl aspartate specific proteinase 3 （caspase-3） and caspase-9. The transcriptional level of caspase-3， caspase-9， forkhead box O3a （FoxO3a） and B cell lymphoma 2 interacting mediator of cell death （Bim） mRNA were detected by real-time quantitative polymerase chain reaction （qRT-PCR）. The protein expression of phosphorylated FoxO3a （p- FoxO3a） and phosphorylated Akt （p-Akt） were detected by Western blot method. The nuclear translocation of FoxO3a protein was detected by immunostaining combined with laser confocal microscopy. RESULTS 10 μmol/L DP and 10 μmol/L DP+LY294002 could inhibit the proliferation and induce the apoptosis of HL60 cells （P＜0.01）. After treatment of 5， 10， 20 μmol/L DP， HL60 cells showed typical morphological characteristics of apoptosis； DP could significantly increase the levels of LDH release and the activities of caspase-3 and caspase-9 （P＜0.05 or P＜0.01）， in dose-dependent manner. After treatment of 10 μmol/L DP and 10 μmol/L DP+LY294002， the transcriptional levels of caspase-3， caspase-9 and Bim mRNA were increased significantly （P＜0.05 or P＜0.01）， and transcriptional level of FoxO3a mRNA and protein expressions of p-FoxO3a and p-Akt were decreased significantly （P＜0.05 or P＜0.01）. Nuclear translocation changes were observed in FoxO3a protein in 10 μmol/L DP+LY294002 group， and the change was more significant than that of LY294002 group. CONCLUSIONS DP can inhibit the proliferation and induce the apoptosis of HL60 cells via inhibiting PI3K/Akt signaling pathway.

Hop-derived Xanthohumol Induces HL-60 Leukemia Cells Death

Background : Acute promyelocytic leukemia (APL) affects both kids and adults, however it is more prevalent in younger population. Although APL has a favorable prognostic, patients that relapse often do not respond positively to additional chemotherapy. Therefore, there is a need to further identify ways to overcome these challenges. Hypothesis: In this study, we examined antileukemic effects of xanthohumol (XN), a prenylated flav onoid derived from hops ( Humulus lupulus L ), on human promyelocytic HL - 60 cells. Materials and Methods : HL - 60 cells were exposed to different concentrations of XN (?M) for 24 h. Cell viability, cell morphology, chromatin condensation, cPARP - 1 level, and caspase - 3 activation, and the expression of p21 WAF1/Cip1 were analyzed. Results : XN reduced HL - 60 cell viability in a dose - dependent manner. XN induced a dose - dependent morphological changes including cell shrinkage and b lebbing , and significantly increased the number of cells with condensed chromatin. XN significantly increased the level of cPARP - 1, active caspase - 3, and the expression of p21WAF/CIP mRNA. Conclusion : These data indicate that XN induces HL - 60 cell death by regula ting cell cycle progression and apoptosis. This study suggests that XN may have antileukemic preventive effects.

Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis

BACKGROUND: Juglone is a naphthoquinone currently obtained by chemical synthesis with biological activities including antitumor activity. Additionally, juglone is present in the green husk of walnut, which suggests evaluating the effect of GH extracts on carcinogenic cell lines. RESULTS: Walnut green husk ethanolic extract was obtained as 169.1 mg juglone/100 g Green Husk and antioxidant activity (ORAC) of 44,920 µmol Trolox Equivalent/100 g DW Green Husk. At 1 µM juglone in HL-60 cell culture, green husk extract showed an antiproliferative effect, but pure juglone did not; under these conditions, normal fibroblast cells were not affected. A dose-dependent effect on mitochondrial membrane potential loss was observed. Apoptosis of HL-60 was detected at 10 µM juglone. Despite high ORAC values, neither purified juglone nor the extract showed protective effects on HL-60 cells under oxidative conditions. CONCLUSIONS: Green husk extract generates an antiproliferative effect in HL-60 cells, which is related to an induction of the early stages of apoptosis and a loss of mitochondrial membrane potential. The normal cells were not affected when juglone is present at concentrations of 1 µM, while at higher concentrations, there is loss of viability of both cancerous and healthy cells.

Inhibitory effect of PARP inhibitor olaparib on acute myeloid leukemia HL-60 cells / 实用肿瘤学杂志

Objective The inhibitory effect of the PARP inhibitor olaparib on human acute myeloid leukemia HL-60 cells was studied. Methods The HL-60 cells in logarithmic growth phase were treated with different concentrations(1. 25,2. 5,5 and 10 μmol/L) of olaparib for different time. The CCK-8 assay was used to detect the inhibitory effect of olaparib on HL-60 cells. The apoptotic level of HL-60 cells was detected by Annexin-V/PI double staining method,and the expression of related signal proteins ( PARP-1 and caspase-3)in HL-60 cells was detected by Western blot. Results HL-60 cells were inhibited by olaparib at dif-ferent concentrations(1. 25,2. 5,5 and 10 μmol/L) for 48 h,and the inhibition rate gradually increased with the prolongation of the action time;at the same time,the apoptotic rate was increased in HL-60 cells after olaparib treatment for 48 h,showing a dose-de-pendent manner;the PARP activity was inhibited and caspase-3 was activated in HL-60 cells treated with olaparib. Conclusion The PARP inhibitor olaparib not only inhibits proliferation of HL-60 cells,but it also promotes apoptosis of HL-60 cells by inhibi-ting PARP activity and activating caspase-3.

Effect of 12-Deoxyphorbol-13-Palmitate on Proliferation Inhibition and Apoptosis Induction of HL60 Cells / 中国药学杂志

OBJECTIVE: To investigate the effects of 12-deoxyphorbol-13-palmitate (DP) on the proliferative inhibition and induction apoptosis of human acute myelocytic leukemia cell line HL60. METHODS: HL60 cells were treated with different concentrations of DP. The morphological changes were observed with optical microscope. The effect of DP in cell proliferation was tested using cell counting kit-8(CCK-8) assay, to analyze the cell cloning capacity by methyl cellulose colone-forming experiment. DNA agarose electrophoresis method was used to detect apoptosis. The expression of pro-and anti-apoptotic genes Bcl-2 and Bax were examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: CCK-8 METHODS and methyl cellulose colone-forming experiment indicated DP had an certainly inhibitory effect on HL60 cells(P<0.05, P<0.01). The characteristics of apoptosis was presented under optical microscope. DNA agarose electrophoresis showed the obvious DNA 1adder. In accordance with RT-PCR experiments, compared with the control group(0 mg·L-1), DP could down-regulate the gene expression of Bcl-2 and up-regulate the gene expression of Bax in HL60 cells(P<0.01). CONCLUSION: DP can inhibit the proliferation and induce the apoptosis of cultured HL60 cells in a dose-effect and time-effect relationship in vitro, and its mechanism may be related to down-regulating gene expression of Bcl-2, up-regulating gene expression of Bax, rising Bax/Bcl-2 value.

Induction effects of rabdosin B on differentiation of human promyelocytic leukemia HL-60 cells / 中草药

Objective To investigate the characteristics and mechanism of spironolactone ent-kaurane diterpene type diterpene rabdosin B (RB) induced HL-60 differentiation into mature granulocytes. Methods The effects of RB on proliferation, cell cycle, NBT reducing power, phagocytosis, and cell surface antigen CD11b expression of HL-60 were detected by trypan blue staining, Giemsa staining, NBT reducing power assay, and flow cytometry, respectively. Results RB inhibited the proliferation of HL-60 cells at the concentration of 1.0, 3.0, and 5.0 μmol/L, which resulted in the arrest of G0/G1 phase, increased the ratio of renal nucleated and lobate nucleus, and markedly enhanced the NBT reducing power and phagocytic capacity and the significant increase of CD11b positive cell rate. Further tests showed that the active oxygen scavenger NAC (300 μmol/L), NADPH oxidase inhibitor APO (100 μmol/L), and DPI (0.1 μmol/L) not only significantly inhibited the intracellular ROS upregulation induced by RB, but also inhibited various features of RB induced HL-60 cell differentiation. Conclusion RB can increase the activity of NADPH oxidase in HL-60 cells, increase the intracellular ROS concentration, and induce the differentiation of HL-60 cells to mature granulocytes.

Effects of Treponema pallidum on the expression of chemokine ligand 6, 8, 10 in human brain microvascular endothelial cells / 中华皮肤科杂志

Objective To evaluate the effects of Treponema pallidum (T.pallidum) on the expression of chemokine ligands (CXCL) in human brain microvascular endothelial cells (HBMECs).Methods HBMECs were randomly divided into 4 groups,which were treated with viable T.pallidum suspension (T.pallidum group),heat-inactivated T.pallidum suspension (inactivated T.pallidum group),200 μg/L lipopolysaccharide (LPS group) and cell culture medium (blank control group),respectively,for 6,12 and 24 hours.Fluorescence-based quantitative PCR and enzyme-linked immunosorbent assay (ELISA) were performed to determine the mRNA and protein expression of CXCL6,CXCL8 and CXCL10 in HBMECs in the above groups respectively.Transwell migration assay was conducted to evaluate the effects of T.pallidum-stimulated HBMECs on the chemotaxis of human promyelocytic HL-60 leukemia cells (HL-60 cells).Results At 6,12 and 24 hours,the T.pallidum group showed significantly higher mRNA expression of CXCL6,CXCL8 and CXCL10 in HBMECs compared with the blank control group and inactivated T.pallidum group (all P ＜ 0.05),while there were no significant differences between the blank control group and inactivated T.pallidum group (all P ＞ 0.05).Compared with the LPS group,the T.pallidum group showed significantly decreased mRNA expression of CXCL6 and CXCL8 (P ＜ 0.05),but similar mRNA expression of CXCL10(P ＞ 0.05)at 6,12 and 24 hours.At these time points,the levels of CXCL6 and CXCL8 in the culture supernatant of HBMECs were significantly higher in the T.pallidum group than in the blank control group and the inactivated T.pallidum group (all P ＜ 0.05),but no significant differences were observed between the blank control group and the inactivated T.pallidum group (both P ＞ 0.05).Moreover,there were no significant differences in the level of CXCL10 in the culture supernatant of HBMECs among the T.pallidum group,the inactivated T.pallidum group and the blank control group (all P ＞ 0.05).The number of migratory HL-60 cells in the lower Transwell chambers was significantly higher in the T.pallidum group than in the inactivated T.pallidum group and the blank control group (both P ＜ 0.05).Conclusion Viable T.pallidum can up-regulate the gene expression of CXCL6,CXCL8 and CXCL10 in HBMECs,promote the secretion of CXCL6 and CXCL8,and enhance the chemotactic effect of HBMECs on HL-60 cells,which may play a certain role in the occurrence of neurosyphilis.

Suppression of mel18 enhances differentiation of acute myeloid leukemia cell line HL60 induced by cinnamaldehyde / 中国病理生理杂志

AIM:To investigate the effect of suppression of mel18 gene on the differentiation of human acute myeloid leukemia cell line HL 60 induced by cinnamaldehyde ( CA) .METHODS:HL60 cells were treated with low con-centration of CA or all-trans retinoic acid (ATRA).shRNAmel18 vector and shRNALuc control vector were employed to package lentiviruses which were then used to infect HL 60 cells.The virus-infected HL60 cells were treated with low con-centration of CA , and ATRA was used as a positive control of differentiation-inducing agent .The differentiation markers on the cell surface and cell cycle of virus-infected HL60 cells were analyzed by flow cytometry .Western blot was used to deter-mine the expression of MEL18, cyclin D1 and p27, as well as the phosphorylation level of Akt .RESULTS:Low concen-tration of CA and ATRA increased the expression of granulocytic differentiation marker CD 11b on the HL60 cells, with the decreased expression of MEL 18 in the HL60 cells.The expression of MEL18 decreased in shmel18 virus-infected HL60 cells (shmel18-HL60 cells), but did not change in shLuc-HL60 cells.The expression of CD11b on shmel18-HL60 cells increased with G 1-phase arrest , which went even higher after treatment with CA .The phosphorylation level of Akt and the expression of cyclin D1 decreased in shmel18-HL60 cells with the increase in the expression of p27.CONCLUSION:In-hibition of mel18 gene leads HL60 cell granulocytic differentiation .mel18 gene may affect the differentiation of HL 60 cells by regulating cyclin D1 and p27 via PI3K/Akt signaling pathway.PI3K/Akt signaling pathway is also involved in CA-in-duced differentiation of HL60 cells by suppressing mel18 gene expression.

Effects of ICAT silencing in Wnt signaling pathway and NSC67657 induced cell differentiation of HL-60 cells / 中华血液学杂志

Objectives@#To investigate the effect of β-catenin interacting protein 1 (ICAT) silence in Wnt signaling pathway and sterol drug NSC67657 induced cell differentiation of HL60 cell.@*Methods@#HL-60 cells were treated with NSC67657, the cell surface antigen CD14 expression was detected by flow cytometry. Lentivirus LV-ICAT-RNAi vector was constructed and infected HL-60 cells. Then the ICAT gene and protein expression were analyzed using real-time qPCR and Western blot technique. Furthermore, Co-immunoprecipitation assay was used to confirm the interaction of β-catenin/ICAT proteins, and Western blot was employed to compare the expressions of Wnt signaling pathway downstream targets Cyclin D1, TCF-1 and c-Jun between Lentivirus LV-ICAT-RNAi vector infected HL-60 (HL-60i) cells and un-infected HL-60 (HL-60v) cells. The cellular differentiation of HL-60i and HL-60v cells treated with NSC67657 for 24 h was evaluated by Wright’s staining, transmission electron microscopy and flow cytometry analysis.@*Results@#HL-60 cells could be induced to differentiate into monocytes by 10 μmol/L NSC67657. The CD14 positive cells could reach to (92.30±5.14) % after NSC67657 treatment for 5d. The co- immunoprecipitation assay demonstrated that ICAT protein did interact with β-catenin protein, and the absorbance of protein electrophoresis bands increased in differentiated cells. The expressions of Wnt signaling pathway downstream target proteins in HL-60i cells were higher than that in HL-60v cells when they were treated by 10 μmol/L NSC67657, but lower than NSC67657 untreated cells. CD14 positive HL-60i cells were significantly lower than that of HL-60v cells[ (8.33±3.14) % vs (19.08±4.73) %]when treated with NSC67657, but still higher than that of uninfected and untreated HL60 cells[ (0.60±0.03) %] (F=119.24, P=0.010) . The results of cellular morphology and ultrastructure observation were also in accord with that of cell surface antigen analysis.@*Conclusions@#ICAT does participate in HL-60 cells monocytic differentiation induced by NSC67657, and Wnt/β-catenin signaling pathway might play a bridge role.

Arsenic Trioxide Induces Apoptotic Cell Death through Mitochondrial Pathway in Human Leukemia HL-60 Cells / 现代生物医学进展

Objective:To investigate the potential pro-apoptotic activity of arsenic trioxide (ATO) in human leukemia HL-60 cells,as well as the potential mechanism with focus on mitochondrial pathway.Methods:After treatment with different concentrations of ATO (1 μg/mL,5 μg/mL or 10 μg/mL) for 24 h,apoptotic cell death was detected by flow cytometry,oxidative stress was determined by measuring MDA and GSH levels,the expression of apoptotic factors was detected by western blot,and mitochondrial membrane potential (MMP) was determined by immunofluorescence staining.Results:ATO at the concentrations of 5 μg/mL or 10 μg/mL induces apoptotic cell death and increases oxidative stress in human leukemia HL-60 cells.ATO significantly increases the expression of pro-apoptotic factors (Bax and Caspase-3),whereas decreases the expression of anti-apoptotic factor Bcl-2.Compared with the control group,ATO treatment significantly decreases the MMP level in HL-60 ceils.Conclusions:Arsenic trioxide induces apoptotic cell death through mitochondrial pathway in human leukemia HL-60 cells.

Suppression of mel18 enhances differentiation of acute myeloid leukemia cell line HL60 induced by cinnamaldehyde / 中国病理生理杂志

AIM:To investigate the effect of suppression of mel18 gene on the differentiation of human acute myeloid leukemia cell line HL 60 induced by cinnamaldehyde ( CA) .METHODS:HL60 cells were treated with low con-centration of CA or all-trans retinoic acid (ATRA).shRNAmel18 vector and shRNALuc control vector were employed to package lentiviruses which were then used to infect HL 60 cells.The virus-infected HL60 cells were treated with low con-centration of CA , and ATRA was used as a positive control of differentiation-inducing agent .The differentiation markers on the cell surface and cell cycle of virus-infected HL60 cells were analyzed by flow cytometry .Western blot was used to deter-mine the expression of MEL18, cyclin D1 and p27, as well as the phosphorylation level of Akt .RESULTS:Low concen-tration of CA and ATRA increased the expression of granulocytic differentiation marker CD 11b on the HL60 cells, with the decreased expression of MEL 18 in the HL60 cells.The expression of MEL18 decreased in shmel18 virus-infected HL60 cells (shmel18-HL60 cells), but did not change in shLuc-HL60 cells.The expression of CD11b on shmel18-HL60 cells increased with G 1-phase arrest , which went even higher after treatment with CA .The phosphorylation level of Akt and the expression of cyclin D1 decreased in shmel18-HL60 cells with the increase in the expression of p27.CONCLUSION:In-hibition of mel18 gene leads HL60 cell granulocytic differentiation .mel18 gene may affect the differentiation of HL 60 cells by regulating cyclin D1 and p27 via PI3K/Akt signaling pathway.PI3K/Akt signaling pathway is also involved in CA-in-duced differentiation of HL60 cells by suppressing mel18 gene expression.

Mechanism of coke oven emissions-induced acute toxicity in HL-60 cells / 中国职业医学

OBJECTIVE: To establish the cell model using human leukemia cell line HL-60 for exposure of coke oven emissions( COE) in vitro and to explore the mechanism of COE-induced acute toxicity in HL-60 cells. METHODS: HL-60 cells were collected in their logarithmic growth phase and cultured in medium that had final concentrations of COE in 2. 5,5. 0,10. 0 and 20. 0 mg / L for 24 hours. Cell survival rate was examined by CCK-8 assay. The cytotoxicity was evaluated using lactate dehydrogenase release assay. Reactive oxygen species( ROS) production was determined by the 2',7'-dichlorofluorescein diacetate and nitroblue tetrazolium method. The activation of nuclear factor-κB( NF-κB) pathway was evaluated by western blot. RESULTS: With the increasing exposure concentrations of COE,the cytotoxicity of HL-60 cells increased( P < 0. 01),the cell survival rate decreased( P < 0. 01),intracellular ROS decreased( P < 0. 01),whereas extracellular ROS increased( P < 0. 01). These changes had a dose-effect relationship. The levels of phospho-nuclear factor-kappa B p65 and phospho-inhibitor of kappa Bα were higher in all the COE-treated cells compared with untreated cells( P < 0. 05),with no dose-effect relationship. CONCLUSION: COE could cause acute toxicity in HL-60 cells in a doseeffect relationship. The mechanism may be related to the COE-induced in-balanced ROS release and removal,leading to the activation of NF-κB pathway. HL-60 cells can be used as a common cell line for COE hematotoxicity analysis.

Differential expression and interaction of β-catenin/ICAT proteins in NSC67657 induced monocytic differentiation of HL60 cells / 中国药理学通报

Aim To analyze differential expression and interaction of β-catenin/ICAT proteins in HL60 cells when they were induced into monocytic differentiation, and to figure out the mechanism of NSC67657 in cellu-lar induction. Methods HL60 cells were treated by 10 μmol · L-1 NSC67657 , and cellular differentiation could be observed by cytochemical staining and flow cytometry. Then, RT-PCR and Western blot were em-ployed to determine the differential expression of β-catenin/ICAT genes and proteins. Co-immunoprecipi-tation assay was used to confirm the interaction of β-catenin/ICAT proteins, and laser co-focus light mi-croscopy technology was used to co-indentify proteins differential expression and intracellular location. Re-sults HL60 cells could be induced into monocytic dif-ferentiation after 5 days treatment using 10μM NSC67657 . The CD14 ( +)% cells could be up to o-ver 90%, and cytochemical staining reports were con-sistent with this result. The expressions of ICAT gene and protein were up-regulated significantly ( P <0. 01 ) , but the expressions ofβ-catenin gene and pro-tein, on the contrary, were down-regulated(P<0. 05) when HL60 cells were induced into monocytic differen-tiation. From co-immunoprecipitation assay findings, ICAT protein interacted with β-catenin protein, and the absorbance of protein electrophoresis bands in-creased in differentiated cells. From laser co-focus light microscopy assay findings, the fluorescence of ICAT and β-catenin protein could be both observed in cytoplasm and nucleus. In drug treated HL60 cells, the fluorescence of ICAT protein was enhanced both in cytoplasm and nucleus, however, the fluorescence ofβ-catenin protein, which looked like transferring into different organelles, decreased significantly in nucleus, but increased in cytoplasm. Conclusions HL60 cells could be induced into monocytic differentiation by NSC67657 and β-catenin/ICAT proteins differentially expressed during cellular differentiation. The enhanced interaction of β-catenin/ICAT proteins and β-catenin protein transferring from nucleus into cytoplasm indi-cates that NSC67657 probably induces HL60 cells into monocytic differentiation through down-regulating β-catenin protein and blockingβ-catenin protein from nu-cleus.

DADS induces G2/M arrest through Chk1/Cdc25C/CyclinB1/CDK1 pathway in human leukemia HL-60 cells / 中国药理学通报

Aim To study the effects of cycle arrest and molecular mechanism in human leukemia HL-60 cells induced by diallyl disulfide ( DADS ) . Methods Cell count, colony formation in soft agar experiments and flow cytometry analysis were employed to observe the DADS-induced cell growth inhibition and the effect of cycle arrest in HL-60 cells. The expressions of Chk1/2 and its downstream element in HL-60 cells were detected by Western blot. Results Cell count revealed that population doubling time increased to 35. 03 h and 71. 82 h, respectively, from 19. 14 h in HL-60 cells treated with 60 and 120 μmol·L-1 DADS ( P0. 05). The expression of Cdc25C, CyclinB1 and CDK1 decreased after treated with 60 μmol·L-1 DADS in a time-dependent manner ( P0. 05 ) . Conclusion DADS can in-hibit the proliferation of HL-60 cells, and induce G2/M arrest through Chk1/Cdc25 C/CyclinB1/CDK1 path-way.

Tetrandrine affects the expression of DNMT in HL-60 cells / 中国医师杂志

Objective To investigate the expression of DNA methyltransferase (DNMT) in HL-60 cells induced by tetrandrine (Tet).Methods HL-60 cells were treated with different concentrations of Tet and decitabine (DAC) alone and in combination with both.Methyl thiazolyl tetrazolium (MTT) assay was used to assess cytotoxic effect.Flow cytometry (FCM) was used to determine apoptosis rate.Real-time quantitative polymerase chain reaction (PCR) assay was used to quantify mRNA levels of DNMT.Western blot was used to quantify the expression of DNMT protein.Results Tet inhibited the growth and proliferation of HL-60 cells in a time-and dose-dependent manners (both P ＜0.01).Tet treated HL-60 cells after 48 h at the concentration of 2 μmol/L,and 4 μmol/L,the levels of DNMT gene and protein in the drug administration group decreased compared to the control group.After incubation for 48 h with Tet 2 μmol/L combined with DAC 4 μmol/L,the combination group was significantly depressed.Conclusions Tet could potently inhibit the growth and proliferation of HL-60 cells,reduce the expression levels of DNMT mRNA and protein,and have a more obvious effect in the combination group.

Study on Mechanism of HL-60 Cell Apoptosis Induced by DMDAI-L / 中国药师

Objective: To explore the effect and mechanism of DMDAI-L in inducing the HL-60 cells apoptosis. Methods:Caspase-3 activity in HL-60 cells was measured with the enzymatic visible substrate DEVD-pNA. The fluorescence changes of mito-chondrial membrane potential (△Ψm) in HL-60 cells were investigated with the fluorescent probe JC-1. Results:The caspase-3 activ-ity was significantly increased in HL-60 cells after the DMDAI-L treatment at the concentration of 1. 25, 2. 5, 5, 10 and 20μg·ml-1 for 24h(P<0. 05). DMDAI-L could significantly reduce the mitochondrial membrane potential in HL-60 cells. Conclusion: The mechanism of DMDAI-L in inducing HL-60 cells apoptosis may involve the activation or regulation of caspase-3 activity as well as the reduction of mitochondrial membrane potential in HL-60 cells within certain concentration and time range.

Enhanced anti-leukemic activity of decitabine to leukemia HL-60 cells by anti-miR-21 oligonucleotide / 中国病理生理杂志

AIM:To investigate the role of anti-miR-21 oligonucleotide ( AMO) in the anti-leukemic activity of decitabine (DCA) in vitro.METHODS:AMO and scramble oligonucleotide (SCR) were constructed and transfected into HL-60 cells.The miR-21 expression was analyzed by real-time PCR to identify the transfection efficiency .The cells were treated with DCA at gradient concentrations (0.5, 2.0 and 4.0 μmol/L) for 48 h.The mRNA expression of human period circadian protein 3 (hPer3) was detected by real-time PCR.The early apoptotic rates were determined by flow cy-tometry with Annexin V/PI staining.Mean fluorescence intensities ( MFI) of CD117 and CD11b were also measured by flow cytometry.RESULTS:The miR-21 relative expression level in AMO group was significantly lower than that in blank group and SCR group (P<0.01).IC50 of DCA in AMO group was significantly lower than that in blank group and SCR group (P<0.01).With the same concentration of DCA, the early apoptotic rate, the mRNA expression of hPer3 and the MFI of CD11b in AMO group were significantly higher than those in blank group and SCR group (P<0.01).The MFI of CD117 in AMO group were significantly lower than those in blank group and SCR group ( P<0.01 ) .CONCLUSION:Activation of hPer3 expression plays an important role in enhanced anti-leukemic activity of decitabine by AMO in vitro.

Fruits and barks extracts of Zanthozyllum heitzii a spice from Cameroon induce mitochondrial dependent apoptosis and Go/G1 phase arrest in human leukemia HL-60 cells

BACKGROUND: Zanthoxylum heitzii is a spice used to prepare several dishes and to treat tumors, syphilis, malaria, cardiac palpitations, urogenital infections in the west region of Cameroon, but the antitumor mechanisms and chemical composition are not yet investigated. This study was aimed to determine the antiproliferative effects of four extracts from the fruits and barks of Zanthoxyllum heitzii (Rutaceae) on apoptosis in human promyelocytic cells, their mechanisms and the chemical composition. The 3-(4, 5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the fifty percent inhibition (IC50) concentration of the cell lines after treatment. The effect on morphology was observed using a light or fluorescence microscopy. The rate of apoptosis and the cell cycle were measured using flow cytometry (FCM). The phytochemical analysis of the extract was carried with HPLC/MS methods. RESULTS: The phytochemical analysis of the extracts indicated the presence of four known polyphenols (Syringic acid, Juglon, Luteolin and Myricetin) in both fruits and barks of Z. heitzii but in different quantities. Syringic acid and Myricetin concentrations were between 17-21 fold higher in the fruits than the stem bark. Rhamnetin (393.35 µg/mL) and Oleuropein (63.10 µg/mL) were identified only in the stem barks of Z. heitzii. Among the four extracts tested for cytotoxicity properties, only the methanol extract of fruits and barks significantly inhibited cell proliferation of HL-60 cells with IC50 value of 20 µg/mL and 12 µg/mL respectively. HL-60 cells treated with Z. heitzii extracts significantly produced reactive oxygen species (ROS) with concurrent loss of mitochondrial membrane potential (MMP). Modifications in the DNA distribution and enhanced of G1/G0 phase cell cycle arrest were observed in a concentration dependent manner. CONCLUSIONS: Polyphenols from Z. heitzii plant exert inhibitory effect on HL-60 cells through the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and cell cycle destabilization.

Inhibition of rapamycin on proliferation of human acute promyelocytic leukemia HL60 cells / 中国药学杂志

OBJECTIVE: To investigate the effect of rapamycin on proliferation, autophagy and apoptosis of human acute promyelocytic leukemia HL60 cells. METHODS: The inhibitory effect of rapamycin on HL60 cell was detected by MTT assay. The expressions of LC3-II autophagy-related protein were determined by Western blot. The cell cycles were analyzed by flow cytometry (FCM). Apoptosis were detected by DNA agarose gel electrophoresis. RESULTS: After treatment with rapamycin of 0, 1, 5, 10, 20, 40 nmol · L-1 for 24 h, proliferation of HL60 cells were inhibited in a dose-dependent manner (r=0.97, P < 0.05). Western-blot shows that the expression of LC3-II protein of each concentration group was higher than that of the control group (P < 0.01). Rapamycin has a role in promoting cell autophagy. Compared with control group, more cells were arrested at G0/G1 phases (P < 0.05) and fewer cells were at S phases (P < 0.05). Agarose gel electrophoresis shows no apoptosis DNA fragments. CONCLUSION: In given concentration range, rapamycin can inhibit the proliferation of human acute promyelocytic leukemia HL60 cells by promoting autophagy rather than inducing apoptosis.

Roles and mechanisms of Fas/FasL in the apoptosis of HL-60 cells induced by euphorbiasteroid / 国际肿瘤学杂志

Objective To investigate the effect of euphorbiasteroid on inducing the apoptosis of HL-60 cells and demonstrate whether the Fas/FasL signaling pathway is involved in the induction of apoptosis. Methods HL-60 cells were treated with dose of 2.5,10,40 μg/ml of euphorbiasteroid in vitro for 24 h respectively.After that,cell counting Kit-8 was used to detect cell proliferation.The morphology of HL-60 cells were observed under light and fluorescent microscopy.The early cell apoptosis was detected by using flow cytometry with Annexin Ⅴ-FITC /PI double staining.The expressions of Fas,FasL,caspase-8 and caspase-3 mRNA were analyzed by the method of RT-PCR.The activities of caspase-8 and caspase-3 were examined by chromatometry.Results Compared with 1640 control group,HL-60 cell proliferation was inhibited significant-ly by euphorbiasteroid.The inhibition rates were (34.9 ±3.7)%,(54.6 ±5.2)% and (61.3 ±4.3)%respectively.Moreover,HL-60 cells exhibited typical morphological features.Early cell apoptosis rates of HL-60 cells were (23.4 ±3.1)%,(35.7 ±4.3)% and (53.2 ±3.9)% respectively.Furthermore,the expressions of Fas,FasL,caspase-3 and caspase-8 mRNA were up-regulated significantly after euphorbiasteroid administration in a dose-dependent manner (P<0.01 ).After treated with euphorbiasteroid,the activities of caspase-8 and caspase-3 were significantly enhanced (P<0.01 ).Conclusion The up-regulation effect of euphorbiasteroid on Fas/FasL signaling pathway might contribute to the apoptosis of HL-60 cells.