Caspase-3 mRNA反义核苷酸对γ-射线诱导的HL-60细胞凋亡的影响

目的观察caspase-3 mRNA反义寡核苷酸(ASODN)对HL-60细胞凋亡的抑制作用,筛选有效ASODN。方法用脂质体介导法将针对caspase-3 mRNA不同序列的4条ASODN导入HL-60细胞中,γ-射线照射。应用电泳法检测DNA梯状条带;Hoechst 33258-碘化丙啶染色,荧光显微镜分析凋亡细胞百分率;流式细胞术进行细胞凋亡定量。结果以caspase-3 mRNA5’非编码区(-62至-46位)与编码起始区(-1至16位)ASODN转染,当转染终浓度≥3μmol/L时,DNA电泳梯状条带消失,流式细胞术亦未见明显的亚二倍体峰;荧光染色分析,凋亡细胞百分率比未转染对照组和错配寡核苷酸对照组显著降低(P<0.01),且随转染终浓度的增加,凋亡抑制率显著增加。另外,5’非编码区ASODN的抑制作用显著强于编码起始区ASODN(P<0.05)。结论caspase-3 mRNA ASODN可抑制γ-射线诱导的HL-60细胞凋亡,作用有序列特异性及剂量依赖性。该结果为细胞过度凋亡相关疾病的基因治疗提供了实验基础。     

Caspase-3反义寡核苷酸对γ-射线诱导的HL-60细胞中caspase-3表达与细胞凋亡的抑制作用

γ-射线可诱导人髓性白血病细胞株HL-60细胞凋亡,但其机制尚未完全明了。为了观察caspase-3在这种细胞凋亡模型中的作用,本研究设计合成针对caspase-3mRNA5′-非编码区和编码起始区的反义寡核苷酸(ASODNs),即ASODN-1和ASODN-2,以脂质体介导法将不同浓度ASODN-1和ASODN-2转染进入HL-60细胞,γ-射线照射。应用TUNEL法观察凋亡细胞形态学变化及检测凋亡细胞百分率,免疫细胞化学、Westernblotting和RT-PCR技术分别检测caspase-3及其mRNA在引入ASODNs前后的表达水平,并以错配寡核苷酸(MODN)转染及未转染细胞作为对照组。TUNEL法检测发现,当ASODN-1和ASODN-2转染终浓度≥3μmol/L时,γ-射线诱导的HL-60细胞凋亡率降低,与对照组相比均有显著性差异(P<0.01)。免疫细胞化学结果显示,与两对照组相比,转染ASODNs后各组caspase-3阳性细胞率显著下降,阳性细胞染色减弱,其平均灰度值显著增高(P<0.01)。Westernblotting检测显示,转染ASODNs组细胞caspase-3蛋白酶原表达降低,其中ASODN-1组显著低于ASODN-2组。RT-PCR结果显示两对照组细胞caspase-3mRNA均有明显表达,转染ASODNs后caspase-3mRNA表达丰度降低。另外,ASODN-1抑制细胞凋亡和caspase-3表达的作用显著强于ASODN-2(分别为P<0.05和P<0.01)。实验结果表明,caspase-3mRNAASODNs能够抑制γ-射线照射诱导的HL-60细胞凋亡,下调caspase-3蛋白和caspase-3mRNA的表达水平,其抑制作用在一定范围内呈剂量依赖性。     

CD11b/DNA双参数流式细胞术检测HL-60细胞分化的细胞周期

目的采用双参数流式细胞术研究全反式维甲酸(alltransretinoidacid,ATRA)诱导人类急性早幼粒白血病细胞HL-60细胞分化的细胞周期。方法HL-60细胞经分化诱导剂ATRA(终浓度为1μmol/L)诱导不同时间点后,利用CD11b/DNA双参数流式细胞术同时检测分化细胞表面抗原CD11b的表达及分化细胞DNA含量。结果HL-60细胞经ATRA诱导后,细胞表面分化抗原CD11b表达明显升高,细胞阻滞于G0/G1期,且CD11b阳性细胞主要位于G0/G1期。结论CD11b/DNA双参数流式细胞术能简便,快速,直观地检测细胞分化的细胞周期。     

在fMLP刺激的HL-60细胞中PI3-K介导的肌动蛋白聚合

趋化肽fMLP能够诱导中性粒细胞粘附、游走和吞噬.为了澄清这种趋化反应的发生机理,将HL-60细胞诱导分化为中性粒细胞样细胞,然后利用激酶特异性抑制剂研究了在fMLP刺激下细胞内PI3-K、p38和ERK激酶在肌动蛋白聚合中的作用.结果0.1 μmol/L的PI3-K抑制物Wortmannin抑制fMLP诱导的肌动蛋白聚合;而50 μmol/L的p38激酶抑制物SB203580和50 μmol/L的ERK激酶抑制物PD098059对fMLP诱导的肌动蛋白聚合没有影响, 但p38和ERK在不同程度上受到PI3-K的调节.这说明PI3-K介导的肌动蛋白聚合信号传导途径不同于PI3-K介导的p38和ERK激活途径.     

DNA甲基化作用对HL-60细胞中蛋白质-核酸相互作用的影响

以S-腺苷酰-L-甲硫氨酸(SAM)为诱导物,在10μmol/L的最佳浓度下,可诱导16%的HL-60细胞分化.HPLC法检测碱基含量,发现在细胞分化过程中伴有基因组DNA甲基化水平升高.选择对5-甲基胞嘧啶敏感的限制性核酸内切酶切割DNA,证实基因组DNA对HaeⅢ,SmaⅠ,SalⅠ,XhoⅠ和HindⅢ的切割产生阻抗作用.以凝胶滞留法检测DNA与核蛋白的结合状况,表明DNA与胞内DNA结合蛋白的结合能力发生改变.     

雷帕霉素对低氧下人HL-60细胞增殖和凋亡的影响

本研究拟通过小分子化合物氯化钴（CoCl2）模拟的低氧环境,探讨雷帕霉素（RPM）对该低氧下人急性髓细胞白血病HL-60细胞的生物学行为的影响。低氧模拟组、低氧雷帕霉素处理组、常氧雷帕霉素处理组HL-60细胞分别采用CoCl2、CoCl2／RPM、RPM进行处理,对照组为常氧下常规培养的HL-60细胞,处理及培养24h、48h、72h后收集细胞,采用倒置相差显微镜观察细胞生长状况,常规瑞氏染色后光学显微镜下观察细胞形态;MTT比色法检测各组细胞的活性和增殖能力;AnnexinV—FITC／PI双染法流式细胞术检测细胞凋亡。结果表明,与对照组细胞形态规则,胞核呈圆形或椭圆形相比,低氧模拟组和低氧雷帕霉素处理组细胞密度降低,生长明显受抑,细胞胞核呈不规则形或杆状,染色质粗糙,伴扭曲折叠等变化。各组间不同时问细胞增殖抑制率差异显著（P〈0．05）,低氧模拟组和低氧雷帕霉素处理组增殖抑制率随着处理时间延长而增大,且低氧雷帕霉素处理组的增殖抑制率大于低氧模拟组。与常氧下的对照组及雷帕霉素处理组比较,低氧的模拟组和雷帕霉素处理组诱导细胞发生较明显的凋亡,且后期72h低氧雷帕霉素处理组凋亡率显著高于模拟低氧处理组。以上结果表明,模拟低氧环境下,HL-60细胞生长明显受抑制,且诱导细胞凋亡;雷帕霉素可增强对低氧对细胞的生长抑制和诱导凋亡作用。     

羊栖菜多糖诱导HL-60细胞凋亡的研究

用MTT法观察羊栖莱多糖(SFPS)在体外抗人白血病HL-60细胞增殖作用;扫描电镜、透射电镜、DNA电泳和流式细胞仪检测HL-60细胞凋亡。结果表明SFPS对HL-60细胞具有显著生长抑制作用,并呈量效和时效关系,药物作用24,36,48,72h的IC50分别为390,362,402,421mg／L;药物浓度为300mg／L和500mg／L作用HL-60细胞后,琼脂糖凝胶电泳显示有凋亡细胞特有的DNA梯状条带,细胞微绒毛减少、染色质固缩、边集,凋亡小体形成;DNA直方图出现亚G1峰。在一定浓度范围内,SFPS诱导细胞凋亡的作用呈现浓度和时间依赖性,同时G2／M期细胞比例增多。因此,SFPS抗肿瘤作用与诱导细胞凋亡和G2／M期细胞阻滞有关。     

锂和三尖杉酯碱对HL—60细胞增殖,分化和c—myc表达的影响

本研究利用细胞培养技术观察了氯化锂和三尖杉酯碱（ＨＴ）对ＨＬ－６０细胞增殖的影响,不同浓度的氯化锂对ＨＬ－６０细胞的集落形成和３Ｈ－ＴｄＲ参入均呈剂量依赖式抑制;三尖杉酯碱亦有类似的作用。在培养体系中加氯化锂和三尖杉酯碱时,对ＨＬ－６０细胞数及集落形成抑制作用与单用二者相比较有明显增加。用ＮＢＴ还原试验,氯化锂和三尖杉酯碱均促进ＨＬ－６０细胞的分化,小剂量氯化锂还能加强三尖杉酯碱对ＨＬ－６０细胞诱导分化作用。从氯化锂和三尖杉酯碱处理的ＨＬ－６０细胞中提取总ＲＮＡ,应用ＲＴ／ＰＣＲ检测ｃ－ｍｙｃ的表达,结果表明经氯化锂和三尖杉酯碱处理的ＨＬ－６０细胞ｃ－ｍｙｃ表达均降低,与未处理的ＨＬ－６０细胞ｃ－ｍｙｃ比较,说明氯化锂和三尖杉酯碱均能抑制ｃ－ｍｙｃ的表达,提示ｃ－ｍｙｃ很可能在白血病细胞增殖、分化中起调控作用。     

雷帕霉素对低氧下HL-60细胞的低氧调控信号分子表达的影响

摘要目的：通过小分子化合物氯（CoCt2）模拟的低氧环境,分析低氧下及其雷帕霉素（RPM）作用下人急性髓细胞白血病细胞HL．60的低氧调控信号分子表达的变化;方法：常规方法复苏、传代、培养HL-60细胞,培养细胞进入对数生长期后用于实验。低氧模拟组、低氧雷帕霉素处理组、常氧雷帕霉素处理组分别用含2001xmol／LCoCl2、2001xmol／LCOCl2／20nmol／LRPM、20nmol／LRPM的1640培养基处理生长状态良好的细胞,对照组细胞用1640培养基培养,各组置培养箱以37℃、5％CO2培养,并于处理后24h、48h、72h收集细胞用于检测;采用实时荧光定量PCR方法检测低氧诱导因子（HIF-1α）、内皮细胞生长因于（VEGF）、雷帕霉素靶蛋白（mTOR）及GAPDH在转录水平的表达;结果：①与各时段对照组相比,低氧模拟组HIF-1α表达随时间逐渐增加,72h明显上调;与常氧雷帕霉素处理组各时段比较,低氧雷帕霉素处理组HIF-1α表达早期（24h）相对下调,后期相对上调;②．与对照组比较,各处理组mTOR表达均下调,低氧雷帕霉素处理组在早期（24h）下调显著;与常氧雷帕霉素处理组比较,低氧雷帕霉素处理组mTOR各时段的表达均相对下调;③与对照组各时段相比,低氧模拟组VEGF的表达在早期显著上调,但后期呈下调;常氧雷帕霉素处理组各时段VEGF的表达下调,与其比较,低氧雷帕霉素处理组各时段均呈相对下调。结论：常氧和低氧下RPM作用HL-60细胞后VEGF、mTOR的mRNA均表达下调,RPM可在低氧环境下增强了这种下调表达作用。     

Isoverbascoside对HL-60细胞的诱导分化和细胞毒作用

不同时间、不同浓度的isoverbascoside体外处理HL-60细胞,以形态改变(光镜和透射电镜观察)、功能分化(化学发光检测吞噬能力)、恶性度降低(裸鼠成瘤试验)等指标观察其诱导分化作用;以台盼蓝拒染作用和电镜下形态变化确定其细胞毒作用;用流式细胞术测定其对HL-60细胞周期的影响。20—25μmol/L Isov 1—3天诱导HL-60细胞向粒系方向分化,细胞吞噬能力提高,裸鼠成瘤性降低。30—35μmol/L Isov 2—3天对HL-60细胞有强烈的细胞毒作用。20μmol/L Isov处理12h可引起HL-60细胞的G_1期阻滞,在72h时引起HL-60细胞的G_2/M期的阻滞。     

Kaempferol induced inhibition of HL-60 cell growth results from a heterogeneous response, dominated by cell cycle alterations

Dietary flavonoids may be exploitable as chemotherapeutics and preventatives for critical health conditions, including cancer. Antiproliferative effects are commonly ascribed to such compounds but ambiguity exists as to the principal mechanism of action and the universal benefit of exposure, particularly at high concentrations. Here, we identify heterogeneous responses within HL-60 promyelocytic leukaemia cells that explain contradictions in the reported origin of the antiproliferative action of kaempferol, a dietary abundant flavonoid. At > or =10 microM, kaempferol exposure is predominantly characterised by cell cycle alterations, notably a significant increase in S-phase and a progressive accumulation in G2-M with 10 and > or =20 microM kaempferol, respectively. However, a limited but consistent membrane damage is observed across the 1-100 microM exposure and at 1 microM occurs devoid from indices of apoptosis which are only consistently observed with > or =10 microM kaempferol treatment. At the most cytotoxic exposures, multiparametric flow cytometric analysis revealed distinct sub populations of cells. Cells with decreased size, typical of apoptosis and necrosis, possessed heightened caspase-3 activity, decreased anti-apoptotic Bcl-2 expression and changes to membrane asymmetry and integrity. The remaining population had elevated active caspase-3 but no change or a moderate increase in Bcl-2 expression and no plasma membrane alterations. Differentiation was not a significant factor in HL-60 growth inhibition. In conclusion, kaempferol-induced growth inhibition is dominated by cell cycle changes but involves a limited cytotoxicity, which we propose results from a membrane damage centred as well as an apoptotic process. This heterogeneity of response may confound the disease-preventative role and pharmacological application of this flavonoid.     

Identification and expression of haponin, a new protein from HL-60 cells

We found a new protein haponin (an HLDF-like protein) in promyelocyte HL-60 cells that is immunoreactive to polyclonal antibodies against HLDFβ. Determination of the partial primary structure of the protein allowed us to reveal an immunogenic peptide of haponin and, on the basis of the amino acid sequence of this peptide, the degenerate primers were synthesized, which enabled us to clone the full-size cDNA of haponin. The stable heterologous expression of this cDNA in E. coli cells (Rosetta? strain) was obtained. Preparations of natural and recombinant proteins exhibited antigenic cross-reactivity to polyclonal antibodies against this peptide.     

灰毡毛忍冬次皂苷乙抑制白血病细胞HL-60的增殖及其机制研究

研究了灰毡毛忍冬次皂苷乙(MB)在体外对白血病细胞HL-60和结肠癌细胞LOVO增殖的抑制作用,并初步探讨其分子机制。采用MTT法检测MB的增殖抑制作用;利用RT2ProfilerTMPCR Array芯片实时定量PCR扩增肿瘤发生中84个关键基因。结果表明MB对两种肿瘤细胞生长均有抑制作用,且对HL-60效果更好。以HL-60作为细胞模型,总共发现差异基因20个,其中上调基因14个,下调基因6个,主要作用是阻滞细胞周期和降低细胞侵袭转移。     

5－氮－2＇－脱氧胞苷（5－aza－CdR）对HL－60细胞分化和DNA甲基化酶的影响

以５－氮－２＇－脱氧胞苷（５－ａｚａ－ＣｄＲ）为诱导物,在０．５μｍｏｌ／Ｌ的最佳浓度下,可诱导ＨＬ－６０细胞分化达１５％左右。同时,用［￣３Ｈ］－ｍｅｔｈｙｌ－ｓ－ａｄｅｎｏｓｙｌｍｅｔｈｉｏｎｉｎｅ（￣３Ｈ－ＳＡＭ）为底物,通过同位素参入法,测定了不同浓度诱导物对ＨＬ－６０细胞ＤＮＡ甲基化酶活力的影响,发现在最佳诱导物浓度下,可使ＨＬ－６０细胞ＤＮＡ甲基化酶活力明显下降,此外,也比较了不同分化水平的ＨＬ－６０细胞中具有不同甲基化水平的ＤＮＡ在体外接受甲基的能力,从而证明５－ａｚａ－ＣｄＲ诱导ＨＬ－６０细胞分化与其ＤＮＡ甲基化状态密切相关。     

Involvement of caspase-3 activation in squamocin-induced apoptosis in leukemia cell line HL-60

Annonaceous acetogenins have potent antitumor effect in vitro and in vivo. Squamocin is one of the annonaceous acetogenins and has been reported to have antiproliferative effect on cancer cells. Our results from this study showed that squamocin inhibited proliferation of HL-60 cells with IC50 value of 0.17 microg/ml and induced apoptosis of HL-60 cells. Investigation of the mechanism of squamocin-induced apoptosis revealed that treatment of HL-60 cells with squamocin resulted in extensive nuclear condensation. DNA fragmentation, cleavage of the death substrate poly (ADP-ribose) polymerase (PARP) and induction of caspase-3 activity. Pretreatment of HL-60 cells with caspase-3 specific inhibitor DEVD-CHO prevented squamocin-induced DNA fragmentation, PARP cleavage and cell death. The expression levels of protein bcl-2, bax have no change in response to squamocin treatment in HL-60 cells, whereas stress-activated protein kinase (SAPK/JNK) was activated after treatment with squamocin in HL-60 cells. These results suggest that apoptosis of HL-60 cells induced by squamocin requires caspase-3 activation and is related to SAPK activation.     

UV辐射所致HL－60细胞DNA不均一修复的研究

在特定基因水平检测了ＵＶ照射后ＨＬ－６０细胞的ＤＮＡ修复。结果显示活性转录的ｃ－ｍｙｃ基因的修复水平明显高于非活性转录的β珠蛋白基因和全基因组。而进一步应用链专一性ＲＮＡ探针检测,发现ｃ－ｍｙｃ基因中的转录链和非转录链的修复效率没有明显差异。上述结果表明,ＨＬ－６０细胞能够对活跃表达基因的损伤进行选择性高效修复,但不能对活跃表达基因中的转录链进行进一步的选择性修复。     

RGD peptide-induced apoptosis in human leukemia HL-60 cells requires caspase-3 activation

RGD motif-containing peptides have been used in various studies of cell adhesion and growth. We report that RGD triggered apoptosis at a concentration of 1 mmol/L, whereas RAD-containing peptides failed to induce apoptosis in HL-60 cells. RGD-treated cells revealed internucleosomal DNA fragmentation. Western blot reveals caspase-3 activation in RGD peptide-treated cells. A caspase-3 inhibitor z-VAD-FMK completely blocked the apoptosis, but a caspase-1 inhibitor (Ac-YVAD-CMK) and caspase-2 inhibitor (z-VDVAD-FMK) did not block the apoptosis, suggesting that caspase-3 might have a critical role in the execution process of apoptosis induced by RGD. RGD peptides have been used extensively to inhibit tumor metastasis. Our results should help in further understanding the RGD peptide-induced apoptosis, which is important since RGD peptides have a potential role in therapies of the future. This revised version was published online in July 2006 with corrections to the Cover Date.     

Tyrosine phosphorylation is an early and requisite signal induced by interferon-γ in HL-60 cells

Interferon-γ (IFNγ) is a potent immunomodulatory cytokine. However, the early mechanisms which mediate the pleiotropic effects of IFNγ on different cells are as yet poorly understood. Therefore, we tested the role of tyrosine phosphorylation in signalling induced by IFNγ. IFNγ was found to induce rapid tyrosine phosphorylation of several proteins in HL-60 cells. This effect was detectable by 2 min, reached a maximum by about 4–16 min and thereafter declined. Tyrosine phosphorylation was dependent on receptor occupation and was maximally stimulated by 10 ng/ml IFNγ. Treatment of HL-60 cells with the tyrosine kinase inhibitors, genistein and herbimycin A, inhibited both IFNγ-stimulated tyrosine phosphorylation and IFNγ-induced Fc receptor expression. Thus, increased tyrosine phosphorylation appears to be an obligatory early and proximal signal mediating at least some of the later cellular responses induced by IFNγ in HL-60 cells.