Growth inhibitory effect of ethyl acetate-soluble fraction of Cynara cardunculus L. in leukemia cells involves cell cycle arrest, cytochrome c release and activation of caspases

An extract of artichoke Cynara cardunculus L. (CCE) has been shown to exhibit antioxidant and antigenotoxic properties. In this study, the ability of CCE to inhibit the growth of L1210 and HL-60 leukemia cells was studied. Treatment of leukemia cells with a variety of concentrations of CCE (500-2500 microg/microL) for 24 h resulted in dose-dependent inhibition of leukemia cell growth. The cell growth inhibition was accompanied by G(0)/G(1) cell cycle arrest and by a loss of cells in S phase. Futhermore, apoptosis detected as a sub-G(0) cell population and apoptotic DNA fragmentation was observed. More detailed analyses of apoptosis induced by CCE in HL-60 cells revealed that apoptosis progressed through the caspase-9/-3 pathway, as release of cytochrome c, caspase-9/-3 activations and specific proteolytic cleavage of poly(ADP-ribose) polymerase. Taken together, the results suggest that CCE exerts an antiproliferative activity on leukemia cells and induces apoptosis of these cells through a mitochondrial/caspase dependent pathway.     

Stellettin A induces oxidative stress and apoptosis in HL-60 human leukemia and LNCaP prostate cancer cell lines

The present study has demonstrated a differential cytotoxicity of stellettin A (1) between human leukemia HL-60 cells (IC50 0.4 microg/mL) and human prostate cancer LNCaP cells (IC50 120 microg/mL). Treatment of cells with 1 revealed the activation of NADPH oxidase, the dramatic generation of reactive oxygen species, and the dissipation of mitochondrial membrane potentials, with HL-60 cells being more sensitive than LNCaP cells by an order of magnitude. Immunoblotting analysis further demonstrated a stronger upregulation of the apoptosis marker proteins, FasL and caspase-3, in HL-60 cells, and pretreatment of cells with antisense oligonucleotide for caspase-3 abolished apoptosis. All available evidence suggests that 1 induces oxidative cell death through a FasL-caspase-3-apoptotic pathway.     

昆明山海棠根部水提液诱导HL-60细胞凋亡及对c-Myc基因表达的调控

目的 研究昆明山海棠Tripterygium hypoglaucum(Celastraceae)(THH)根部水提液对早幼粒白血病HL-60细胞凋亡的诱导作用及机制。方法 通过特征性的形态学观察，Annexin—V标记，以及流式细胞仪检测中次G1峰的形成确定THH的诱导细胞凋亡作用；应用Western Blotting研究THH对c—Myc蛋白表达的影响。结果 THH根部水提液可诱导早幼粒白血病HL-60细胞凋亡。在浓度高于18μg／mL时，THH对HL-60细胞的诱导凋亡作用呈现浓度与时间的相关性。在THH处理2～4h后，癌基因蛋白c—Myc表达降低99％以上。结论 THH抑制了c—Myc蛋白的翻译或后翻译过程，从而降低了c—Myc在细胞周期运转中的作用，导致大量细胞凋亡．     

Plumbagin induces apoptosis in Her2-overexpressing breast cancer cells through the mitochondrial-mediated pathway

Breast cancer is the leading cause of death-related cancers in women. Approximately 30% of breast cancers overexpress the Her2 oncogene, which is associated with a poor prognosis and increased resistance to chemotherapy. Plumbagin (1), a constituent of species in the plant genera Drosera and Plumbago, displays antineoplastic activity toward various cancers. The present study was aimed at determining the anticancer potential of 1 toward Her2-overexpressing breast cancer cells and defining the mode of cell death induced in these cells. The results showed that 1 exhibited high antiproliferative activity toward the Her2-overexpressing cell lines SKBR3 and BT474. The antiproliferative activity of 1 was associated with apoptosis-mediated cell death, as revealed by caspase activation and an increase in the sub-G1 fraction of the cell cycle. Compound 1 increased the levels of the proapoptotic Bcl-2 family of proteins and decreased the level of the antiapoptotic Bcl-2 protein in SKBR3 and BT474 cells. Thus, these findings indicate that 1 induces apoptosis in Her2-overexpressing breast cancers through the mitochondrial-mediated pathway and suggest its potential for further investigation for the treatment of Her2-overexpressing breast cancer.     

基因芯片分析显示昆明山海棠有机萃取液经NF- κB及线粒体信号传导途径诱导HL- 60细胞凋亡

目的　研究中草药昆明山海棠 Tripterygium hypoglaucum( THH)有机萃取液诱导人早幼粒白血病 HL-6 0细胞凋亡过程的信号传导通道及分子机制。方法　应用流式细胞仪研究了 THH有机萃取液诱导 HL - 6 0细胞的凋亡过程 ,并应用包含 3 0 0 0人类基因与 EST的基因芯片进行基因表达差异分析。结果　基因芯片杂交结果显示有 16个基因表达发生大于 2倍的显著变化 ,这些基因同细胞生长 ,细胞周期调控 ,细胞分化 ,以及压力反应有关。部分基因在细胞凋亡过程中起关键作用 ,如 Caspase3和 Caspase8。结论　 THH有机萃取液诱导 HL- 6 0细胞凋亡 ,该过程与 NF- κB和线粒体信号传导途径有关。     

罗仙子提取物诱导白血病细胞凋亡作用研究

目的：观察中药罗仙子提取物体外对白血病细胞的凋亡诱导作用。方法：罗仙子提取物处理人白血病HL-60细胞24 h后,MTT法检测细胞活率;采用光学显微镜、荧光显微镜、透射电镜观察细胞形态学改变,流式细胞仪检测细胞凋亡率。结果：不同浓度罗仙子提取物可抑制HL-60细胞增殖同时诱导典型的细胞凋亡形态学变化,与对照组相比细胞凋亡率显著升高。结论：罗仙子提取可显著抑制白血病细胞增殖、诱导细胞凋亡。     

羊栖菜多糖诱导肿瘤细胞凋亡的实验研究

目的研究羊栖菜多糖(SFPS)对人白血病HL-60细胞系增殖抑制和凋亡诱导作用。方法MTT法检测SFPS对HL-60细胞增殖的抑制作用;扫描电镜、透射电镜、琼脂糖凝胶电泳和流式细胞仪检测细胞凋亡。结果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;药物浓度为300 mg/L和500 mg/L作用HL-60细胞后,观察到典型的细胞凋亡形态学特征;DNA凝胶电泳呈现梯状条带;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。结论SFPS抗肿瘤作用与诱导细胞凋亡和G2/M期细胞阻滞有关。     

The water extract of Omija protects H9c2 cardiomyoblast cells from hydrogen peroxide through prevention of mitochondrial dysfunction and activation of caspases pathway

The water extract of Omija (Omija) has been used traditionally in the treatment of ischemic damage of the heart and brain tissues. However, little is known about the mechanism by which it rescues myocardial cells from oxidative stress. This study was designed to investigate the protective mechanisms of Omija on H(2)O(2)-induced cytotoxicity in H9c2 cardiomyoblast cells. Treatment with H(2)O(2) resulted in the death of H9c2 cells, characterized by apparent apoptotic features, including fragmentation of the nucleus and an increase in the sub-G(0)/G(1) fraction of the cell cycle. However, Omija markedly suppressed the apoptotic characteristics of H9c2 cells induced by H(2)O(2). In addition, Omija suppressed the features of mitochondrial dysfunction, including changes in the mitochondrial membrane potential and cytosolic release of cytochrome c in H(2)O(2)-treated cells. Treatment with Omija further inhibited the catalytic activation of caspase-9 and caspase-3 and induction of Fas by H(2)O(2). Taken together, these data indicate that the water extract of Omija protects H9c2 cardiomyoblast cells from oxidative stress of H(2)O(2) through inhibition of mitochondrial dysfunction and activation of intrinsic caspase cascades, including caspase-3 and caspase-9.     

G1 arrest and caspase-mediated apoptosis in HL-60 cells by dichloromethane extract of Centrosema pubescens

Cell division and apoptosis are two crucial components of tumor biology and the importance of increased cell proliferation and reduced cell death have made them valid therapeutic targets. The plant kingdom is a relatively underexploited cache of novel drugs, and crude extracts of plants are known for their synergistic activity. The present study assessed the anti-proliferative activity of the medicinal plant Centrosema pubescens Benth. Centrosema pubescens dichloromethane extract (CPDE) inhibited the proliferation of HL-60 (promyelocytic acute leukaemia) cells with an IC?? value of 5 μg/ml. Further studies also showed that CPDE induces growth arrest at the G1 phase and specifically down-regulates the expressions of cyclin E and CDK2 and up-regulates p27(CKI) levels. These events apparently lead to the induction of apoptosis, which was demonstrated qualitatively by a DNA fragmentation assay and propidium iodide staining. Quantitative assessment of the effective arrest of the cell cycle and of apoptosis was confirmed by flow cytometry. CPDE exhibited negligible cytotoxicity even at the highest dose tested (100 μg/ml) in both normal peripheral blood mononuclear cells and in an in vitro model (HL-60). Our results strongly suggest that CPDE arrests the cell cycle at the G1 phase and triggers apoptosis by caspase activation.     

Induction of apoptosis in HL-60 cells treated with medicinal herbs

In order to develop a new apoptosis inducer, we screened 22 crude drugs for their apoptosis-inducing activity. It was found that Glycyrrhiza uralensis, Cynomorium songaricum, Eucommia ulmoides, Phellodendron amurense, Cinnamomum cassia and Paeonia lactiflora induced the death of HL-60 cells. To investigate the mechanism of apoptosis induced by these six crude drugs, the mitochondrial transmembrane potential and the activity of caspase-3 were measured. Reduced mitochondrial transmembrane potentials within 12 hours after the administration of Glycyrrhiza uralensis, Cynomorium songaricum, Phellodendron amurense and Paeonia lactiflora, and within 24 hours after the administration of Eucommia ulmoides and Cinnamomum cassia were observed. All of the six apoptosis-inducing crude drugs increased caspase-3 activity within 12-36 hours after administration. After further examining the apoptosis-inducing activity of berberine, palmatine, panelofuroline and glycyrrhizin, which were the ingredients obtained from Phellodendron amurense, Glycyrrhiza uralensis and Paeonia lactiflora, it was found that only berberine could induce apoptosis. From these results, it was concluded that the apoptosis induced by the six crude drugs (Glycyrrhiza uralensis, Cynomorium songaricum, Eucommia ulmoides, Phellodendron amurense, Cinnamomum cassia and Paeonia lactiflora) occurred via the mitochondrial route and that the apoptosis-conducting mechanism acted through a cascade involving caspase-3.     

丹参酮ⅡA诱导白血病细胞凋亡过程中端粒酶活性的改变

目的观察丹参酮Ⅱ_A(TanⅡ_A)对HL60,K562细胞端粒酶活性的抑制作用和对凋亡相关基因的影响,探讨丹参酮Ⅱ_A对造血细胞的作用机理。方法以HL60,K562为靶细胞,应用细胞培养技术,流式细胞术,透射电镜观察TanⅡ_A对HL60,K562细胞的作用,利用PCRTRAP方法检测TanⅡ_A处理前后HL60,K562细胞端粒酶活性的改变。结果经05μg·mL^-1TanⅡ_A作用6d后,HL60,K562细胞生长明显受到抑制,生长抑制率分别为756%和563%。经丹参酮诱导后,HL60,K562细胞发生凋亡,出现亚二倍体峰;同时显著下调HL60及K562细胞的cmyc,bcl2基因表达,上调cfos基因表达。HL60,K562细胞在TanⅡ_A作用后,端粒酶活性受到抑制,端粒酶活性抑制率分别为308%,508%。结论TanⅡ_A可明显抑制HL60和K562细胞的增殖和细胞端粒酶活性,并诱导细胞凋亡。     

冬凌草甲素对HL-60细胞的诱导凋亡作用及其作用机制

目的:探讨冬凌草甲素对白血病HL-60细胞的诱导凋亡作用及其作用机制.方法:以不同浓度的冬凌草甲素作用于体外培养的HL-60细胞,应用MTT法检测细胞生长抑制率,流式细胞术(FCM)检测细胞凋亡率,Hoechst 33258荧光染色法观察细胞凋亡,TRAP-PCR-ELISA及FCM法检测细胞凋亡前后端粒酶活性及P53蛋白表达水平的变化.结果:8 umol/L以上的冬凌草甲素对HL-60细胞具有显著的诱导凋亡及增殖抑制作用,并呈现出明显的量-效与时-效关系.药物作用48小时后细胞的凋亡率达高峰,在Hoechst染色图片上可见核浓缩及核碎裂等典型的凋亡改变.在细胞凋亡过程中,端粒酶活性下降,同时P53蛋白的表达水平显著升高.结论:冬凌草甲素对HL-60细胞具有显著的诱导凋亡及增殖抑制作用,升高P53蛋白的表达水平及降低细胞端粒酶活性可能是其重要作用机制之一;这为冬凌草甲素进一步应用于临床治疗急性白血病提供了有力的试验依据.     

Apoptosis Induction of Human Lung Carcinoma Cells by Chan Su (Venenum Bufonis) Through Activation of Caspases

Chan Su is a traditional Chinese medicine prepared from the dried white secretion of the auricular and skin glands of toads, and has been used as an oriental drug for the treatment of a number of diseases, including cancer. In this study, the potential of Chan Su (skin of Venenum Bufonis) to induce apoptosis in human lung carcinoma A549 cells was investigated. Treatment of A549 cells with skin of Venenum Bufonis resulted in the inhibition of cell growth and viability and the induction of apoptosis, which was shown by trypan blue counts, MTT assay, DAPI staining and flow cytometry analysis. The increase in apoptosis that was induced by skin of Venenum Bufonis was correlated with down-regulation of anti-apoptotic Bcl-2 expression, up-regulation of pro-apoptotic Fas ligand and death receptor 4, and a decrease in the mitochondrial membrane potential. Skin of Venenum Bufonis treatment induced the proteolytic activation of caspases and a concomitant degradation of poly(ADP-ribose)-polymerase and β-catenin protein. Cleavage of Bid and a down-regulation of the inhibitor of apoptosis family proteins were also observed in skin of Venenum Bufonis-treated A549 cells. Data from this study indicates that SVB induces the apoptosis of A549 cells through a signaling cascade of death receptor-mediated extrinsic and mitochondria-mediated intrinsic caspase pathways.     

Anticancer activity of isoobtusilactone A from Cinnamomum kotoense: involvement of apoptosis, cell-cycle dysregulation, mitochondria regulation, and reactive oxygen species

In this study, we investigate the anticancer effect of isoobtusilactone A (IOA), a constituent isolated from the leaves of Cinnamomum kotoense, on human non-small cell lung cancer (NSCLC) A549 cells. IOA was found to induce the arrest of G2-M phase, induce apoptosis, increase sub-G1, and inhibit the growth of these cells. Further investigation revealed that IOA's blockade of the cell cycle was associated with increased levels of p21/WAF1, p27 (kip1), and p53. In addition, IOA triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratios, resulting in a loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of PARP. We also found the generation of reactive oxygen species (ROS) to be a critical mediator in IOA-induced inhibition of A549 cell growth. In antioxidant and NO inhibitor studies, we found that by pretreating A549 cells with either N-acetylcystenine (NAC), catalase, mannitol, dexamethasone, trolox, or L-NAME we could significantly decrease IOA production of ROS. Moreover, using NAC to block ROS, we could significantly suppress IOA-induced antiproliferation, antimigration, and anti-invasion. Finally, we found that IOA inhibited the migration and invasion of A549 cell migration and invasion. Taken together, these results suggest that IOA has anticancer effects on A549 cells.     

Reactive oxygen species mediation of baizhu-induced apoptosis in human leukemia cells

Baizhu (Atractylodes macrocephala Koidz) has traditionally been used as an important ingredient of several Chinese herbal medicines, which have been used for abdominal pain and gastroenterology diseases for thousands of years. Despite its popularity in herbal therapies, little is known about the anticancer effect of Baizhu. In this study, the anticancer potential of Baizhu on human hepatoma and leukemia cell lines was evaluated. Baizhu methanol extract induced apoptosis in human lymphoma Jurkat T cells, leukemia U937, and HL-60 cells. This was confirmed by several methods, including hypodiploid cells detection using flow cytometry, the examination of apoptotic bodies containing cells using confocal laser scanning microscopy, and hypodiploid cell population inhibition using the broad spectrum caspase inhibitor z-VAD. Finally, the intracellular reactive oxygen species (ROS), especially hydrogen peroxide (H(2)O(2)) and superoxide anion (O(2)(-)), were found to be elevated after treatment of these cells with Baizhu extracts. Antioxidant N-acetyl cysteine (NAC) pretreatment almost completely inhibited Baizhu-induced apoptosis, suggesting that ROS are the key mediators for Baizhu-induced apoptosis. All these data indicate that Baizhu is a possible anti-tumor agent that induces apoptosis of human leukemia cells through ROS generation.     

Antiproliferative action of Xylopia aethiopica fruit extract on human cervical cancer cells

The anticancer potential of Xylopia aethiopica fruit extract (XAFE), and the mechanism of cell death it elicits, was investigated in various cell lines. Treatment with XAFE led to a dose-dependent growth inhibition in most cell lines, with selective cytotoxicity towards cancer cells and particularly the human cervical cancer cell line C-33A. In this study, apoptosis was confirmed by nuclear fragmentation and sub-G(0)/G(1) phase accumulation. The cell cycle was arrested at the G(2)/M phase with a decreased G(0)/G(1) population. A semi-quantitative gene expression study revealed dose-dependent up-regulation of p53 and p21 genes, and an increase in the Bax/Bcl-2 ratio. These results indicate that XAFE could be a potential therapeutic agent against cancer since it inhibits cell proliferation, and induces apoptosis and cell cycle arrest in C-33A cells.     

雄黄纳米微粒对人白血病细胞株HL-60的诱导分化作用

目的：探讨雄黄（As4S4）纳米微粒对于人急性早幼粒白血病细胞HL-60的抑制增殖和诱导分化作用。 方法：采用MTT法观察低浓度雄黄对HL-60细胞增殖的影响,Wright-Giemsa 染色观察细胞形态,硝基四氮唑蓝（NBT）还原反应和流式细胞术抗原检测等鉴定细胞的分化。结果：细胞经雄黄处理后呈现明显的分化形态。经0.25～1.0 μmol·L^-1 雄黄作用24 h 后,NBT阳性率升高。用0.50 μmol·L^-1雄黄处理48 h,细胞表面分化抗原CD11b表达升高,细胞周期阻滞于G1期。 结论：低浓度雄黄对HL-60细胞具有诱导分化作用。     

斑蝥素对HL—60细胞和QGY7703细胞的作用研究

采用MTT法和流氏细胞仪技术,研究了斑蝥素对HL－60细胞和QGY7703细胞的存活率和细胞周期分布影响。结果表明,斑蝥素对HL－60细胞的IC50是15．34μmol/L,对QGY7703细胞的IC50是18．54μmol/L。按蝥素处理HL－60细胞和QGY7703细胞24h后,G2－M期细胞分布都有所增加,G0－G1期细胞分布都有所降低;斑蝥素处理HL－60细胞24h后,G0－G1期峰前有亚二倍体峰出现,说明斑蝥素在所用剂量下降够诱导HL－60细胞发生凋亡。     

线粒体膜电位在PUVA诱导HL-60、K562细胞凋亡时的变化

目的:研究补骨脂素(PSO)加长波紫外线(UVA)光化学疗法(PUVA)诱导人白血病细胞HL-60、K562凋亡时对线粒体膜电位(ΔΨm)的影响。方法:细胞以不同浓度PSO,接受或不接受UVA照射后共同培养,电镜下观察细胞超微结构改变,流式细胞仪(FCM)检测细胞凋亡率和线粒体膜电位变化,采用多因素方差分析法进行统计学处理。结果:PUVA处理后的HL-60、K562细胞超微结构出现明显的凋亡形态学改变;PSO、UVA照射及PUVA均可使细胞凋亡率增加,ΔΨm下降,PUVA的作用显著强于前两者(P<0.01)。结论:PUVA可诱导人白血病细胞发生凋亡,诱导凋亡的途径之一为下调线粒体膜电位水平。     

Antitumor activity of bruceantin: an old drug with new promise

Bruceantin was first isolated from Brucea antidysenterica, a tree used in Ethiopia for the treatment of cancer, and activity was observed against B16 melanoma, colon 38, and L1210 and P388 leukemia in mice. Phase I and II clinical trials were then initiated, but no objective tumor regressions were observed and clinical development was terminated. Recently, the activity of bruceantin has been studied with a number of leukemia, lymphoma, and myeloma cell lines. Cell differentiation was induced and c-MYC was down-regulated, suggesting a mechanistic correlation between c-MYC down-regulation and induction of cell differentiation or cell death. Treatment of HL-60 and RPMI 8226 cell lines induced apoptosis, and this involved the caspase and mitochondrial pathways. Moreover, an in vivo study using RPMI 8226 human-SCID xenografts demonstrated that bruceantin induced regression in early as well as advanced tumors, and these significant antitumor responses were facilitated in the absence of overt toxicity. Apoptosis was significantly elevated in tumors derived from animals treated with bruceantin. In sum, bruceantin interferes with the growth of leukemia, lymphoma, and myeloma cells in culture and xenograft models. Responses of this type suggest bruceantin should be reinvestigated for clinical efficacy against hematological malignancies.