PAEDERUS ALFIERI EXTRACT INDUCES APOPTOSIS IN HUMAN MYELOID LEUKEMIA K562 CELLS

2016 ◽  
Vol 10 (1) ◽  
pp. 72
Author(s):  
Amer Mohamed ◽  
Osama Rakha
Keyword(s):  
Myeloid Leukemia ◽  
Caspase 3 ◽  
Insect Pests ◽  
Flow Cytometric Analysis ◽  
K562 Cells ◽  
Akt Pathway ◽  
Dependent Manner ◽  
Proliferative Effect ◽  
Induced Apoptosis ◽  
Dose Dependent

ABSTRACTObjective: The rove beetle Paederus alfieri Koch. (Coleoptera: Staphylinidae) is well-known among natural enemies in Egypt as an important predatorof agricultural insect pests, it used as an essential agent in the integrated pest management programs. Recent studies have revealed that Paederus mayhave anti-proliferative effect; however, its mechanisms remain unclear. The aim of the present study is to investigate the anticancer effect of P. alfieriextract (PAE) on K562 human myeloid leukemia cancer cells and elucidation of its mechanism.Methods: Human myeloid leukemia K562 cells were treated with PAE at different concentrations. Cell proliferation was measured using the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was evaluated using flow cytometry analysis. The expressions ofBcl-2, Bax, active caspase-3, t-Akt, and p-Akt were evaluated by western blotting.Results: PAE has a dose-dependent antiproliferative effect against K562 cells. The half maximal inhibitory concentration was estimated as212±2.3 ng/ml. Flow cytometric analysis showed that PAE induces apoptosis in a dose-dependent manner in K562 cells. We also investigated themolecular mechanism of PAE-induced apoptosis. PAE downregulated Bcl-2 and upregulated Bax and cleaved caspase-3 proteins. Furthermore, thelevels of p-Akt are dose-dependently decreased in response to PAE, whereas the total Akt protein levels remained constant during PAE treatment.Conclusion: Taken together PAE-induced apoptosis in human myeloid leukemia K562 cells by modulating PI3K/Akt pathway. Our findings suggestthat may be PAE is a good extract for developing anticancer drugs for human myeloid leukemia cancer treatment.Keywords: Paederus alfieri, Pederin, K562, Apoptosis, PI3K/Akt pathway.

Berbamine-Induced Apoptosis in Human Leukemia K562 Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4234-4234
Author(s):  
Xiaoying Zhao ◽  
Lei Xu ◽  
Dong Wu ◽  
Rongzhen Xu
Keyword(s):  
Flow Cytometry ◽  
Cell Proliferation ◽  
Caspase 3 ◽  
K562 Cells ◽  
Human Leukemia ◽  
Dependent Manner ◽  
Flow Cytometry Assay ◽  
Transcript Levels ◽  
Induced Apoptosis ◽  
Dose Dependent

Abstract Purpose: To investigate apoptosis-inducing effects of Berbamine on human leukemia cells and to explore the underlying mechanism. Materials and methods: Berbamine was dissolved in 0.9% sodium chloride to an initial concentration of 1mg/ml and subsequently diluted to desired concentrations with cell culture medium. MTT was used to examine the effect of Berbamine on cell proliferation of K562 cells. Characteristic cellular morphological changes were used as indicators of apoptosis in K562 cells while the rate of apoptosis was measured by flow cytometry assay. Expression levels of apoptosis related genes bcl-2 and bax were determined by RT-PCR and the levels of bcr/abl were evaluated by nested-PCR. Levels of Caspase 3 were measured by flow cytometry assay. Results: Berbamine inhibited the cell proliferation significantly and in a dose-dependent manner in tested K562 cells. Its IC50 value was 5.23ug/ml. As determined by morphological observations and flow cytometry assay, Berbamine was able to induce apoptosis of K562 cells within 6 hours. The apoptosis rate of K562 was also dose-dependent. Steady-state transcript levels of bcr/abl decreased dramatically (half-quantity ratio from 1.284 to 0.506 within 72 hours following 8mg/ml Berbamine treatment. On the other hand, the protein levels of Caspase 3 surged from 18.36% to 38.25% (p<0.001) within 24 hours after treatment of 12mg/ml Berbamine. During the same period, no changes of bcl-2 or bax transcript levels were detected in the cells that were treated with 8mg/ml Berbamine. Conclusions: Our results suggest that Berbamine is a potent inhibitor of cell proliferation and a strong inducer of apoptosis in human K562 cells. The Berbamine-induced apoptosis pathway involves down regulation of bcr/abl and up regulation of Caspase 3 expressions. Neither bcl-2 nor bax plays substantial roles in Berbamine-induced K562 cell apoptosis.

Molecular Mechanism of Matrine-Induced Apoptosis in Leukemia K562 Cells

2006 ◽  
Vol 34 (06) ◽  
pp. 1095-1103 ◽  
Author(s):  
Xiao-Shan Liu ◽  
Jikai Jiang
Keyword(s):  
Cytochrome C ◽  
Caspase 3 ◽  
Chinese Herb ◽  
K562 Cells ◽  
Dependent Manner ◽  
Nih3t3 Cells ◽  
Proapoptotic Protein ◽  
General Caspase Inhibitor ◽  
Induced Apoptosis ◽  
Dose Dependent

Matrine, a low toxic alkaloid purified from the Chinese herb Kushen, has been reported to induce apoptosis in leukemia K562 cells. In this study, the mechanism underling this apoptotic event was investigated. Treatment of K562 cells with matrine resulted in inhibition of cell survival more significantly than treatment of non-cancer fibroblast NIH3T3 cells. When K562 cells were incubated with matrine in higher than 0.2 mg/ml doses for 48 hours, the apoptotic cells were increased and both poly (ADP-ribose) polymerase (PARP) and caspase-3 were cleaved in a dose dependent manner. General caspase inhibitor (z-VAD-fmk) or caspase-3 inhibitor (z-DEVD-fmk) almost completely suppressed matrine-induced apoptosis. In addition, matrine increased proapoptotic protein bax and caused the release of cytochrome C. Taken together, the results suggest that matrine induces a cytochrome C-mediated, caspase-dependent apoptosis.

Peroxisome Proliferator-Activated Receptor-γ Agonist Rosiglitazone– Induced Apoptosis in Leukemia K562 Cells and Its Mechanisms of Action

2009 ◽  
Vol 28 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Jia-Jun Liu ◽  
Ting Hu ◽  
Xiang-Yuan Wu ◽  
Chun-Zhi Wang ◽  
Yan Xu ◽  
...  
Keyword(s):  
Caspase 3 ◽  
K562 Cells ◽  
Telomerase Activity ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Apoptotic Protein ◽  
Induced Apoptosis ◽  
Dose Dependent

This study investigates the ability of a synthetic PPAR-γ agonist, rosiglitazone (RGZ), to induce apoptosis in leukemia K562 cells. The results revealed that RGZ (>40 mmol/L) inhibits the growth of K562 cells and causes apoptosis in a time and dose-dependent manner. Apoptosis is observed clearly by Hoechst 33258 staining. Western blotting analysis demonstrates the cleavage of caspase-3 zymogen protein with the appearance of its 17-kD subunit and a dose-dependent cleavage of poly (ADP-ribose) polymerase. Furthermore, RGZ treatment down-regulates anti-apoptotic protein Bcl-2 and up-regulates pro-apoptotic protein Bax in a dosedependent manner after the cells are treated for 48 hours. Telomerase activity is decreased concurrently in a dosedependent manner. We therefore conclude that RGZ induces apoptosis in K562 cells in vitro, and that RGZ-induced apoptosis in K562 cells is highly correlated with activation of caspase-3, decreasing telomerase activity, down-regulation of the anti-apoptotic protein Bcl-2, and up-regulation of the pro-apoptotic protein Bax.

scholarly journals Autophagy Inhibition Enhances Apoptosis Induced by Dioscin in Huh7 Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ming-Ju Hsieh ◽  
Shun-Fa Yang ◽  
Yih-Shou Hsieh ◽  
Tzy-Yen Chen ◽  
Hui-Ling Chiou
Keyword(s):  
Cell Apoptosis ◽  
Caspase 3 ◽  
Natural Food ◽  
Dependent Manner ◽  
Caspase Activation ◽  
Huh7 Cells ◽  
Dependent Cell ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Autophagy Inhibition

Extensive research results support the application of herbal medicine or natural food as an augment during therapy for various cancers. However, the effect of dioscin on tumor cells autophagy has not been clearly clarified. In this study, the unique effects of dioscin on autophagy of hepatoma cells were investigated. Results found that dioscin induced caspase-3- and -9-dependent cell apoptosis in a dose-dependent manner. Moreover, inhibition of ERK1/2 phosphorylation significantly abolished the dioscin-induced apoptosis. In addition, dioscin triggered cell autophagy in early stages. With autophagy inhibitors to hinder the autophagy process, dioscin-induced cell apoptosis was significantly enhanced. An inhibition of caspase activation did not affect the dioscin-induced LC3-II protein expression. Based on the results, we believed that while apoptosis was blocked, dioscin-induced autophagy process also diminished in Huh7 cells. In conclusion, this study indicates that dioscin causes autophagy in Huh7 cells and suggests that dioscin has a cytoprotective effect.

Butyric Acid Induces Apoptosis in Inflamed Fibroblasts

2008 ◽  
Vol 87 (1) ◽  
pp. 51-55 ◽  
Author(s):  
T. Kurita-Ochiai ◽  
S. Seto ◽  
N. Suzuki ◽  
M. Yamamoto ◽  
K. Otsuka ◽  
...  
Keyword(s):  
Butyric Acid ◽  
Caspase 3 ◽  
Chromatin Condensation ◽  
Dependent Manner ◽  
Gingival Fibroblasts ◽  
T And B Cells ◽  
Healthy Humans ◽  
Extracellular Metabolite ◽  
Induced Apoptosis ◽  
Dose Dependent

Butyric acid, an extracellular metabolite from periodontopathic bacteria, induces apoptosis in murine and human T- and B-cells, whereas intact gingival fibroblasts isolated from healthy humans are resistant to butyric-acid-induced apoptosis. We examined the susceptibility of inflamed gingival fibroblasts isolated from adult persons with periodontitis to butyric-acid-induced apoptosis. Butyric acid significantly suppressed the viability of inflamed gingival fibroblasts and induced apoptosis in a dose-dependent manner. The incubation of inflamed gingival fibroblasts with butyric acid induced DNA fragmentation and apoptotic changes such as chromatin condensation, hypodiploid nuclei, and mitochondrial injury. Furthermore, butyric-acid-induced apoptosis in inflamed gingival fibroblasts was reduced by caspase-3/7, -6, -8, and -9 inhibitors. Thus, inflamed gingival fibroblasts from adult persons with periodontitis appear to be highly susceptible to mitochondria- and caspase-dependent apoptosis induced by butyric acid, compared with healthy gingival fibroblasts.

A Novel Mechanism of Nilotinib-Induced Apoptosis; Sphingolipids.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4246-4246
Author(s):  
Yusuf Baran ◽  
Emel Basak Gencer ◽  
Aylin Camgoz ◽  
Ferit Avcu ◽  
Ali Ugur Ural
Keyword(s):  
Cell Cycle ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
De Novo ◽  
Dependent Manner ◽  
Ceramide Synthase ◽  
Proliferation Assay ◽  
Rt Pcr ◽  
Induced Apoptosis ◽  
Dose Dependent

Abstract Abstract 4246 Chronic myeloid leukemia (CML) is a hematological malignancy resulting from the reciprocal translocation of chromosomes 9 and 22 that generates BCR/ABL oncogene. Nilotinib is a rationally designed, specific BCR/ABL tyrosine kinase inhibitor. Ceramide is a novel regulator of cell growth and proliferation, differentiation, senescence, cell cycle and also acts a strong apoptotic molecule while its conversion to antiapoptotic glucosyle ceramide (GC) and sphingosine-1-phosphate (S1P) by glucosyle ceramide synthase (GCS) and sphingosine kinase-1 (SK-1) enzymes result in more aggressive and resistant cancers. In this study, we studied the roles of ceramide metabolising genes in nilotinib induced apoptosis and possibility of increasing the sensitivity of BCR/ABL positive K562 and Meg-01 cells to nilotinib through targeting ceramide metabolism. The cytotoxicity analyses of nilotinib, C8:ceramide to induce de novo generation of ceramides, 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) to inhibit GCS and SK1 inhibitor were conducted by XTT cell proliferation assay. The changes in caspase-3 enzyme activity and mitochondrial membrane potential (MMP) were measured by caspase-3 colorimetric assay and JC-1 MMP detection kit, respectively. Expression analyses of ceramide synthase (LASS) genes, SK-1 and GCS genes were performed by RT-PCR. We have shown that nilotinib induces apoptosis and inhibits cell-cycle progression in K562 and Meg-01 cells in a dose dependent manner. We have shown significant synergistic apoptotic effects of nilotinib in combination with C8:ceramide or PDMP or SK-1 inhibitor by XTT cell proliferation assay in addition to the changes in caspase-3 enzyme activity and changes in mitochondrial membrane potential, as compared to any agent alone. These results revealed that increasing de novo generation of ceramides or inhibiting conversion of ceramides to antiapoptotic GC or S1P increased sensitivity of BCR/ABL CML cells to nilotinib. More importantly, RT-PCR results revealed that there were significant decreases in expression levels of SK1 in response to increasing concentrations of nilotinib. On the other hand increases in expression levels of LASS2, -4, -5, and -6 ceramide synthase genes were determined in a dose dependent manner as compared to untreated controls. It was shown for the first time by this study that targeting ceramide metabolism in addition to inhibition of BCR/ABL by nilotinib induces apoptosis synergistically in BCR/ABL positive K562 and Meg-01 CML cells. This study was supported by The Scientific and Technological Council of Turkey Disclosures: No relevant conflicts of interest to declare.

Disulfiram, an Clinically Used Anti-Alcoholism Drug Has the Potential to Target Leukemia Stem and Progenitor Cells in a Copper-Dependent Manner

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4088-4088
Author(s):  
Bing Xu ◽  
Shiyun Wang ◽  
Feili Chen ◽  
Pengcheng Shi ◽  
Jie Zha ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Mononuclear Cells ◽  
Nuclear Translocation ◽  
Conflicts Of Interest ◽  
Therapeutic Option ◽  
Flow Cytometric Analysis ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Acute Myeloid

Abstract Abstract 4088 Backgrounds Acute myeloid leukemia(AML) is a hierarchical disease initiating from a rare population of cells known as leukemia stem cells (LSCs), which are typically enriched in CD34+CD38- cells and presumed responsible for the relapse and refractory of AML. Moreover, current regimens may not effectively discriminate between normal and malignant cells. For this reason, it is important to identify therapies that can specifically target the LSC population without affecting normal cells. Disulfiram (DS) is an anti-alcoholism drug that has recently been indicated to show cytotoxic to multiple cancers including acute myeloid leukemia (AML) and the antineoplastic activity was enhanced in the present of copper (Cu). In the present study, we investigated the effect of DS/Cu on LSCs and further explored its mechanism. Methods and Results CD34+CD38- leukemia stem cell (LSC) enriched subpopulations were sorted from both KG1a cell lines and primary AML bone marrow or peripheral blood mononuclear cells (n=6) by fluoresce-activated cell sorting (FACS) analysis. Using MTT cell proliferation assay and Annexin-V/PI staining assay, We demonstrated that DS/Cu inhibited proliferation and induced apoptosis in CD34+CD38−KG1a cells (IC50= 0.788± 0.451 μM at 24h). With the increasing concentrations of DS (DS=0.05, 0.5, 5, 50μM), the apoptotic proportion increased from 7.2% to 89.5% at 24h. Apoptosis was also observed in CD34+CD38- primary AML cells and the exposure to DS/Cu (DS=0.01, 0.1, 1μM;Cu=0.5μM clearly inhibited the growth of AML-colony-forming units (CFUs) for both CD34+CD38-LSC enriched subpopulations (AML-CFUs decreased from 34.2% to 0% in KG1a cells), but was relatively sparing to normal hematopoietic progenitors. Further more, using flow cytometric analysis, western blot and RT-PCR, we identified that the change in redox status and redox-dependent signaling events play a crucial role in DS/Cu-induced apoptosis. We showed that DS/Cu(DS= 0.625,1.25,2.5,5μM, Cu=1μM) increased reactive oxygen species (ROS) and activated its downstream apoptosis-related SAPK/JNK pathway in association with blockade translocation of Nrf2 and expression of Nrf2-regulated genes in CD34+CD38−KG1a cells. Notably, blockade of ROS by glutathione precursor N-acetylcysteine (NAC)(10mM) strongly diminished DS/Cu mediated lethality and restored Nrf2 nuclear translocation and blocked JNK activation. Additionally, consistent with the ROS accumulation, we also seen that translocation of RelA/p65 and the expression of NF-κb-related gene, associated with abnormal apoptotic response of LSCs, were significantly inhibited by DS/Cu. Conclusion Taken together, we concluded that DS/Cu might selectively eradicate LSCs by induction of oxidatibe stress and blockade the NF-κb pathway and offers a potential therapeutic option in AML. Disclosures: No relevant conflicts of interest to declare.

The antiangiogenic protein kinase inhibitors SU5416 and SU6668 inhibit the SCF receptor (c-kit) in a human myeloid leukemia cell line and in acute myeloid leukemia blasts

Blood ◽  
2001 ◽  
Vol 97 (5) ◽  
pp. 1413-1421 ◽  
Author(s):  
Beverly D. Smolich ◽  
Helene A. Yuen ◽  
Kristina A. West ◽  
Francis J. Giles ◽  
Maher Albitar ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Growth Factor ◽  
Myeloid Leukemia ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Acute Myeloid ◽  
Myeloid Leukemia Cell

SU5416 and SU6668 are potent antiangiogenic small-molecule inhibitors of receptor tyrosine kinases, including those of the vascular endothelial growth factor and platelet-derived growth factor receptor families. The stem cell factor (SCF) receptor, c-kit, is structurally related to these receptors and, although not expressed on mature peripheral blood cells, is expressed in leukemic blasts derived from 60% to 80% of acute myeloid leukemia (AML) patients. The c-kit kinase inhibitory activity of SU5416 and SU6668 was evaluated in MO7E cells, a human myeloid leukemia cell line. Tyrosine autophosphorylation of the receptor, induced by SCF, was inhibited in these cells by SU5416 and SU6668 in a dose-dependent manner (inhibitory concentration of 50% [IC50] 0.1-1 μM). Inhibition of extracellular signal–regulated kinase 1/2 (ERK1/2) phosphorylation, a signaling event downstream of c-kit activation, was also inhibited in a dose-dependent manner. Both compounds also inhibited SCF-induced proliferation of MO7E cells (IC50 0.1 μM for SU5416; 0.29 μM for SU6668). Furthermore, both SU5416 and SU6668 induced apoptosis in a dose- and time-dependent manner as measured by the increase in activated caspase-3 and the enhanced cleavage of its substrate poly(ADP-ribose) polymerase. These findings with MO7E cells were extended to leukemic blasts from c-kit+ patients. In patient blasts, both SU5416 and SU6668 inhibited SCF-induced phosphorylation of c-kit and ERK1/2 and induced apoptosis. These studies indicate that SU5416 and SU6668 inhibit biologic functions of c-kit in addition to exhibiting antiangiogenic properties and suggest that the combination of these activities may provide a novel therapeutic approach for the treatment of AML.

Anti-Leukemic Effect of a Synthetic Compound, (±)Trans-Dihydronarciclasione (HYU-01) Via Cell Cycle Arrest and Apoptosis

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4017-4017
Author(s):  
Seoju Kim ◽  
Jinsun Yoon ◽  
Eun Shil Kim ◽  
Byoungbae PARK ◽  
Junghye Choi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Myeloid Leukemia ◽  
Flow Cytometric Analysis ◽  
Cyclin B ◽  
G1 Arrest ◽  
Dependent Manner ◽  
Flow Cytometric ◽  
Human Acute Myeloid Leukemia ◽  
Related Proteins ◽  
Dose Dependent

Abstract Over the past several decades, there has been considerable effort in the synthesis of narciclasine, lycoricidine, and pancratistatin. These naturally occurring isocarbostryls are known to have potent antitumoral and antiviral effects. Among them, trans-dihydronarciclasine isolated from the Chinese medicinal plant, Zephyranthes candida, exhibits even higher potency than pancratistatin against several human cancer cell lines and murine P388 lymphocytic leukemia cell line. However, much remains to be known about antitumoral mechanism of this natural product. In addition, the effect of transdihydronarciclasine in human acute myeloid leukemia (AML) has been not elucidated. The present study was undertaken to investigate the effect of novel synthetic (±)trans-dihydronarciclasine compound (code name; HYU-01) in human acute myeloid leukemia (AML). Treatment of HYU-01 for 72 hr inhibited the proliferation of human AML cell lines as well as primary leukemic blasts from AML patients in a dose-dependent manner with IC50 ranging from 1×10−7M to 5×10−8M. To address the mechanism of the antiproliferative effect of HYU-01, cell cycle analysis was performed in HL-60 cells. DNA flow cytometric analysis indicated that HYU-01 (2.5×10−7M) efficiently induced G1 arrest. Analysis of cell cycle-related proteins demonstrated that expression levels of CDK2, CDK4, CDK6, cyclin E and cyclin A were decreased in a time-dependent manner, and expression of cyclin D1 was up-regulated. In contrast, the level of cyclin B was not altered. In addition, HYU-01 (2.5×10−7M, 72 hr) increased the expression level of the CDKI p27kip1 and markedly enhanced the binding of p27 with CDK2, CDK4, and CDK6 compared to HYU-01-untreated cells. Furthermore, the activity of CDK2-associated kinase was decreased, which resulted in the hypophosphorylation of Rb protein. HYU- 01 also induced the apoptosis in HL-60 cells. The apoptotic process was associated with increased Bax and decreased Bid, Bcl-XL and poly(ADP-ribose) polymerase (PARP), primary leukemic blasts from AML patients in a dose-dependent manner with IC50 ranging from 1×10−7M to 5×10−8M. To address the mechanism of the antiproliferative effect of HYU-01, cell cycle analysis was performed in HL-60 cells. DNA flow cytometric analysis indicated that HYU-01 (2.5×10−7M) efficiently induced G1 arrest. Analysis of cell cycle-related proteins demonstrated that expression levels of CDK2, CDK4, CDK6, cyclin E and cyclin A were decreased in a time-dependent manner, and expression of cyclin D1 was up-regulated. In contrast, the level of cyclin B was not altered. In addition, HYU-01 (2.5×10− 7M, 72 hr) increased the expression level of the CDKI p27kip1 and markedly enhanced the binding of p27 with CDK2, CDK4, and CDK6 compared to HYU-01-untreated cells. Furthermore, the activity of CDK2-associated kinase was decreased, which resulted in the hypophosphorylation of Rb protein. HYU-01 also induced the apoptosis in HL-60 cells. The apoptotic process was associated with increased Bax and decreased Bid, Bcl-XL and poly(ADP-ribose) polymerase (PARP), and activation of caspase-8, -9, and -3, and release of cytochrome C from mitochondria into cytosol. In addition, the apoptosis by HYU-01 was accompanied with the down-regulation of ERK and P90RSK. These results suggest that HYU-01 inhibit the proliferation of AML cells via triggering the apoptosis as well as the induction of p27 and the reduction of CDK2 activity leading to G1 arrest.

Level of Myeloperoxidase Expression as a Crucial Determinant of Sensitivity of Myeloid Leukemia Cells to Parthenolide-Induced Apoptosis

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2945-2945
Author(s):  
Soo Jeong Kim ◽  
Ju In Eom ◽  
Hye Won Lee ◽  
Hoi Kyung Jeung ◽  
Jin Seok Kim ◽  
...  
Keyword(s):  
Cell Death ◽  
Myeloid Leukemia ◽  
Prognostic Significance ◽  
Flow Cytometric Analysis ◽  
Leukemia Cell ◽  
K562 Cells ◽  
Leukemia Cells ◽  
Apoptotic Cells ◽  
Strong Inhibitor ◽  
Induced Apoptosis

Abstract Parthenolide (PTL) is a sesquiterpene lactone found as the major active component in Feverfew (Tanacetum parthenium). PTL is a strong inhibitor of NF-kB activation and STAT transcriptional activity, resulting in a downregulation of antiapoptotic gene transcription. Recently, PTL was demonstrated to have promising anti-cancer effects through inhibition of DNA synthesis and reactive oxygen species (ROS)-associated intrinsic apoptosis. However, the sensitivity to PTL-induced cell death was different according to leukemia cells. Therefore, it will be important to identify parameters predicting response to PTL-induced cell death. Myeloperoxidase (MPO), a typical lineage marker for acute myeloid leukemia (AML), was also shown to have a prognostic significance in this disorder. Since it was shown that MPO is a potential regulator of oxidative stress, we examined the effect of MPO expression upon the PTL-induced leukemia cell death. First we compared the extent and mechanism of PTL-induced cell death between parental K562 and MPO-overexpressing K562 (K562/MPO) cells. K562/MPO cells were kindly provided by Dr. Sawayama (Nagasaki University, Japan). Annexin V labeling evaluation revealed that PTL induced apoptosis in K562/MPO cells in a dosedependent manner. The fraction of apoptotic cells after 24 hours treatment with 10mM of PTL was significantly higher in K562/MPO cells (52.2 ± 0.4%) compared to parental K562 cells (13.1 ± 4.8%, p&lt;0.001). When the cells were treated with PTL, the population that lost mitochondrial membrane disruption (MMP) was 45.1 ± 12.4% in K562/MPO cells, which was significantly higher than K562 cells (0.7 ± 0.1%, p&lt;0.001). Cleavage of caspase-3, -8, -9, and PARP was observed in K562/MPO cells after PTL treatment, whereas it was not shown in K562 cells. We next examined the possible involvement of ROS in PTL-induced cell death by flow cytometric analysis using dihydroethidium fluorescent probe. PTL drastically increased relative ROS levels in K562/MPO cells (4.1 ± 0.1). However, the increase in ROS levels induced by PTL was not demonstrated in K562 cells (1.5 ± 0.1, p&lt;0.01). Marked downregulation of Bcl-2, Bcl-xL, and NF-kB was demonstrated preferentially in K562/MPO cells. c-Jun N-terminal kinase phosphorylation was remarkably increased only in K562/MPO cells. We next evaluated the PTL-induced cell death in primary leukemic blasts obtained from patients with AML. Quantitative measurement of MPO expression was done using flow cytometry analysis. Interestingly, the fraction of apoptotic cells induced by 24 hours treatment of PTL was significantly higher in AML specimens consisting of higher than 50% of MPO-positive cells (MPOhi cases; 44.5 ± 1.6%, n = 6) compared to AML specimens consisting of lower than 20% of MPO-positive cells (MPOlo cases; 1.4 ± 1.1%, n = 4, p&lt;0.001). Our findings indicate that PTL induces apoptosis in myeloid leukemia cells is associated with increased ROS and the extent of MPO expression is a crucial determinant of their sensitivity to PTL-induced cell death.

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