Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P08758 (annexin V)
 9,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eicosapentaenoic acid (EPA; 20:5n-3) may reduce the cell number in cultured leukemia/lymphoma cells owing to reduced cell proliferation, induction of cell death, or a combination of these processes. EPA has been shown to promote apoptosis in Ramos cells, and our present study was focused on a possible cell cycle arrest and the pathways by which the apoptotic process is induced. Apoptosis may proceed along the intrinsic (mitochondrial) or the extrinsic (death receptor) pathway, which are mediated via different caspases. Caspases are a class of homologous cysteine proteases recognized as pivotal mediators of apoptosis. We investigated whether EPA affects progression of the cell cycle or promotes apoptosis directly. By incorporation of [3H]thymidine and [3H]valine, we showed that DNA, as well as protein synthesis, was reduced after incubation of Ramos cells with EPA for 6 h. We monitored cell cycle distribution by 5-bromo-2'-deoxyuridine staining and observed no cell cycle arrest in the EPA-incubated cells. Incubation of cells with EPA caused PS-flipping, as demonstrated by annexin V-binding (flow cytometry), and cleavage of poly(ADP-ribose) polymerase measured by Western blot analysis. Furthermore, we observed increased activity of caspase-3 and -9, but not of caspase-8. Whereas inhibitors of caspase-3 and -9 reduced EPA-induced apoptosis, inhibition of caspase-8 did not. This suggests that EPA may promote apoptosis via the intrinsic pathway in Ramos cells. Thus, the reduction in cell number can be explained by a direct apoptotic effect of EPA rather than via cell cycle arrest.
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PMID:Eicosapentaenoic acid promotes apoptosis in Ramos cells via activation of caspase-3 and -9. 1237 51

Refractory anemia with excess blasts in transformation (RAEB-T) is a subgroup of myelodysplastic syndrome (MDS) in which the bone marrow blast count ranges from 20% to 30%. The recently proposed World Health Organization Classification of Hematologic Malignancies eliminated this category from MDS by lowering the blast count cutoff for acute myeloid leukemia (AML) from 30% to 20%. However, MDS is distinguished from AML by a significant increase in apoptosis. To investigate the difference in apoptosis between RAEB-T, AML, and other categories of MDS, we prospectively analyzed fresh bone marrow samples using the Annexin V and mitochondrial potential assays. There was a significantly higher level of apoptosis in RAEB-T than in AML according to both assays, while no significant differences between RAEB-T and other categories of MDS were noted. The data suggest that RAEB-T is more likely to be an advanced stage of MDS and biologically different from AML.
Leukemia 2002 Nov
PMID:More cell death in refractory anemia with excess blasts in transformation than in acute myeloid leukemia. 1239 69

We previously reported the isolation of the novel human DENN gene, which is differentially expressed in normal and neoplastic cells. DENN is identical to MADD (mitogen-activated protein kinase-activating death domain), which interacts with tumor necrosis factor receptor 1 through their death domains. DENN is also homologous to Rab3 GEP, a rat Rab3 GDP/GTP exchange protein. Real-time reverse transcription-polymerase chain reaction analysis showed that DENN expression in cancer cell lines was 26-50 times that in normal cells. The Jurkat human leukemia, PLC/PRF/5 human hepatoma, and NS-1 mouse myeloma cell lines as well as the MRC-5 human fetal lung and Vero monkey kidney cell lines were treated successfully with four separate DENN-targeted antisense oligodeoxynucleotides (ODNs) to abrogate DENN expression. Quantitative assessment of cell viability and apoptosis by flow cytometry via fluorescein diacetate and propidium iodide membrane-integrity tests, terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate-biotin nick end-labeling, and annexin V assays showed that antisense silencing of DENN resulted in markedly more pronounced cell death in cancer cells compared with nonmalignant cells. Antisense-treated cell lines exhibited extensive loss of DNA content, forming distinct sub-G(1) peaks, while cell proliferation diminished significantly. Ultrastructural features of programmed cell death in cells subjected to antisense ODNs were authenticated by electron microscopy. In contrast, transfection of cell lines with a plasmid construct to achieve DENN overexpression augmented cellular proliferation and could reverse the apoptotic effect of antisense and staurosporine treatment. Our findings suggest that DENN is intimately involved in anti-apoptotic and cell-survival processes.
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PMID:Induction of marked apoptosis in mammalian cancer cell lines by antisense DNA treatment to abolish expression of DENN (differentially expressed in normal and neoplastic cells). 1241 May 63

The hydroxymethylglutaryl-CoA reductase inhibitor lovastatin is used widely to treat hypercholesterolemia and has been shown to have cell cycle-specific effects. In these studies, we have examined the effects of combining lovastatin and paclitaxel (Taxol), a microtubule-stabilizing agent, in the human leukemia K562 and HL-60 cell lines. Isobologram analysis of cytotoxicity assays revealed that there is a synergistic interaction between the two agents in both cell lines. Cell cycle analyses showed that lovastatin enhances paclitaxel-induced G2-M arrest in both cell lines. In addition, Annexin V apoptotic studies revealed that lovastatin enhances paclitaxel-induced apoptosis in HL-60 cells. Lovastatin did not affect levels of [3H]paclitaxel in cells. Whereas lovastatin induced an accumulation of unmodified Ras and caused an up-regulation of both RhoB and Rap1A, paclitaxel was found to have no effect on the isoprenylated proteins. Studies of the centromere-associated protein mitosin revealed that treatment with lovastatin and paclitaxel resulted in increased mitosin levels and that lovastatin altered the association of mitosin with condensed chromosomes. These findings provide insight into the mechanisms underlying the cell cycle effects of lovastatin and support the development of a novel therapeutic strategy directed toward altering deleterious cell proliferation.
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PMID:Synergistic interaction of lovastatin and paclitaxel in human cancer cells. 1246 31

To determine whether the Fas receptor-Fas ligand (FasR-FasL) system, which triggers apoptosis in sensitive cells, is an important mechanism of cytotoxicity in myeloid leukemia. FasL expression was investigated in myeloid leukemia cells and its upregulation by a combination of IL-2 and INF-gamma, +/- as well as its function of inducing Jurkat cells to apoptosis mainly by flow cytometry (FCM). Results showed that leukemia cells expressed more FasL (3.59 +/- 1.05)% than that expressed in the healthy individuals (0.36% +/- 0.16)%, P < 0.001 and the FasL was upregulated (7.78 +/- 3.40)%, P < 0.01 when treated with IL-2 and IFN-gamma. Leukemia cells were co-cultivated with Jurkat cells for 24 hours. Then Jurkat cells were labeled with FITC-annexin V and PE-CD3 to assess apoptosis by FCM. The leukemia cells, which had been incubated with IL-2 and IFN-gamma, induced more Jurkat cells to apoptosis than the ones that freshly isolated from the peripheral blood mononuclear cells, which raised the figure from (8.28 +/- 1.61)% to (10.73 +/- 2.16%). And the supernatant derived from the former killed more Jurkat cells than the latter. It was concluded that human myeloid leukemia cells expressed high levels of functional FasL that can kill Jurkat T-cells by apoptosis. FasR-FasL sys tem could play a role in the "immune escape" and relapse of the leukemia. The induction of apoptosis through the Fas pathway might be a novel and effective approach for leukemia immunotherapy.
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PMID:[Study on expression and function of fas ligand in human myeloid leukemia cells]. 1251 81

The objective of this study was to explore the effect of p21(WAF1) on the sensitivity to chemotherapeutic agent VP-16, etoposide, in leukemia cell line K562. A p21(WAF1) retroviral expression vector was constructed, and mediated by FuGENE(TM)6, it was transfected into K562 cells, which without p21(WAF1) expression. The ecotropic expression of p21(WAF1) in K562 cells was identified by RT-PCR and Western blot, and named K562-p21(WAF1) cell. The K562-p21(WAF1) cells were exposed to VP-16 at different concentrations and different times, then, the sensitivity to VP-16 was examined by cell viability and MTT assay, the apoptosis induced by VP-16 was examined by DNA fragments electrophoresis and flow cytometric Annexin V-PI dual labeling technique. The results showed that the ecotropic expression of p21(WAF1) decreased the sensitivity of K562 cells to VP-16. After treatment of VP-16, the DNA ladder was examined in control K562-neo cells at 20 microgram/ml, but in K562-p21(WAF1) cells at 80 microgram/ml. With FCM, the number of apoptotic K562-neo cells was 14.9% and 25.4% respectively after treated with 20 microgram/ml VP-16 for 12 and 24 hours, and it was 6.94% and 10.96% in K562-p21(WAF1) cells. Our results suggest that the expression of p21(WAF1) could reduce the sensitivity of K562 cells to VP-16 and inhibit the apoptosis of K562 cells
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PMID:[p21(WAF1) transfection decreases sensitivity of K562 cells to VP-16]. 1251 33

OBJECTIVE: To study the mechanism of inhibitory effect of Ubenimex on human leukemic cells. METHODS: K562 and HL60 cells were treated with Ubenimex at different concentrations, and the growth inhibition was analysed by MTT assay. Cell apoptosis was evaluated by light microscopy, agrose gel electrophoresis, TUNEL labeling method and flow cytometry (FCM) assay. RESULTS: (1)Treatment with Ubenimex remarkably inhibited the growth of HL60 cells, the IC(50) of Ubenimex for HL60 cells was 13.03&mgr;g/ml. But K562 cells were less sensitive than HL60. Ubenimex inhibited the growth of HL60 and K562 cells in a dose-dependent manner. (2)Apoptosis of leukemic cells was induced by Ubenimex, which was shown by the changes in morphology, DNA ladder on agrose gel, TUNEL labeling,typical peak before G1 phase of cell cycle and the positive of Annexin V(FITC) on the cells membrane with FCM. (3)Ubenimex induced apoptosis of K562 and HL60 cells in a dose-and-time-dependent manner. (4)The cell cycle analysis by FCM showed that the HL60 cells were blocked in G1 phase after treated by Ubenimex. Conclution Ubenimex can efficiently induce apoptosis of HL60 and K562 cells, this may be one of the mechanisms for inhibiting effect of Ubenimex on leukemia.
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PMID:[Mechanisms of inhibitory effect of Ubenimex on human leukemic cells] 1260 5

Magnolol, isolated from the stem bark of Magnolia officnalis, was found to inhibit proliferation of human HL-60 cells and Jurkat T leukemia cells via inducing apoptosis in a dose- and time-dependent manner. By contrast, magnolol did not cause apoptosis in neutrophils and peripheral blood mononuclear cells of healthy donors. Apoptosis was determined by detection of DNA fragmentation in gel electrophoresis, morphological alternations by flow cytometry, quantification of phosphatidylserine externalization by Annexin V labeling and oligonucleosomal DNA content by TUNEL labeling. Activation of caspase-9, -3 and -2, and the proteolytic cleavage of poly(ADP-ribose) polymerase were found during apoptosis induced by magnolol. In addition, both pan-caspase and selective caspase-9 inhibitor blocked magnolol-induced apoptosis. The apoptosis could also be partially attenuated by caspase-3 and -2 inhibitors. Magnolol induced the reduction of mitochondrial transmembrane potential and the release of cytochrome c into cytoplasm. In conclusion, our findings indicate that magnolol-induced apoptotic signaling is carried out through mitochondria alternations to caspase-9 and that then the downstream effector caspases are activated sequentially. Magnolol could be a potentially effective drug for leukemia with low toxicity to normal blood cells and it merits further investigation.
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PMID:Magnolol induces apoptosis in human leukemia cells via cytochrome c release and caspase activation. 1263 15

Recently, it was suggested the potential role of gamma-tocopheryl quinone (gamma-TQ), an oxidative metabolite of gamma-tocopherol, as a powerful chemotherapeutic agent, since it was shown that this molecule exerts powerful cytotoxic effects, induces apoptosis and escapes drug resistance in human acute lymphoblastic leukemia and promyelocytic leukemia cells. We have studied the apoptogenic potential of gamma-TQ in cultured human leukemia HL-60 and colon adenocarcinoma WiDr cells, and in murine thymoma cells growing in vivo in ascites form. The cells were treated with gamma-TQ and apoptosis was evaluated morphologically by acridine-orange staining and cytofluorimetrically by Annexin V binding assay. gamma-TQ-induced apoptosis in a dose- and time-dependent manner in all the cell types tested, although HL-60 and thymoma cells were much more sensitive than WiDr cells. In HL-60 cells apoptosis was mediated by the activation of the caspase-3 cascade. In particular, we observed a time- and dose-dependent increase in the activities of the upstream caspase-9 and caspase-8 and of the downstream caspase-3. The activation of caspase-9 preceded that of caspase-8 and its specific inhibition completely prevented apoptosis. These findings and data showing the precocious release of cytochrome c from mitochondria, a decrease in Bcl-2, and a change in mitochondrial transmembrane potential (Delta psi(m)), all suggest that the intrinsic mitochondrial pathway is primarily involved in the development of gamma-TQ-induced apoptosis. The late activation of caspase-8 and data showing the partial cleavage of pro-apoptotic protein BID suggest that the initial activation of caspase-9 may be potentiated by a feedback amplification loop involving the caspase-8/BID pathway.
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PMID:gamma-Tocopheryl quinone induces apoptosis in cancer cells via caspase-9 activation and cytochrome c release. 1266 1

HIV-1 is an enveloped retrovirus that acquires its outer membrane as the virion exits the cell. Because of the association of apoptosis with the progression of AIDS, HIV-1-infected T cells or macrophages might be expected to express elevated levels of surface phosphatidylserine (PS), a hallmark of programmed cell death. Virions produced by these cells would also be predicted to have PS on the surface of their envelopes. In this study, data are presented that support this hypothesis and suggest that PS is required for macrophage infection. The PS-specific protein annexin V was used to enrich for virus particles and to inhibit HIV-1 replication in primary macrophages, but not T cells. HIV-1 replication was also significantly inhibited with vesicles consisting of PS, but not phosphatidylcholine. PS is specifically required for HIV-1 infection because viruses pseudotyped with vesicular stomatitis virus G and amphotropic murine leukemia virus envelopes were not inhibited by PS vesicles or annexin V. These data indicate that PS is an important cofactor for HIV-1 infection of macrophages.
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PMID:Phosphatidylserine on HIV envelope is a cofactor for infection of monocytic cells. 1270 67


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