Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0023418 (leukemia)
93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

High levels of cytokines are associated with a poor prognosis in acute myeloid leukemia (AML). However, cytokines may induce, on one hand, survival factor expression and cell proliferation and, on the other hand, expression of inhibitory signals such as up-regulation of suppressors of cytokine signaling (SOCS) and induce apoptotic cell death. Because blasts from patients with AML express high procaspase protein levels, we asked whether granulocyte-macrophage colony-stimulating factor (GM-CSF) enhances procaspase protein production in AML cells. In the GM-CSF-responsive OCIM2 AML cell line, GM-CSF induced signal transducer and activator of transcription 5 (Stat 5) phosphorylation, up-regulated cyclin D2, and stimulated cell cycle progression. Concurrently, GM-CSF stimulated expression of SOCS-2 and -3 and of procaspases 2 and 3 and induced caspase 3 activation, poly(ADP[adenosine 5'-diphosphate]-ribose) polymerase (PARP) cleavage, and apoptotic cell death. The Janus kinase (Jak)-Stat inhibitor AG490 abrogated GM-CSF-induced expression of procaspase 3 and activation of caspase 3. Under the same conditions GM-CSF up-regulated production of BAX as well as Bcl-2, Bcl-XL, survivin, and XIAP. GM-CSF also increased procaspase 3 protein levels in OCI/AML3 and Mo7e cells, suggesting that this phenomenon is not restricted to a single leukemia cell line. Our data suggest that GM-CSF exerts a dual effect: it stimulates cell division but contemporaneously up-regulates Jak-Stat-dependent proapoptotic proteins. Up-regulation of procaspase levels in AML is thus a beacon for an ongoing growth-stimulatory signal.
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PMID:Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces antiapoptotic and proapoptotic signals in acute myeloid leukemia. 1266 43

The objective of this study is to investigate the effect of vaccination with dendritic cells pulsed with survivin antigen on activation of antileukemic T cells, and inhibiting proliferation of leukemic cells. The expression of survivin on acute leukemic cells were detected by cofocal microscopy and immunoprecipitation-Western blot. DCs collected from peripheral blood mononuclear cells were pulsed with survivin purified proteins. Stimulation index (SI) and antileukemia CTL induction were analyzed with (3)H-TdR incorporation and (51)Cr releasing assay, respectively. The phenotype of T cells and DCs were identified by flow cytometry. By immunofluorescence of bone marrow and peripheral blood mononuclear cells, survivin expression was detected in 16 out of 19 AML cases (84.2%). The results showed that survivin fluorescence distribution was in cytoplasm. DCs from peripheral blood mononuclear cells were successfully induced, with typical DC morphologic characteristic. The vaccination with dendritic cells pulsed with survivin antigen dramatically stimulated the proliferation of T cells. The DCs loading survivin activated T cells with higher CD4(+) T(H) ratio as compared with DCs group, T cells activated with DCs expressed CD8 and CD56. Survivin DCs significantly inhibited the growth of leukemic cells in vitro. In conclusion, survivin antigen expressed in the cytoplasm of leukemic cells, leukemic vaccination with DCs pulsed with survivin antigen in vitro inhibited the proliferation of leukemic cells, that may be a pathway for therapy of leukemia.
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PMID:[Experimental study on activating antileukemic T cells by vaccination with dendritic cells pulsed with survivin]. 1266 93

Resveratrol, a phytoalexin found in grapes and wine, has been shown to exhibit a wide range of pharmacological properties and is believed to play a role in the chemoprevention of human cancer. Resveratrol has also been shown to induce antiproliferation and apoptosis of several leukemia cell lines. In the present study, we investigated the effect of resveratrol in adult T cell leukemia. Our present observations showed that resveratrol induced growth inhibition in all five human T cell lymphotrophic virus-1-infected cell lines examined, with 50% effective dose of 10.4-85.6 mM. In the resveratrol-treated cells, induction of apoptosis was confirmed by annexin V-based analyses and morphological changes. The most surprising observation was that resveratrol treatment resulted in a gradual decrease in the expression of survivin, an antiapoptotic protein, during cell apoptosis. These findings indicate that resveratrol inhibits the growth of human T cell lymphotrophic virus-1-infected cell lines, at least in part, by inducing apoptosis mediated by downregulation in survivin expression. In view of the accumulating evidence that survivin may be an important determinant of a clinical response in adult T cell leukemia, our present findings have led to the suggestion that resveratrol, a common constituent of the human diet, merits further investigation as a potential therapeutic agent for this incurable disease.
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PMID:Resveratrol induces downregulation in survivin expression and apoptosis in HTLV-1-infected cell lines: a prospective agent for adult T cell leukemia chemotherapy. 1273 68

We have investigated the expression of the IAPs (inhibitory of apoptosis proteins) in the human HL-60 leukemia and in its multidrug resistant, P-glycoprotein (P-gp) over-expressing variant, HL-60R. HL-60R exhibits resistance to apoptosis induced from P-gp substrate drugs and also from other triggers (cisplatin, TNF-alpha, Fas ligation, TRAIL, IFN-gamma and serum starvation) not related to the multidrug transporter. Except for c-IAP-1 mRNA, HL-60R significantly over-expressed both the mRNAs and the proteins of all the IAPs studied, i.e. c-IAP-1, c-IAP-2, XIAP, NAIP and survivin. Determination of the DNA-binding capacity of NF-kappaB (p50 or p65 subunits) indicated that, while HL-60 cells show constitutive activation of p50 only, HL-60R cells contain the activated forms of both p50 and p65. Since p65 is necessary to form the NF-kappaB heterodimers able to increase transcription, its presence in HL-60R cells might well correlate to their increased levels of IAPs and, possibly of P-gp, which, reportedly, are NF-kappaB target genes. These results underline the possible role that the coordinated over-expression of the different IAPs may play in tumor cell resistance to drug induced apoptosis. Inhibition of NF-kappaB might be a useful strategy to block their up-regulation.
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PMID:Expression of the IAPs in multidrug resistant tumor cells. 1465 15

Survivin is a member of the inhibitor of apoptosis protein (IAP) family and functions both as an apoptosis inhibitor and a regulator of cell division. Survivin overexpression is common in many human tumors and correlates with survival in large cell non-Hodgkin's lymphoma. To evaluate this molecule as a potential therapeutic target in large-cell lymphoma, we evaluated the effect of survivin inhibition both in vitro and in vivo. Using an antisense oligonucleotide (ASO) approach, cell growth was significantly inhibited in the DoHH2, RL and HT lymphoma cell lines. In a lymphoma xenograft model, the development of tumors as well as the growth of established tumors was inhibited in the survivin ASO-treated mice compared to controls. To assess the efficacy of the survivin ASO in combination with other biological agents, we combined the survivin ASO with an anti-CD20 monoclonal antibody, rituximab. The effect of survivin ASO and rituximab in combination was additive in vitro. In vivo, however, suppression of tumor growth with the combination was not significantly superior to controls. We conclude that inhibition of survivin expression is an attractive therapeutic strategy in aggressive non-Hodgkin's lymphomas, and that combining survivin ASO with rituximab may enhance the efficacy of this approach.
Leukemia 2004 Mar
PMID:Inhibition of survivin expression suppresses the growth of aggressive non-Hodgkin's lymphoma. 1474 4

Cancer cells are thought to possess mechanisms for evading the host's immune surveillance system. Survivin, a member of the inhibitor-of-apoptosis family overexpressed by cancer cells, inhibits Fas-mediated apoptosis induced by immune cells. In addition, cancer cells express Fas ligand (FasL) on their surfaces as a counterattack against immune cells. Mechanisms by which cancer cells express FasL, including involvement of survivin, are unclear. In the present study, we demonstrated that survivin up-regulated FasL expression and investigated how this might occur. Quantitative immunostaining showed correlation between survivin and FasL protein expression in colon cancer tissues (r=0.79). FasL expression was up-regulated in LS180 colon cancer cells transfected with the survivin gene. Transfectants showed increased cytotoxicity against a Fas-sensitive human T leukemia cell line, Jurkat. In contrast, FasL expression was down-regulated in SW480 cells transfected with a small inhibitory RNA to prevent survivin expression. Survivin gene transfectants showed increased DNA binding of transcription factor specificity protein 1 (Sp1) to the FasL promoter, and up-regulation of Sp1 phosphorylation at serine and threonine residues; the total amount of Sp1 was unchanged. Thus, survivin enables cancer cells not only to suppress immune cell attack by inhibiting Fas-mediated apoptotic signaling, but to attack immune cells by induction of FasL.
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PMID:Survivin enhances Fas ligand expression via up-regulation of specificity protein 1-mediated gene transcription in colon cancer cells. 1500

Survivin has been identified as one of the top 4 transcripts among 3.5 million human transcriptomes uniformly up-regulated in cancer tissues but not in normal tissues. Therefore, we quantitatively determined the messenger RNA (mRNA) expression profile for survivin by a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) technique in 113 patients with leukemias, such as adult T-cell leukemia (ATL), acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia in crisis, and chronic lymphocytic leukemia (CLL), and in 25 cell lines, including 7 ATL cell lines and 15 solid-tumor cell lines. Furthermore, we examined whether the plasma level of survivin protein as measured by enzyme-linked immunosorbent assay (ELISA) substituted for mRNA expression by PCR quantification. Gene expression was quantitatively confirmed to be up-regulated in approximately 90% of ATL and acute leukemia cases and in all of the cell lines tested, whereas it was down-regulated in almost all cases of CLL. Furthermore, with respect to the interpretation of the gene expression findings, attention was paid to standardization with a housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), in the real-time PCR quantification, because the variability in GAPDH expression among the different cell types was significant. GAPDH expression was relatively low in ATL cells and high in ALL and AML cells. The rates of increase in the levels of survivin protein in the plasma of ATL patients and in the supernatants from in vitro cultures of solid-tumor cell lines were low compared with rates of increase of the mRNA and protein level in the cells, suggesting that the protein levels in plasma do not always reflect survivin expression in tumor cells. Our findings indicate the potential clinical relevance of survivin quantified by real-time PCR but not for the protein level in plasma as determined by ELISA, especially in cases of ATL and acute leukemias.
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PMID:Clinical relevance of survivin as a biomarker in neoplasms, especially in adult T-cell leukemias and acute leukemias. 1529 68

Survivin is a unique member of the inhibitor of apoptosis protein family, and its expression is regulated by p53. Recent identification of several functionally divergent survivin variants augments the complexity of survivin action as well as its regulation. Here we report that survivin-2B (retaining a part of intron 2 as a cryptic exon) is positively regulated by p53, and its overexpression plays a role in sensitizing leukemia cells to chemotherapeutic drug doxorubicin. Doxorubicin treatment activated p53, downregulated survivin and survivin-DeltaEx3 but upregulated survivin-2B in EU-3, an acute lymphocytic leukemia (ALL) cell line with wild-type (wt)-p53 phenotype. In contrast, doxorubicin treatment failed to induce these alterations in EU-6 cells, a mutant-p53 ALL cell line. To specify the role of wt-p53 in regulating survivin and its variants, a temperature-sensitive p53 mutant plasmid p53-143 was transfected into EU-4, a p53-null ALL cell line, to establish a subline EU-4/p53-143. When EU-4/p53-143 cell culture was shifted from 37.5 degrees C to the wt-p53-permissive temperature (32.5 degrees C), the expression of survivin and survivin-DeltaEx3 was decreased whereas survivin-2B expression was increased, confirming the distinct regulatory effect of p53 on survivin and its variants. To clarify the role of survivin-2B in the process of apoptosis, survivin-2B cDNA was cloned into pcDNA3HA vector and transfected into EU-4 cells. Enforced expression of survivin-2B in EU-4 cells inhibited cell growth and sensitized these cells to doxorubicin-induced apoptosis. These results suggest that survivin-2B variant is a proapoptotic factor and its expression is upregulated by p53.
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PMID:An alternatively spliced survivin variant is positively regulated by p53 and sensitizes leukemia cells to chemotherapy. 1533 64

Bone marrow cells of patients with myelodysplastic syndromes (MDS) frequently undergo apoptosis, though the apoptotic cell ratio decreases when overt leukemia (OL) develops. Thus, we compared the expression of the inhibitor of apoptosis protein (IAP) gene family proteins in bone marrow samples from control, MDS, OL transformed from MDS (MDS --> OL), and de novo acute myelogenous leukemia (AML) subjects by the quantitative real-time RT-PCR method and an immunohistochemical approach. Overexpression of mRNA for survivin, cIAP1, NAIP and XIAP was significant in MDS bone marrow cells compared with control samples. However, the expression of mRNA for survivin, cIAP1 and cIAP2 exhibited a remarkable decrease after the development of OL (MDS --> OL). By immunohistochemistry, survivin was found to localize to the nucleus of myeloid cells in the majority of MDS cases. Next, the chronological changes in the expression of IAPs were determined in cases of MDS with evolution of OL. Although the expression of cIAP1 and cIAP2 revealed a sudden or gradual decrease as OL developed, survivin in many cases and XIAP in the majority of cases exhibited a peak of expression before a decline, indicating that these IAPs could be associated with the early events in the development of OL.
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PMID:Expression of IAP family proteins in myelodysplastic syndromes transforming to overt leukemia. 1538 Mar 46

Interactions between the cyclin-dependent kinase inhibitor flavopiridol (FP) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L), were examined in human leukemia cells (U937 and Jurkat). Coexposure of cells to marginally toxic concentrations of TRAIL and FP (24 h) synergistically increased mitochondrial injury (eg, cytochrome c, AIF, Smac/DIABLO release), cytoplasmic depletion of Bax, activation of Bid as well as caspase-8 and -3, PARP cleavage, and apoptosis. Coadministration of TRAIL markedly increased FP-induced apoptosis in leukemic cells ectopically expressing Bcl-2, Bcl-x(L), or a phosphorylation loop-deleted form of Bcl-2 (DeltaBcl-2), whereas lethality was substantially attenuated in cells ectopically expressing CrmA, dominant-negative-FADD, or dominant-negative-caspase-8. TRAIL/FP induced no discernible changes in FLIP, DR4, DR5, Mcl-1, or survivin expression, modest declines in levels of DcR2 and c-IAP, but resulted in the marked transcriptional downregulation of XIAP. Moreover, cells stably expressing an XIAP-antisense construct exhibited a pronounced increase in TRAIL sensitivity comparable to degrees of apoptosis achieved with TRAIL/FP. Conversely, enforced XIAP expression significantly attenuated caspase activation and TRAIL/FP lethality. Together, these findings suggest that simultaneous activation of the intrinsic and extrinsic apoptotic pathways by TRAIL and FP synergistically induces apoptosis in human leukemia cells through a mechanism that involves FP-mediated XIAP downregulation.
Leukemia 2004 Nov
PMID:Potent antileukemic interactions between flavopiridol and TRAIL/Apo2L involve flavopiridol-mediated XIAP downregulation. 1538 34


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