Øystein Bruserud

University of Bergen, Bergen, Hordaland, Norway

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Publications (258)861.04 Total impact

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    ABSTRACT: Extracorporeal photopheresis (ECP) is an immunomodulatory alternative for treatment of graft versus host disease (GVHD). The blood is then separated into its various components through apheresis; buffy coat cells are thereafter treated with 8-methoxypsoralen before exposure to ultraviolet light and finally reinfused into the patient. There is a general agreement that this treatment has an anti-GVHD effect, but the mechanisms of action behind this effect are only partly understood. However, altered maturation of dendritic cells (DC) and thereby indirect modulation of T-cell reactivity seems to be one important mechanism together with DC-presentation of antigens derived from apoptotic donor T cells and induction of regulatory T cells. The treatment has been best studied in patients with chronic GVHD (both pediatric and adult patients), but most studies are not randomized and it is difficult to know whether the treatment is more effective than the alternatives. The clinical studies of ECP in adults with acute GVHD are few and not randomized; it is not possible to judge whether this treatment should be a preferred second- or third-line treatment. There is no evidence for increased risk of leukemia relapse or suppression of specific graft versus leukemia reactivity by this treatment, so specific antileukemic immunotherapy may still be possible. Thus, even though the treatment seems effective in patients with GVHD, further clinical (especially randomized) as well as biological studies with careful standardization of the treatment are needed before it is possible to conclude how ECP should be used in acute and chronic GVHD.
    Cancer immunology, immunotherapy : CII. 07/2014;
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    ABSTRACT: As a direct consequence of the high diversity of the aggressive blood cancer acute myeloid leukemia (AML), proteomic samples from patients are strongly heterogeneous, rendering their accurate relative quantification challenging. In the present study, we investigated the benefits of using a super-SILAC mix of AML derived cell lines as internal standard for quantitative shotgun studies. The Molm-13, NB4, MV4–11, THP-1, and OCI-AML3 cell lines were selected for their complementarity with regard to clinical, cytogenetic and molecular risk factors used for prognostication of AML patients. The resulting internal standard presents a high coverage of the AML proteome compared to single cell lines allied with high technical reproducibility, thus enabling its use for AML patient comparison. This was confirmed by comparing the protein regulation between the five cell lines and applying the internal standard to patient material: we were able to reproduce specific functional regulations known to be related to disease progression and molecular genetic abnormalities. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the dataset identifier PXD000441.This article is protected by copyright. All rights reserved
    Proteomics 07/2014; · 4.43 Impact Factor
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    ABSTRACT: Introduction: Heat shock proteins (HSPs) are molecular chaperones that stabilize folding and conformation of mature proteins. HSPs are, therefore, considered as possible therapeutic targets in the treatment of human cancers, including acute myeloid leukemia (AML). This strategy offers the possibility of targeting several oncogenic proteins or several intracellular signaling pathways through the use of a single therapeutic agent. Areas covered: Several specific HSP70 inhibitors have now been developed. We describe: i) the molecular structure of HSP70 and the molecular interactions especially with its co-chaperones; ii) the immunoregulatory functions of HSP70; iii) the expression and function of HSP70 in human AML cells; iv) the molecular and pharmacological characteristics of potential HSP70 inhibitors; and v) the clinical and experimental studies of HSP70 inhibition in human AML. Our review is based on careful selection of relevant publications identified in the PubMed database. Expert opinion: HSP70 inhibitors have antileukemic activity in human AML. However, additional experimental studies using in vitro models as well as animal models are required, including detailed toxicology studies, as a scientific basis for the optimal design of future clinical studies.
    Expert opinion on therapeutic targets. 06/2014;
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    ABSTRACT: The small-molecule MDM2 antagonist nutlin-3 has proved to be an effective p53 activating therapeutic compound in several preclinical cancer models, including acute myeloid leukemia (AML). We and others have previously reported a vigorous acetylation of the p53 protein by nutlin-treatment. In this study we aimed to investigate the functional role of this p53 acetylation in nutlin-sensitivity, and further to explore if nutlin-induced protein acetylation in general could indicate novel targets for the enhancement of nutlin-based therapy.
    Molecular cancer. 05/2014; 13(1):116.
  • Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række. 05/2014; 134(10):1058-61.
  • Håkon Reikvam, Randi Hovland, Oystein Bruserud
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    ABSTRACT: BACKGROUND Acute promyelocytic leukaemia (APL) is a subtype of acute myeloid leukaemia (AML) with unique biological and clinical features and unique therapeutic requirements. The article provides a brief description of the development, pathophysiology, diagnosis and treatment of APL.METHOD The article is based on the authors' own experience and reviews of key articles and national and international guidelines.RESULTS The disease is caused by a single genetic event, namely the translocation t(15;17), which gives rise to the oncoprotein PML-RARA. Clinical and morphological characteristics arouse suspicion of the disease, and the diagnosis is verified by detecting the translocation. At the time of diagnosis most patients have severe coagulopathy and the predominant clinical manifestation is bleeding. Early mortality is due to severe haemorrhage, usually intracranial. Early treatment start with all-trans retinoic acid (ATRA) on suspicion of APL is essential to reduce this early mortality. ATRA is also an important part of continued treatment, in combination with anthracycline-based chemotherapy and possibly arsenic. After this treatment, the prognosis for disease-free long-term survival is > 90 %. There are also safe and effective treatment options for elderly patients with complex comorbidities.INTERPRETATION With APL it is particularly important to start disease-targeting therapy in the form of ATRA quickly because of the high risk of serious haemorrhages and high early mortality. If serious haemorrhages are avoided, the prognosis is very good.
    Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række. 05/2014; 134(10):1052-5.
  • Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 02/2014; · 10.16 Impact Factor
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    ABSTRACT: Acute myeloid leukaemia (AML) is a heterogeneous malignancy. Intracellular signalling through the phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway is important for regulation of cellular growth and metabolism, and inhibitors of this pathway is considered for AML treatment. Primary human AML cells, derived from 96 consecutive adult patients, were examined. The effects of two mTOR inhibitors (rapamycin, temsirolimus) and two PI3K inhibitors (GDC-0941, 3-methyladenine) were studied, and we investigated cytokine-dependent proliferation, regulation of apoptosis and global gene expression profiles. Only a subset of patients demonstrated strong antiproliferative effects of PI3K-mTOR inhibitors. Unsupervised hierarchical clustering analysis identified two main clusters of patients; one subset showing weak or absent antiproliferative effects (59%) and another group showing a strong growth inhibition for all drugs and concentrations examined (41%). Global gene expression analyses showed that patients with AML cell resistance against PI3K-mTOR inhibitors showed increased mRNA expression of the CDC25B gene that encodes the cell cycle regulator Cell Division Cycle 25B. The antileukaemic effect of PI3K-Akt-mTOR inhibition varies between patients, and resistance to these inhibitors is associated with the expression of the cell cycle regulator CDC25B, which is known to crosstalk with the PI3K-Akt-mTOR pathway and mediate rapamycin resistance in experimental models.
    British Journal of Haematology 01/2014; 164(2):200-11. · 4.94 Impact Factor
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    ABSTRACT: The combined use of the histone deacetylase inhibitor valproic acid (VPA), the retinoic acid receptor- α agonist all-trans retinoic acid (ATRA), and the deoxyribonucleic acid polymerase- α inhibitor cytarabine (Ara-C) is now considered for disease-stabilizing treatment of acute myeloid leukemia (AML). Leukemogenesis and leukemia cell chemoresistance seem to be supported by neighbouring stromal cells in the bone marrow, and we have therefore investigated the effects of these drugs on primary human endothelial cells and the osteoblastic Cal72 cell line. The results show that VPA and Ara-C have antiproliferative effects, and the antiproliferative/cytotoxic effect of Ara-C was seen at low concentrations corresponding to serum levels found during low-dose in vivo treatment. Furthermore, in functional assays of endothelial migration and tube formation VPA elicited an antiangiogenic effect, whereas ATRA elicited a proangiogenic effect. Finally, VPA and ATRA altered the endothelial cell release of angiogenic mediators; ATRA increased levels of CXCL8, PDGF-AA, and VEGF-D, while VPA decreased VEGF-D and PDGF-AA/BB levels and both drugs reduced MMP-2 levels. Several of these mediators can enhance AML cell proliferation and/or are involved in AML-induced bone marrow angiogenesis, and direct pharmacological effects on stromal cells may thus indirectly contribute to the overall antileukemic activity of this triple drug combination.
    Leukemia research and treatment. 01/2014; 2014:143479.
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    ABSTRACT: Arginine is a conditionally essential amino acid important in growing individuals and under non-homeostatic conditions/disease. Many pathogens interfere with arginine-utilization in host cells, especially nitric oxide (NO) production, by changing the expression of host enzymes involved in arginine metabolism. Here we used human intestinal epithelial cells (IEC) and three different isolates of the protozoan parasite Giardia intestinalis to investigate the role of arginine and arginine-metabolizing enzymes during intestinal protozoan infections. RNA expression analyses of major arginine-metabolizing enzymes revealed the arginine-utilizing pathways in human IECs (differentiated Caco-2 cells) grown in vitro. Most genes were constant or down-regulated (e.g. arginase 1 and 2) upon interaction with Giardia, whereas inducible NO synthase (iNOS) and ornithine decarboxylase (ODC) were up-regulated within 6 h of infection. Giardia was shown to suppress cytokine-induced iNOS expression, thus the parasite has both iNOS inducing and suppressive activities. Giardial arginine consumption suppresses NO production and the NO-degrading parasite protein flavohemoglobin is up-regulated in response to host NO. In addition, the secreted, arginine-consuming giardial enzyme arginine deiminase (GiADI) actively reduces T-cell proliferation in vitro. Interestingly, the effects on NO production and T cell proliferation could be reversed by addition of external arginine or citrulline. Giardia affects the host's arginine metabolism on many different levels. Many of the effects can be reversed by addition of arginine or citrulline, which could be a beneficial supplement in oral rehydration therapy.
    BMC Microbiology 11/2013; 13(1):256. · 3.10 Impact Factor
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    ABSTRACT: Proliferative capacity of acute myelogenous leukaemia (AML) blasts is important for leukaemogenesis, and we have investigated whether proliferative capacity of primary human AML cells could be used for subclassification of patients. In vitro proliferative capacity of AML cells derived from two independent groups was investigated. Cells were cultured under highly standardized conditions and proliferation assayed by (3) H-thymidine incorporation after seven days culture. Patients were subclassified by clustering models, and gene expression profile was examined by microarray analyses. Based on proliferative capacity of the AML cells, three different patient clusters were identified: (i) autocrine proliferation that was increased by exogenous cytokines; (ii) detectable proliferation only in presence of exogenous cytokines; and (iii) low or undetectable proliferation even in presence of exogenous cytokines. Patients with highest proliferative capacity cells had no favourable prognostic impact by NPM-1 mutation. Analysis of gene expression profiles showed that the most proliferative cells generally had altered expression of genes involved in regulation of transcription/RNA functions, whereas patients with high proliferative capacity and internal tandem duplications (ITDs) in the FLT3 cytokine receptor gene had altered expression of several molecules involved in cytoplasmic signal transduction. In vitro proliferative capacity of primary human AML cells was considerably variable between patients and could be used to identify biologically distinct patient subsets.
    Cell Proliferation 10/2013; 46(5):554-62. · 2.27 Impact Factor
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    ABSTRACT: The retinoid-responsive gene CXXC5 localizes to the 5q31.2 chromosomal region and encodes a retinoid-inducible nuclear factor (RINF) that seems important during normal myelopoiesis. We investigated CXXC5/RINF expression in primary human acute myeloid leukemia (AML) cells derived from 594 patients, and a wide variation in CXXC5/RINF mRNA levels was observed both in the immature leukemic myeloblasts and in immature acute lymphoblastic leukemia cells. Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML. This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML. CXXC5/RINF knockdown in AML cell lines caused increased susceptibility to chemotherapy-induced apoptosis, and regulation of apoptosis also seemed to differ between primary human AML cells with high and low RINF expression. The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.
    Oncotarget 08/2013; · 6.64 Impact Factor
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    ABSTRACT: Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9) L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients. During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML). We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9) L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9) L(-1) . No serious side effects were seen during or immediately after apheresis. The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy.
    Transfusion Medicine 08/2013; · 1.26 Impact Factor
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    ABSTRACT: A large proportion of patients with acute myeloid leukemia (AML) are not fit for intensive and potentially curative therapy due to advanced age or comorbidity. Previous studies have demonstrated that a subset of these patients can benefit from disease-stabilizing therapy based on all-trans retinoic acid (ATRA) and valproic acid. Even though complete hematological remission is only achieved for exceptional patients, a relatively large subset of patients respond to this treatment with stabilization of normal peripheral blood cell counts. In this clinical study we investigated the efficiency and safety of combining (i) continuous administration of valproic acid with (ii) intermittent oral ATRA treatment (21.5 mg/m2 twice daily) for 14 days and low-dose cytarabine (10 mg/m2 daily) for 10 days administered subcutaneously. If cytarabine could not control hyperleukocytosis it was replaced by hydroxyurea or 6-mercaptopurin to keep the peripheral blood blast count below 50 x 109/L. The study included 36 AML patients (median age 77 years, range 48 to 90 years) unfit for conventional intensive chemotherapy; 11 patients responded to the treatment according to the myelodysplastic syndrome (MDS) response criteria and two of these responders achieved complete hematological remission. The most common response to treatment was increased and stabilized platelet counts. The responder patients had a median survival of 171 days (range 102 to > 574 days) and they could spend most of this time outside hospital, whereas the nonresponders had a median survival of 33 days (range 8 to 149 days). The valproic acid serum levels did not differ between responder and nonresponder patients and the treatment was associated with a decrease in the level of circulating regulatory T cells. Treatment with continuous valproic acid and intermittent ATRA plus low-dose cytarabine has a low frequency of side effects and complete hematological remission is seen for a small minority of patients. However, disease stabilization is seen for a subset of AML patients unfit for conventional intensive chemotherapy.
    Clinical epigenetics. 08/2013; 5(1):13.
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    Hanne Fredly, Bjørn Tore Gjertsen, Oystein Bruserud
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    ABSTRACT: Several new therapeutic strategies are now considered for acute myeloid leukemia (AML) patients unfit for intensive chemotherapy, including modulation of protein lysine acetylation through inhibition of histone deacetylases (HDACs). These enzymes alter the acetylation of several proteins, including histones and transcription factors, as well as several other proteins directly involved in the regulation of cell proliferation, differentiation and apoptosis. Valproic acid (VPA) is a HDAC inhibitor that has been investigated in several clinical AML studies, usually in combination with all-trans retinoic acid (ATRA) for treatment of patients unfit for intensive chemotherapy, for example older patients, and many of these patients have relapsed or primary resistant leukemia. The toxicity of VPA in these patients is low and complete hematological remission lasting for several months has been reported for a few patients (<5% of included patients), but increased peripheral blood platelet counts are seen for 30 to 40% of patients and may last for up to 1 to 2 years. We review the biological effects of VPA on human AML cells, the results from clinical studies of VPA in the treatment of AML and the evidence for combining VPA with new targeted therapy. However, it should be emphasized that VPA has not been investigated in randomized clinical studies. Despite this lack of randomized studies, we conclude that disease-stabilizing treatment including VPA should be considered especially in unfit patients, because the possibility of improving normal blood values has been documented in several studies and the risk of clinically relevant toxicity is minimal.
    Clinical epigenetics. 07/2013; 5(1):12.
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    ABSTRACT: Amphetamine and amphetamine derivatives are suggested to induce an immunosuppressive effect. However, knowledge of how amphetamines modulate intracellular signaling pathways in cells of the immune system is limited. We have studied phosphorylation of signal transduction proteins (Akt, CREB, ERK1/2, NF-kappaB, c-Cbl, STAT1/3/5/6) and stress sensors (p38 MAPK, p53) in human leukocyte subsets following in vitro treatment with the natural amphetamine cathinone, the cathinone derivatives cathine and norephedrine, in comparison with a defined extract of the psychostimulating herb khat (Catha edulis Forsk.). Intracellular protein modifications in single cells were studied using immunostaining and flow cytometry, cell viability was determined by Annexin V-FITC/Propidium Iodide staining, and T-lymphocyte proliferation was measured by 3H-thymidine incorporation. Cathinone, cathine and norephedrine generally reduced post-translational modifications of intracellular signal transducers in T-lymphocytes, B-lymphocytes, natural killer cells and monocytes, most prominently affecting c-Cbl (pTyr700), ERK1/2 (p-Thr202/p-Tyr204), p38 MAPK (p-Thr180/p-Tyr182) and p53 (both total p53 protein and p-Ser15). In contrast, the botanical khat-extract induced protein phosphorylation of STAT1 (p-Tyr701), STAT6 (p-Tyr641), c-Cbl (pTyr700), ERK1/2 (p-Thr202/p-Tyr204), NF-kappaB (p-Ser529), Akt (p-Ser473), p38 MAPK (p-Thr180/p-Tyr182), p53 (Ser15) as well as total p53 protein. Cathinone, cathine and norephedrine resulted in unique signaling profiles, with B-lymphocytes and natural killer cells more responsive compared to T-lymphocytes and monocytes. Treatment with norephedrine resulted in significantly increased T-lymphocyte proliferation, whereas khat-extract reduced proliferation and induced cell death. Single-cell signal transduction analyses of leukocytes distinctively discriminated between stimulation with cathinone and the structurally similar derivatives cathine and norephedrine. Cathinone, cathine and norephedrine reduced phosphorylation of c-Cbl, ERK1/2, p38 MAPK and p53(Ser15), and norephedrine induced T-lymphocyte proliferation. Khat-extract induced protein phosphorylation of signal transducers, p38 MAPK and p53, followed by reduced cell proliferation and cell death. This study suggests that protein modification-specific single-cell analysis of immune cells could unravel pharmacologic effects of amphetamines and amphetamine-like agents, and further could represent a valuable tool in elucidation of mechanism(s) of action of complex botanical extracts.
    BMC pharmacology & toxicology. 07/2013; 14(1):35.
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    ABSTRACT: Acute myeloid leukemia (AML) is a heterogeneous and aggressive malignancy with poor overall survival. Constitutive as well as cytokine-initiated activation of PI3K/Akt/mTOR signaling is a common feature of AML patients, and inhibition of this pathway is considered as a possible therapeutic strategy in AML. Human AML cells and different stromal cell populations were cultured under highly standardized in vitro conditions. We investigated the effects of mTOR inhibitors (rapamycin and temsirolimus) and PI3K inhibitors (GDC-0941 and 3-methyladenin (3-MA)) on cell proliferation and the constitutive release of angioregulatory mediators by AML and stromal cells. Primary human AML cells were heterogeneous, though most patients showed high CXCL8 levels and detectable release of CXCL10, Ang-1, HGF and MMP-9. Hierarchical clustering analysis showed that disruption of PI3K/Akt/mTOR pathways decreased AML cell release of CXCL8-11 for a large subset of patients, whereas the effects on other mediators were divergent. Various stromal cells (endothelial cells, fibroblasts, cells with osteoblastic phenotype) also showed constitutive release of angioregulatory mediators, and inhibitors of both the PI3K and mTOR pathway had anti-proliferative effects on stromal cells and resulted in decreased release of these angioregulatory mediators. PI3K and mTOR inhibitors can decrease constitutive cytokine release both by AML and stromal cells, suggesting potential direct and indirect antileukemic effects.
    Oncotarget 06/2013; 4(6):830-43. · 6.64 Impact Factor
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    ABSTRACT: Heat shock proteins (HSPs) are molecular chaperones that assist proteins in their folding to native structures. HSP90, and more recently HSP70, have emerged as possible therapeutic targets in human malignancies, including acute myeloid leukemia (AML). The authors investigated the effects of the HSP70 inhibitor VER-155008 tested alone or in combination with the HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) on proliferation, viability, constitutive cytokine release and intracellular HSP levels of primary human AML cells. VER-155008 caused a dose-dependent inhibition of cytokine-dependent AML cell proliferation both in suspension cultures and in a colony formation assay, and the drug also had a proapoptotic effect. HSP70 and HSP90 inhibition had additive antiproliferative and proapoptotic effects. VER-155008 caused a strong inhibition of the constitutive AML cell release of several growth factors/regulators of hematopoiesis (i.e., TNF-α, VEGF, IL-3, IL-1β, IL-1 receptor antagonist), but had relatively weak effects on the constitutive chemokine release. HSP70 inhibition did not induce any compensatory increase of other HSPs. HSP70 inhibition has antileukemic effects when tested alone, and the combination of HSP70 and HSP90 inhibition seems to have additive antileukemic effects for primary human AML cells in vitro.
    Expert Opinion on Investigational Drugs 05/2013; 22(5):551-63. · 4.74 Impact Factor
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    ABSTRACT: BACKGROUND AIMS: Stem cell mobilization and harvesting by peripheral blood leukapheresis in patients with myeloma can alter plasma levels of certain cytokines. In the present study, we investigated the effects of these interventions on a larger group of cytokines. METHODS: Plasma cytokine levels were determined in 15 patients with myeloma who were undergoing peripheral blood stem cell harvesting, and we compared the patients with healthy donors who were undergoing platelet apheresis. RESULTS: Several cytokines showed altered levels in patients with myeloma when examined after chemotherapy plus granulocyte colony-stimulating factor-induced stem cell mobilization. The most striking effect was increased levels of several CCL (CCL2/3/4) and CXCL (CXCL5/8/10/11) chemokines as well as increased thrombopoietin, interleukin 1 receptor antagonist, interleukin-4, granulocyte colony-stimulating factor and hepatocyte growth factor. Stem cell harvesting by apheresis altered the plasma levels of several mediators (CD40 ligand, interleukin 1 receptor antagonist, CCL5 and CXCL5/8/10/11). Apheresis in patients with myeloma had divergent effects on these chemokine levels, although they were all still significantly higher than for healthy individuals. Thrombapheresis in healthy individuals had only minor effects on plasma cytokine levels. Stem cell graft supernatants showed high levels of several cytokines, especially CCL and CXCL chemokines. Analyses of chemokine profiles in pre-apheresis plasma and graft supernatants suggested that such profiling can be used to detect prognostically relevant differences between patients. CONCLUSIONS: Our results demonstrate that patients with myeloma have an altered cytokine network during stem cell mobilization, and the network is further altered during stem cell harvesting by leukapheresis. These treatment- or procedure-induced alterations involve several mediators known to affect myeloma cell proliferation, migration and survival.
    Cytotherapy 04/2013; · 3.06 Impact Factor
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    ABSTRACT: We show that cyclic AMP (cAMP) elevating agents protect blasts from patients with acute promyelocytic leukemia (APL) against death induced by first-line anti-leukemic anthracyclines like daunorubicin (DNR). The cAMP effect was reproduced in NB4 APL cells, and shown to depend on activation of the generally cytoplasmic cAMP-kinase type I (PKA-I) rather than the perinuclear PKA-II. The protection of both NB4 cells and APL blasts was associated with (inactivating) phosphorylation of PKA site Ser118 of pro-apoptotic Bad and (activating) phosphorylation of PKA site Ser133 of the AML oncogene CREB. Either event would be expected to protect broadly against cell death, and we found cAMP elevation to protect also against 2-deoxyglucose, rotenone, proteasome inhibitor and a BH3-only mimetic. The in vitro findings were mirrored by the findings in NSG mice with orthotopic NB4 cell leukemia. The mice showed more rapid disease progression when given cAMP-increasing agents (prostaglandin E analog and theophylline), both with and without DNR chemotherapy. The all-trans retinoic acid (ATRA)-induced terminal APL cell differentiation is a cornerstone in current APL treatment and is enhanced by cAMP. We show also that ATRA-resistant APL cells, believed to be responsible for treatment failure with current ATRA-based treatment protocols, were protected by cAMP against death. This suggests that the beneficial pro-differentiating and non-beneficial pro-survival APL cell effects of cAMP should be weighed against each other. The results suggest also general awareness toward drugs that can affect bone marrow cAMP levels in leukemia patients.
    Cell Death & Disease 02/2013; · 6.04 Impact Factor

Publication Stats

3k Citations
861.04 Total Impact Points

Institutions

  • 1994–2014
    • University of Bergen
      • • Institute of Medicine
      • • Section of Haematology
      • • Section of Medical Biochemistry
      Bergen, Hordaland, Norway
  • 1991–2013
    • Haukeland University Hospital
      • • Department of Medicine
      • • Dept. of Immunology and Transfusion Medicine
      • • Centre for Medical Genetics and Molecular Medicine
      Bergen, Hordaland Fylke, Norway
  • 2008–2011
    • Oslo University Hospital
      • Center for Clinical Heart Research
      Kristiania (historical), Oslo County, Norway
  • 2009
    • Haraldsplass Deaconess University College
      Bergen, Hordaland, Norway
  • 2008–2009
    • University of Stavanger (UiS)
      • Department of Health Studies
      Stavanger, Rogaland Fylke, Norway
  • 2007
    • Stanford University
      • Department of Microbiology and Immunology
      Stanford, CA, United States
  • 2006
    • NORUT Northern Research Institute
      Tromsø, Troms, Norway
  • 1991–2006
    • University of Tuebingen
      • • Department of Internal Medicine
      • • Eye Hospital
      Tübingen, Baden-Wuerttemberg, Germany
  • 2003
    • Тольяттинский государственный университет ТГУ
      Stawropol, Samara, Russia
  • 1998–1999
    • Høgskolen i Bergen
      Bergen, Hordaland, Norway
  • 1991–1993
    • Universitätsklinikum Tübingen
      • Sektion für Transplantationsimmunologie und Immunhämatologie
      Tübingen, Baden-Württemberg, Germany