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  • 1
    In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 2568-2568
    Abstract: Acute Myeloid Leukemia (AML) is a form of cancer that affects the cells of the hematopoietic system. The currently applied WHO classification of genetically defined AML subtypes based on cytogenetic and molecular aberrations of known oncogenes and tumor suppressors allows to stratify patients into genetically defined low-, intermediate, and high-risk groups. Yet, this detailed genetic information has rarely resulted in the development of targeted therapies that are directed at the underlying genetic lesions, or even personalized therapies. With the notable exceptions of chronic myeloid leukemia (CML) and acute promyelocytic leukemia (APL), the prognosis for most AML subtypes treated with standard chemotherapy regimens remains for the most part poor with a median overall survival of approximately 18 months. The development of cancer may have both genetic and epigenetic causes, but what is common to all cancers is a unique gene-expression pattern (GEP) that drives the malignant phenotype and thus partly differs from that of normal cells representing the same type of cells/tissue and developmental stage. Significantly the unique GEP of cancer cells have been illustrated in a multitude of gene-expression profiling studies where mRNA were quantified using microarray or deep sequencing platforms. These technologies have been outstanding to group, diagnose and forecast AML subtypes based on differences in GEPs. However, they have only demonstrated a marginal role in the identification of potential therapeutic targets. This is mainly due to the fact that these studies have compared AMLs with other AMLs and not with corresponding normal cells of the same developmental stages. This is an obvious prerequisite if one wants to define the genes that drives the malignant phenotype of AML cells. Our hypothesis is that a comparison of the GEPs of AML cells with their closest normal counterparts within the hematopoietic hierarchy will provide a better understanding of AML biology, which we could then use to improve prognostication and as a starting point for the development of targeted therapeutic strategies including combinations of both new drugs or existing ones. To test this hypothesis, we FACS sorted hematopoietic stem and progenitors and generated micro-array based GEPs. Together with other normal hematopoietic cell GEPs derived from public repositories, we generated a gene expression-based map of the hematopoietic system (Frederik Otzen Bagger et al., HemaExplorer: a database of mRNA expression profiles in normal and malignant haematopoiesis., Nucleic acids research (2012); Frederik Otzen Bagger et al., HemaExplorer: a Web server for easy and fast visualization of gene expression in normal and malignant hematopoiesis., 119 Blood 6394–6395 (2012)) , using the first components of a principal component analysis (PCA). Once established, we mapped the AML-patient samples GEP ( 〉 1300) into this PCA space to identify the normal populations closest to each individual AML GEP (see Figures 1A and 1B). Finally, gene-expression changes between individual AML samples and their corresponding individual normal counterparts were computed for further analyses, such as gene set enrichment and survival analysis.Figure 1(A, B) PCA plots of individual GEP profiles from two AML subtypes mapped to the normal landscape of hematopoietic differentiation. (C-E) Stratification of three independent patient cohorts with survival gene signature generated by comparison of cancer and direct normal counterpart.Figure 1. (A, B) PCA plots of individual GEP profiles from two AML subtypes mapped to the normal landscape of hematopoietic differentiation. (C-E) Stratification of three independent patient cohorts with survival gene signature generated by comparison of cancer and direct normal counterpart. Our method resulted in improved clinical prognostication of AML patients and enabled us to identify new potential therapeutic target genes and oncogenic pathways activity that are over-expressed in AML cells as compared to their normal counterparts. Similarly, using the connectivity-map database (a collection of genome-wide transcriptional expression data from cultured human cells treated with bioactive small molecules), we could screen substances that could reverse the aberrant gene-expression signatures; some of these drugs are already in use in AML treatment or in clinical trials, which strengthens the validity of our bioinformatics method. A singularly interesting perspective in this regard is the possibility to tailor individualized drug combinations potentially targeting cancer cells synergistically by combined inhibition of multiple oncogenic targets and pathways. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2013
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  • 2
    In: Blood, American Society of Hematology, Vol. 118, No. 8 ( 2011-08-25), p. 2170-2173
    Abstract: Recent reports have described complete or major molecular remission in patients with polycythemia vera after long-term treatment with the immunomodulatory agent IFN-α2. Accordingly, there are reasons to believe that the immune system is a key player in eradicating the JAK2 mutated clone in these patients. Foxp3+ regulatory T cells play a pivotal role in maintaining immune homeostasis and, importantly, preventing immune reactivity to self-antigens; however, their suppressive activity can compromise an effective antitumor immune response, and high frequencies of regulatory T cells in peripheral blood have been reported in both hematologic and solid cancers. We have analyzed the number, phenotype, and function of circulating CD4+CD25+Foxp3+ T cells in patients with chronic myeloproliferative neoplasms. Surprisingly, we found a marked expansion of this subset of lymphocytes in patients treated with IFN-α2 (13.0%; 95% confidence interval [CI] 10.8% to 15.2%) compared with healthy donors (6.1%; 95% CI 4.9% to 7.2%), patients with untreated chronic myeloproliferative neoplasms (6.9%; 95% CI 5.8% to 7.4%), or patients treated with hydroxyurea (5.8%; 95% CI 4.3% to 7.4%; P 〈 .0001).
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2011
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  • 3
    In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 2590-2590
    Abstract: Cancer emerges as a consequence of multiple genetic aberrations that ultimately cause global changes in gene expression driving the malignant phenotype. Hence, identification of aberrantly expressed genes in cancer cells, as compared to their corresponding normal cells, provides information on the biology of the cancer as well as potential targets for therapeutic interventions. Here, we report an access-free internet platform for visualization of mRNA expression profiles in acute myeloid leukemia (AML) patient samples as compared to normal bone marrow (BM) populations representing successive stages of differentiation along the myeloid differentiation pathway. The internet platform allows for quick visualization of user selected genes in AML patients in either human or murine hematopoietic stem cells (HSC), myeloid hematopoietic progenitor cells (HPC) and their progeny, as well as mature cells of innate and adaptive immune system. Significantly, users can upload own microarray data to compare gene expression in their samples of interest to those available at the internet platform. Overall, our internet platform represents a powerful tool for studies of normal hematopoietic development as well as aberrantly expressed genes in AML and potentially other hematological malignancies. The web tool will be made available at http://servers.binf.ku.dk/hemaexplorer/ Methods Raw Affymetrix microarray data from our own repository and public available databases were normalized and batch corrected to build an integrated gene expression database for a series of normal hematopoietic cells and AML patient samples, at progressing stages of differentiation, which can be visualized directly or compared to external samples added by the user. A complete database of internal and user-supplied samples is build at each run of the analysis, using uniform transformation and correction parameters adjusted to ensure full integrity and comparability across all samples. The microarray database includes 44 highly purified sorted human normal blood samples and BM populations including HSCs, myeloid HPCs and their progeny, as well as mature cells of the innate and adaptive immune system. 10 samples were from public sources. In addition, our database includes microarray data from multiple AML studies ( 〉 1000 samples across platforms) allowing for comparison of gene expression in WHO defined AML subclasses and normal hematopoietic cells. Results The main strength of the data-driven HemaExplorer 2.0 tool is the ability to quickly assess the main trends in how an AML sample diverges from normal cells during normal myeloid development. This can be accessed by specifying a gene of interest (Figure panel A-B. A user-supplied sample is marked in red in panel B) which provides interactive plots and hierarchical visualisations of gene expression where parameters including gene of interest, data source, and cell types can be selected and presented directly on the output figures usable for publications. Furthermore, a principal component analysis (PCA) plot can be performed, which allows for an unsupervised gene expression based mapping of user provided samples to the most closely related normal cell populations (figure panel C - here shown with cell lines commonly used in AML research). Discussion Several websites offer visualisation of gene expression in cells from the hematopoietic system, including Gene Expression Atlas (Nucl. Acids Res., 40, D1077–D1081) and our own HemaExplorer (Blood, 119(26), 6394-5 and Nucl. Acids Res. 41, D1034-D1039), without the possibility of external sample addition provided by the users. Gene Expression Commons (PLoS ONE 7(7), e40321) provides this option for public data, based on a common expression model. Here we offer the ability to add and compare unpublished microarray gene expression profiles to various types of normal blood and BM populations, in a ready-to-use platform normalized on single sample level, independently on the overall distribution of expression in a selected set of reference samples. Future efforts will include the ability to provide a standard differential expression analysis, comparing the user-supplied sample with a selection of the normal hematopoietic hierarchy. Furthermore, we aim to be able to offer a standalone version of the tool, which can be implemented internally on hospital servers, and expand the list of accepted microarray platforms. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2013
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  • 4
    In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 4097-4097
    Abstract: Introduction Gene expression profiling studies in the Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) have unraveled significant deregulation of several immune and inflammation genes of potential importance for clonal evolution (Skov V et al., Eur J Haematol 2011; Leuk Res 2012; Exp Hematol 2012). Other mechanisms might be downregulation of major histocompatibility (MHC) class I and II genes, which are used by tumor cells to escape antitumor T-cell-mediated immune responses. In a previous study, several genes encoding human leukocyte antigen (HLA) class I and II molecules, beta2microglobulin and members of the antigen processing machinery of HLA class I molecules (LMP2, LMP7, TAP1, TAP2 and tapasin) have been shown to be significantly downregulated (Skov V, Leuk Lymphoma 2012). Upregulation of HLA-genes is considered one of the mechanisms of action of interferon-alpha2 (IFN-alpha2) but regulation of these genes during IFN-alpha2 treatment of patients with MPNs has never been studied. The purpose of this study was to assess the regulation of several HLA genes before and during treatment with IFN-alpha2, the hypothesis being that IFN-alpha2 - as in other cancers - may restore downregulation of HLA genes in MPNs as well. Patients and Methods Using Affymetrix HG-U133 2.0 Plus microarrays, gene expression profiling have been performed on whole blood from patients with ET (n =8), PV (n = 21), and PMF (n = 4) before and after 3 months of treatment with IFN-alpha2. Background correction, normalization, and gene expression index calculation were performed with the robust multi-array (rma) method. The regularized t-test limma for pairwise data was used to calculate differences in gene expression between patients before and after treatment with IFN-alpha2. A p-value 〈 0.05 was considered significant. Results Statistical analysis of all 54,675 probe sets on the microarray revealed 6261, 10,008, 2828, and 12,390 probe sets to be significantly differentially expressed in ET, PV, PMF, and MPNs as a whole, respectively, in response to treatment with IFN-alpha2 (P-value 〈 0.05). To examine if treatment with IFN-alpha2 restores preexisting abnormalities of HLA genes in MPNs, pretreatment vs. posttreatment gene expression changes of MPNs were analyzed. Several HLA genes were significantly deregulated. Of 23 HLA major histocompatibility complex (MHC) class I and II genes and 26 HLA associated and complex group genes, 15, 24, 6 and 24 genes were significantly deregulated in ET, PV, PMF, and MPNs as a whole, respectively (P 〈 0.05). In ET patients, BAT4, HCG26, HCP5, HLA-B, HLA-C, HLA-F, HLA-G, TAP1, and PSMB9 were significantly upregulated and BAT5, CIITA, HCG11, HLA-DOA, HLA-DQA1, and HLA-DRB4 were significantly downregulated. In PV patients, the significantly upregulated genes included CD74, HCG26, HCG8, HCP5, HLA-A, HLA-B, HLA-C, HLA-E, HLA-F, HLA-G, HLA-DOB, HLA-DPA1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MR1, TAP1, TAP2, TAPBPL, PSMB8, and PSMB9 and the significantly downregulated genes included CITTA, HLA-DOA, and HLA-DPB2. In PMF, HCP5, HLA-DOA, and HLA-DQA1 were significantly upregulated and HCP5, TAP1, and PSMB9 significantly downregulated. In MPNs as a whole, BAT4, HCG26, HCG8, HCP5, HLA-A, HLA-B, HLA-C, HLA-E, HLA-F, HLA-G, HLA-DOB, HLA-DPA1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MR1, TAP1, TAP2, TAPBPL, PSMB8, and PSMB9 were significantly upregulated and CIITA, HLA-DOA, and HLA-DPB2 were significantly downregulated (all P 〈 0.05). Conclusions: Whole blood transcriptional profiling has unraveled that IFN-alpha2 potently up-regulates several HLA-genes of importance for tumor immune surveillance. Our findings may be crucial for the efficacy of IFN-alpha2 in the treatment of MPNs, since the potential of cytotoxic immune cells for tumor killing is likely by this mechanism significantly enhanced and the path towards induction of minimal residual disease accordingly improved as well. Disclosures Bjerrum: Bristoll Myers Squibb, Novartis and Pfizer: Other: educational activities. Hasselbalch:Novartis: Research Funding.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2015
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  • 5
    In: Blood, American Society of Hematology, Vol. 123, No. 6 ( 2014-02-06), p. 894-904
    Abstract: This study describes a method for the comparison of gene expression data of any type of cancer cells with their corresponding normal cells. Our analyses reveal novel disease entities, identify common deregulated transcriptional networks, and predict survival.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2014
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  • 6
    In: Blood, American Society of Hematology, Vol. 108, No. 11 ( 2006-11-16), p. 401-401
    Abstract: Systemic PTCL, with the exception of alk-positive anaplastic large cell lymphoma (ALCL), have a poor prognosis. ASCT has been shown to have a favourable impact on relapsed PTCL. Therefore, the NLG designed a prospective multicenter phase II study to evaluate the impact of a dose-intensified induction schedule (6 courses of two-weekly CHOEP) consolidated in 1st PR/CR with high-dose therapy (BEAM) followed by ASCT in previously untreated systemic PTCL. This is the largest prospective PTCL-specific trial published so far. Newly diagnosed non-primary cutaneous PTCL cases aged 18–67 yrs were eligible for enrollment. Cases of alk-positive ALCL were excluded. From Oct 2001 to Feb 2006, 99 histologically confirmed PTCL cases were included in the study: PTCL unspecified (n=41), alk-neg ALCL (n=24), AILT (n=15), enteropathy-type (n=12), panniculitis-like (n=3), T/NK nasal-type (n=2), hepatosplenic (n=2). The M/F ratio was 1.8 and the median age 55 yrs (range 20–67 yrs). Although almost 2/3 of the cases presented with advanced-stage disease (62%), B-symptoms (61%) and/or elevated s-LDH (63%), the majority of them (65%) had a good performance score (WHO 0–1) at diagnosis. Of the 77 patients, where information was available for all 6 induction courses, 68 (88%) were in CR (31) or PR (37) after the 3rd and 66 (86%) after the 6th course. A total of 58 patients (75%) went through ASCT indicating that at least a fourth of this younger patient cohort has a primary refractory disease and fails therapy before reaching the transplant. Treatment-related toxicity after both induction and high-dose treatment was manageable. Of the 58 transplanted patients, 50 (86%) were still in remission at re-evaluation short after transplant. In 39 patients follow-up data one year post-transplant were available: 30 are still in CR and 9 have relapsed, suggesting that post-transplant relapses probably account for another 25% of the original patient cohort. In conclusion, the present data indicate that a time- and dose-intensified schedule is feasible and effective in previously untreated systemic PTCL. Continuous remissions are not uncommon, but a longer follow-up is needed to further characterize long-term remission rates and evaluate their impact on time-to-treatment failure and overall survival.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2006
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  • 7
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4117-4117
    Abstract: Abstract 4117 Introduction: The proteasome is an ubiquituous enzyme complex that plays a critical role in the degradation of many proteins involved in cell cycle regulation, apoptosis, and angiogenesis. Since these pathways and functions are often deregulated in cancer cells, inhibition of the proteasome is an attractive potential anticancer therapy. Bortezomib (Velcade, formerly PS-341) is an extremely potent and selective proteasome inhibitor that shows strong activity against many solid and hematologic tumor types. Moreover, bortezomib, mainly by inhibition of the NF-kappaB pathway, has a chemosensitizing effect when administered together with other antitumoral drugs. Bortezomib is a well-established treatment in multiple myeloma and studies are focusing in the potential benefit of bortezomib in other haematological malignancies, including malignant lymphomas. Since the NF-kappaB pathway is considered to be implicated in the abnormal release of cytokines in primary myelofibrosis (PMF), the proteasome inhibitor bortezomib might be a potential therapy. In a murine model, bortezomib has been demonstrated to inhibit thrombopoietin (TPO)-induced NF-kappaB activation in megakaryocytes and to reduce myeloproliferation induced by high TPO levels. Accordingly, from in vitro studies it was concluded that bortezomib might be a promising therapy for future treatment of PMF patients. Surprisingly, however, these encouraging results have not been achieved in clinical trials testing bortezomib in patients with myelofibrosis. We have performed gene expression profiling of patients with PMF and in patients with other chronic myeloproliferative neoplasms (CMPNs) in order to describe aberrant genes in the proteasome pathway in PMF. Materials and methods: The HG-U133 Plus 2.0 microarray from Affymetrix was used to profile expression of 38500 genes in whole blood from 70 patients with CMPNs, including 9 patients with PMF and 61 patients with other CMPNs. All patients were diagnosed according to the WHO criteria of a CMPN (ET=19, PV=41, PMF=9). The patients were diagnosed and followed in two institutions. Most patients were studied on cytoreductive therapy, which for the large majority included hydroxyurea. Total RNA was purified from whole blood and amplified to biotin-labeled aRNA and hybridized to microarray chips. Differences in gene expression between the two groups were calculated for each gene in the dataset by using Welch two sample t test, and the Benjamini Hochberg method was applied to control for multiple hypothesis testing (false discovery rate (FDR) 〈 0.05). Data were integrated with biological pathways and networks using Gene Microarray Pathway Profiler (GenMAPP 2.1) and Cytoscape 2.6.3, respectively. Hypothesis driven discovery was used to find significantly differentially expressed genes and pathways associated with PMF. Results: Single gene analysis demonstrated significantly elevated expression of seventeen proteasomal subunit genes in patients with PMF (PSMA1, PSMA2, PSMA6, PSMA7, PSMB4, PSMB5, PSMB6, PSMB7, PSMC2, PSMC3, PSMD10, PSMD14, PSMD4, PSMD8, PSMD9, PSMG1, and PSMG3 (FDR 〈 0.05). Only one gene, PSMB4, was significantly downregulated (FDR 〈 0.05). Global pathway analysis showed a significant upregulation of the proteasome degradation pathway (adjusted P 〈 0.03), and the network analysis revealed a significant subnetwork only composed of upregulated genes (CDC25A, CDC6, CDT1, GMNN, ORC1L, PSMA6, PSMA7, PSMB5, PSMB6, PSMB7, PSMC3, PSMD5, PSMD8, PSMD9, PSMD14) of which 10 were proteasomal genes (Z=2.6). Conclusion: In this study, we have for the first time described the gene signature of the proteasome in peripheral blood cells from patients with myelofibrosis and patients with ET and PV. Using single gene analysis, global pathway and network analysis, we found significant upregulation of the proteasomal transcriptome in patients with PMF as compared to patients with ET and PV as a group. This study has added new important information of the genes involved in the upregulation of the proteasome degradation pathway in these patients. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
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  • 8
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4119-4119
    Abstract: Abstract 4119 Introduction: Several new treatment strategies within the Philadelphia-negative chronic myeloproliferative neoplasms CMPNs are beeing explored, among these, agents belonging to the class of HDAC-inhibitors, including givinostat (ITF2357) and vorinostat (suberoylanilide hydroxamic acid (SAHA)). These agents are inhibitors of class I and II HDAC enzymes, promoting cell-cycle arrest and apoptosis of cancer cells. Recently, enhanced histone deacetylase (HDAC) enzyme activity has been found in CD34+ cells from patients with primary myelofibrosis (PMF), enzyme activity levels highly exceeding those recorded in essential thrombocythemia (ET) and polycythemia vera (PV). The raised levels correlated to the degree of splenomegaly, suggesting that HDAC might be recruited as ET or PV progresses into myelofibrosis or PMF progresses into a more advanced stage. In order to further describe HDACs in CMPNs, we have assessed gene expression of several HDACs in a larger cohort of patients with ET, PV and PMF. Patients and Methods: Gene expression microarray studies have been performed on control subjects (n=21) and patients with ET (n =19), PV (n=41), and PMF (n=9). Most patients were studied on cytoreductive therapy, which for the large majority included hydroxyurea. Gene expression profiles were generated using Affymetrix HG-U133 2.0 Plus microarrays recognizing 54675 probe sets (38.500 genes). Total RNA was purified from whole blood and amplified to biotin-labeled aRNA and hybridized to microarray chips. Results: We identified 20439, 25307, 17417, and 25421 probe sets which were differentially expressed between controls and patients with ET, PV, PMF, and CPMNs as a whole, respectively (false discovery rate (FDR) adjusted p values 〈 0.05). Several HDAC-genes were significantly deregulated. In ET patients upregulated genes included HDAC5, HDAC9 and downregulated genes HDAC1, HDAC4, HDAC7. In PV-patients HDAC4, HDAC5, HDAC6, HDAC9, and HDAC11 genes were upregulated, and HDAC1, HDAC7, HDAC9, and HDAC11 genes were downregulated. In PMF -patients HDAC4, HDAC6, HDAC9, and HDAC11 genes were upregulated, and HDAC1 and HDAC7 were downregulated. Compared to controls the CMPN-patients as a group exhibited upregulation of HDAC4, HDAC5, HDAC6, HDAC9, and HDAC11 genes. The HDAC genes 9 and 11 were significantly upregulated in both ET, PV, PMF, and CMPNs as a whole, the highest values being recorded in patients with ET, PMF, and CMPNs as compared to controls. In regard to HDAC9 gene expression, the fold changes (FC) were 1.3, 1.2, 1.3, and 1.3 for ET, PV, PMF, and CMPNs, respectively; for HDAC11 the highest values were recorded in patients with ET with the following FCs 1.2, 1.1, 1.1, 1.1 for ET, PV, PMF, and CMPNs, respectively; FDR adjusted p values 〈 0.05). Within patients, the HDAC6-gene was also differentially expressed with the highest levels being recorded in patients with PMF (FC 1.2, FDR adjusted p values 〈 0.01). When comparing non-PMF-patients with PMF-patients, a significant upregulation of the HDAC2-gene was found in PMF patients (FC 1.5, FDR adjusted p-value=0.007), whereas the HDAC7-gene was significantly downregulated (FC -1.3, FDR adjusted p-value=0,001. Discussion and Conclusions: Using global gene expression profiling of whole-blood from patients with CMPNs, we have found a pronounced deregulation of HDAC-genes, involving significant upregulation of the HDAC-genes 9 and 11 with the highest expression levels being found in patients with ET, in PMF (HDAC9) and in CMPNs both HDAC9 and HDAC11. Furthermore, we have identified that the HDAC-6 gene is progressively expressed in patients with ET, PV, and PMF reflecting a steady accumulation of abnormally expressed HDAC-6 during disease evolution. Our results lend further support to HDACs as important epigenetic targets in the future treatment of patients with CMPNs. Since the highest expression levels of HDAC-genes was recorded in ET (HDACs 9 and 11), in PMF (HDAC9) and in the whole CMPN-group both HDACs 9 and 11, their downregulation by HDAC-inhibitors might be associated with decreased disease activity including reduction of splenomegaly in MF. Preliminary data indicate that enlarged spleens are diminished in subsets of patients during treatment with HDAC-inhibitors. Studies are in progress on the impact of vorinostat on global gene expression profiling, including HDAC- gene expression subclasses in patients with CMPNs. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
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  • 9
    In: Blood, American Society of Hematology, Vol. 114, No. 22 ( 2009-11-20), p. 1586-1586
    Abstract: Abstract 1586 Poster Board I-612 Background Mutations in the nucleophosmin 1 (NPM1) gene represent the most frequent gene mutations in acute myeloid leukemia (AML), with highest frequency (50-60%) in cytogenetically normal (CN)-AML. Several studies have shown the applicability and prognostic value of an NPM1 mutation (NPM1mut)-based assay for detection of minimal residual disease (MRD). So far, there are no studies evaluating the prognostic value of NPM1mut MRD levels in a large controlled cohort of AML patients (pts) enrolled on prospective clinical trials. Aims To evaluate the prognostic value of NPM1mut MRD levels in younger (16 to 60 years) AML pts harbouring NPM1 mutations type A, B or D, and to assess the influence of concurrent FLT3 internal tandem duplications (ITD). Methods All pts were enrolled in the prospective AMLSG 07-04 and AML HD98A treatment trials. Treatment comprised double induction therapy with ICE (idarubicin, cytarabine, etoposide) followed by high-dose cytarabine-based consolidation, autologous or allogeneic stem cell transplantation. Levels of NPM1mut expression ratios, defined as NPM1mut copies per 104ABL copies, were determined by RQ-PCR using TaqMan technology. Dilution series showed a maximum sensitivity of 10-6 and high specificity as no wildtype NPM1 could be detected. Results A total of 1079 samples, [bone marrow (BM), n=1062; peripheral blood, n= 17) from 212 pts were analyzed at diagnosis, after each treatment cycle, during follow-up and at relapse (median number of samples per pt, n=4; range, 1-16). NPM1mut expression ratios at diagnosis varied between 1.1×104 and 10.4×106 (median, 6.9×105). Pretreatment transcript levels were not associated with clinical characteristics (e.g., age, white cell counts, BM blasts) and did not impact on relapse-free (RFS) and overall survival (OS). Following the first induction cycle, the median decrease of the MRD level ratio normalized to pretreatment levels was 4.21×10-3, independent of the presence of concurrent FLT3-ITD (p=0.39). After the 2nd induction cycle, the median reduction of MRD levels was significantly stronger in the FLT3-ITDneg group (6.75×10-5) compared with the FLT3-ITDpos group (4.19×10-4) (p=0.003) and this differential effect was observed throughout consolidation therapy. For evaluation of the prognostic impact of NPM1mut MRD levels, we compared patients achieving PCR-negativity with those with positive values at different checkpoints. The first reliable checkpoint was after double-induction therapy: the cumulative incidence of relapse (CIR) at 4 years of PCR-negative patients (n=27) was 0% compared with 48% (SE, 4.4%, p 〈 0.00001) for PCR-positive patients (n=105). This translated into a significant better OS (p=0.0005). The second checkpoint was after completion of consolidation therapy (first measurement during follow-up period). Again, 4-year CIR was significantly (p 〈 .00001) lower in the PCR-negative group with 11% (SE, 6.5%) compared with 51% (SE, 4.8%) in PCR-positive patients, again translating in a significantly better OS (p 〈 .00001). In addition, the level of NPM1mut expression ratio at any time point examined after completion of therapy correlated with the risk of relapse, since 20 of 22 pts with a value above 1000 NPM1mut/104ABL copies relapsed after a median interval of 90 days (range, 11-709 days). The remaining 2 pts had increasing levels at last follow-up but are still in continuous complete remission (CR). In a few cases relapse prediction appeared to be limited due to inadequate increase of NPM1mut expression levels or to loss of NPM1 mutation at the time of relapse (n=5). On the other hand, we observed a number of pts (n=17) in continuous CR who had intermittent low ( 〈 1000 NPM1mut/104ABL copies) NPM1mut expression ratios. Conclusions The levels of NPM1mut expression at two distinct checkpoints, after double induction therapy and after completion of consolidation therapy, can be used as a prognostic factor in NPM1mut AML pts. The adverse outcome of pts carrying a concurrent FLT3-ITD is reflected by a significant lower reduction of tumor burden. Disclosures Göhring: Celgene Corp.:. Schlegelberger:Celgene Corp.:.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2009
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  • 10
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4115-4115
    Abstract: Abstract 4115 Introduction: The classical Philadelphia-negative chronic myeloproliferative neoplasms (CMPNs) encompass polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). After several years, a proportion of patients with PV may develop increasing splenomegaly and bone marrow fibrosis to terminate in postpolycythemic myelofibrosis, which then has a very poor prognosis with median survival of only a few years. A high proportion of the ET-population has been shown to have prefibrotic PMF or a “PV-like” phenotype, which after a variable time may terminate in myelofibrosis with myeloid metaplasia (MMM). Although the concept of prefibrotic myelofibrosis as a separate disease entity to be distinguished from ET by distinct histopathological features has been questioned, it seems logical that a continuum exists from “early” myelofibrosis with no or minimal bone marrow fibrosis to the advanced stage of myelofibrosis with myeloid metaplasia. Accordingly, a new concept of these diseases as a biological continuum from ET over PV to PMF has emerged. Indeed, this biological continuum reflects the various clinical stages as also described for chronic myelogenous leukaemia (CML) – a chronic stable phase (ET-PV), an accelerated phase (transitional phase), and a terminal myelofibrosis or blast phase of the disease (PMF-BP). It is evident that the JAK2 V617F mutational load is an important determinant of phenotype, but other genetic and epigenetic events contribute to the phenotypic presentation. Several gene expression studies have identified genes which might be of pathogenetic relevance for the development of CMPNs. However, no study has applied an unsupervised method as Principal Component Analysis (PCA) to discover unknown trends in the data. We have carried out gene expression profiling with PCA to ascertain if this analysis might unravel distinct grouping of disease entities supporting the biological continuum from early ET over PV to the advanced myelofibrosis phase. Patients and Methods: Using HG-U133 Plus 2.0 microarray from Affymetrix, recognizing 54675 probe sets (38500 genes), gene expression microarray studies have been performed on control subjects (n=21) and patients with ET (n =19), PV (n=41), and PMF (n=9). An unsupervised statistical method, PCA, which is an exploratory tool used to uncover unknown trends in the data based on gene expression profiles, was applied to the data. Results: The results from the PCA confirm the hypothesis of a biological continuum from control subjects over ET to PV and finally PMF (figure 1). The figure also reveals that patients with PV in a transitional stage (PVtrans) with pancytosis, huge splenomegaly, and bone marrow fibrosis have a gene profile between PV and PMF. Furthermore, single gene analysis revealed that several genes are highly dysregulated in patients with ET, PV, and PMF compared to control subjects even after correcting for multiple testing. Discussion and Conclusions: Using global gene expression profiling with PCA in patients with different CMPNs (ET, PV, PMF), we have yielded support to the concept of a biological continuum from early ET to the advanced myelofibrosis stage. Studies are in progress to identify single genes or clusters of genes accounting for the biological continuum and accordingly the progression from ET over PV to myelofibrosis. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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