GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Bruns, Ingmar  (5)
  • Czibere, Akos G.  (5)
  • 2005-2009  (5)
  • 1
    Online Resource
    Online Resource
    Molecular Signature of Distinct CD34+ Hematopoietic Stem and Progenitor Cell Subsets of Patients with CML in Chronic Phase.
    American Society of Hematology ; 2007
    In:  Blood Vol. 110, No. 11 ( 2007-11-16), p. 3170-3170
    Details
    In: Blood, American Society of Hematology, Vol. 110, No. 11 ( 2007-11-16), p. 3170-3170
    Abstract: During the last decade, chronic myeloid leukemia (CML) has been mainly characterized by the reciprocal translocation between chromosomes 9 and 22, resulting in the formation of the protooncogene BCR-ABL. This constitutively active tyrosine kinase is widely considered as the cause of the disease. Even though BCR-ABL transcripts are found in every dividing hematopoietic cell and thus, the disease is likely to originate from a primitive stem cell, the “cell of origin” is still a matter of debate. Despite the active “leukemia stem cell” discussion, very few characteristics of the “cancer stem cell” are established to date. In order to get further molecular insights into CML stem and progenitor cells, we examined CD34+ cell subsets obtained from bone marrow of 7 patients with CML in chronic phase in comparison with 5 healthy volunteers. CD34+ cells were immunomagnetically selected and high-speed cell sorting of lineage-negative, CD34+, CD38−, hematopoietic stem cells and myeloid progenitors was performed. Progenitors were further subdivided by anti-IL-3Ralpha and anti-CD45RA staining. Following RNA extraction, a two-cycle amplification procedure was used to generate cDNA for the hybridization with Affymetrix U133A2.0 arrays. After performing smoothening spline normalization, we applied the perfect match-mismatch difference model algorithm to calculate expression values (dChip). Hierarchical cluster analysis was performed using a correlation based centroid linkage algorithm. Hereby we could discriminate the HSCs, CMPs, and MEP subsets. Corroboration of RNA expression was performed by real-time RT-PCR for selected genes. Comparing the HSC subsets of CML patients with healthy controls we found 98 differentially expressed genes. 87 genes had a lower expression level in CML HSCs whereas 11 genes had a higher one. Among the downregulated genes in CML were transcriptions factors involved in myelogenesis and proliferation and several adhesion molecules associated with homing and migration of the HSCs. On the other hand, the Leptin receptor and BCR-ABL downstream targets were found to be upregulated. Within the common myeloid progenitor (CMP) compartment 37 genes were significantly differentially regulated. Twenty genes had a higher expression level in CML CMPs, 17 genes were downlegulated. Hematopoietic cell-specific cell cycle inhibitor MS4A3 was among the significantly downregulated genes whereas genes of the retinoblastoma and E2F families as well as inhibitors of the Wnt-signaling pathway were upregulated. Looking at megakaryocte-erythrocyte progenitors (MEP) in CML, key mediators of G2-M cell cycle transition were downregulated indicating a lower proliferative capacity of this subset. No transcriptional differences have been observed between granulocyte-macrophage progenitors from CML patients and healthy volunteers. Interestingly, among all other subsets myeloperoxidase (MPO) was downregulated in the CML samples and the Leptin receptor was upregulated. Our results provide novel insights into the biology of CML and potentially provide the basis for the characterization of a candidate CML stem cell.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    URL: Article
    DOI: 10.1182/blood.V110.11.3170.3170
    RVK:
    XA 33000
    RVK:
    XA 10000
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2007
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Neuropeptides Orexin A and B Are Funktionally Aktive in CD34+ Hematopoietic Stem and Progenitor Cells.
    American Society of Hematology ; 2009
    In:  Blood Vol. 114, No. 22 ( 2009-11-20), p. 4593-4593
    Details
    In: Blood, American Society of Hematology, Vol. 114, No. 22 ( 2009-11-20), p. 4593-4593
    Abstract: Abstract 4593 Orexin receptors are involved in the regulation of sleep-wake-rhythm, food intake and energy homeostasis and it was still recently believed that their expression is restricted to the nervous system. But, during the last years orexin receptors have been detected in an increasing number of peripheral tissues. We have earlier found orexin receptor 1 and 2 expression on human CD34+ hematopoietic stem and progenitor cells. Still, the sources of their physiological ligands, the peptides orexin A and B, seemed so far to be restricted to the central nerve system. Ca2+-dependent signaling and activation of mitogen-activated protein kinase (MAPK) and extracellular signal-related kinase 1/2 (ERK1/2) pathways are considered as main downstream signaling pathways of the orexin receptors. In this study, we investigated the signaling and functional role of orexin receptors in CD34+ hematopoietic stem and progenitor cells. Using confocal fluorescence microscopy and flow cytometry we found that stimulation of purified CD34+ cells with orexin A and B led to an increase of the intracellular calcium concentration due to both calcium influx and calcium release from intracellular stores. Of interest, incubation with orexin reduces the SDF-1β-induced calcium influx. Furthermore orexin receptor stimulation led to a decrease of the intracellular cAMP concentration. Following orexin receptor stimulation with orexin A and B, we observed an initial increase of ERK1/2 phosphorylation up to 30 minutes upon incubation with orexin followed by a decrease at several time points up to 8 hours in comparison to the unstimulated control. To investigate a potential impact on the functional properties of human CD34+ cells we performed proliferation and apoptosis assays, migration and adhesion assays as well as colony forming and long-term culture assays. Remarkably, stimulation with orexin A and B led to a significant higher proportion of early pluripotent hematopoietic progenitor (CFU-GEMM) colonies and a significant reduction of erythroid precursors. A more immature phenotype of orexin-stimulated CD34+ cells is also reflected by array-based gene expression profiling. Long-term culture assays revealed a significant higher frequency of LTC-IC indicating also a more immature phenotype of orexin-stimulated cells. In line, orexin receptor stimulation led to a significant increase of the proportion of Lin-, CD34+, CD38- HSC in the G0-phase of the cell cycle. Furthermore, stimulation with orexin A and B increased the number of apoptotic cells in the Lin-, CD34+, CD38- HSC fraction and the total hematopoietic stem and progenitor population determined by flowcytometric analysis of intracellular cleaved caspase 3 content. The adhesive capacity of CD34+ cells to fibronectin and collagen coated dishes and the migratory capacity was significantly decreased upon orexin receptor stimulation. Concurrent incubation with the selective Gi-protein inhibitor pertussis toxin abrogated these effects. Given the functional impact of the orexin system on CD34+ cells, we asked if orexins are secreted locally in the bone marrow or autocrine by CD34+ cells or if they are humorally transported to the bone marrow cavity. Using FACS analysis, immunfluorescent staining and western blotting we could detect prepro-Orexin in CD34+ cells and using ELISA orexin was found in the serum obtained by bone marrow biopsies and peripheral blood. Taken together, the phenotype of orexin-stimulated hematopoietic stem and progenitor cells suggest a mobilizing effect of the orexin receptor stimulation as well as an increased repopulation capacity which might be of relevance in clinical stem cell mobilization and transplantation and is currently verified in murine models. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    URL: Article
    DOI: 10.1182/blood.V114.22.4593.4593
    RVK:
    XA 33000
    RVK:
    XA 10000
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2009
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Relevance of HLA-C Epitopes C1 and C2 for the Survival of Patients with AML and CML after Allogeneic Blood Stem Cell Transplantation.
    American Society of Hematology ; 2007
    In:  Blood Vol. 110, No. 11 ( 2007-11-16), p. 1974-1974
    Details
    In: Blood, American Society of Hematology, Vol. 110, No. 11 ( 2007-11-16), p. 1974-1974
    Abstract: BACKGROUND HLA-C epitopes can be grouped in C1C1, C1C2 or C2C2 ligands and mediate NK cell dependent immune response. Especially in haploidentical allogeneic stem cell transplantation a HLA-C ligand mismatch improves event free survival (EFS) in patients with AML known as Velardi effect. Recently, we could show in 109 CML patients that those with a C1C1 phenotype showed better overall survival (OS) and lower rates of treatment related mortality (TRM) (Fischer JC et al. J Immunology. 2007). But, the role of HLA-C ligands in allogeneic transplantations remains controversial. PATIENTS AND METHODS In this study we retrospectively analyzed a group of 88 patients with AML or CML (n=34), MDS (n=21) or lymphoid malignancies (Non-Hodgkin-Lymphoma or ALL) (n=31) receiving unrelated allogeneic blood stem cell transplantation after myeloablative and non-myeloablative conditioning regimens. HLA-C alleles were determined by DNA-based direct sequencing of all donors and recipients included into this study. RESULTS Looking at the group of 34 patients with AML or CML, the 13 recipients with a C1C1 phenotype showed increased OS compared to those with C1C2 and C2C2 phenotypes (all patients alive with a median follow-up of 154 days, range 90 to 665 days vs. a mean survival of 381 days, respectively; p=0.049). All recipients with a C1C1 phenotype received grafts with matched HLA-C alleles. Within the subgroup of patients with C1C2 or C2C2 phenotypes 6 patients had a HLA-C mismatch which was associated with significantly (p=0.016) increased OS (all patients alive with a median follow-up of 575 days, range 133 to 899) compared to matched HLA-C phenotypes (median survival of 254 days). In recipients with C1C1 phenotype the risk for TRM following HLA-C matched hematopoietic stem cell transplantation was reduced as reflected by an odds ratio of 0.13. In turn, the group receiving HLA-C mismatched grafts had a lower incidence of relapse. This effect was independent from the direction of the mismatch, graft vs. host or host vs. graft. The effects described above were not observed in patients with MDS, ALL or lymphoid malignancy. CONCLUSION The beneficial effects of a C1C1 HLA-C phenotype could be confirmed for patients with CML and AML in our patient cohort. Our data also suggest that patients with myeloid malignancies and an unfavourable C1C2 or C2C2 HLA-C phenotype benefit from a donor with HLA-C ligand mismatch.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    URL: Article
    DOI: 10.1182/blood.V110.11.1974.1974
    RVK:
    XA 33000
    RVK:
    XA 10000
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2007
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Malignant Myeloma Cells Impair Phenotype and Function of stem and Progenitor Cells.
    American Society of Hematology ; 2009
    In:  Blood Vol. 114, No. 22 ( 2009-11-20), p. 1799-1799
    Details
    In: Blood, American Society of Hematology, Vol. 114, No. 22 ( 2009-11-20), p. 1799-1799
    Abstract: Abstract 1799 Poster Board I-825 Multiple myeloma (MM) patients often present with anemia at the time of initial diagnosis. This has so far only attributed to a physically marrow suppression by the invading malignant plasma cells and the overexpression of Fas-L and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) by malignant plasma cells triggering the death of immature erythroblasts. Still the impact of MM on hematopoietic stem cells and their niches is scarcely established. In this study we analyzed highly purified CD34+ hematopoietic stem and progenitor cell subsets from the bone marrow of newly diagnosed MM patients in comparison to normal donors. Quantitative flowcytometric analyses revealed a significant reduction of the megakaryocyte-erythrocyte progenitor (MEP) proportion in MM patients, whereas the percentage of granulocyte-macrophage progenitors (GMP) was significantly increased. Proportions of hematopoietic stem cells (HSC) and myeloid progenitors (CMP) were not significantly altered. We then asked if this is also reflected by clonogenic assays and found a significantly decreased percentage of erythroid precursors (BFU-E and CFU-E). Using Affymetrix HU133 2.0 gene arrays, we compared the gene expression signatures of stem cells and progenitor subsets in MM patients and healthy donors. The most striking findings so far reflect reduced adhesive and migratory potential, impaired self-renewal capacity and disturbed B-cell development in HSC whereas the MEP expression profile reflects decreased in cell cycle activity and enhanced apoptosis. In line we found a decreased expression of the adhesion molecule CD44 and a reduced actin polymerization in MM HSC by immunofluorescence analysis. Accordingly, in vitro adhesion and transwell migration assays showed reduced adhesive and migratory capacities. The impaired self-renewal capacity of MM HSC was functionally corroborated by a significantly decreased long-term culture initiating cell (LTC-IC) frequency in long term culture assays. Cell cycle analyses revealed a significantly larger proportion of MM MEP in G0-phase of the cell cycle. Furthermore, the proportion of apoptotic cells in MM MEP determined by the content of cleaved caspase 3 was increased as compared to MEP from healthy donors. Taken together, our findings indicate an impact of MM on the molecular phenotype and functional properties of stem and progenitor cells. Anemia in MM seems at least partially to originate already at the stem and progenitor level. Disclosures Off Label Use: AML with multikinase inhibitor sorafenib, which is approved by EMEA + FDA for renal cell carcinoma.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    URL: Article
    DOI: 10.1182/blood.V114.22.1799.1799
    RVK:
    XA 33000
    RVK:
    XA 10000
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2009
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Patient Characteristics Associated with Successful Mobilization of Peripheral Blood Stem and Progenitor Cells Following Cytotoxic Chemotherapy and Peg-G-CSF Stimulation.
    American Society of Hematology ; 2007
    In:  Blood Vol. 110, No. 11 ( 2007-11-16), p. 4920-4920
    Details
    In: Blood, American Society of Hematology, Vol. 110, No. 11 ( 2007-11-16), p. 4920-4920
    Abstract: Mobilized peripheral blood stem and progenitor cells are nowadays widely used for transplantation of hematopoietic stem and progenitor cells (PBSCT). These cells can be mobilized into the peripheral blood with cytotoxic chemotherapy, cytokines or both. Currently, G-CSF is most frequently used due to its high efficacy and lack of serious toxicity. However, a serious patient-to-patient variation in the yield of peripheral blood stem and progenitor cells is a feature common of all mobilizations schemes. Therefore, factors determining the collection efficacy have been identified for G-CSF mobilization. Recently a polyethylenglycole-conjugated G-CSF (Peg-G-CSF) has been introduced which has a 12-fold longer half-life than the original compound and therefore leads to long-lasting G-CSF serum-levels after a single injection. Studies on Peg-G-CSF included only small cohorts and no attempts have been made to identify factors influencing the mobilization of blood stem and progenitor cells. Therefore, we retrospectively analyzed 101 unselected patients (66 with multiple myeloma, 26 with non-Hodgkin-lymphoma, 7 with Hodgkin’s disease, 1 with Ewing sarcoma, 1 with malignant germ cell tumor). 27% of patients had active disease, while all others where at least in partial remission after conventional chemotherapy. Patients were treated with a broad range of chemotherapy regimens. The number of cytotoxic chemotherapy cycles administered prior to the mobilization therapy ranged from 1 to 11 (median 4). Mobilization chemotherapy was followed by 6 mg or 12 mg Peg-G-CSF (median 6 mg). Median peripheral blood CD34+ cell maximum in all patients was 65.3/μl (range 0.2–1084 per μl). 12 mg Peg-G-CSF led to a significantly earlier CD34+ cell maximum in the peripheral blood compared to 6 mg Peg-G-CSF (median 13 days vs 15 days, respectively; p=0.01). Overall, a median yield of 8.5 x 10^6 CD34+ cells/kg bodyweight (range 0.2–72.4 x 10^6) was reached with a single apheresis (median, range 1–4). To search for predictors of hematopoietic stem and progenitor cell mobilization, multiple regression analysis was used and revealed CD34+ cell count/μl peripheral blood at the day of apheresis and the processed blood volume during apheresis as predictors for the CD34+ cell yield per kilogram bodyweight. Age, sex, disease type and status were not significantly related to the CD34+ cell count/μl peripheral blood nor the CD34+ cell yield. Interestingly, the number of previous chemotherapy cycles was correlated with the CD34+ cell maximum (p=0.027) with fewer chemotherapy cycles leading to a higher peripheral blood CD34+ cell count and vice versa. In contrast, radiation therapy prior to CD34+ cell mobilization led to a significantly later occurrence of the CD34+ cell maximum in the peripheral blood. Our results confirm the feasibility and efficacy of PBPC mobilization with single dose Peg-G-CSF after cytotoxic chemotherapy shown in previous clinical trials analyzing the largest patient cohort to date and predictors for successful stem cell mobilization with Peg-G-CSF could be identified.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    URL: Article
    DOI: 10.1182/blood.V110.11.4920.4920
    RVK:
    XA 33000
    RVK:
    XA 10000
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2007
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...