| 11. |
- Andersson, Helena M., et al.
(författare)
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Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain
- 2010
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 115:23, s. 4878-4885
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Tidskriftsartikel (refereegranskat)abstract
- Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S-deficient plasma. Of 27 variants tested initially, only one, protein S D95A (within the EGF1 domain), was largely devoid of functional APC cofactor activity. Protein S D95A was, however, gamma-carboxylated and bound phospholipids with an apparent dissociation constant (Kd(app)) similar to that of wildtype (WT) protein S. In a purified assay using FVa R506Q/R679Q, purified protein S D95A was shown to have greatly reduced ability to enhance APC-induced cleavage of FVa Arg306. It is concluded that residue Asp95 within EGF1 is critical forAPC cofactor function of protein S and could define a principal functional interaction site for APC. (Blood. 2010;115(23):4878-4885)
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| 12. |
- Aplenc, Richard, et al.
(författare)
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Effect of body mass in children with hematologic malignancies undergoing allogeneic bone marrow transplantation.
- 2014
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 123:22, s. 3504-11
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Tidskriftsartikel (refereegranskat)abstract
- The rising incidence of pediatric obesity may significantly affect bone marrow transplantation (BMT) outcomes. We analyzed outcomes in 3687 children worldwide who received cyclophosphamide-based BMT regimens for leukemias between 1990 and 2007. Recipients were classified according to age-adjusted body mass index (BMI) percentiles as underweight (UW), at risk of UW (RUW), normal, overweight (OW), or obese (OB). Median age and race were similar in all groups. Sixty-one percent of OB children were from the United States/Canada. Three-year relapse-free and overall survival ranged from 48% to 52% (P = .54) and 55% to 58% (P = .81) across BMI groups. Three-year leukemia relapses were 33%, 33%, 29%, 25%, and 21% in the UW, RUW, normal, OW, and OB groups, respectively (P < .001). Corresponding cumulative incidences for transplant-related mortality (TRM) were 18%, 19%, 21%, 22%, and 28% (P < .01). Multivariate analysis demonstrated a decreased risk of relapse compared with normal BMI (relative risk [RR] = 0.73; P < .01) and a trend toward higher TRM (RR = 1.28; P = .014). BMI in children is not significantly associated with different survival after BMT for hematologic malignancies. Obese children experience less relapse posttransplant compared with children with normal BMI; however, this benefit is offset by excess in TRM.
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| 13. |
- Argiropoulos, Bob, et al.
(författare)
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Linkage of the potent leukemogenic activity of Meis1 to cell-cycle entry and transcriptional regulation of cyclin D3.
- 2010
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 115:20, s. 4071-82
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Tidskriftsartikel (refereegranskat)abstract
- MEIS1 is a three-amino acid loop extension class homeodomain-containing homeobox (HOX) cofactor that plays key roles in normal hematopoiesis and leukemogenesis. Expression of Meis1 is rate-limiting in MLL-associated leukemias and potently interacts with Hox and NUP98-HOX genes in leukemic transformation to promote self-renewal and proliferation of hematopoietic progenitors. The oncogenicity of MEIS1 has been linked to its transcriptional activation properties. To further reveal the pathways triggered by Meis1, we assessed the function of a novel engineered fusion form of Meis1, M33-MEIS1, designed to confer transcriptional repression to Meis1 target genes that are otherwise up-regulated in normal and malignant hematopoiesis. Retroviral overexpression of M33-Meis1 resulted in the rapid and complete eradication of M33-Meis1-transduced normal and leukemic cells in vivo. Cell-cycle analysis showed that M33-Meis1 impeded the progression of cells from G(1)-to-S phase, which correlated with significant reduction of cyclin D3 levels and the inhibition of retinoblastoma (pRb) hyperphosphorylation. We identified cyclin D3 as a direct downstream target of MEIS1 and M33-MEIS1 and showed that the G(1)-phase accumulation and growth suppression induced by M33-Meis1 was partially relieved by overexpression of cyclin D3. This study provides strong evidence linking the growth-promoting activities of Meis1 to the cyclin D-pRb cell-cycle control pathway.
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| 14. |
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| 15. |
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| 16. |
- Astermark, Jan, et al.
(författare)
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The polygenic nature of inhibitors in hemophilia A: results from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort.
- 2013
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 121:8, s. 1446-1454
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Tidskriftsartikel (refereegranskat)abstract
- Studies of determinants of development of inhibitory antibodies to factor VIII in people with hemophilia A indicate a complex process involving multiple factors. The Hemophilia Inhibitor Genetics Study Combined Cohort was formed to extend understanding of the genetic background of risk. The study group contains 833 subjects from three independent cohorts: brother pairs and singletons with and without a history of inhibitors, as well as 104 brother pairs discordant for inhibitor status. Using an Illumina iSelect platform, 13,331 SNPs from 1,081 genes, primarily immune response and immune modifier genes, were typed. Each cohort was analyzed separately with results combined using a meta-analytic technique. After adjustment for potential confounders, 53 SNPs were significant predictors of inhibitor status using the criteria of odds ratios (OR) in the same direction in all cohorts, or allowing for a 20% interval around an OR of 1 in one of the three, and significant in at least two. Of the 53, 13 markers had meta p-values of <0.001. Eight of the 53 were significant predictors among the discordant pairs. Results support the complexity of the immune response, and encourage further research with the goal of understanding the pathways involved.
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| 17. |
- Attarbaschi, Andishe, et al.
(författare)
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Limited stage I disease is not necessarily indicative of an excellent prognosis in childhood anaplastic large cell lymphoma.
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 117:21, s. 5616-9
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Tidskriftsartikel (refereegranskat)abstract
- Data on incidence, characteristics, and prognosis in stage I childhood anaplastic large cell lymphoma are scarce. Of 463 patients enrolled in the international ALCL99 trial, 36 (8%) had stage I disease and were treated with a prephase chemotherapy, followed by either 3 chemotherapy courses in case of initial complete resection (6 patients) or otherwise by 6 courses of chemotherapy (30 patients). Disease localization was to the peripheral lymph nodes in 26, soft tissue mass in 8, and solitary bone and bronchial disease in 1 patient each. Of the 6 patients with complete resection, none experienced relapse, whereas of the 30 remaining stage I patients, 9 (30%) relapsed, including in all cases a new site of disease involvement and including 3 of 5 anaplastic lymphoma kinase-negative patients. In summary, the failure rate for incompletely resected stage I disease was similar to that for patients with stage II and stage III/IV disease. Whether anaplastic lymphoma kinase negativity contributed to this moderate outcome has to be proven prospectively. This study was registered at www.clinicaltrials.gov as NCT00006455.
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| 18. |
- Aurelius, Johan, 1980, et al.
(författare)
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Monocytic AML cells inactivate antileukemic lymphocytes: role of NADPH oxidase/gp91(phox) expression and the PARP-1/PAR pathway of apoptosis.
- 2012
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 119:24, s. 5832-7
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Tidskriftsartikel (refereegranskat)abstract
- Dysfunction of T cells and natural killer (NK) cells has been proposed to determine the course of disease in acute myeloid leukemia (AML), but only limited information is available on the mechanisms of lymphocyte inhibition. We aimed to evaluate to what extent human malignant AML cells use NADPH oxidase-derived reactive oxygen species (ROS) as an immune evasion strategy. We report that a subset of malignant myelomonocytic and monocytic AML cells (French-American-British [FAB] classes M4 and M5, respectively), recovered from blood or BM of untreated AML patients at diagnosis, expressed the NADPH oxidase component gp91(phox). Highly purified FAB M4/M5 AML cells produced large amounts of ROS on activation and triggered poly-[ADP-ribose] polymerase-1-dependent apoptosis in adjacent NK cells, CD4(+) T cells, and CD8(+) T cells. In contrast, immature (FAB class M1) and myeloblastic (FAB class M2) AML cells rarely expressed gp91(phox), did not produce ROS, and did not trigger NK or T-cell apoptosis. Microarray data from 207 AML patients confirmed a greater expression of gp91(phox) mRNA by FAB-M4/M5 AML cells than FAB-M1 cells (P < 10(-11)) or FAB-M2 cells (P < 10(-9)). Our data are suggestive of a novel mechanism by which monocytic AML cells evade cell-mediated immunity.
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| 19. |
- Avagyan, Serine, et al.
(författare)
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Quantitative trait mapping reveals a regulatory axis involving peroxisome proliferator-activated receptors, PRDM16, transforming growth factor-β2 and FLT3 in hematopoiesis.
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 118:23
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoiesis is the process whereby BM HSCs renew to maintain their number or to differentiate into committed progenitors to generate all blood cells. One approach to gain mechanistic insight into this complex process is the investigation of quantitative genetic variation in hematopoietic function among inbred mouse strains. We previously showed that TGF-β2 is a genetically determined positive regulator of hematopoiesis. In the presence of unknown nonprotein serum factors TGF-β2, but not TGF-β1 or -β3, enhances progenitor proliferation in vitro, an effect that is subject to mouse strain-dependent variation mapping to a locus on chr.4, Tb2r1. TGF-β2-deficient mice show hematopoietic defects, demonstrating the physiologic role of this cytokine. Here, we show that TGF-β2 specifically and predominantly cell autonomously enhances signaling by FLT3 in vitro and in vivo. A coding polymorphism in Prdm16 (PR-domain-containing 16) underlies Tb2r1 and differentially regulates transcriptional activity of peroxisome proliferator-activated receptor-γ (PPARγ), identifying lipid PPAR ligands as the serum factors required for regulation of FLT3 signaling by TGF-β2. We furthermore show that PPARγ agonists play a FLT3-dependent role in stress responses of progenitor cells. These observations identify a novel regulatory axis that includes PPARs, Prdm16, and TGF-β2 in hematopoiesis.
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| 20. |
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