Human T-cell leukemia virus type-1 Tax oncoprotein regulates G-protein signaling.
Twizere, Jean-Claude ; ; Boxus, Mathieu et al
in Blood (2007), 109(3), 1051-60
Human T-cell leukemia virus type-1 (HTLV-1) is associated with adult T-cell leukemia (ATL) and neurological syndromes. HTLV-1 encodes the oncoprotein Tax-1, which modulates viral and cellular gene ... [more ▼]
Human T-cell leukemia virus type-1 (HTLV-1) is associated with adult T-cell leukemia (ATL) and neurological syndromes. HTLV-1 encodes the oncoprotein Tax-1, which modulates viral and cellular gene expression leading to T-cell transformation. Guanine nucleotide-binding proteins (G proteins) and G protein-coupled receptors (GPCRs) constitute the largest family of membrane proteins known and are involved in the regulation of most biological functions. Here, we report an interaction between HTLV-1 Tax oncoprotein and the G-protein beta subunit. Interestingly, though the G-protein beta subunit inhibits Tax-mediated viral transcription, Tax-1 perturbs G-protein beta subcellular localization. Functional evidence for these observations was obtained using conditional Tax-1-expressing transformed T-lymphocytes, where Tax expression correlated with activation of the SDF-1/CXCR4 axis. Our data indicated that HTLV-1 developed a strategy based on the activation of the SDF-1/CXCR4 axis in the infected cell; this could have tremendous implications for new therapeutic strategies. [less ▲]Detailed reference viewed: 250 (40 ULg)
Diffuse Large B-cell Lymphomas of the waldeyer's ring frequently have a germinal center-like phenotype: a clinico-pathological study of 209 patients from the groupe d'étude des lymphomes de l'adulte (GELA).
; Bonnet, Christophe ; et al
in Blood (2007)Detailed reference viewed: 10 (0 ULg)
What is the role for donor NK cells after nonmyeloablative conditioning ?
Baron, Frédéric ; ; et al
in Blood (2007), 110
Background: The potential role of donor NK cells after nonmyeloablative conditioning for allogeneic hematopoietic cell transplantation (HCT) is not defined. We investigated the impact of the kinetics of ... [more ▼]
Background: The potential role of donor NK cells after nonmyeloablative conditioning for allogeneic hematopoietic cell transplantation (HCT) is not defined. We investigated the impact of the kinetics of donor NK cell engraftment as well as the impact of missing recipient KIR ligands and the number of donor inhibitory and activating KIR genes on HCT outcomes in 282 patients (153 with HLA-matched related donors and 129 with unrelated donors) conditioned with 2 Gy TBI +/– fludarabine. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. Diagnoses were hematological malignancies (n=274) or solid tumors (8). Methods: NK cells were isolated from peripheral blood by flow cytometry on days 14, 28 and 42 after HCT. The proportions of cells of donor and host origin were assessed by FISH or by VNTR-PCR. High-resolution HLA-typing was performed using oligonucleotide probe and/or direct sequencing methods. Donor KIR genotyping was performed using a commercial PCR-SSP kit (Invitrogen) following manufacturers protocol. Results: High numbers of T (P=0.01) and CD34+ (P=0.009) cells in the graft, as well as lower numbers of donor inhibitory KIR genes (P=0.01) were each associated with higher levels of donor NK cell chimerism. There was a suggestion of an association between lower numbers of activating KIR genes and higher CD56 chimerism, however this was not statistically significant. NK cell chimerism levels were comparable in patients who had all KIR ligands present vs. in those who were missing any ligand, and there was no association between the specific missing ligand and NK chimerism. A day-14 NK cell chimerism level of < 50% was associated with increased risks of graft rejection (P=.009). Modeling chimerism levels as a continuous linear variable, there was no association between NK cell chimerism levels on day 14 and occurrence of grade II-IV acute GVHD. In contrast, high levels of donor NK cell chimerism on days 14–42 were associated with a lower risk of relapse (P=0.006) and better progression-free survival (P=0.003) in time-dependent analyses. The qualitative associations between donor NK cell chimerism and graft rejection, GVHD, relapse or progression-free survival did not change after adjustment for the presence of recipient KIR ligands nor after adjustment for the number of donor inhibitory or activating KIR genes. Finally, the 3-year cumulative incidence of relapse was 42% in patients who have all ligand for donor NK cell KIR, versus 38% in patients who miss one or more ligand for donor NK cell KIR (adjusted hazard ratio = 1.05; 95% confidence interval 0.65–1.68; p=0.85). Conclusions: Robust engraftment of donor NK cells correlated with low risk of graft rejection, low risk of relapse and high progression-free survival but not with acute GVHD. The clinical importance of donor KIR inhibitory and activating genes on post-transplant donor NK chimerism merits further study. Footnotes Disclosure: Off Label Use: Fludarabine, Mycophenolate mofetil, Cyclosporine. [less ▲]Detailed reference viewed: 9 (0 ULg)
Array-CGH analysis of T-ALL patients and cell lines
; ; et al
in Blood (2006, November 16), 108(11, Part 2), 195-196Detailed reference viewed: 39 (1 ULg)
New role for ATP P2X1 receptors in the control of neutrophil apoptosis and respiratory burst activity.
Faccinetto, Céline ; Lecut, Christelle ; Greimers, Roland et al
in Blood (2006), 108(11, Part 1), 1647Detailed reference viewed: 30 (11 ULg)
Use of glycosylated recombinant human G-CSF (lenograstim) during and/or after induction chemotherapy in patients 61 years of age and older with acute myeloid leukemia : final results of AML-13, a randomized phase-3 study
; ; et al
in Blood (2005), 106Detailed reference viewed: 17 (4 ULg)
Hematopoietic cell transplantation (HCT)-specific comorbidity index: a new tool for risk assessment before allogeneic HCT.
; ; et al
in Blood (2005), 106(8), 2912-9
We previously reported that the Charlson Comorbidity Index (CCI) was useful for predicting outcomes in patients undergoing allogeneic hematopoietic cell transplantation (HCT). However, the sample size of ... [more ▼]
We previously reported that the Charlson Comorbidity Index (CCI) was useful for predicting outcomes in patients undergoing allogeneic hematopoietic cell transplantation (HCT). However, the sample size of patients with scores of 1 or more, captured by the CCI, did not exceed 35%. Further, some comorbidities were rarely found among patients who underwent HCT. Therefore, the current study was designed to (1) better define previously identified comorbidities using pretransplant laboratory data, (2) investigate additional HCT-related comorbidities, and (3) establish comorbidity scores that were suited for HCT. Data were collected from 1055 patients, and then randomly divided into training and validation sets. Weights were assigned to individual comorbidities according to their prognostic significance in Cox proportional hazard models. The new index was then validated. The new index proved to be more sensitive than the CCI since it captured 62% of patients with scores more than 0 compared with 12%, respectively. Further, the new index showed better survival prediction than the CCI (likelihood ratio of 23.7 versus 7.1 and c statistics of 0.661 versus 0.561, respectively, P < .001). In conclusion, the new simple index provided valid and reliable scoring of pretransplant comorbidities that predicted nonrelapse mortality and survival. This index will be useful for clinical trials and patient counseling before HCT. [less ▲]Detailed reference viewed: 25 (0 ULg)
No role for chemoradiotherapy when compared with chemotherapy alone in elderly patients with localized low risk aggressive lymphoma: final results of the LNH93-4 GELA study.
Fillet, Georges ; Bonnet, Christophe ; et al
in Blood (2005), 106 (15)Detailed reference viewed: 15 (1 ULg)
Nonmyeloablative stem cell transplantation with CD8-depleted or unmanipulated peripheral blood stem cells: a prospective randomized trial.
WILLEMS, Evelyne ; CASTERMANS, Emilie ; Baron, Frédéric et al
in Blood (2005), 106 (1075)Detailed reference viewed: 15 (6 ULg)
Expression analyses identify MLL as a prominent target of 11q23 amplification and support an etiologic role for MLL gain of function in myeloid malignancies
; ; et al
in Blood (2004), 103(1), 229-235
MLL amplification was recently recognized as a recurrent aberration in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), associated with adverse prognosis and karyotype complexity. Here we ... [more ▼]
MLL amplification was recently recognized as a recurrent aberration in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), associated with adverse prognosis and karyotype complexity. Here we present detailed results of fluorescence in situ hybridization (FISH) and expression analyses of MLL and 5 selected 11q candidate oncogenes (CBL, DDX6, ETS1, FLI1, and PLZF) in 31 patient samples and one cell line with 11q23 gain. FISH analyses revealed that the 11q23 amplicon invariably encompassed MLL, DDX6, ETS1, and FLI1, whereas expression analyses identified MLL and DDX6 as the most differentially expressed genes among samples with and without 11q23 copy gain or amplification. In MLL-amplified samples, a significant transcriptional up-regulation of MEIS1, PROML1, ADAM10, NKG2D, and ITPA was noted. Further analyses, designed to elucidate a possible role of the 11q overexpressed genes (MLL, DDX6, FLI1, and ETS1) in unselected MDS and AML samples, revealed a significant upregulation of MLL in MDS. Our findings confirm the MLL gene as a prominent target of 11q23 amplification and provide further evidence for an etiologic role for MLL gain of function in myeloid malignancies. In addition, our results indicate that the transcriptional program associated with MLL rearrangements and MLL overexpression displays significant similarities. [less ▲]Detailed reference viewed: 10 (0 ULg)
Severe deficiency of glycoprotein VI in a patient with gray platelet syndrome.
; ; et al
in Blood (2004), 104(1), 107-14
We report a novel case of gray platelet syndrome (GPS) where a severe deficiency of the platelet collagen receptor, glycoprotein (GP) VI, accompanies classical symptoms of a low platelet count and ... [more ▼]
We report a novel case of gray platelet syndrome (GPS) where a severe deficiency of the platelet collagen receptor, glycoprotein (GP) VI, accompanies classical symptoms of a low platelet count and platelets lacking alpha-granules. Dense granules were normally present. Platelet aggregation with collagen was severely decreased, as was the response to convulxin (Cvx), a GPVI agonist. Quantitative analysis of GPVI using fluorescein isothiocyanate (FITC)-Cvx in flow cytometry showed its virtual absence on the patient's platelets. The GPVI deficiency was confirmed using monoclonal antibodies in Western blotting and in immunogold labeling on frozen thin sections where internal pools of GPVI were confirmed for normal platelets. The Fc receptor gamma-chain, constitutively associated with GPVI in normal platelets, was present in subnormal amounts, and the phospholipase C gamma 2-dependent activation pathway appeared to function normally. No autoantibodies to GPVI were found in the patient's serum using monoclonal antibody immobilization of platelet antigen (MAIPA). Sequencing of coding regions of the GPVI gene failed to show abnormalities, and mRNA for GPVI was present in the patient's platelets, pointing to a probable acquired defect in GPVI expression. Our results may provide a molecular explanation for the subgroup of patients with severely deficient collagen-induced platelet aggregation as previously described for GPS in the literature. [less ▲]Detailed reference viewed: 42 (2 ULg)
Kinetics of engraftment in patients with hematologic malignancies given allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning.
Baron, Frédéric ; ; et al
in Blood (2004), 104(8), 2254-62
We analyzed the kinetics of donor engraftment among various peripheral blood cell subpopulations and their relationship to outcomes among 120 patients with hematologic malignancies given hematopoietic ... [more ▼]
We analyzed the kinetics of donor engraftment among various peripheral blood cell subpopulations and their relationship to outcomes among 120 patients with hematologic malignancies given hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning consisting of 2 Gy total body irradiation (TBI) with or without added fludarabine. While patients rapidly developed high degrees of donor engraftment, most remained mixed donor/host chimeras for up to 180 days after HCT. Patients given preceding chemotherapies and those given granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell (G-PBMC) grafts had the highest degrees of donor chimerism. Low donor T-cell (P = .003) and natural killer (NK) cell (P = .004) chimerism levels on day 14 were associated with increased probabilities of graft rejection. High T-cell chimerism on day 28 was associated with an increased probability of acute graft-versus-host disease (GVHD) (P = .02). Of 93 patients with measurable malignant disease at transplantation, 41 achieved complete remissions a median of 199 days after HCT; 19 of the 41 were mixed T-cell chimeras when complete remissions were achieved. Earlier establishment of donor NK-cell chimerism was associated with improved progression-free survival (P = .02). Measuring the levels of peripheral blood cell subset donor chimerisms provided useful information on HCT outcomes and might allow early therapeutic interventions to prevent graft rejection or disease progression. [less ▲]Detailed reference viewed: 4 (0 ULg)
Graft-versus-tumor effects after allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning
Baron, Frédéric ; ; et al
in Blood (2004), 104
We have used a nonmyeloablative conditioning regimen consisting of 2 Gy total body irradiation +/– fludarabine, 30 mg/m²/day x 3 days, to condition elderly or ill patients (pts) with hematological ... [more ▼]
We have used a nonmyeloablative conditioning regimen consisting of 2 Gy total body irradiation +/– fludarabine, 30 mg/m²/day x 3 days, to condition elderly or ill patients (pts) with hematological malignancies for allogeneic hematopoietic cell transplantation (HCT). This approach relies almost exclusively on graft-versus-tumor (GVT) effects for control of malignancy. Here, we analyzed GVT effects in 322 pts with hematological malignancies given grafts from HLA-matched related (n=192) or unrelated (n=130) donors. Grades I, II, III and IV acute GVHD were seen in 26 (8.1%), 141 (43.8%), 34 (10.6%) and 11 (3.4%) pts, respectively. Extensive chronic GVHD was seen in 181 (56.2%) pts and of these, 64 (19.9%) cases had de novo chronic GVHD. Putative GVT effects were evaluated using time-dependent Cox regression models. Of the 221 pts with measurable disease at HCT, 126 (57%) achieved complete (n=98) or partial (n=28) remissions. Multivariate analysis identified chemosensitivity for B-cell malignancies (p=.02), and tandem autologous/allogeneic HCT (p=.04) as pre-transplant factors associated with higher probabilities of achieving complete remissions (CR) after HCT. After adjusting for these factors, acute GVHD of any grade was not found to be associated with an increased probability of achieving CR. There was a trend for a higher probability of achieving CR in pts with chronic GVHD (p=.07). Progression/relapse was observed in 108 pts. Multivariate analysis identified that lower disease-risk (p=.0004), tandem autologous/allogeneic HCT (p=.02) and adapted Charlson comorbidity index (CCI) score at transplant < 3 (p=.002) resulted in significantly decreased risk of progression/relapse. After correcting for these factors, extensive chronic GVHD was associated with a decreased risk of progression/relapse (p=.006). Pts with grade 1 acute GVHD tended to have less progression/relapse (p=.07). Conversely, grade II–IV acute GVHD did not significantly affect the risk of progression/relapse. Nonrelapse mortality was observed in 70 pts. Multivariate analysis showed that lower disease-risk (p=. 001), tandem autologous/allogeneic HCT (p=.002) and CCI score at transplant < 3 (p<.0001) significantly decreased nonrelapse mortality. After adjusting for these variables, grade II (p=.04) and grade III–IV (p<.0001) acute GVHD increased nonrelapse mortality while extensive chronic GVHD did not. The 3-year probability of progression-free survival (PFS) was 38.5%. In multivariate analysis, lower disease-risk (p<.0001), tandem autologous/allogeneic HCT (p=.0008) and CCI score at transplant < 3 (p<.0001) resulted in significantly better PFS. After adjusting for theses variables, grade 1 acute GVHD (p=.02) and chronic extensive GVHD (p=.003) were both associated with significantly better PFS, while grade III–IV acute GVHD (p<.0001) was associated with decreased PFS. In summary, chronic GVHD in pts given nonmyeloablative conditioning was associated with substantial GVT effects which led to improved PFS. Conversely, any potential GVT benefits from grade II–IV acute GVHD were offset by higher nonrelapse mortality resulting in worse PFS. Efforts should be directed at reducing the risk of grade II–IV acute GVHD while allowing de novo chronic GVHD for best PFS after allogeneic HCT with nonmyeloablative conditioning. [less ▲]Detailed reference viewed: 5 (0 ULg)
Sustained correction of B-cell development and function in a murine model of X-linked agammaglobulinemia (XLA) using retroviral-mediated gene transfer
; ; et al
in Blood (2004), 104(5), 1281-90
X-linked agammaglobulinemia (XLA) is a human immunodeficiency caused by mutations in Bruton tyrosine kinase (Btk) and characterized by an arrest in early B-cell development, near absence of serum ... [more ▼]
X-linked agammaglobulinemia (XLA) is a human immunodeficiency caused by mutations in Bruton tyrosine kinase (Btk) and characterized by an arrest in early B-cell development, near absence of serum immunoglobulin, and recurrent bacteria infections. Using Btk- and Tec-deficient mice (BtkTec-/-) as a model for XLA, we determined if Btk gene therapy could correct this disorder. Bone marrow (BM) from 5-fluorouracil (5FU)-treated BtkTec-/- mice was transduced with a retroviral vector expressing human Btk and transplanted into BtkTec-/- recipients. Mice engrafted with transduced hematopoietic cells exhibited rescue of both primary and peripheral B-lineage development, revocery of peritoneal B1 B cells, and correction of serum immunoglobulin M (IgM) and IgG3 levels. Gene transfer also restored T-independent type II immune responses, and B-cell antigen receptor (BCR) proliferative responses. B-cell progenitors derived from Btk-transduced stem cells exhibited higher levels of Btk expression than non-B cells; and marking studies demonstrated a selective advantage for Btk-transduced B-lineage cells. BM derived from primary recipients also rescued Btk-dependent function in secondary hosts that had received a transplant. Together, these data demonstrate that gene transfer into hematopoietic stem cells can reconstitute Btk-dependent B-cell development and function in vivo, and strongly support the feasibility of pursuing Btk gene transfer for XLA. [less ▲]Detailed reference viewed: 4 (0 ULg)
Pharmacological evaluation of BM-573, a dual thromboxane A(2) receptor antagonist and thromboxane synthase inhibitor, as potential anti-metastatic agent
; ; et al
in Blood (2003, November 16), 102(11, Part 2), 72Detailed reference viewed: 13 (4 ULg)
Antithrombotic activity of BM-573, a novel thromboxane modulator, in rat arterial thrombosis model, pig myocardial infarction model and its effect on bleeding time
Dogné, Jean-Michel ; Kolh, Philippe ; et al
in Blood (2003)Detailed reference viewed: 24 (6 ULg)
BM-613, a new thromboxane A2 antagonist, is characterized by a preferential activity on platelet thromboxane A2 receptors
Hanson, Julien ; ; et al
in Blood (2003)Detailed reference viewed: 42 (17 ULg)
Pharmacological evaluation of BM-573, a dual thromboxane A2 receptor antagonist and thromboxane synthase inhibitor, as potential anti-metastatic agent
; ; et al
in Blood (2003)Detailed reference viewed: 16 (6 ULg)
Overexpression of the platelet P2X1 ion channel in transgenic mice generates a novel prothrombotic phenotype.
Oury, Cécile ; ; et al
in Blood (2003)
This study describes transgenic mice overexpressing the human P2X(1) ion channel in the megakaryocytic cell lineage. Platelets from these mice display increased secretion and aggregation evoked by low ... [more ▼]
This study describes transgenic mice overexpressing the human P2X(1) ion channel in the megakaryocytic cell lineage. Platelets from these mice display increased secretion and aggregation evoked by low doses of collagen, convulxin, or the thromboxane A(2) mimetic U46619. Perfusing whole blood from transgenic mice over collagen fibers at a shear rate of 1000 seconds(-1) resulted in increased P2X(1)-dependent aggregate formation and phosphatidylserine exposure. Platelet hyperreactivity to collagen was correlated with up-regulated extracellular signal-regulated kinase 2 (ERK2) phosphorylation. In a viscometer, shear stress caused potent aggregation of transgenic platelets under conditions in which wild-type platelets did not aggregate. In an in vivo model of thromboembolism consisting of intravenous injection of a low dose of collagen plus epinephrine, transgenic mice died more readily than wild-type mice. Preinjection of U0126 not only fully protected transgenic mice against thrombosis, it also enhanced the survival of wild-type mice injected with a higher collagen dose. Hence, the platelet P2X(1) ion channel plays a role in hemostasis and thrombosis through its participation in collagen-, thromboxane A(2)-, and shear stress-triggered platelet responses. Activation of the ERK2 pathway is instrumental in these processes. [less ▲]Detailed reference viewed: 28 (2 ULg)
Intensive conventional chemotherapy (ACVBP regimen) compared with standard CHOP for poor-prognosis aggressive non-Hodgkin lymphoma
; ; et al
in Blood (2003), 102(13), 4284-4289
We conducted a randomized trial to compare the intensive conventional chemotherapy regimen ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, prednisone) with standard CHOP (cyclophosphamide ... [more ▼]
We conducted a randomized trial to compare the intensive conventional chemotherapy regimen ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, prednisone) with standard CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) in previously untreated patients with poor-risk aggressive lymphoma. Patients aged 61 to 69 years who had aggressive non-Hodgkin lymphoma with at least one prognostic factor of the age-adjusted international prognostic index (IPI) were included. ACVBP consisted of an induction phase of intensified chemotherapy and central nervous system (CNS) prophylaxis followed by a sequential consolidation phase. Of the 708 patients registered for the study, 635 were eligible. The rate of complete response was 58% in the ACVBP group and 56% in the CHOP group (P =.5). Treatment-related death occurred in 13% of the ACVBP group and 7% of the CHOP group (P =.014). At 5 years, the event-free survival was 39% in the ACVBP group and 29% in the CHOP group (P =.005). The overall survival was significantly longer for patients treated with ACVBP, at 5 years it was 46% compared with 38% for patients treated with CHOP (P =.036). CNS progressions or relapses were more frequent in the CHOP group (P =.004). Despite higher toxicity, the ACVBP regimen, used as first-line treatment for patients with poor-risk aggressive lymphoma, is superior to standard CHOP with regard to both event-free survival and overall survival. (C) 2003 by The American Society of Hematology. [less ▲]Detailed reference viewed: 102 (0 ULg)