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In this study, we determined the respective roles of RelA and RelB NF-κB subunits in Epstein-Barr virus (EBV)-transformed B cells. Using different EBV-immortalized B-cell models, we showed that only RelA activation increased both survival and cell growth. RelB activity was induced secondarily to RelA activation and repressed RelA DNA binding by trapping the p50 subunit. Reciprocally, RelA activation repressed RelB activity by increasing expression of its inhibitor p100. To search for such reciprocal inhibition at the transcriptional level, we studied gene expression profiles of our RelA and RelB regulatable cellular models. Ten RelA-induced genes and one RelB-regulated gene, ARNTL2, were repressed by RelB and RelA, respectively. Apart from this gene, RelB signature was included in that of RelA Functional groups of RelA-regulated genes were for control of energy metabolism, genetic instability, protection against apoptosis, cell cycle and immune response. Additional functions coregulated by RelA and/or RelB were autophagy and plasma cell differentiation. Altogether, these results demonstrate a cross-inhibition between RelA and RelB and suggest that, in fine, RelB was subordinated to RelA. In the view of future drug development, RelA appeared to be pivotal in both classical and alternative activation pathways, at least in EBV-transformed B cells. [ABSTRACT FROM AUTHOR]

To clarify the relationships between marginal zone lymphomas (MZLs) and Waldenström macroglobulinemia/lymphoplasmacytic lymphomas (WM/LPLs), immunoglobulin heavy chain variable gene (IGHV) features were analyzed and the occurrence of MYD88 L265P mutations was identified in a series of 123 patients: 53 MZLs from the spleen (SMZLs), 11 from lymph nodes (NMZLs), 28 mucosa-associated lymphatic tissue (MALT) lymphomas and 31 WM/LPLs. SMZLs were characterized by overrepresentation of IGHV1-2 gene rearrangements with a canonical motif, without selection pressure and with long CDR3 segments. NMZLs had increased frequencies of IGHV3 genes. The IGHV gene was unmutated in most cases, often with long CDR3 segments. MALT lymphomas were usually associated with a mutated IGHV gene, but with the absence of selection pressure. WM/LPLs were associated with an IGHV3-23 overrepresentation and high IGHV mutation rate, with features of selection pressure and short CDR3 segments. MYD88 L265P mutations were almost restricted exclusively to WM/LPL patients. Taken all diagnoses together, all patients with MYD88 L265P mutations had an immunoglobulin M peak and almost all patients except one had bone marrow infiltration. These results demonstrate that the history of antigen exposure of the four entities studied was different and MYD88 L265P was specifically associated with WM/LPLs. WM/LPL may thus be functionally associated with constitutive nuclear factor-κB activation. [ABSTRACT FROM AUTHOR]

Recently, DNA methyltransferase 3A (DNMT3A) mutations have been identified in acute myeloid leukemia (AML), the highest frequency being found within cytogenetically normal (CN) AML. In this study, diagnostic samples from 123 adults younger than 60 years with primary CN-AML homogeneously treated in the Acute Leukemia French Association-9801 and -9802 trials were screened for mutations in DNMT3A-conserved domains by direct sequencing. Patients were also assessed for the presence of FLT3 (fms-like tyrosine kinase receptor-3), NPM1 (nucleophosmin), CEBPA, WT1 (Wilms tumor 1), IDH1 (isocitrate dehydrogenase 1) and IDH2 mutations. Thirty-eight mutations were detected in 36 patients (29%): 36 nucleotide substitutions, mostly affecting amino-acid residue R882 and two frameshift deletions. DNMT3A mutations were significantly associated with the French-American-British subtypes M4/M5 and the presence of NPM1 mutations. In the whole cohort, DNMT3A mutated patients had a shorter event-free survival (5-year EFS: 13% vs 32%, P=0.02) and overall survival (5-year OS: 23% vs 45%, P=0.02) compared with DNMT3A wild-type patients. In multivariate analysis including age, white blood cell count, NPM1/FLT3-internal tandem duplication/CEBPA risk group and DNMT3A mutational status, the presence of a DNMT3A mutation remained an independent adverse prognostic factor for EFS and OS, suggesting that testing for DNMT3A mutations could help further improve risk stratification in CN-AML. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented discussing genes encoding multiple forms of phospholipase A2 which are expressed in immature forms of human leukemic blasts.

A letter to the editor is presented discussing the role of SOCS3 in the inhibition of TPO-stimulated megakaryocytic growth in primary myelofibrosis.

MPL (or thrombopoietin receptor, TPO-R) 515 mutations have recently been described in 5–10% of primitive myelofibrosis (PMF) cases as decisive oncogenic events capable of triggering the disease. Here we report additional mutations located in exon 10 of MPL in PMF patients. We investigated whether these new mutations also lead to cell transformation. MPL exon 10 was systematically sequenced in 100 PMF patients. Seven different mutations were found in eight patients. We introduced each MPL mutant in Ba/F3 cells to determine whether they correspond to gain-of-function mutations. Only MPL W515 mutations induced (1) Ba/F3 proliferation independently of growth factors, (2) tumorigenesis in nude mice, (3) spontaneous activation of JAK/STAT, RAS/MAPK and PI3K transduction pathways and (4) increased S phase of cell cycle. Similar to all other myeloproliferative disorder oncogenic events identified to date, these results demonstrate that only the detected MPL W515 mutations trigger spontaneous MPL activation leading to a G1/S transition activation. The other mutations are devoid of significant transforming activity but may synergize with JAK2 V617F or other not yet characterized molecular events.Leukemia (2008) 22, 1557–1566; doi:10.1038/leu.2008.137; published online 5 June 2008 [ABSTRACT FROM AUTHOR]

Summary:Through two consecutive trials, a policy that considered allogeneic stem cell transplantation (SCT) from a sibling donor in second rather than first complete remission (CR) in selected younger patients with acute myeloid leukemia (AML) with t(8;21)/inv(16) (core binding factor (CBF) group) or a normal karyotype (NN group) was followed by Acute Leukemia French Association (ALFA) centers. The outcome of 92 of these patients in first relapse (32 CBF, 60 NN) was reviewed with the aim of validating this strategy. The presence of an FLT3 internal tandem duplication (ITD) was retrospectively assessed in 50 patients. A total of 61 patients (66%) reached a second CR. Donor availability was an independent prognostic factor for survival in the whole patient population as well as in the CBF subset, but not in NN patients, further supporting this strategy for CBF-AMLs. In NN patients, FLT3-ITD was the main bad-prognosis factor for second CR achievement and survival, leading to consider SCT earlier, at least in FLT3-ITD patients with a donor.Bone Marrow Transplantation (2005) 35, 767-773. doi:10.1038/sj.bmt.1704884 Published online 28 February 2005 [ABSTRACT FROM AUTHOR]

With improved treatment of acute promyelocytic leukemia (APL) by all trans retinoic acid (ATRA) combined to anthramyelodysplastic syndrome (MDS) or acute myeloid leukemia (AML, non-APL) occurring cy-cline-aracytin chemotherapy (CT), a larger number of those patients may be at risk of late complications. Recently, the Rome group reported five cases of during the course of 77 APL patients (6.5%) in complete remission (CR). From 1991 to 1998, we treated 677 newly diagnosed cases of APL, and 617 of them achieved CR with ATRA combined to CT (n = 579) or CT alone (n = 38); 246 of them received subsequent maintenance CT with 6 mercapto-purine and methotrexate. With a median follow-up of 51 months, 6 patients (0.97%) developed MDS, 13-74 months after the diagnosis of APL. In all six cases, t(15;17) and PML-RARalpha rearrangement were absent at the time of MDS diagnosis, and karyotype mainly showed complex cytogenetic abnormalities involving chromosomes 5 and/or 7, typical of MDS observed after treatment with alkylating agents, although none of the six patients had received such agents for the treatment of APL. Our findings suggest that MDS can indeed be a long-term complication in APL, although probably at lower incidence than that previously reported. [ABSTRACT FROM AUTHOR]

First results of a randomized trial (APL91 trial) and other randomized or non-randomized studies have shown that ATRA followed by chemotherapy significantly increased event-free survival (EFS) and survival, and decreased the incidence of relapse by comparison to chemotherapy alone in newly diagnosed APL. We present here long-term follow-up of the APL91 trial. In this trial, 101 patients had been randomized between ATRA followed by three courses of daunorubicin-AraC chemotherapy (ATRA group) and the same chemotherapy alone (chemotherapy group). Results were reanalyzed 73 months after closing of patient entry. Updated results of APL 91 trial found a Kaplan-Meier estimate of EFS and relapse rate at 4 years of 63% and 31% in the ATRA group, as compared to 17% and 78% in the chemotherapy group (P= 10(-4) and relative risk 2.95, P= 10(-4) and relative risk 3.68, respectively). Kaplan-Meier survival at 4 years was 76% in the ATRA group and 49% in the chemotherapy group (P= 0.026, relative risk 2.7). In the chemotherapy group, seven of the 27 relapses occurred after 18 months, but no relapse was seen after 43 months. In the ATRA group, four of the 17 relapses occurred after 18 months, including two late relapses (at 58 and 74 months). In the chemotherapy group, 23 of the 25 patients who relapsed achieved a second CR with ATRA, and the Kaplan-Meier estimate of second relapse was 40% at 30 months. In the ATRA group, the 10 patients who relapsed and were retreated with ATRA achieved a second CR. In conclusion, long-term results of APL91 trial confirm the superiority of the combination of ATRA and chemotherapy over chemotherapy alone in newly diagnosed APL, and that ATRA should be incorporated in the front-line treatment of APL. [ABSTRACT FROM AUTHOR]

The EMA86 study showed efficacy of intensive sequential chemotherapy with mitoxantrone, 12 mg/m2 day on days 1-3, etoposide, 200 mg/m2/day as a continuous infusion on days 8-10 and cytarabine (araC), 500 mg/m2/day as continuous infusion on days 1-3 and 8-10 (EMA regimen) in previously treated patients with AML. The goal of the EMA91 study was to determine whether administration of GM-CSF between the two sequences of EMA chemotherapy and during the second sequence could increase therapeutic efficacy by potentially increasing leukemic cell recruitment into the S phase of cell cycle before the second sequence. One hundred and ninety-two patients aged less than 65 years with previously treated AML received GM-CSF, 5 microg/kg/day or placebo from day 4 to day 8 of EMA chemotherapy. One hundred and twenty were refractory and 72 were in first relapse after a complete remission (CR) of more than 6 months duration. CR rates after one course of chemotherapy were 65% in the GM-CSF group (refractory: 51%; first relapse: 89%), not significantly different from the 59% CR rate (refractory: 46%; first relapse: 81%) in the placebo group. Median time to recovery of neutrophils was 38 and 37 days and median time to last platelet transfusion 32 and 32 days respectively in the GM-CSF and placebo groups. WHO grade > or = 3 non-hematologic toxicities were mainly sepsis (45% and 51%, respectively) and mucositis (34% and 31%) and did not differ between the two groups. Toxic death rate was 5% and 8%, respectively, in the GM-CSF and placebo groups. Patients achieving CR were scheduled to receive six courses of maintenance with reduced-dose EMA. Time to progression tended to be longer in the GM-CSF group (median 154 vs 115 days, progression-free rate at 18 months 33% vs 19%, P = 0.08), particularly in refractory patients (P = 0.06). However, at the current follow-up, this did not translate into a significantly longer disease-free survival and survival. Cell cycle studies showed increased recruitment of cells in the S phase between day 4 and day 8 in the GM-CSF group compared to placebo (P = 0.006). However, this did not significantly relate to prognosis in this cohort of patients. GM-CSF might marginally increase efficacy of sequential chemotherapy without increasing its toxicity in the absence of any detected relationship between this effect and observed leukemic cell recruitment into the cell cycle. [ABSTRACT FROM AUTHOR]

Aplastic anemia is a rare complication of thymoma and is properly documented in only few cases. Here, we report the case of a previously healthy, 65-year-old patient who was found simultaneously to have a spindle-cell thymoma and severe hypoplastic anemia with a mild infiltration of the bone marrow by CD4+ and CD8+ T lymphocytes, CD16+ natural killer cells, and a decrease in blood CD4/CD8 ratio. Cultures of marrow erythroid progenitors demonstrated serum inhibitor. While steroids, cyclophosphamide and antilymphocyte globulin failed to improve hematopoiesis, cyclosporine A (Cy-A) led to a partial, stable remission that was sustained for 4 years. Since Cy-A has been associated with good responses in three cases of thymoma-associated red cell aplasia, we recommend its use in cases of thymoma-associated cytopenias refractory to steroids and cyclophosphamide. [ABSTRACT FROM AUTHOR]

From 1981 to 1995, we diagnosed, followed and treated at our institution fifty-eight cases of essential thrombocythemia (ET), using hydroxyurea (HU) as first-line therapy in these patients. Three patients who were continuously receiving HU had a leukemic transformation after a chronic phase of respectively 47, 81 and 90 months. One patient developed an acute leukemia with minimal myeloid differentiation (AML MO) and soon died of refractory disease; the second developed a refractory anemia with excess blasts in transformation (t-RAEB) and survived one year; the third patient developed a chronic myelomonocytic leukemia (CMML) and is alive at 21 months. The two former patients had complex nonrandom bone marrow karyotypic abnormalities, suggestive of therapy-related leukemia, whereas the latter one had a normal karyotype throughout the chronic and leukemic phase. These findings, together with recently published results on myeloproliferative disorders (MPD) treated with HU, suggest that this drug might be as leukemogenic as other myelosuppressive therapies in patients with ET. Long-term HU therapy should be reserved for patients in whom the treatment benefits obviously outweigh the risk of inducing leukemia. [ABSTRACT FROM AUTHOR]

The article analyzes the incidence and causes of early death (ED) in acute promyelocytic leukemia (APL) in French centers from December 2006 to December 2011. APL diagnosis is confirmed by the presence of t(15;17) translocation and/or promyelocytic leukemia gene-retinoic acid recepter alpha gene rearrangement. ED is caused by differentiation syndrome, myocardial infarction and multiple organ failure. The rapid admission of patients follows as all-trans retinoic acid is rapidly started.

A letter to the editor is presented which discusses a study on the prognosis of late relapses in acute promyelocytic leukemia treated with all-trans-retinoic-acid and anthracycline-based chemotherapy.