DSIF and RNA Polymerase II CTD Phosphorylation Coordinate the Recruitment of Rpd3S to Actively Transcribed Genes

Histone deacetylase Rpd3 is part of two distinct complexes: the large (Rpd3L) and small (Rpd3S) complexes. While Rpd3L targets specific promoters for gene repression, Rpd3S is recruited to ORFs to deacetylate histones in the wake of RNA polymerase II, to prevent cryptic initiation within genes. Methylation of histone H3 at lysine 36 by the Set2 methyltransferase is thought to mediate the recruitment of Rpd3S. Here, we confirm by ChIP–Chip that Rpd3S binds active ORFs. Surprisingly, however, Rpd3S is not recruited to all active genes, and its recruitment is Set2-independent. However, Rpd3S complexes recruited in the absence of H3K36 methylation appear to be inactive. Finally, we present evidence implicating the yeast DSIF complex (Spt4/5) and RNA polymerase II phosphorylation by Kin28 and Ctk1 in the recruitment of Rpd3S to active genes. Taken together, our data support a model where Set2-dependent histone H3 methylation is required for the activation of Rpd3S following its recruitment to the RNA polymerase II C-terminal domain

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Intérêt de l'irradiation corporelle totale dans le conditionnement de l'autogreffe des patients atteints de lymphome à cellules du manteau

L'efficacité de la chimiothérapie sur les cellules tumorales hématologiques est liée à l'intensité de la dose administrée. Celle-ci est limitée par la toxicité, notamment sur l'hématopoïèse. La réinjection de cellules souches autologues permet de s'affranchir de ce problème. Le lymphome à cellules du manteau est une hémopathie dont le pronostic est sombre. L'intensification du traitement par autogreffe apparaît donc comme une solution potentielle. Cependant certaines questions restent en suspens, comme celle de l'impact sur la survie de l'irradiation corporelle totale dans le conditionnement avant autogreffe. Pour essayer d'y répondre, nous avons mené une étude rétrospective monocentrique sur 73 patients atteints de LCM traités par autogreffe dans le service d'hématologie du CHU de Nantes, entre 1992 et 2008. Nous n'avons pas retrouvé de supériorité de l'ICT par rapport à la chimiothérapie. Concernant la survie sans événement ; en analyse univariée, les facteurs influençant étaient : le score MIPI (Mantle Cell International Pronostic Index), l'âge au diagnostic et à la greffe, le performens status et le taux d'hémoglobine. En analyse multivariée, aucun de ces facteurs n'étaient relevant. Concernant la survie globale (SG), le MIPI et le taux d'hémoglobine avaient un impact statistiquement significatif en analyse univariée. En multivariée seul ces 2 facteurs avaient tendance à influer sur la SG. Nous concluons d'une part à la capacité du score MIPI à prédire la survie chez des patients autogreffés et d'autre-part, nous ne recommandons plus l'utilisation de l'ICT au vu des myélodysplasies secondaires qu'elle pourvoit et de la complexité logistique qu'elle implique.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

FLT3 ligand in acute myeloid leukemia: a simple test with deep implications

International audienceIn contrast to Fms-like tyrosine kinase 3 (FLT3), the influence of FLT3 ligand (FLT3L) on acute myeloid leukemia (AML) biology and disease prognosis has been poorly described. Here we provide an overview of the role played by FLT3L in AML. While being a cytokine implicated in the regulation of hematopoiesis, both in normal situation and after intensive chemotherapy, FLT3L has also a role in enhancing proliferation, inhibiting apoptosis and conferring resistance to FLT3 inhibitors in AML. Moreover, recent independent data show how its measurement may be helpful in the disease management. Indeed, FLT3L could provide a low cost, rapid and noninvasive assessment of chemosensitivity and blast clearance that has robust prognostic significance for patients with AML

Post‐transplant cyclophosphamide as sole GHVD prophylaxis after matched reduced‐intensity conditioning allotransplant

Abstract Background Post‐transplant cyclophosphamide (PTCY) alone as graft‐versus‐host disease (GVHD) prophylaxis may avoid/reduce short‐ and mid‐term toxicities of drugs commonly used for GVHD prophylaxis, accelerate immune reconstitution after the graft to decrease infections and facilitate the early integration of adjunct maintenance therapies to prevent relapse. Objective A prospective phase 2 study was designed in order to assess the feasibility and safety of PTCY as a sole GVHD prophylaxis in adult patients receiving a Baltimore‐based reduced‐intensity conditioning (RIC) peripheral blood (PB) allogeneic hematopoietic stem cell transplantation (Allo‐HSCT) with a matched donor. Study design Patients were planned to be included stepwise up to 59 evaluable PTCY recipients, in order to be able to stop the protocol in case of excessive corticosteroid resistant grade 3–4 severe acute GVHD (aGVHD). Because a high incidence of grade 2–4 aGVHD was observed after analysis of the first 27 patients, the protocol was amended to test the addition of 1 day of anti‐thymoglobulin to PTCY. In spite of this, the trial had to be stopped after 38 treated patients, because of an unacceptable rate of grade 3–4 aGVHD. Donors were matched related to 12 patients and unrelated to 26. Results With a median follow‐up of 29.6 months, 2‐year overall, disease‐free and GVHD‐free relapse‐free (GRFS) survivals were respectively 65.4%, 62.1% and 46.9%. Cumulative incidences of grade 2–4 and 3–4 aGVHD at day 100 were 52.6% and 21.1%, respectively, while that of moderate/severe chronic(c) GVHD was 15.7% at 2 years. Addition of ATG to PTCY did influence neither aGVHD, cGVHD nor GRFS. Conclusion Despite paradoxically good survivals, especially GRFS, this study failed to demonstrate that PTCY (± ATG) alone can be used for Baltimore‐based RIC PB Allo‐HSCT with matched donors. Other combinations should be tested to try and avoid long‐term use of immunosuppressive drugs following Allo‐HSCT in this setting

Targeting cell-bound MUC1 on myelomonocytic, monocytic leukemias and phenotypically defined leukemic stem cells with anti-SEA module antibodies

International audienceCell surface molecules aberrantly expressed or overexpressed by myeloid leukemic cells represent potential disease-specific therapeutic targets for antibodies. MUC1 is a polymor-phic glycoprotein, the cleavage of which yields two unequal chains: a large extracellular a subunit containing a tandem repeat array bound in a strong noncovalent interaction to a smaller b subunit containing the transmembrane and cytoplasmic domains. Because the a-chain can be released from the cell-bound domains of MUC1, agents directed against the a-chain will not effectively target MUC1 + cells. The MUC1 SEA (a highly conserved protein module so called from its initial identification in a sea urchin sperm protein, in enterokinase, and in agrin) domain formed by the binding of the a and b chains represents a stable structure fixed to the cell surface at all times. DMB-5F3, a partially human-ized murine anti-MUC1 SEA domain monoclonal antibody, was used to examine MUC1 expression in acute myeloid leukemia (AML) and was found to bind acute myelomonocytic and monocytic leukemia (AML-M4 and AML-M5) cell lines. We also examined monocytic neoplasms freshly obtained from patients including chronic myelomonocytic leukemia and juvenile myelomonocytic leukemia, which were found to uniformly express MUC1. CD34 + / lin − /CD38 − or CD38 + presumed leukemic stem cell populations from CD34 + AML and CD34 − CD38 − or CD38 + populations from CD34 − AML were also found to express MUC1, although at low percentages. Based on these studies, we generated an anti-MUC1 immuno-toxin to directly gauge the cytotoxic efficacy of targeting AML-bound MUC1. Using single-chain DMB-5F3 fused to recombinant gelonin toxin, the degree of AML cytotoxicity was found to correlate with MUC1 expression. Our data support the use of an anti−MUC1 SEA module−drug conjugates to selectively target and inhibit MUC1-expressing myelomo-nocytic leukemic cells

Higher Early Monocyte and Total Lymphocyte Counts Are Associated with Better Overall Survival after Standard Total Body Irradiation, Cyclophosphamide, and Fludarabine Reduced-Intensity Conditioning Double Umbilical Cord Blood Allogeneic Stem Cell Transplantation in Adults

International audienceThis single-center retrospective study aimed to report the impact of early hematopoietic and immune recoveries after a standard total body irradiation, cyclophosphamide, and fludarabine (TCF) reduced-intensity conditioning (RIC) regimen for double umbilical cord blood (dUCB) allogeneic stem cell transplantation (allo-SCT) in adults. We analyzed 47 consecutive patients older than 17 years who engrafted after a dUCB TCF allo-SCT performed between January 2006 and April 2013 in our department. Median times for neutrophil and platelet recoveries were 17 (range, 6 to 59) and 37 days (range, 0 to 164), respectively. The 3-year overall (OS) and disease-free survivals, relapse incidence, and nonrelapse mortality were 65.7%, 57.2%, 27.1%, and 19%, respectively. In multivariate analysis, higher day þ30 monocyte (!615/mm 3 ; hazard ratio [HR], .04; 95% confidence interval [CI], .004 to .36; P < .01) and day þ42 lymphocyte (!395/mm 3 ; HR, .16; 95% CI, .03 to .78; P ¼ .02) counts were independently associated with better OS. These results suggest that early higher he-matopoietic and immune recovery is predictive of survival after dUCB TCF RIC allo-SCT in adults. Factors other than granulocyte colonyestimulating factor, which was used in all cases, favoring expansion of monocytes or lymphocytes, should be tested in the future as part of the UCB transplantation procedure

SARS-CoV-2 T-cell responses after one or two COVID-19 vaccine boosters in allogeneic transplant recipients

International audienc