LABORATORY RESEARCH Rare and Low-Frequency Coding Variants in CXCR2 and Other Genes Are Associated with Hematological Traits To test the effects of rare and low-frequency coding variants on hematological traits, researchers analyzed hemoglobin concentration, hematocrit levels, white blood cell counts and platelet counts in 31,340 individuals genotyped on an exome array. [Nat Med] Abstract Bone Marrow-on-a-Chip Replicates Hematopoietic Niche Physiology In Vitro Scientists describe a method for fabricating ‘bone marrow-on-a-chip’ that permits culture of living marrow with a functional hematopoietic niche in vitro by first engineering new bone in vivo, removing it whole and perfusing it with culture medium in a microfluidic device. [Nat Method] Abstract Loss of β-Catenin Triggers Oxidative Stress and Impairs Hematopoietic Regeneration Using Wnt reporter mice, scientists showed that radiation triggers activation of Wnt signaling in hematopoietic stem and progenitor cells. β-Catenin-deficient mice, which lack the ability to activate canonical Wnt signaling, exhibited impaired hematopoietic stem cell regeneration and bone marrow recovery after radiation. [Genes Dev] Abstract | Press Release Functional and Molecular Features of the Calmodulin-Interacting Protein IQCG Required for Hematopoiesis in Zebrafish Investigators used zebrafish to investigate the role of iqcg in hematopoietic development, and find that the numbers of hematopoietic stem cells and multilineage-differentiated cells are reduced in iqcg-deficient embryos. [Nat Commun] Abstract Post-Transcriptional Regulation of c-Myc Expression in Adult Murine HSCs during Homeostasis and Interferon-α Induced Stress Response Scientists showed that hematopoietic stem cells (HSCs) and more committed progenitors express similar levels of c-myc transcripts. Using knock-in mice expressing a functional eGFP-c-Myc fusion protein under control of the endogenous c-myc locus, c-Myc protein levels were assessed. [Blood] Abstract Integrated Genetic Approaches Identify the Molecular Mechanisms of Sox4 in Early B Cell Development: Intricate Roles for RAG1/2 and CK1ϵ The authors used integrated genetic approaches and systematically determined the role of Sox4 and the underlying molecular mechanisms in early B cell development. They found that Sox4 coordinates multilevel controls in the differentiation of early-stage B cells. [Blood] Abstract CLINICAL RESEARCH Sensitivity of Hematological Malignancies to Graft-versus-Host Effects: An EBMT Megafile Analysis In chronic myeloid leukemia (CML), the relapse risk declined clearly and proportionally to severity of acute and chronic graft-versus-host disease (GvHD). Acute lymphoblastic leukemia and BCR-ABL negative myeloproliferative neoplasias were comparably sensitive to GvHD as CML, whereas myelodysplastic syndromes and lymphoproliferative disorders showed intermediate sensitivity. [Leukemia] Abstract Allogeneic Stem Cell Transplantation for Mantle Cell Lymphoma – Final Report from the Prospective Trials of the East German Study Group Hematology/Oncology (OSHO) Investigators evaluated allogeneic stem cell transplantation (alloSCT) as consolidation for patients with mantle cell lymphoma. Thirty-three of 39 patients underwent alloSCT after myeloablative or toxicity-reduced conditioning. [Ann Hematol] Abstract |