LABORATORY RESEARCH CXCL12 in Early Mesenchymal Progenitors Is Required for Hematopoietic Stem-Cell Maintenance Scientists selectively deleted Cxcl12 from candidate niche stromal cell populations and characterized the effect on hematopoietic progenitor cells. Deletion of Cxcl12 from mineralizing osteoblasts has no effect on hematopoietic stem cells or lymphoid progenitors. [Nature] Abstract | Press Release Xist RNA Is a Potent Suppressor of Hematologic Cancer in Mice Researched deleted Xist in the blood compartment of mice and demonstrate that mutant females develop a highly aggressive myeloproliferative neoplasm and myelodysplastic syndrome with 100% penetrance. Significant disease components include primary myelofibrosis, leukemia, histiocytic sarcoma, and vasculitis. Xist-deficient hematopoietic stem cells show aberrant maturation and age-dependent loss. [Cell] Abstract | Graphical Abstract Attenuation of AML1-ETO Cellular Dysregulation Correlates with Increased Leukemogenic Potential Scientists investigated the role of two AML1-ETO C-terminal-interacting proteins, N-CoR, a transcriptional co-repressor, and SON, a splicing/transcription factor required for cell cycle progression, in AML1-ETO-induced leukemia development. [Blood] Abstract DNA Damage in Stem Cells Activates p21, Inhibits p53, and Induces Symmetric Self-Renewing Divisions Researchers showed that irradiation of hematopoietic and mammary stem cells up-regulates the cell cycle inhibitor p21, a known target of p53, which prevents p53 activation and inhibits p53 basal activity, impeding apoptosis and leading to cell cycle entry and symmetric self-renewing divisions. [Proc Natl Acad Sci USA] Abstract The Novel Arsenical Darinaparsin Circumvents BRG1-Dependant, HO-1-Mediated Cytoprotection in Leukemic Cells Scientists observed that, unlike arsenic trioxide (ATO), darinaparsin does not induce HO-1, even though it induces expression of other nuclear factor (erythroid-derived 2)-like 2-dependant detoxifying enzymes to a greater extent than ATO, in both cancer cell lines and patient-derived leukemic cells. [Leukemia] Abstract Hematopoietic Protein-1 Regulates the Actin Membrane Skeleton and Membrane Stability in Murine Erythrocytes The authors utilized mice lacking Hematopoietic Protein-1 (Hem-1) expression due to a non-coding point mutation in the Hem1 gene to show that absence of Hem-1 results in microcytic, hypochromic anemia characterized by abnormally shaped erythrocytes with aberrant F-actin foci and decreased lifespan. [PLoS One] Full Article CLINICAL RESEARCH T-Cell-Replete HLA-Haploidentical Hematopoietic Transplantation for Hematologic Malignancies Using Post-Transplantation Cyclophosphamide Results in Outcomes Equivalent to Those of Contemporaneous HLA-Matched Related and Unrelated Donor Transplantation Outcomes of 271 consecutive patients undergoing T-cell-replete first allogeneic hematopoietic cell transplantation for hematologic malignancies performed contemporaneously at a single center were compared. Overall and disease-free survival were adjusted for effects of significant patient-, disease-, and transplantation-related covariates using a stratified Cox model. [J Clin Oncol] Abstract Phase II Clinical Trial of Rapamycin-Resistant Donor CD4+ Th2/Th1 (T-Rapa) Cells after Low-Intensity Allogeneic Hematopoietic Cell Transplantation Researchers performed a Phase II multi-center clinical trial of rapamycin-resistant donor CD4+ Th2/Th1 cells after allogeneic matched-sibling donor hematopoietic cell transplantation for therapy of refractory hematologic malignancy. [Blood] Abstract Phase II Study of Arsenic Trioxide Followed by Autologous Hematopoietic Cell Transplantation for Relapsed Acute Promyelocytic Leukemia The authors conducted a Phase II study to evaluate the efficacy and feasibility of a sequential treatment consisting of induction and consolidation with arsenic trioxide, peripheral blood stem cell harvest after high-dose cytarabine chemotherapy, and autologous hematopoietic cell transplantation. [Blood] Abstract |