title: In vitro functional defects of bone marrow-derived CD34+ progenitors from newly diagnosed mature B-cell malignancies with bone marrow tumor involvement.
abstract: OBJECTIVE
  We hypothesized that the presence of tumor cells in bone marrow (BM) could alter hematopoietic progenitor cell functions. Therefore, we evaluated phenotypic and in vitro functional properties of BM-derived CD34+ progenitors issued from untreated and newly diagnosed patients presenting a mature B-lymphoproliferative disorder (LPD) involving the BM (Inv+).
  
  
  METHODS
  In vitro proliferation and differentiation capacities of primitive and committed progenitors were evaluated by cobblestone area-forming cell (CAFC) and colony-forming cell (CFC) assays, and ex vivo cell expansion. Migratory capacities of CD34+ cells were explored by chemotaxis assays using a CXCL12alpha gradient.
  
  
  RESULTS
  Our results showed that CD34+ cells from Inv+ patients overexpressed CD117 and had a significant decrease of week-3 and -6 CAFC, and CFC frequencies, compared to cells obtained from healthy volunteers and LPD patients without BM involvement (Inv-). In addition, progenitors from Inv+ patients maintained a significantly decreased CFC capacity after ex vivo cell expansion, compared to healthy volunteers. However, the former cells held their migratory capacity in response to CXCL12alpha.
  
  
  CONCLUSIONS
  Functional defects of primitive and committed CD34+ progenitors detected among LPD patients with BM tumor involvement suggest either that tumor cells may induced bystander effects on progenitors or that "unusual" CD34+ cells may exist in the BM that could belong to the proliferating tumor tissue.
authors.affiliation: Department of Hematology, University Hospital Jean Minjoz, Besançon, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Amé-Thomas
authors.forename: Frédéric
authors.initials: F
authors.lastname: Deschaseaux
authors.forename: Frédéric
authors.initials: F
authors.lastname: Mauny
authors.forename: Claude-Eric
authors.initials: CE
authors.lastname: Bulabois
authors.forename: Thierry
authors.initials: T
authors.lastname: Lamy
authors.forename: Patrick
authors.initials: P
authors.lastname: Hervé
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Cahn
authors.forename: Thierry
authors.initials: T
authors.lastname: Fest
mesh_terms: D000328:Adult; D000368:Aged; D018952:Antigens, CD34; D001402:B-Lymphocytes; D001853:Bone Marrow / Q000503:physiopathology*; D019046:Bone Marrow Neoplasms / Q000503:physiopathology* / Q000556:secondary; D024201:Bystander Effect; D016022:Case-Control Studies; D005260:Female; D006412:Hematopoietic Stem Cells; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
chemical_list: D018952:Antigens, CD34