title: Molecular purging of multiple myeloma cells by ex-vivo culture and retroviral transduction of mobilized-blood CD34+ cells.
abstract: BACKGROUND
  Tumor cell contamination of the apheresis in multiple myeloma is likely to affect disease-free and overall survival after autografting.
  
  
  OBJECTIVE
  To purge myeloma aphereses from tumor contaminants with a novel culture-based purging method.
  
  
  METHODS
  We cultured myeloma-positive CD34+ PB samples in conditions that retained multipotency of hematopoietic stem cells, but were unfavourable to survival of plasma cells. Moreover, we exploited the resistance of myeloma plasma cells to retroviral transduction by targeting the hematopoietic CD34+ cell population with a retroviral vector carrying a selectable marker (the truncated form of the human receptor for nerve growth factor, DeltaNGFR). We performed therefore a further myeloma purging step by selecting the transduced cells at the end of the culture.
  
  
  RESULTS
  Overall recovery of CD34+ cells after culture was 128.5%; DeltaNGFR transduction rate was 28.8% for CD34+ cells and 0% for CD138-selected primary myeloma cells, respectively. Recovery of CD34+ cells after DeltaNGFR selection was 22.3%. By patient-specific Ig-gene rearrangements, we assessed a decrease of 0.7-1.4 logs in tumor load after the CD34+ cell selection, and up to 2.3 logs after culture and DeltaNGFR selection.
  
  
  CONCLUSIONS
  We conclude that ex-vivo culture and retroviral-mediated transduction of myeloma leukaphereses provide an efficient tumor cell purging.
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), Scientific Institute HS Raffaele, Milan, Italy. deola.sara@hsr.it
authors.forename: Sara
authors.initials: S
authors.lastname: Deola
authors.forename: Samantha
authors.initials: S
authors.lastname: Scaramuzza
authors.forename: Roberto Sciarretta
authors.initials: RS
authors.lastname: Birolo
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Cergnul
authors.forename: Francesca
authors.initials: F
authors.lastname: Ficara
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dando
authors.forename: Claudia
authors.initials: C
authors.lastname: Voena
authors.forename: Sergio
authors.initials: S
authors.lastname: Vai
authors.forename: Marta
authors.initials: M
authors.lastname: Monari
authors.forename: Enrico
authors.initials: E
authors.lastname: Pogliani
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Corneo
authors.forename: Jacopo
authors.initials: J
authors.lastname: Peccatori
authors.forename: Silvia
authors.initials: S
authors.lastname: Selleri
authors.forename: Claudio
authors.initials: C
authors.lastname: Bordignon
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Roncarolo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Aiuti
authors.forename: Marco
authors.initials: M
authors.lastname: Bregni
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D001781:Blood Component Removal / Q000379:methods*; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division; D019650:Hematopoietic Stem Cell Mobilization; D006801:Humans; D009101:Multiple Myeloma / Q000473:pathology*; D010950:Plasma Cells / Q000473:pathology; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic; D047368:Tumor Burden
chemical_list: D018952:Antigens, CD34