Exogenous c-Myc Blocks Differentiation and Improves Expansion of Human Erythroblasts In vitro

BACKGROUND: Engineered blood has the greatest potential to combat a predicted future shortfall in the blood supply for transfusion treatment. The production of red blood cells from hematopoietic stem cells in the laboratory is possible but the mass production of red blood cells to the level present in a blood transfusion unit is currently not possible. The proliferation capacity of the immature red blood cell will need to be increased to enable mass production. This work focused on the hypothesis that exogenous c-Myc can delay the differentiation process of highly proliferative immature erythroblasts, and increase the proliferation capacity of erythroblast cell cultures. OBJECTIVES: The objective of this research effort was to improve in vitro erythropoiesis from stem cells without gene transfection with the eventual goal of producing blood for transfusion treatment in a manner that could be easily translated into clinical medicine. METHODS: The hematopoietic stem cell containing mononuclear cell fraction of venous blood samples was cultured in a liquid media containing erythroblasts growth factors with and without exogenous c-Myc combined with a cell -penetrating peptide. The cells were maintained in the liquid culture media for 23 days. Viable cells were counted and analyzed with flow cytometry. RESULTS: Our results show a 4 fold increase in expansion of the erythroblasts grown in the c-Myc containing growth media compared to the control. Eighty percent of these cells retained the CD117 surface receptor, indicating immature cells. CONCLUSION: Exogenous c-Myc blocks the differentiation and improves in vitro expansion of human erythroblasts.