Abstract
ABSTRACTGenerating Hematopoietic Stem Cells (HSCs) from Pluripotent Stem Cells (PSCs) has been a long-lasting quest in the field of hematopoiesis. Previous studies suggested that enforced expression of BCR-ABL, the unique oncogenic driver of Chronic Myelogeneous Leukemia (CML), in Embryonic Stem Cells (ESCs)-derived hematopoietic cells is sufficient to confer long-termin vivorepopulating potential. To precisely uncover the molecular events regulated by the Tyrosine-kinase activity of BCR-ABL1 (p210) during the course of hematopoietic differentiation, we engineered a Tet-ON inducible system to modulate its expression in murine ESC. We showed in unique site-directed knock-in ESC model, thatBCR-ABLexpression tightly regulated by doxycycline (dox) controls the formation and the maintenance of immature hematopoietic progenitors. Interestingly, these progenitors can be expandedin vitrofor several passages in the presence of dox. Our analysis of cell surface markers and transcriptome compared to wild-type fetal and adult HSCs unraveled a similar molecular signature. LTC-IC assay confirmed their self-renewal capacities albeit with a differentiation bias towards erythroid and myeloid cells. Collectively, our novel Tet-ON system represents a uniquein vitromodel to shed lights on ESC-derived hematopoiesis, CML initiation and maintenance.KEY POINTSWe report a unique BCR-ABL-induced-embryonic stem cell -derived hematopoiesis model in murine embryonic stem cellsThis BCR-ABL-induced self-renewal and differentiation model can be of major interest to uncover molecular events required for ESC-derived hematopoiesis
Publisher
Cold Spring Harbor Laboratory