Application of iPS cells derived from congenital myelodysplastic syndrome for research of nomal hematopoesis and hematological malignancies.

Induced pluripotent stem cells (iPSCs) are not only a valuable resource for regenerative medicine, but also a promising tool for disease modeling and drug discovery. Patient-specific iPSCs harboring disease-specific mutations are extremely useful for investigating disease mechanisms and novel treatment approaches. In the field of hematology, attempts to establish iPSCs from tumor cells such as those of leukemia or myelodysplastic syndrome (MDS) were largely unsuccessful because proper reprogramming processes were hampered by their extensive genetic alterations. In contrast, congenital disorders caused by a single genetic mutation are ideal candidates for deriving iPSCs. We have been investigating the molecular mechanisms underlying leukemia and MDS by implementing iPSC technology. Familial platelet disorder (FPD) is a rare autosomal dominant disorder characterized by thrombocytopenia and a high propensity for developing acute leukemia, which is caused by heterozygous mutation of RUNX1. We have successfully established iPSCs from three distinct FPD pedigrees and examined the responsible defect during hematopoietic development. This system will serve as a novel unprecedented platform for prospectively studying hematologic disorders using human cells.