Generation of induced pluripotent stem cells derived from primary and secondary myelofibrosis patient samples.

Induced pluripotent stem cells (iPS) derived from disease cells are expected to provide a new experimental material, especially for diseases from which samples are difficult to obtain. In this study, we generated iPS from samples from patients with primary and secondary myelofibrosis. The primary myelofibrosis cells had chromosome 13q deletions, and the secondary myelofibrosis (SMF) cells had JAK2V617F mutations. The myelofibrosis patient cell-derived iPS (MF-iPS) were confirmed as possessing these parental disease-specific genomic markers. The capacity to form three germ layers was confirmed by teratoma assay. By co-culture with specific feeder cells and cytokines, MF-iPS can re-differentiate into blood progenitor cells and finally into megakaryocytes. We found that mRNA levels of interleukin-8, one of the candidate cytokines related to the pathogenesis of myelofibrosis, was elevated predominantly in megakaryocytes derived from MF-iPS. Because megakaryocytes from myelofibrosis clones are considered to produce critical mediators to proliferate fibroblasts in the bone marrow and iPS can provide differentiated cells abundantly, the disease-specific iPS we established should be a good research tool for this intractable disease.