Induced pluripotent stem cells in clinical hematology: Potentials, progress, and remaining obstacles

Purpose of review: With the advent of reprogramming came the possibility of generating patient-specific clinical therapies. The purpose of this review is to discuss the recent key developments and remaining limitations in the stem cell and hematopoietic fields toward the goal of translating induced pluripotent stem cell (iPSC) technologies into the hematology clinic. Recent findings: Recent progress in the hematopoietic and reprogramming fields has included identification of hematopoietic stem cells (HSCs) capable of long-term engraftment at the single-cell level, improvements in ex-vivo expansion of HSCs, transdifferentiation of somatic cells into hematopoietic progenitors, and the 'correction' of several disease-specific iPSCs using various gene-targeting strategies. Summary: In light of recent advances, it is the hope that the hurdle of obtaining fully functional HSCs in a laboratory setting will be overcome through either in-vitro differentiation of pluripotent stem cells, ex-vivo expansion of HSCs obtained in vivo, or transdifferentiation from other somatic sources. Equally important will be for the reprogramming field to better understand the causes and consequences of the recently reported genetic/epigenetic variations present in iPSCs, especially within the context of gene-targeted strategies for correcting disease. The progress in the reprogramming and hematopoietic fields provides a strong foundation for future work toward the possible treatment of numerous hematological disorders using iPSC technologies.