Divergent roles of miR-126 in normal and malignant stem cells

Malignant blasts in acute myeloid leukemia (AML) are organized in a hierarchal manner resembling normal hematopoiesis, with leukemic stem cells (LSCs) at the apex, giving rise to more differentiated progeny with reduced capacity to self-renew (1). Functionally, LSCs demonstrate the ability to propagate disease upon transplantation (demonstrating leukemia-initiating cell, or LIC, activity), as well as serial transplantation. With each transplantation, LSCs cells are capable of retaining properties of the original leukemia, which reflects their unique capacity to self-renew, similar to normal hematopoietic stem cells (HSCs).