[Regulation of leukemic stem cells by manipulating the Geminin activity]

Geminin regulates cellular proliferation and differentiation through the inhibition of DNA replication licensing and chromatin remodeling, respectively, to sustain the activity of hematopoietic stem cells (HSCs) and possibly that of leukemic stem cells (LSCs). Thus, Geminin is presumed to act as a cell fate determinant by turning on and off self-renewal and differentiation of the stem cells. We visualized Geminin expression by generating knock-in mice expressing Geminin fusion protein with enhanced yellow fluorescent protein. We further established a new method for manipulating the Geminin expression level and activity by generating cell -penetrating (CP) - Geminin. Here we argue for a new strategy for expanding HSCs ex vivo to provide a cellular source of HSCs for transplantation and further for eradicating LSCs, which are resistant to conventional chemotherapy.