The enzymatic activity of KDM2b/JHDM1b is required for the self-renewal of leukemic stem cells. (A) Flow chart of experimental procedure for analyzing the role of Kdm2b/Jhdm1b in LSC self-renewal. Leukemic cells were isolated from primary AML mice and selected for LSCs through replating on methylcellulose. Cells derived from the colonies were transduced with various lentiviral (LV) vectors, followed by methylcellulose colony formation assay in vitro and secondary transplantation assays in vivo. (B) Photographs of the methylcellulose colony formation assay plates show that Kdm2b/Jhdm1b KD results in a decease of both size and number of colonies. This phenotype can be rescued by wild-type but not a catalytic mutant Kdm2b/Jhdm1b or LacZ. (C) Quantification of the colony numbers derived from the methylcellulose colony replating assays. (D) Survival curve shows prolonged survival of mice that received a transplant of primary Hoxa9-Meis1 leukemia cells with KD of Jhdm1b. This phenotype can be reversed by wild-type but not catalytic mutant Kdm2b/Jhdm1b or LacZ. CFC indicates colony-forming cell; Wt, wild-type; and Mut, mutant.