Figure 4.
Meis1 modulates myeloid differentiation arrest, as well as CFC and LSC frequencies of MLL leukemias. (A) FACS profiles demonstrate representative c-kit and Mac1 expression on splenocytes from mice with AML induced by transplantation of progenitors transduced with genes indicated at the tops of the panels. Bar graph summarizes data from five mice in each category. (B) Splenocytes from leukemic mice were analyzed for the proportion of cells with morphologic features of blasts versus differentiation following May Grunwald Giemsa staining of cytospin preparations. Bar graph indicates the number of cells with the indicated morphologic features for five mice in each cohort. (C) FACS-sorted Mac1+ leukemic splenocytes were cultured in methylcellulose medium for 6 d to determine CFC frequencies. Bar graph indicates the numbers of clonogenic cells for each of five leukemias in the respective cohorts. (D) Survival curves of sublethally irradiated mice transplanted with single AML colonies (3000 cells) plucked after 7 d in semisolid culture and directly injected into secondary recipients, or expanded in semisolid culture for 5 d prior to injection (2.5 × 105 cells).