CBX7 inhibitors delay leukemogenesis. (A) Experimental setup. Primary AML cells were ex vivo culture and exposed to DMSO only, 50 μM MS452, or 8 μM BDA-41. After 24 hours, cells were harvested and equal number of cells per mouse were transplanted into irradiated immune-deficient mice. After transplantation, the PB was collected to check human AML cell chimerism in the mice over time. In the final week, mice were euthanized and the PB, BM, and spleen were collected and analyzed. (B-C) PB chimerism; (B) flow plots indicating the gates for mouse CD45⁺ cells and human AML CD45⁺ cell populations in the PB. (C) Amount of hCD45⁺ AML cells in the PB over time. Each symbol is a mouse. Lines go through the means of the individual data points of ≥3 mice. (D-G) BM and spleen analysis. (D-E) Flow plots indicating the gates for mouse CD45⁺ cells and human AML CD45⁺ cell populations in the (D) spleen and (E) BM. (F-G) Absolute human AML CD45⁺ cell count in the (F) spleen and (G) BM. Each symbol is a mouse, and medians are indicated as a flat line. For AML9, filled symbols indicate mice that were euthanized 8 weeks after transplantation, and open symbols indicate mice that were euthanized 10 weeks after transplantation. Student t test was used to calculate the P value between the DMSO- and CBX7-inhibitor– pretreated mice, ∗P < .05.