Figure 2

Selective shh inhibition reduces lsc burden in stromal co-cultures. a. Chemical structure of PF-04449913, a selective smoothened (SMO) antagonist. b. FACS analysis revealed a significant (Student’s t-test, *p = 0.047) reduction in blast crisis leukemic progenitor survival (n = 4 patient derived samples) following 7 days of PF-04449913 (1 μM, purple) compared with vehicle (DMSO, blue) treatment in SL/M2 co-cultures. c. Cord blood (n = 3) CD34⁺ cells were plated on SL/M2 co-cultures and treated with vehicle (DMSO) or PF-04449913 (1uM) for 7 days. Colony forming unit (CFU) survival was determined and compared to vehicle treatment. d. Spleen weight in blast crisis CML LSC engrafted mice after 14 days of treatment with vehicle (n = 16, blue) or PF-04449913 (n = 12; 100 mg/kg daily, purple). A significant (Student t-test, *p = 0.006) reduction is observed after PF-044449913 treatment. e. Nanoproteomic (CB1000) traces of total GLI2 protein of CD34 + CD38+ FACS sorted derived from the spleen of mice (n = 5) after vehicle (blue) or PF-04449913 (green) treatment for 14 days with 100 mg/kg daily. f. GLI2 expression was determined after normalizing the area under the curve (AUC) to a β2-microglobulin (β₂M) loading control (Student’s t-test *p = 0.001) g. Confocal fluorescence microscopic analysis of spleen sections from no transplant or LSC engrafted mice treated with vehicle or PF-04449913. Photomicrographs of sections stained with DAPI and antibodies specific for human CD45, human GLI2 and the merged image.