Expression of phosphatase gain-of-function SHP2D61Y increases, while expression of phosphatase dead SHP2C463A decreases human cord blood CD34+ cell-derived colony formation by myeloid progenitor cells. (A) CD34+ cord blood cells were retrovirally transduced with wild-type (WT) SHP2, SHP2D61Y, or SHP2C463A and enriched by sorting for cells expressing enhanced yellow fluorescent protein. Cells were plated at 2000 cells/mL in 1% methylcellulose culture medium with 30% FBS plus increasing concentrations of GM-CSF (0.1 ng/mL, 1 ng/mL, or 10 ng/mL). Total colonies (CFU) were scored after 14 days of incubation; n=3, *P<0.003 by students t test comparing SHP2D61Y to WT SHP2 at each concentration of GM-CSF and **P<0.01 comparing SHP2C463A to WT SHP2 at GM-CSF 1 ng/mL GM-CSF 10 ng/mL. (B) WT SHP2-, SHP2D61Y-, and SHP2C463A-transduced cells were plated at 1000 cells/mL with GM-CSF (20 ng/mL), IL-3 (20 ng/mL), EPO (2 U/mL), and SCF (50 ng/mL). Colonies were scored after 12 days of incubation for CFU-GM and CFU-GEMM; n=3, *P=0.005 for SHP2D61Y versus WT SHP2 CFU-GM, *P=0.02 for SHP2C463A versus WT SHP2 CFU-GM, **P<0.05 for SHP2D61Y versus WT SHP2 CFU-GEMM, and **P<0.05 for SHP2C463A versus WT SHP2 CFU-GEMM. Statistics performed by student's t test.