Growth rate of Ba/F3 cells expressing wild-type and ITD mutant FLT3 receptor.

(A) Cell number is indicated on the y-axis, and time in days on the x-axis. Ba/F3 cells transduced with MSCV-neo retroviruses containing FLT3 wild-type and ITD mutant cDNAs were selected for 14 days with G418 in the presence of IL-3. The cell numbers plotted represent the viable cells in each population over 5 days when cells were cultured in the absence of IL-3. The legend on the right indicates the symbols used for the curves of Ba/F3 cells, cells transduced with wild-type Flt3 (Wt) and each of the FLT3-ITD mutants, W51, W73, W78, T6, and Npos. (B) Western analysis of Ba/F3 cells expressing either wild-type (Wt) or ITD mutant FLT3 using an anti-FLT3 antibody. Two FLT3-specific bands are detected in cells transduced with the FLT3 constructs as indicated by arrows, where the upper band is a more glycosylated form. The position of molecular weight markers of 216 and 91 kd is indicated.