Glycosylation pattern and cell surface expression of FLT3 receptor differ in FLT3 mutants.

<p>(A) FLT3 mutants were cultured without IL-3 for 24 hours prior to lysis. One out of three independently representative experiments is shown. (B) To illustrate the expression of the 150/130 kDa forms of FLT3 semi-quantitive analyses of western blot band intensity were performed. Depicted is the ratio of the 150 kDa to the 130 kDa FLT3 form. Values are expressed as mean +/− S.D. of three independent experiments. Ratio of 150 kDa to 130 kDa form of FLT3 was significantly different for each FLT3-TKD (p≤0.009) and each FLT3-ITD (p≤0.002) cell line, but not for FLT3-V592A and -I867S expressing cells compared to FLT3-WT expressing cells. FLT3-WT expressing cells showed a significant differnence to the groups of FLT3-WT-like mutants (p = 0.039), FLT3-TKD mutants (≤0.001) and FLT3-ITD mutants (p≤0.001). Further FLT3-WT like mutants were significantly different compared to the FLT3-TKD group (p≤0.001) and FLT3-TKD mutants were significantly different compared to FLT3-ITD cell lines (p = 0.004). (*) indicates significance of grouped analyses and individually compared to FLT3-WT expressing cells. (C) Ba/F3 cell lines stably expressing the indicated FLT3 constructs were stained with CD-135 antibody and analyzed by flow cytometry. Expression is depicted as difference of geometric mean to isotype control (ΔGmean). Values are expressed as means +/− S.D. of four independent experiments. (*) indicates significance compared to FLT3-WT expressing cells.