Fig. 4.

Activation of STAT species by GIST mutants. (a) Nuclear translocation of STAT species. Nuclear extracts were prepared as previously done [4], diluted in 4 times Laemmli buffer and subjected to Western blot analysis. Phosphorylation status of STAT5, STAT3 and STAT1 is shown for nuclear extract prepared from Hek293 cells expressing KIT WT, KIT Ex11, KIT Ex9 and KIT V559D. (b) Induction of known STAT target genes by GIST mutants. Gene expression level of known STAT target genes, previously identified to be induced in PDGFRA GIST mutants [3], was retrieved from micro-array data and presented as heat map. Grey boxes indicate that the genes are not part of the DEG list for the corresponding mutant (FDR>0.05 or AbsFC<0.5). The intensity of the red color corresponds to the value of the ratio to the background (Hek293 KIT WT non-stimulated for KIT WT and mutants and Hek293 PDGFRα non-stimulated for PDGFRα mutants). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article) .