Fig. 6

AATK regulated VAV1 cellular localization. a AATK is co-expressed with VAV1 in tumor sections of human pancreatic cancer stained with AATK and VAV1 antibodies. Statistical assessment was based on Fisher’s exact test (AATK/VAV1 marker positivity in IHC imaging assays). b Tumor sections of KPC2 mice treated with vehicle (upper panel) or 5 mg/kg GW788388 (lower panel) were stained with AATK/VAV1/pan-cytokeratin/DAPI and analyzed by multiple immunofluorescence imaging assays. Representative foci showed that loss of AATK expression in cancer cells co-expresses with cytosolic VAV1 in comparison to those with restored AATK expression after GW788388 treatment were noted with enrichment of nuclear VAV1 expression. Rectangular boxes indicate the region of interest to be magnified in the adjacent panel. Scale bar: 50 μm (left panel) and 10 μm (right panel). AATK, green; VAV1, red; CK19, grey; and DAPI, cyan. c Co-immunoprecipitation followed by Western blotting indicated that AATK and VAV1 proteins were incorporated into a protein complex. d AATK overexpression increased nuclear VAV1 protein expression. e VAV1 tyrosine phosphorylation decreased in response to IL-1β and the TGFβ inhibitor GW788388 but did not decrease in response to TGFβ treatment in Bx-PC3 cells. VAV1 tyrosine phosphorylation were expressed at a low level in Panc-1 PDA cells