The alternative splicing of the extracellular domain of
fibroblast growth factor receptor (FGFR)-2 generates the IIIb and IIIc
isoforms. Expression of FGFR-2 IIIb correlates with
vascular endothelial growth factor-A (
VEGF-A) expression and venous invasion of pancreatic ductal
adenocarcinoma (PDAC). By contrast, FGFR-2 IIIc expression correlates with faster development of liver
metastasis after surgery, and increased proliferation rates and invasion of the
cancer. In this study, we analyzed the expression and roles of total FGFR-2 (both
isoforms) to determine the effectiveness of FGFR-2-targeting
therapy for PDAC. Immunohistochemically, FGFR-2 was highly expressed in 25/48 (52.1%) PDAC cases, and correlated with advanced stage
cancer. In FISH analysis, FGFR2 was amplified in 3/7 PDAC cell lines. We stably transfected an FGFR-2
shRNA targeting the IIIb and IIIc
isoforms into FGFR2-amplified PDAC cells. The proliferation rates, migration, and invasion of FGFR-2-shRNA-transfected cells were lower than those of control cells in vitro. In response to
FGF-2, FGFR-2-shRNA-transfected cells showed decreased phosphorylation of ERK compared with control cells. The FGFR-2-shRNA-transfected cells also expressed lower levels of
vascular endothelial growth factor-A than control cells, and formed smaller s.c.
tumors in nude mice. These findings suggest that FGFR-2 is a therapeutic target for inhibition in PDAC.