Conclusions
This study demonstrates that Gab1 and apatinib affect tumor cell invadopodia and autocrine VEGF expression through the Gab1/SHP2/ERK1/2 axis in hilar cholangiocarcinoma cells.
Methods
The expression of Gab1 and vascular endothelial growth factor receptor 2 (VEGFR-2) in tumor cells was detected by real-time PCR. MTT, flow cytometry and transwell assays were used to determine the effect of Gab1 on the biological behavior of tumor cells. In situ gelatin zymogram, western blotting, ELISA and immunofluorescence were used to study Gab1- and apatinib-regulated invadopodia, epithelial-mesenchymal transition (EMT), and VEGF autocrine signaling through the SHP2/ERK1/2 pathway.
Results
Gab1 controlled invadopodia maturation via the regulation of cortactin and EMT. Additionally, Gab1-regulated autocrine VEGF was observed in tumor cells expressing VEGFR-2, and endogenous and exogenous VEGF regulated VEGF expression through p-VEGFR-2 nuclear aggregation. Furthermore, the Gab1/SHP2/ERK1/2 axis regulated invadopodia and VEGF autocrine function in tumor cells. Finally, apatinib inhibited the malignant behavior of tumor cells and the nuclear aggregation of p-VEGFR-2 by inhibiting the phosphorylation of VEGFR-2 (direct) and the expression of Gab1 (indirect) in tumor cells. Conclusions: This study demonstrates that Gab1 and apatinib affect tumor cell invadopodia and autocrine VEGF expression through the Gab1/SHP2/ERK1/2 axis in hilar cholangiocarcinoma cells.