Nintedanib induces apoptosis in human pterygium cells through the FGFR2-ERK signalling pathway

AIM: To investigate whether nintedanib can inhibit pterygium cells through the fibroblast growth factor receptor 2 (FGFR2)/extracellular-signal-regulated kinase (ERK) pathway. METHODS: Human primary pterygium cells were cultured in vitro. After treatment with nintedanib, the cell morphology was observed under microscopy, the morphological changes of the nucleus were observed after DAPI staining, apoptosis was analyzed by Annexin-V FITC/PI double staining, and the changes of apoptosis-associated proteins were detected by Western blot. The binding ability of nintedanib to FGFR2 was predicted by molecular docking. Finally, by silencing FGFR2, we explored whether nintedanib inhibited FGFR2/ERK pathway. RESULTS: The results showed that nintedanib inhibited the growth of pterygium cells and caused nuclear pyknosis. The results of Annexin-VFITC/PI double staining showed that nintedanib was able to induce early and late apoptosis of pterygium cells, significantly increasing the expression of apoptosis-associated proteins Bax and cleaved-Caspase3 (P<0.05), and reducing the expression of Bcl-2 (P<0.05). In addition, nintedanib significantly inhibited ERK1/2 phosphorylation through FGFR2 (P<0.05). After silencing the expression of FGFR2, there was no significant difference in the inhibition of ERK1/2 phosphorylation by nintedanib (P>0.05). CONCLUSION: Nintedanib induces apoptosis of pterygium cells by inhibiting FGFR2/ERK pathway.