Studies On The Interaction Between Mutant Soluble Ectodomain Of Human Fibroblast Growth Factor Receptor 2Ⅲc(ms FGFR2c) And EGFR

Objective:Abnormal activation of various Receptor tyrosine kinase pathways exists in many cancers,and there is a complementary mechanism between each pathway.When one of the signal pathways was inhibited,another or multiple pathways were enhanced,making the efficacy of single target drug for cancer treatment continues decline.Previous studies have shown that ms FGFR2c prepared in our experiment can effectively block the FGFR signaling pathway.Under the condition of EGF induction,msFGFR2c can also inhibit the phosphorylation of EGFR,however the mechanism is not yet clear.To explore its mechanism of action for the development of double-target or multi-target drugs is valuable.Methods:The recombinant EGFR extracellular domain protein was constructed using prokaryotic expression system.CCK-8 method was used to detect its biological activity.WB was used to detect the inhibitory effect of msFGFR2c on EGFR phosphorylation in DU145.Co-IP was used to detect the interaction between msFGFR2c and EGFR.Confocal microscopy were used to show the co-localization of msFGFR2c and EGFR;ITC detection of the binding force between ms FGFR2c and EGFR.Results:The results of CCK-8 showed that the recombinant EGFR extracellular domain had the activity to repress H1299 cell’s proliferation.WB results showed that msFGFR2c could significantly inhibit the phosphorylation of EGFR in DU145 cells.Co-IP results showed that msFGFR2c could bind to EGFR.Laser confocal results showed that there was a clear co-localization of msFGFR2c with overexpressed EGFR on the membrane.ITC results showed that msFGFR2c could bind specifically with EGFR,K=5.41E4M^-1.Conclusions:The mutant soluble ectodomain of FGFR2IIIc that msFGFR2c constructed in our laboratory can be used as a potential dual target（FGFR and EGFR）drug for the treatment of tumors.