Preliminary Study Of EGFR-targeted Fluorescent Probes

ErbB family proteins are members of receptor tyrosine kinase superfamily.They play crucial role in cellular functions,including cell proliferation,differentiation and survival.Mutation or overexpression of ErbB family proteins has impacts on cellular homeostasis and their micro-environment through MAPK,PI3K/AKT and STATs signaling pathways.Dysregulation of their signals drives the development of a variety of cancers,including lung and breast cancer.ErbB receptors are activated by ligand-dependent dimerization.In addition,to tightly regulate Erb B activities,inhibition mechanism have also been evolved: on one hand,the extracellular domain of EGFR adopts autoinhibitory conformations to inhibit the dimerization of EGFR;on the other hand,intracellular proteins,like Mig6,act as feedback inhibitor to downregulate activated receptor activities.A variety of drugs,such as Lapatinib,Gefitinib,and Herceptin,have been developed as targeted therapeutics in the treatment of cancers associated with ErbB dysfunctions.However,each one of them has its own therapeutic window,and long-term application of those drugs will eventually lead to resistance.Therefore,it necessitate to have a deep understanding of ErbB receptor structures and functions,and to develop novel thera-diagnostic probes.Herein,I studied the heterodimerization of EGFR and HER2.I added acid and basic coiled coil to the C-terminals of EGFR and HER2,respectively,to drive the heterodimerization of thos two receptors.In addition,we designed and synthesized three EGFR-targeted fluorescent probes.I measured the absorption,excitation,and emition spectrum of these probes.I also observed the binding of these fluorescent probes to EGFR and HER2 on the cell level with Confocal and Microplate Reader.Unfortunately,because it was impossible to exclude the influence of endocytosis and the nonspecific adsorption of fluorescence probes,at current stage,I cound not differentiate the specific binding from non-specific binding of three probes in cell-based assays.As the probes have the potencial in thera-diagnostic of cancers and high-throughput screeing of ErbB-targeted compounds,further studies will be takin to improve the specificity and effacy of those probes.