The Correlation And Activation Mechanism Of EGFR And C-Met In Triple Negative Breast Cancer

Breast cancer is the most common malignant tumor in women and has become the second leading cause of cancer death.Triple negative breast cancer(TNBC)refers to invasive breast cancer that is negative for progesterone receptor(PR),estrogen receptor(ER),and human epidermal growth factor receptor 2(HER2).It accounts for 10%-20% of all breast cancer cases,and its malignancy is higher than that of non-TNBC.Due to the lack of effective targeted therapy,the prognosis of patients with TNBC is generally poor.Therefore,it is a current research hotspot to find TNBC treatment targets and treatment methods.Epidermal growth factor receptor(EGFR)is abnormally activated through a variety of mechanisms,forms a dimer after binding to ligand EGF,and induces its autophosphorylation,thereby initiating downstream signaling pathways,promoting cell proliferation,and inhibiting apoptosis Death and promote cell invasion.Cellular mesenchymal-epithelial transition factor(c-Met)has a high degree of binding to ligand HGF.After the ligand binds to c-Met in the extracellular domain,it induces phosphorylation of c-Met,and the pathway is unregulated It has been reported in various human cancers.The abnormally high expression of EGFR and c-Met in TNBC makes it an important drug target for the treatment of TNBC.To visualize EGFR and c-Met on the surface of triple-negative breast cancer cells,using nucleic acid aptamers to mediate the linking of gold nanoparticles,the singlemolecule imaging technique of scanning electron microscopy was used to compare EGFR and c-Met on the cell membrane at the nanometer scale The expression quantity and aggregation state of the surface and the co-localization relationship between the two were characterized.At the same time,combined with the study of the structure and functional characteristics of the two membrane proteins,the interaction of EGFR and c-Met and the protein activation mechanism were explored,which provided a new visual research method for a clearer understanding of the function and regulatory mechanism of the protein.Provide reference for drug research and development and development of precision targeted therapy research.Specific experimental work includes the following aspects:1.Co-localization of EGFR and c-Met on cell membrane.Using streptavidin-biotin technology,using two different sizes of gold nanoparticles combined with nucleic acid aptamers to co-label and co-localize EGFR and c-Met.The ultra-high resolution imaging observation of the two membrane proteins on the nanometer scale by environmental scanning electron microscopy verified the existence of heterodimers and multimers formed by EGFR and c-Met,and carried out statistical analysis.2.The interaction and regulation relationship between EGFR and c-Met.Using small interfering RNA(si RNA)to conduct gene silencing on EGFR and c-Met respectively,using Realtime PCR and Western blot technology to detect the m RNA transcription level and protein expression level of EGFR and c-Met in cells,and explore the expression of the two proteins There is a dynamic balance of quantity.3.C-Met activation and inhibition mechanism.Using high-resolution environmental scanning electron microscope imaging technology to observe the colocalization of HGF / c-Met and c-Met / p-Met on the membrane of MB-231 cell,and explore the activation mechanism of c-Met.The c-Met small molecule inhibitor INCB28060 was selected for cell administration,to explore the mechanism of action of the small molecule inhibitor and to test its effect.