Study On The Physical Mechanism Of N-cadherin Tension Regulating The Invasion And Metastasis Of Lung Adenocarcinoma

Objective:Invasion and metastasis of tumor cells is a difficult point in the treatment of clinical lung adenocarcinoma,and its suppression is essential for improving the poor prognosis of malignant lung tumor.The movement of the tumor is closely related to the mechanical activity of the cell,and how it controls the invasion and metastasis of the lung tumor is still unclear.Methods:This study verified the invasion and metastasis model of lung adenocarcinoma cell A549 using scratch experiment and transwell experiment;according to the FRET principle,three types of ?-actin,?-catenin,and N-cadherin were constructed in order from the cytoskeleton to the cell membrane.Fluorescent tension probe,using these three probes to detect changes in intracellular tension conduction;at the same time,we performed point mutation or domain truncation on the ?-catenin probe and the N-cadherin probe,and obtained ?-catenin(Y489 mutant)and N-cadherin(??-catenin)tension probes for reveal the source and transmission of intracellular tension;cytoskeletal stabilizers,overexpression point mutation probes and domain truncation probes were used to study the relationship between cell structural tension and cell invasion and metastasis ability;observation through transfection lifeact and immunofluorescence experiments:the effect of microfilament skeleton depolymerization changes on the above tension transmission;quantification of changes in cytoplasmic osmotic pressure using freezing point osmometer;combined with calcium ion detection experiment,MQAE experiment and nanoparticle analyzer to evaluate:changes in intracellular fluid calcium,chloride ion concentration and protein particle number and distribution.Results:EGF stimulation enhanced the invasion and metastasis ability of A549 cells;in the tumor cell invasion and metastasis model,?-actin,?-catenin,and N-cadherin protein molecules showed basically the same changes in tension and were significantly enhanced;transfected with?-catenin(Y489 mutant)probe detects the molecular tension of P-catenin,which increases with the increase of invasion and metastasis ability.However,the tensile tension of the N-cadherin molecule detected by the N-cadherin(??-catenin)probe did not show an increase with the increase of invasion and metastasis force.After administration of microfilament microtubule stabilizers,the structural tension and invasion and metastasis ability of?-actin\?-catenin\N-cadherin in A549 cells were significantly weakened;lung tumor cells that lost probes in overexpression domains and lost tension conduction:Obviously showed weakened invasion and metastasis force;EGF stimulation induced enhanced depolymerization of microfilaments in A549 cells,accompanied by up-regulated osmotic pressure,calcium and chloride ion concentration,and protein particle number,while the tumor invasion model treated with framework stabilizer showed weak osmotic pressure,calcium and chloride ion Concentration and number of protein particles.Conclusion:The EGF-induced invasion and metastasis model of lung adenocarcinoma can induce the increase of microfilament tension,through the action of N-cadherin and ?-catenin connexin conduction tension,and ultimately produce inward membrane tension.This inward membrane tension,in combination with the outward osmotic pressure generated by EGF-induced microfilament depolymerization,synergistically regulates tumor cell invasion and metastasis.This discovery provides a new mechanism of intracellular mechanics for the migration of lung adenocarcinoma cells and a new therapeutic idea for inhibiting the invasion and metastasis of lung cancer cells.