The Role Of USP7 In The Regulation Of C-Myc In Lung Adenocarcinoma

Objective: In this experiment,we mainly investigated the expression of USP7 and C-Myc in lung adenocarcinoma and their correlation with clinicopathological features,epithelial-mesenchymal transition(EMT)-related tumor invasion and transfer factors,so as to preliminarily explore the role of USP7 in lung adenocarcinoma proliferation,apoptosis,invasion and metastasis,and further explore the regulatory role of USP7 on C-Myc in lung adenocarcinoma,which provides a theoretical basis for lung adenocarcinoma drug development and clinical treatment.Methods:(1)A total of 50 cases of high,medium and low differentiated paraffin specimens and 50 cases of adjacent tissues diagnosed as lung adenocarcinoma in the department of pathology from 2016 to 2020 were collected,and the expression of USP7 and C-Myc in lung adenocarcinoma and its relationship with clinicopathological features were detected by immunohistochemical method;(2)si RNA was transfected into lung adenocarcinoma A549 and H1975 cell lines,and the effects of USP7 knock-down on invasion,metastasis,proliferation and apoptosis of lung adenocarcinoma were detected by cell scratch test,Transwell test,MTT test,Hoechst test and flow cytometry;(3)si RNA was transfected into lung adenocarcinoma cell lines A549 and H1975,and Western blot was used to determine the regulatory mechanism of related cell signals;(4)Immunoprecipitation assay was used to detect the interaction between USP7 and C-Myc in lung adenocarcinoma;(5)si RNA was transfected into lung adenocarcinoma cell lines A549 and H1975,and then proteasome inhibitor MG132 was added.Western blot was used to confirm that USP7 regulated C-Myc through ubiquitin proteasome pathway in lung adenocarcinoma.Results:(1)Compared with the adjacent tissues of lung adenocarcinoma,USP7 and C-Myc were highly expressed,and the difference was statistically significant(p<0.01),but there was no significant correlation between their expression and gender,age,tumor size,differentiation degree,TNM stage and lymph node metastasis of lung adenocarcinoma patients(p>0.05);(2)Down-regulation of USP7 inhibited the proliferation,invasion and metastasis of lung adenocarcinoma,and promoted the apoptosis of lung adenocarcinoma;(3)USP7and C-Myc interact in lung adenocarcinoma,and USP7 has a positive regulatory effect on C-Myc;(4)In lung adenocarcinoma,USP7 regulates C-Myc through ubiquitin proteasome pathway.Conclusion: USP7 regulates the transcription factor C-Myc through the ubiquitin proteasome to regulate multiple life activities such as lung adenocarcinoma invasion and metastasis.