Function And Regulation Mechanism Of TRIM56 In Lung Adenocarcinoma

Objective: Ubiquitination modification is an important and common protein posttranslational modification process,which plays an important role in the occurrence and development of tumors.Ubiquitin ligase is a key molecule that catalyzes this process.Studies have shown that the ubiquitin ligase TRIM56(Tripartite Motif-Containing Protein56)can ubiquitinate and modify a variety of important substrate molecules and regulate the occurrence and development of a variety of tumors.However,the function and mechanism of TRIM56 in lung adenocarcinoma have not been reported,and the substrate protein of TRIM56 needs to be further enriched.In order to explore the function and mechanism of TRIM56 in lung adenocarcinoma,we conducted research.Methods: Through bioinformatics data retrieval and analysis combined with experimental verification,explore the expression changes of ubiquitin ligase TRIM56 in lung adenocarcinoma and its relationship with the prognosis of lung adenocarcinoma.Combined with the relationship between the expression of TRIM56 and the clinicopathological characteristics of tumors,the relationship between the changes of TRIM56 expression and the occurrence and development of lung adenocarcinoma was further analyzed.By constructing a lung adenocarcinoma cell line stably expressing TRIM56,the effect of overexpression of TRIM56 on the invasion and migration of lung adenocarcinoma was detected.Use bioinformatics data retrieval and analysis to explore the underlying mechanism of TRIM56 low expression in lung adenocarcinoma: respectively analyze the effects of TRIM56 gene sequence copy number changes,mutations and methylation levels on the expression of TRIM56.Using miRNA expression data and TRIM56 gene promoter region analysis in lung adenocarcinoma samples,combined with lung adenocarcinoma prognostic data,we explored the miRNA and transcriptional regulators that potentially regulate TRIM56.Through Co-IP,ubiquitination and q PCR experiments to analyze the potential mechanism of TRIM56 regulating lung adenocarcinoma.Results: Bioinformatics analysis and experiments verified that TRIM56 expression is down-regulated in lung adenocarcinoma tissues and cell lines and is related to the poor prognosis of lung adenocarcinoma(Figure 1).It is speculated that TRIM56 may play a role in suppressing tumors in lung adenocarcinoma.Combined with the analysis of clinicopathological characteristics of lung adenocarcinoma samples,the down-regulation of TRIM56 expression is closely related to the occurrence and development of lung adenocarcinoma(Figure 2).By constructing a lung adenocarcinoma cell line stably overexpressing TRIM56,it was proved that overexpression of TRIM56 can inhibit the invasion and migration of lung adenocarcinoma cells(Figure 3).By analyzing the gene sequence changes and epigenetic changes(copy number changes,mutations and methylation levels)and miRNA expression changes of TRIM56 in lung adenocarcinoma samples,we found that copy number changes may be the main cause of the down-regulation of TRIM56 expression,and explored two potential miRNAs(hsa-mir-542,hsa-mir-627)that regulate the expression of TRIM56 in lung adenocarcinoma(Figure 4,Figure 5 and Table 1).Through the analysis of the promoter region,the potential transcription factors TFII-1,RXR-alpha,AP-2alpha A,Pax-5,c-Ets-1,ZBTB7 B and SP2 that regulate the expression of TRIM56 were explored(Table 2).Through Co-IP and ubiquitination experiments,we found that TRIM56 can increase the ubiquitination level of the deubiquitinase OTUD3(ovarian tumor deubiquitinase 3)and promote its ubiquitinproteasome pathway degradation(Figure 6).Interestingly,OTUD3 can deubiquitinate TRIM56 and stabilize its protein expression(Figure 7).At the transcriptional level,TRIM56 can also down-regulate the mRNA level of the oncogene TOP2A(Figure 8).Conclusion: The expression of ubiquitin ligase TRIM56 is down-regulated in lung adenocarcinoma and is closely related to the poor prognosis of lung adenocarcinoma.TRIM56 suppresses lung adenocarcinoma invasion and migration.On the one hand,TRIM56 exerts E3 ubiquitin ligase activity to promotes the ubiquitination and degradation of lung adenocarcinoma tumor-promoting molecule OTUD3.On the other hand,TRIM56 acts as a transcriptional regulator and regulates the transcription of TOP2 A.In summary,These findings demonstrate that TRIM56 is a negative regulator of lung adenocarcinoma and it is a potential early diagnostic marker and therapeutic target for lung adenocarcinoma.