The Role And Molecular Mechanism Of USP4 In Proliferation,Migration And Invasion Of Pancreatic Cancer

Objective: Ubiquitin specific proteases(USPs)are the largest of the five subgroups of Deubiquitinases(DUBs),which stabilize the expression levels of proteins related to cell proliferation,apoptosis,invasion and metastasis through deubiquitination.It is closely related to the occurrence and development of various tumors.USP4 is a member of the USPs family.Recent studies have found that USP4 can also accelerate tumor progression,but its role and mechanism in pancreatic cancer are not clear.Therefore,in-depth study of the mechanism of USP4 in pancreatic cancer will provide theoretical and experimental basis for further development of molecular targeted drugs.Methods: 1.Gene Expression Profiling Interactive Analysis(GEPIA)was used to analyze the Expression of USP4 in pancreatic and normal pancreatic tissues.2.Fifty clinically diagnosed cases of pancreatic cancer and 10 adjacent tissues were collected,and the expression of USP4 in pancreatic and adjacent tissues was detected by immunohistochemical method.3.The expression levels of USP4 and Survivin in four pancreatic cancer cell lines(SW1990,PANC-1,MIA Pac A-2 and ASC-1)were detected by western blotting,and the cell lines with high expression were screened out.4.Cell proliferation assay(MTT)and cell invasion and migration assay were used to study the effects of USP4 on the proliferation,invasion and migration of pancreatic cancer cells,and the expression of proteins related to cell proliferation,invasion and migration was further detected by western blot assay.Results: 1.USP4 was highly expressed in pancreatic cancer and correlated with survival rate.2.The expression of USP4 and Survivin in pancreatic cancer was positively correlated,and the high expression of USP4 and Survivin was significantly correlated with tumor differentiation and lymph node metastasis.3.USP4 and Survivin were highly expressed in all four pancreatic cancer cell lines,especially in PANC-1 and MIA Pa Ca-2 cells.4.MTT assay showed that upregulation of USP4 significantly increased cell proliferation,while downregulation of USP4 significantly decreased cell proliferation;(P < 0.01)Western blot showed that upregulated USP4 expression increased the expression levels of Cyclin D1 and Survivin,but decreased the expression levels of P53,P21,caspase-3 and c-caspase-3.The results were opposite after downregulated USP4 expression.5.Scratch test showed that the wound healing rate of USP4 overexpression group was significantly higher than that of the control group,while the wound healing rate of USP4 downregulation group was significantly lower.Transwell assay showed that the number of us P4-overexpressed cells was significantly increased,while the number of us P4-downregulated cells was significantly decreased;(P < 0.05)Western blot assay showed that USP4 overexpression enhanced the expression of invasion and migration related factor Wnt-3a,decreased the expression of epithelial marker E-cadherin,increased the expression of Vimentin,Snail and Slug,and significantly increased p-Akt.The results were reversed after USP4 downregulation.Conclusion: 1.USP4 and Survivin are highly expressed in pancreatic cancer tissues,and their expressions are positively correlated.High expression of USP4 and Survivin is associated with differentiation and lymph node metastasis of pancreatic cancer.2.USP4 promotes proliferation and induces apoptosis of pancreatic cancer cells by regulating Survivin expression.The activation of AKT and Wnt signaling pathways promotes the migration and invasion of pancreatic cancer cells,thereby promoting the occurrence and development of pancreatic cancer.