USP25 Affects The Biological Behaviors Of Breast Cancer Cells And Its Underlying Mechanism

Objective: We explored the role of USP25 with its underlying mechanism by observing the expression of USP25 in breast cancer tissues,the biological behaviors of MCF-7 cells after knock-down of USP25 and the relation between UBE3 A and USPs.Methods: The expression of USP25 was detected by immunohistochemical staining in 50 samples of paraffin-embedded breast cancer tissues,and the relation between USP25 and clinicopathological characteristics was statistically analyzed.After shRNA-USP25 lentivirus transfecting into breast cancer cells MCF-7,the expression level of USP25 protein was tested by western blotting and fluorescence quantitative PCR to screen and obtain lentivirus with the highest interference efficiency.CCK8 analysis was used to observe proliferation of cells,and Transwell was used to detect invasion of cells,and apoptosis was detected by flow cytometry after knock-down of USP25.Moreover,we studied the potential mechanism of USP25 affecting breast cancer by observation of USP25 after knock-down,and analysis of transcriptome sequencing,gene expression profile,and bioinformatics.Results: The positive expression rate of USP25 was 72%(36/50)in breast cancer tissues,while it showed negative expression in the adjacent normal tissues,and the difference was statistically significant(P =0.000).The expression level of USP25 was associated with histological grade(P =0.046),lymph node metastasis(P =0.041)and the expression of Ki-67(P =0.029).The expression level of USP25 was the lowest in KD1 group with the highest efficiency of knock-down,so it was the best interference fragment(P =0.0000014),and the expression level of USP25 mRNA decreased significantly(P =0.0000015).After knock-down of USP25,the proliferation of MCF-7 cells was depressed by CCK8 analysis(P < 0.001),and the invasion of cells was significantly decreased by Transwell test(P =0.000045),and the apoptosis was significantly increased by flow cytometry analysis(P =0.0000021).Meanwhile,after knock-down of UBE3 A,protein and mRNA of USP25 were significantly down-expressed(P =0.00000069,P =0.00000070),and there are more than 50 differential USPs genes by the transcriptome sequencing and gene expression profile.USP25 could be involved in the IL-17 pathway by bioinformatics analysis in the KEGG database,and results in tumorigenesis of breast cancer.Conclusion: USP25 was high-expressed in breast cancer,which affected the proliferation,apoptosis,invasion and metastasis of breast cancer cells.USP25 may play an important role in tumorigenesis of breast cancer with a possible UBE3A-mediated mechanism.