The Deubiquitinase RPN11 Promotes Proliferation And Migration Of Breast Cancer Cells

The pathogenesis of breast cancer is unclear.Ubiquitination can affect the occurrence and development of cancer in many ways,and it is a dynamic and reversible process,and that the reverse reaction and regulation of which are controlled by the deubiquitinating enzymes(DUBs).RPN11 is an important DUBs that affect the cell activity and tumor transformation.Studies have shown that RPN11 is upregulated in cancer cells,mainly in melanoma,ovarian cancer and leukemia cells,in which RPN11 can be used as a marker of malignant tumors.And can be used as a target for cancer therapy.In order to investigate the role of RPN11 in the pathogenesis of breast cancer,we first detected the expression of RPN11 in breast cancer and its adjacent tissues.QRT-PCR was used to detect the expression of RPN11 in 59 cases of breast cancer and its adjacent tissues.The results showed that the expression of RPN11 was significantly higher in breast cancer tissues than that in adjacent tissues.In addition,we retrieved and analyzed the GSE3744 dataset,which included 47 cases of breast cancer,and found that the expression of RPN11 was high in breast cancer tissues as well.We detected the expression of RPN11 in 6 cases of fresh breast cancer tissues and adjacent tissues through western-blot,and found that RPN11 was highly expressed in breast cancer tissues.Immunohistochemistry was used to detect the expression of RPN11 in the tissue microarray including 142 cases of breast cancer.The results showed that RPN11 was weakly expressed in normal tissues and was highly expressed in breast cancer tissues.At the same time,high expression of RPN11 was closely associated with high clinical stage(P<0.05).In breast cancer cell line MDA-MB-231 and T47D,we used siRNA to study the effect of reducing the expression of RPN11 on cell proliferation.The results of MTT assay showed that the decreased expression of RPN11 inhibited the proliferation of breast cancer cells MDA-MB-231 and T47D significantly.In addition,the effects of RPN11 on cell apoptosis and cell cycle were detected by flow cytometry.Similarly,the data suggested that knockdown of RPN11 expression may lead to increased in cell apoptosis and cell cycle arrest.We also observed that the decreased expression of RPN11 induced cell cycle arrest in G0/G1.In addition,we detected the expression of cyclin D1 and c-PARP by Western blot.The results showed that knockdown of RPN11 expression could up regulate the expression of c-PARP and inhibit the expression of cyclin D1.In contrast,overexpression of RPN11 in human breast cancer cell line MCF7 and Hs578T showed that overexpression of RPN11 promotes cell proliferation,cell cycle progression,and inhibition of apoptosis.Transwell results showed that knockdown of RPN11 expression decreased the migration ability of breast cancer cells.Epithelial mesenchymal transition(EMT)is an important step in tumor cell migration.We detected the expression of EMT related genes after knockdown of RPN11 by qRT-PCR method.We found that the expression of E-cadherin was up-regulated and the expression of N-cadherin,FN1 and vimentin decreased.EMT related regulatory factors such as Snail(SNAI1)and Slug(SNAI2)were also inhibited.Western blot detection also showed similar results.Overall,our data suggested that high expression of Rpnll in breast cancer may be involved in cancer cell migration.In this study,the expression of RPN11 in breast cancer tissues was confirmed.The effects of a series of cytological experiments on cell proliferation,cell cycle,apoptosis and cell migration were confirmed.RPN11 can be used as a target to provide a theoretical basis for targeted therapy of breast cancer.