title: Ubiquitin-specific protease 4 inhibits breast cancer cell growth through the upregulation of PDCD4.
abstract: Breast cancer is a common malignant tumor affecting women. The study of the association between breast cancer and molecular aberrations may lead to the development of novel diagnostic and therapeutic strategies for the disease. In the present study, we examined the role of ubiquitin-specific protease 4 (USP4) in breast cancer. We found that USP4 expression was significantly decreased in breast cancer tissue samples compared with paired normal breast tissue samples (P<0.001). USP4 was identified as a tumor suppressor. In addition, by inducing USP4 overexpression (using a USP4 overexpression plasmid) or the knockdown of USP4 (by transfection with a USP4 shRNA plasmid), we found that USP4 inhibited cell proliferation in vitro. We also found that USP4 suppressed tumor growth by using a mouse tumor xenograft model. Moreover, programmed cell death 4 (PCD4) was identified to be a target of USP4, which plays a role as a tumor suppressor. As a whole, our findings sugggest that USP4 acts as a tumor suppressor in breast cancer and that it may be an effective target for the treatment of breast cancer.
authors.affiliation: Department of Breast Surgery, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning 110042, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Breast Surgery, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning 110042, P.R. China.
authors.forename: Daqing
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Department of Breast Surgery, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning 110042, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Interventional Radiology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116023, P.R. China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Breast Surgery, The First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning 116023, P.R. China.
authors.forename: Zhengang
authors.initials: Z
authors.lastname: Cai
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics*; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D061986:MCF-7 Cells; D016513:Mice, SCID; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous; D047368:Tumor Burden / Q000235:genetics; D043222:Ubiquitin Thiolesterase / Q000235:genetics* / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases; D015854:Up-Regulation
chemical_list: D051017:Apoptosis Regulatory Proteins; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins; C486203:USP4 protein, human; D043222:Ubiquitin Thiolesterase; D064570:Ubiquitin-Specific Proteases