title: SPAG9 is overexpressed in osteosarcoma, and regulates cell proliferation and invasion through regulation of JunD.
abstract: Sperm-associated antigen 9 (SPAG9) is a recently characterized oncoprotein that is considered to be involved in several forms of malignant tumor. However, its biological function and expression pattern in human osteosarcoma have not yet been elucidated. In the present study, SPAG9 expression was analyzed in 58 cases of human osteosarcoma by immunohistochemistry. The results demonstrated that SPAG9 was overexpressed in 63.8% (37/58) of osteosarcoma tissues, while normal bone tissues exhibited negative SPAG9 expression. SPAG9 small interfering RNA was employed in the U2OS cell line, which has high endogenous expression, and SPAG9 transfection was performed in the MG63 cell line, which has low endogenous expression. MTT and Matrigel invasion assays demonstrated that SPAG-9-knockdown significantly reduced U2OS cell invasion and proliferation, while SPAG9 transfection enhanced MG63 cell proliferation and invasion. Furthermore, it was observed that SPAG9 positively regulated cyclin D1, phosphorylated-c-Jun NH2-terminal kinase (JNK) and JunD expression. Treatment with the JNK inhibitor, SP600125, abolished the upregulatory effect of SPAG9 on JunD. Taken together, the present study identified SPAG9 as a critical oncoprotein involved in osteosarcoma proliferation and invasion, possibly functioning through JNK-JunD signaling.
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Chi
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Department of Pathology, China Medical University, Shenyang, Liaoning 110001, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Fu
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Chongnan
authors.initials: C
authors.lastname: Yan
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Fenyong
authors.initials: F
authors.lastname: Shou
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Shaoqian
authors.initials: S
authors.lastname: Cui
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Jingzhu
authors.initials: J
authors.lastname: Duan
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Jin
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Yuanming
authors.initials: Y
authors.lastname: Bian
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
keywords: JunD; SPAG9; invasion; osteosarcoma; proliferation