title: CIP2A is overexpressed in osteosarcoma and regulates cell proliferation and invasion.
abstract: Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a newly characterized oncoprotein involved in a variety of malignant tumors. However, its expression pattern and biological functions in osteosarcoma remain unclear. In the present study, CIP2A expression was analyzed in 51 human osteosarcoma specimens using immunohistochemistry. CIP2A siRNA was used in the MG-63 cell line, and the effect of CIP2A depletion on cell proliferation and invasion was evaluated. We found that CIP2A was overexpressed in 76.5 % (39/51) of osteosarcoma tissues, while normal bone tissues showed negative CIP2A expression. In addition, the positive rate of CIP2A expression was higher in stage IIB osteosarcoma than stage IIA cases. Knockdown of the CIP2A expression significantly reduced osteosarcoma cell proliferation and invasion, with decreased c-Myc expression and p-AKT expression. CIP2A depletion also facilitated apoptosis and inhibited MMP9 mRNA expression. Taken together, our data identified CIP2A as a critical oncoprotein involved in cell proliferation and invasion, which could serve as a therapeutic target in osteosarcoma.
authors.affiliation: Department of Orthopaedics, The First Hospital of China Medical University, No. 155 Nanjingbei Street, Heping District, Shenyang, 110001, China.
authors.forename: Mo
authors.initials: M
authors.lastname: Zhai
authors.forename: Lin
authors.initials: L
authors.lastname: Cong
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Han
authors.forename: Guanjun
authors.initials: G
authors.lastname: Tu
mesh_terms: D000293:Adolescent; D000328:Adult; D001324:Autoantigens / Q000096:biosynthesis / Q000235:genetics*; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000235:genetics*; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D001324:Autoantigens; C500266:CIP2A protein, human; D047908:Intracellular Signaling Peptides and Proteins; C489427:MYC protein, human; D008565:Membrane Proteins; D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D051057:Proto-Oncogene Proteins c-akt; D020780:Matrix Metalloproteinase 9