title: Correlation of Skp2 overexpression to prognosis of patients with nasopharyngeal carcinoma from South China.
abstract: S-phase kinase-associated protein 2 (Skp2), which plays a role in cell cycle regulation, is commonly overexpressed in a variety of human cancers and associated with poor prognosis. However, its role in nasopharyngeal carcinoma (NPC) is not well understood. In this study, we examined the clinical significance of Skp2, with a particular emphasis on overall survival (OS) and disease-free survival (DFS), in NPC cases in South China, where NPC is an epidemic. Additionally, we explored the function of Skp2 in maintaining a cancer stem cell-like phenotype in NPC cell lines. Skp2 expression was assessed for 127 NPC patients using tissue microarrays and immunohistochemistry and analyzed together with clinicopathologic features, OS, and DFS. Skp2 expression was detectable, or positive, in 75.6% of patients. Although there was no correlation between Skp2 and any clinicopathologic factor, Skp2 expression significantly portended inferior OS (P = 0.013) and DFS (P = 0.012). In the multivariate model, Skp2 expression remained significantly predictive of poor OS [P = 0.009, risk ratio (RR) = 4.06] and DFS (P = 0.008, RR = 3.56), and this was also true for clinical stage (P = 0.012 and RR=3.201 for OS; P = 0.002 and RR=1.94 for DFS) and sex (P = 0.016 and RR=0.31 for OS; P = 0.006 and RR = 0.27 for DFS). After Skp2 knockdown, a colony formation assay was used to evaluate the self-renewal property of stem-like cells in the NPC cell lines CNE-1 and CNE-2. The colony formation efficiency in CNE-1 and CNE-2 cells was decreased. In Skp2-transfected CNE-1 and CNE-2 cells, side population (SP) proportion was increased as detected by flow cytometry. Skp2 is an independent prognostic marker for OS and DFS in NPC. Skp2 may play a role in maintaining the cancer stem cell-like phenotype of NPC cell lines.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, Guangdong 510060, People's Republic of China.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Liang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Chen
authors.forename: Qi-Nian
authors.initials: QN
authors.lastname: Wu
authors.forename: Yun-Miao
authors.initials: YM
authors.lastname: Guo
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Shen
authors.forename: Ru-Hua
authors.initials: RH
authors.lastname: Zhang
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: He
authors.forename: Yi-Xin
authors.initials: YX
authors.lastname: Zeng
authors.forename: Fang-Yun
authors.initials: FY
authors.lastname: Xie
authors.forename: Tie-Bang
authors.initials: TB
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D045744:Cell Line, Tumor; D002681:China; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D014411:Neoplastic Stem Cells / Q000473:pathology*; D034741:RNA, Small Interfering / Q000235:genetics; D044786:S-Phase Kinase-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D012737:Sex Factors; D015996:Survival Rate; D046888:Tissue Array Analysis; D014162:Transfection; D055815:Young Adult
chemical_list: D034741:RNA, Small Interfering; D044786:S-Phase Kinase-Associated Proteins