title: Overexpression of suppressor of zest 12 is associated with cervical node metastasis and unfavorable prognosis in tongue squamous cell carcinoma.
abstract: OBJECTIVE
  Increased expression of suppressor of zest 12 (SUZ12), a core component of the polycomb repressive complex 2, contributes to human tumorigenesis and associates with patient prognosis. In the present study, we sought to investigate the expression of SUZ12 and its clinicopathological significance in primary tongue squamous cell carcinoma (TSCC).
  
  
  METHODS
  The expression of SUZ12 protein was determined by immunohistochemistry in clinical samples from a retrospective cohort of 72 patients with primary TSCC who were treated at our institution from Jan. 2007 to Dec. 2013. The potential associations between SUZ12 abundance and multiple clinicopathological parameters were assessed by Chi square test. Moreover, the effect of SUZ12 expression on patients' survival was further estimated by Kaplan-Meier and Cox regression analyses.
  
  
  RESULTS
  Our immunohistochemical staining data revealed aberrant overexpression of SUZ12 in a large subset of TSCC as compared to normal tongue mucosa. Elevated SUZ12 was found to be significantly associated with cervical nodes metastasis (P= 0.0325) and reduced overall as well as disease-free survival (Log-rank test,P= 0.0225, 0.0179, respectively). Both univariate and multivariate Cox regression analysis identified the expression status of SUZ12 (low/high) as an important independent prognostic factor for patients' survival.
  
  
  CONCLUSIONS
  Our data reveal that aberrant SUZ12 overexpression is associated with cervical nodes metastasis and reduced survival in TSCC. These findings suggest that SUZ12 might play critical roles during tongue tumorigenesis and serve as a novel biomarker with diagnostic and prognostic significance.
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Hu
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.|Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, 136, Hanzhong Road, Nanjing, 210029 People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Zhongwu
authors.initials: Z
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Yumin
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Oral Pathology, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, 136, Hanzhong Road, Nanjing, 210029 People's Republic of China.
authors.forename: Dongmiao
authors.initials: D
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Tangyi
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, 136, Hanzhong Road, Nanjing, 210029 People's Republic of China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029 People's Republic of China.|Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, 136, Hanzhong Road, Nanjing, 210029 People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
keywords: Polycomb repressive complex; Prognosis; SUZ12; Tongue squamous cell carcinoma