title: Prognostic values of apoptosis-stimulating P53-binding protein 1 and 2 and their relationships with clinical characteristics of esophageal squamous cell carcinoma patients: a retrospective study.
abstract: BACKGROUND
  Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related death, and new prognostic biomarkers are urgently needed. Apoptosis-stimulating P53-binding protein 1 (ASPP1) and 2 (ASPP2) have been reported to play important roles in the development, progression, metastasis, and prognosis of cancers, but their roles in ESCC have not been elucidated. In this study, we examined the expression of ASPP1 and ASPP2 in ESCC to evaluate their prognostic values.
  
  
  METHODS
  The protein expression of ASPP1, ASPP2, and P53 in 175 specimens of ESCC was detected using immunohistochemical staining; their expression in cancerous and noncancerous tissues was scored according to the staining intensity and the percentage of stained cells. The associations of ASPP1, ASPP2, and P53 with clinicopathologic parameters, overall survival (OS), and disease-free survival (DFS) were analyzed.
  
  
  RESULTS
  The protein expression levels of ASPP2 and P53 were significantly higher in cancerous tissues than in paired noncancerous tissues (P < 0.001), whereas the expression levels of ASPP1 in the two groups were similar. In ESCCs, ASPP1 expression was significantly associated with histological differentiation (P = 0.002) and invasive depth (P = 0.014); ASPP2 expression was associated with age (P = 0.029) and histological differentiation (P < 0.001); and P53 expression was associated with age (P = 0.021) and tumor size (P = 0.040). No correlations were found between ASPP1, ASPP2, and P53 expression. Survival analysis revealed that high ASPP2 expression was significantly associated with increased 5-year OS (P = 0.001) and DFS rates (P = 0.010) and that high P53 expression was significantly associated with a reduced 5-year DFS rate of ESCC patients (P = 0.015). Multivariate Cox analysis indicated that ASPP2 was an independent predictor of OS [hazard ratio (HR): 0.541, 95% confidence interval (CI) 0.363-0.804] and DFS (HR: 0.599, 95% CI 0.404-0.888) of ESCC patients and that P53 was an independent predictor of DFS (HR: 2.161, 95% CI 1.100-4.245).
  
  
  CONCLUSIONS
  ASPP1 might be involved in the progression of ESCC, and ASPP2 was a potential prognostic biomarker of ESCC and should be evaluated in future studies.
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China.|Department of Endoscopy and Laser, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, Guangdong, 510060, P. R. China.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China.|Department of Endoscopy and Laser, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, Guangdong, 510060, P. R. China.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China.|Department of Endoscopy and Laser, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, Guangdong, 510060, P. R. China.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chi
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Xian-Zi
authors.initials: XZ
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China. wanghyun@mail.sysu.edu.cn.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China. wanghyun@mail.sysu.edu.cn.
authors.forename: Hui-Yun
authors.initials: HY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, P. R. China. sysuccnj@sina.com.|Department of Endoscopy and Laser, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, Guangdong, 510060, P. R. China. sysuccnj@sina.com.|Guangdong Esophageal Cancer Institute, Guangzhou, Guangdong, 510060, P. R. China. sysuccnj@sina.com.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Xu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D018572:Disease-Free Survival; D004938:Esophageal Neoplasms / Q000378:metabolism*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D047368:Tumor Burden; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C498406:PPP1R13B protein, human; C495901:TP53 protein, human; C090468:TP53BP2 protein, human; D016159:Tumor Suppressor Protein p53
keywords: Apoptosis-stimulating protein of P53 1 and 2; Esophageal squamous cell carcinoma; P53; Prognosis