title: Identification of candidate biomarkers for the early detection of nasopharyngeal carcinoma by quantitative proteomic analysis.
abstract: Nasopharyngeal carcinoma (NPC) is a major head and neck cancer with high occurrence in Southeast Asia and southern China. To identify novel biomarkers for the early detection of NPC patients, 2D-DIGE combined with MALDI-TOF-MS analysis was performed to identify differentially expressed proteins in the carcinogenesis and progression of NPC using LCM-purified normal nasopharyngeal epithelial tissues and various stages of NPC biopsies. As a result, 26 differentially expressed proteins were identified, of which two proteins with sharp expressional changes in the carcinogenic process, ENO1 and CYPA, were validated by western blot analysis and identified as critical seed proteins in the functional network. Immunohistochemistry assay was further performed to detect the expression of the two proteins with a tissue microarray that included various stages of NPC tissues. The ability of these proteins to detect NPC early was evaluated via a receiver operating characteristic analysis. The results indicated that the combination of the two proteins could perfectly discriminate NNET and AH from stage I of NPC with high sensitivity and specificity, which is more effective than using either of the two proteins individually. In summary, the combination of ENO1 and CYPA can serve as potential molecular markers for the early detection of NPC.
  
  
  CONCLUSIONS
  NPC is a lethal malignancy that is most prevalent in Southeast Asia, and early detection and treatment are essential for the survival and good prognosis of NPC patients. In the present work, we identified 26 differentially expressed proteins in NNET, AH and different stages of NPC tissues by using 2D-DIGE combined with MALDI-TOF/TOF analysis. Of these proteins, the down-regulation of ENO1 and over-expression of CYPA were confirmed with a high-throughput tissue microarray that included various stages of NPC tissues via an IHC assay, and the results indicated that the combination of ENO1 and CYPA can serve as a potential molecular marker for the early detection of NPC.
authors.affiliation: Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha 410013, China; Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China; High Resolution Mass Spectrometry Laboratory of Advanced Research Center, Central South University, Changsha 410078, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha 410013, China; Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China. Electronic address: zhouming2001@163.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Shuping
authors.initials: S
authors.lastname: Peng
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Luo
authors.affiliation: The Third Xiangya Hospital, Central South University, Changsha 410013, China.
authors.forename: Xiayu
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Li
authors.initials: L
authors.lastname: Cao
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Tang
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: The Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Songqing
authors.initials: S
authors.lastname: Fan
authors.affiliation: Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Schmitt
authors.affiliation: Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Tan
authors.affiliation: Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Li
authors.affiliation: Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha 410013, China; Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha 410078, China. Electronic address: ligy@xysm.net.
authors.forename: Guiyuan
authors.initials: G
authors.lastname: Li
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D002277:Carcinoma; D021984:Cyclophilin A / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D025521:Tumor Suppressor Proteins; C095157:ENO1 protein, human; D010751:Phosphopyruvate Hydratase; D021984:Cyclophilin A
keywords: CYPA; ENO1; Microdissection; Nasopharyngeal carcinoma; Proteomic; Tumor biomarkers