title: Down-regulated ECRG4 expression in breast cancer and its correlation with tumor progression and poor prognosis--A short Report.
abstract: BACKGROUND
  Recently, we identified the esophageal carcinoma related gene 4 (ECRG4) as a novel candidate tumor suppressor gene and a promising therapeutic target in nasopharyngeal carcinoma (NPC). In addition, we found that reduced ECRG4 expression in NPC was associated with promoter hypermethylation. The aim of the current study was to assess the expression status of the ECRG4 protein in breast cancer and to clarify its clinicopathological significance and potential prognostic implications.
  
  
  METHODS
  Western blotting was used to examine ECRG4 protein levels in 20 paired breast cancer tissues and adjacent noncancerous tissues. In addition, we performed ECRG4 immunohistochemistry on 113 clinicopathologically well-characterized breast cancer samples and assessed putative associations between its expression and overall patient survival rates.
  
  
  RESULTS
  We found that ECRG4 protein expression was significantly reduced in the breast cancer tissues compared to the noncancerous tissues. Clinicopathological analyses revealed that loss of ECRG4 protein expression, observed in 41.6 % (47/113) of the primary breast cancer tissues tested, was significantly correlated with lymph node metastasis (P = 0.026), advanced tumor stage (P = 0.042) and unfavorable overall survival (P = 0.004). Additional multivariate analyses revealed that ECRG4 protein expression may serve as an independent prognostic factor for the prediction of patient survival (P = 0.033).
  
  
  CONCLUSIONS
  Our data suggest that loss of ECRG4 protein expression may be involved in tumor progression and may serve as a prognostic biomarker for breast cancer.
authors.affiliation: Pathological Examination and Research Center, Luohe Medical College, Luohe, 462002, China.|Department of Pharmacy, Luohe Medical College, Luohe, 462002, China.|Luohe Key Laboratory of Medical Bioengineering, Luohe Medical College, 148 Daxue-Road, Luohe, 462002, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: You
authors.affiliation: Department of Radiation Oncology, The Second People's Hospital of Neijiang City, Neijiang, 641000, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Li
authors.affiliation: Medical College, Hubei University of Arts and Science, Xiangyang, 441053, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Qin
authors.affiliation: Department of Teaching and Training, Bethune Military Medical NCO Academy of PLA, Shijiazhuang, 050081, China.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Ran
authors.affiliation: Luohe Key Laboratory of Medical Bioengineering, Luohe Medical College, 148 Daxue-Road, Luohe, 462002, China. whovering@yahoo.com.|Bioengineering Laboratory, Luohe Medical College, Luohe, 462002, China. whovering@yahoo.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D018450:Disease Progression; D015536:Down-Regulation / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D015999:Multivariate Analysis; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D025521:Tumor Suppressor Proteins
chemical_list: C476999:ECRG4 protein, human; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins
keywords: Breast cancer; ECRG4; Immunohistochemistry; Prognosis