title: Expression and clinicopathological significance of S100 calcium binding protein A2 in lung cancer patients of Chinese Han ethnicity.
abstract: BACKGROUND
  S100 family of calcium-binding proteins plays a significant role in the process of many kinds of tumors, including lung cancer. As an important member of this family, S100 calcium binding protein A2 (S100A2) has been confirmed to be associated with many biological processes, and has an abnormal expression in non-small cell lung cancer (NSCLC). However, the S100A2 status in lung cancer is still controversial and undefined.
  
  
  METHODS
  We evaluated the pattern and distribution of S100A2 in 109 cases of lung cancer, including five histological types (47 adenocarcinoma, 46 squamous cell carcinoma, 7 small cell carcinoma, 3 large cell carcinoma, and 6 atypical carcinoid), and 30 cases of paired adjacent normal lung tissues by means of immunohistochemistry.
  
  
  RESULTS
  Compared with the normal tissues (0/30), S100A2 experienced a dramatically upward trend of positive expression in lung cancer, with a positive rate of 68/109 (P<0.001). Specifically, squamous cell carcinoma, with 34/12, had the highest expression ratio, followed by large cell carcinoma (2/1), adenocarcinoma (31/16), and atypical carcinoid (1/5) respectively, while no S100A2 protein was detected in small cell carcinoma. Meanwhile, we firstly demonstrated that the high expression of S100A2 was significantly associated with the incidence of lymph node metastasis in adenocarcinoma (P=0.013).
  
  
  CONCLUSIONS
  The association between high S100A2 expression and NSCLC at the level of tissue, and S100A2 may serve as an effective biomarker for the diagnosis and prognosis of NSCLC in future.
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China; Department of Respiratory Medicine, Xi'an No.4 Hospital, Xi'an 710004, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Yiqian
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China; Department of Internal Medicine, Life Guard Hospital, Biratnagar, Nepal; S.R. Laboratory and Diagnostic Center, Biratnagar, Nepal.
authors.forename: Asmitananda
authors.initials: A
authors.lastname: Thakur
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Hamadhaider
authors.initials: H
authors.lastname: Khan
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Puyu
authors.initials: P
authors.lastname: Shi
authors.affiliation: Department of Respiratory Medicine, Xi'an No.4 Hospital, Xi'an 710004, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China. Electronic address: chenmingwei64@hotmail.com.
authors.forename: Mingwei
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China. Electronic address: jessie_renhui@aliyun.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Ren
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000208:ethnology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D002630:Chemotactic Factors / Q000378:metabolism*; D005006:Ethnicity; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009418:S100 Proteins / Q000378:metabolism*
chemical_list: D002630:Chemotactic Factors; D009418:S100 Proteins; C098997:S100A2 protein, human
keywords: Biomarker; Immunohistochemistry; Lung cancer; S100A2