title: Quantitative analysis of EZH2 expression and its correlations with lung cancer patients' clinical pathological characteristics.
abstract: BACKGROUND
  Elevated Enhancer of Zeste Homologue 2 (EZH2) expression is involved in many human malignancies through epigenetically silencing related genes. However, the study of the EZH2 protein expression in lung cancer remains at the qualitative or semi-quantitative level. The present study is to elucidate the roles of EZH2 in the progression and metastasis of different subtypes of lung cancer at quantitative level.
  
  
  METHODS
  Lung carcinoma tissue microarray was constructed containing 32 normal adult lung tissues, 113 lung carcinomas and 57 lymph-node metastases. EZH2 protein expression was detected by immunohistochemistry and assessed quantitatively with Leica Q500MC image analysis system. Positive unit (PU) value was used to evaluate the protein expression intensity of positive cells from systematically selected fields under the microscope.
  
  
  RESULTS
  Elevated Enhancer of Zeste Homologue 2 PU in lung carcinomas was significantly greater than that in normal lung tissues (p = 0.001). Increased EZH2 expression was correlated with histological subtypes, differentiation, TNM stage, and lymph-node metastases (p < 0.05). EZH2 PU of primary lung carcinomas was smaller than that of lymph-node metastasis (p = 0.002). EZH2 PU was not associated with patients' gender, age, smoking status, tumor location, and tumor size (p > 0.05).
  
  
  CONCLUSIONS
  Elevated Enhancer of Zeste Homologue 2 PU is increased with the development of lung cancer. EZH2 may play an important role in the progression and metastasis of lung cancer.
authors.affiliation: Department of Pathology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou North Road, Guangzhou, 510515, Guangdong, People's Republic of China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Wan
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Bai
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D000071221:Enhancer of Zeste Homolog 2 Protein; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D063151:Polycomb Repressive Complex 2 / Q000032:analysis / Q000096:biosynthesis*; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2