title: The abnormal expression of retinoic acid receptor-beta, p 53 and Ki67 protein in normal, premalignant and malignant esophageal tissues.
abstract: OBJECTIVE
  Esophageal cancer remains a significant health problem worldwide. It is important to investigate alterations in expression of retinoic acid receptor-beta, p 53 and Ki67 proteins in esophageal carcinogenesis.
  
  
  METHODS
  To find biomarkers for early identification of esophageal cancer, we analyzed the retinoic acid receptor-beta, p 53 protein and the proliferation marker Ki67 in surgical specimens of normal, mildly, and severely dysplastic and malignant esophageal tissues by in situ hybridization of RNA and immunohistochemistry.
  
  
  RESULTS
  RAR-beta was expressed in 94.3%(33/35) of normal mucosae, 67.8%(19/28) of the mild, 58.1% (18/31) of the severe lesions and 53.2%(116/218) of tumor samples. RAR-beta mRNA was expressed in 62.7%(42/67), 55.1%(43/78) and 29.2%(7/24) of well, moderated and poorly differentiated SSCs. The p 53 and Ki67 proteins were 5.9%(2/34) of the normal mucosa. P53 and Ki67 stained positively in 10.7%(3/28) and 21.4% (6/28) of mild dysplasia, and 51.6%(16/31) and 58.1% (18/31) of severely dysplasia respectively. Samples from esophageal cancer showed no higher levers of p 53 and Ki67 expression than seen in severely dysplastic lesions. There was significant difference of RAR-beta p 53 and Ki67 expression between normal mucosa and dysplastic tissue or esophageal cancer.
  
  
  CONCLUSIONS
  Loss of RAR-beta expression and accumulation of p 53 and Ki67 proteins may serve as biomarkers for early identification of esophageal cancer in the high-risk populations.
authors.affiliation: Central Laboratory for Tumor Biology, Cancer Hospital (Institute), Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100021, China.
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.forename: Yu-Lan
authors.initials: YL
authors.lastname: Jin
authors.forename: Jun
authors.initials: J
authors.lastname: Fu
authors.forename: Hong
authors.initials: H
authors.lastname: Huang
authors.forename: Sheng-Zu
authors.initials: SZ
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Qu
authors.forename: Hai-Mei
authors.initials: HM
authors.lastname: Tian
authors.forename: Zhao-Yang
authors.initials: ZY
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004947:Esophagus / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D017403:In Situ Hybridization; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018168:Receptors, Retinoic Acid; D016159:Tumor Suppressor Protein p53; C082925:retinoic acid receptor beta