title: Changes in p53 and Waf1p21 expression and cell proliferation in esophageal carcinogenesis.
abstract: OBJECTIVE
  To study the correlation between changes in p53 and Waf1p21 expression and cell proliferation, determined by proliferating cell nuclear antigen (PCNA), at different stages of human esophageal carcinogenesis.
  
  
  METHODS
  Biopsied and resected esophageal tissues from a high risk population of esophageal cancer in northern China were used in this study. All specimens were fixed in 85% alcohol and processed for routine histology. The avidin biotin peroxidase complex (ABC) method was used to detect p53, Waf1p21 and PCNA.
  
  
  RESULTS
  Strong nuclear staining of p53, Waf1p21 and PCNA was observed in normal esophageal epithelium and epithelia with different lesion severities. As the lesions progressed to dysplasia (DYS) and to esophageal squamous cell carcinoma (SCC), the Waf1p21 immunoreactivity percentage decreased. The number of Waf1p21-positive cells slightly increased from normal to basal cell hyperplasia (BCH), but did not further increase in DYS and SCC. The total number of Waf1p21-positive cells was lower than the number of p53-positive cells in normal and BCH esophageal epithelia and much lower in DYS and SCC. Waf1p21-positive cells were located in the third and fourth cell layers in half of the samples examined, which was 2-4 cell layers higher than the cells expressing PCNA and p53 in the same histological categories of normal, BCH and DYS.
  
  
  CONCLUSIONS
  Low Waf1p21 levels at the DYS stage may be related to a functional loss of p53. Other mechanisms may also be responsible for the decreased Waf1p21 expression in DYS and SCC.
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: L D
authors.initials: LD
authors.lastname: Wang
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: W C
authors.initials: WC
authors.lastname: Yang
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Jia
authors.affiliation: Li-Dong Wang, Wan-Cai Yang, Qi Zhou, Ying Xing, Xin Zhao, Laboratory for Cancer Research, Henan Medical University, Zhengzhou 450052, Henan Province, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhao
keywords: Esophageal neoplasms; Genes suppressor; Precancerous conditions; Tumor; Waf1p21; p53 genes