title: Expression of cell cycle regulatory proteins in the multistep process of oesophageal carcinogenesis: stepwise over-expression of cyclin E and p53, reduction of p21(WAF1/CIP1) and dysregulation of cyclin D1 and p27(KIP1).
abstract: OBJECTIVE
  Cell cycle regulatory proteins were analysed by immunohistochemistry in order to clarify how their expression changes with the degree of atypia as oesophageal surface squamous epithelium progresses from normal mucosa, through reactive change, low-grade dysplasia, and high-grade dysplasia to mucosal invasive carcinoma.
  
  
  RESULTS
  Immunostaining for cyclin D1, cyclin E, p21, p27, p53 and Ki67 proteins was performed using 22 normal mucosa, 17 reactive change, 22 low-grade dysplasia, 15 high-grade dysplasia and 22 mucosal invasive carcinoma specimens. Normal mucosa, low-grade dysplasia and high-grade dysplasia samples were taken from patients without any oesophageal invasive carcinoma by endoscopic biopsy or endoscopic mucosal resection, and reactive change and mucosal invasive carcinoma were obtained from oesophagectomy material. Stepwise over-expression of cyclin E (P < 0.0001) and p53 (P < 0.0001), reduction of p21 (P=0.0189) and dysregulation of cyclin D1 and p27 were observed in the multistep process of oesophageal carcinogenesis. Significant differences in expression of p27 (P < 0.0001), p53 (P=0.0299) and Ki67 (P=0.0101) were observed between reactive change and low-grade dysplasia. Furthermore, expression of cyclin D1, cyclin E, p27 and p53 in mucosal invasive carcinoma were significantly different from those in high-grade dysplasia (P=0.0079, P=0.0237, P=0.0042 and P= 0.0299, respectively).
  
  
  CONCLUSIONS
  Cell cycle regulatory proteins, cyclin E, p53 and p21 show stepwise over-expression or reduction with progression of oesophageal carcinogenesis, correlating with the increased cell proliferation observed with Ki67 labelling. We conclude that immunohistochemical analysis for p27, p53 and Ki67 is practically useful for the discrimination between low-grade dysplasia and reactive change. Cyclin D1, cyclin E, p27 and p53 help to distinguish high-grade dysplasia from mucosal invasive carcinoma.
authors.affiliation: Department of Pathology, Kitasato University School of Allied Health Sciences, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan. makohbu@ahs.kitasato-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Ohbu
authors.forename: N
authors.initials: N
authors.lastname: Kobayashi
authors.forename: I
authors.initials: I
authors.lastname: Okayasu
mesh_terms: D018797:Cell Cycle Proteins / Q000032:analysis / Q000096:biosynthesis*; D019938:Cyclin D1 / Q000032:analysis; D019927:Cyclin E / Q000032:analysis; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016213:Cyclins / Q000032:analysis; D004938:Esophageal Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D025521:Tumor Suppressor Proteins / Q000032:analysis
chemical_list: C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27