title: A cancer-prone case with a background of methylation of p16 tumor suppressor gene.
abstract: OBJECTIVE
  To date, the presence of p16 gene promoter methylation associated with loss of protein expression has been demonstrated frequently in digestive tract cancers. In this study, we tested for the methylation status of p16 promoter in normal tissue specimens using the methylation-specific PCR technique to examine whether p16 methylation already existed in the background of tumors.
  
  
  RESULTS
  Aberrant promoter methylation of p16 gene was detected in 1 of 40 esophageal and 1 of 69 gastric and no colorectal epithelium specimens, and these 2 specimens were derived from the same patient. We also found the same methylation change in both tumor and blood cell DNA.
  
  
  CONCLUSIONS
  These results suggested that the p16 gene was inactivated by methylation in normal background cells of this patient and that other additional factors may promote tumor development in his esophageal and gastric tissues.
authors.affiliation: Second Department of Surgery, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. khibi@med.nagoya-u.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Hibi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Koike
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakayama
authors.forename: Shinichi
authors.initials: S
authors.lastname: Fujitake
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kasai
authors.forename: Katsuki
authors.initials: K
authors.lastname: Ito
authors.forename: Seiji
authors.initials: S
authors.lastname: Akiyama
authors.forename: Akimasa
authors.initials: A
authors.lastname: Nakao
mesh_terms: D015179:Colorectal Neoplasms / Q000235:genetics; D019175:DNA Methylation; D004938:Esophageal Neoplasms / Q000235:genetics; D019942:Genes, p16; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics; D013447:Sulfites / Q000494:pharmacology
chemical_list: D013447:Sulfites