A cancer-prone case with a background of methylation of p16 tumor suppressor gene.
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.
Hibi
Kenji
K
Second Department of Surgery, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. khibi@med.nagoya-u.ac.jp
Koike
Masahiko
M
Nakayama
Hiroshi
H
Fujitake
Shinichi
S
Kasai
Yasushi
Y
Ito
Katsuki
K
Akiyama
Seiji
S
Nakao
Akimasa
A
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
D013447:Sulfites