Relationship between carcinogenesis and gene abnormalities in Peutz-Jeghers polyps

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06671254
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Digestive surgery
• Research Institution: Niigata University
• Principal Investigator: SUDA Takeyasu Niigata University School of Medicine Assistant, 医学部, 助手 (50251806)
• Co-Investigator(Kenkyū-buntansha): SAITOU Hidetoshi Niigata University Medical Hospital Committee, 医学部・附属病院, 医員 ; OKAMOTO Haruhiko Niigata University Medical Hospital Committee, 医学部・附属病院, 医員 ; SAKAI Yasuo Niigata University Medical Hospital Assistant, 医学部・附属病院, 助手 (60251823)
• Project Period (FY): 1994 – 1995
• Keywords: Peutz-Jeghers syndrome / gene abnormalities / p53 protein / K-ras codon 12 mutation / precancerous lesion / carcinoma of the colon and rectum

Research Abstract

Gene abnormalities in Peutz-Jeghers (P-J) polyps were analyzed for both an ezpression of p53 protein immunohistochemically and K-ras codon 12 mutation by PCR-RFLP method to clarify the carcinogenesis in the P-J polyps. A total of 48 P-J polyps from 32 patients, 67 adenomas and 53 carcinomas of the colon and rectum were examined.
There is no difference between fresh frosen sections and formalin fixed sections at the incidence and the degree of the expression of p53 protein. The expression of p53 protein was seen in 63.2% of adenomas and 78.4% of carcinomas of the colon and rectum. The over-expression of p53 protein was seen in 0% of adenomas and 45.1% of carcinomas. The expression of p53 protein was seen in 29.2% of P-J polyps, but there was no case of over-expression of p53 protein. K-ras codon 12 mutation was detected 48.1% of P-J polyps. The incidence of K-ras codon 12 mutation of P-J polyps increased as the size of polyps increased.
These results suggested P-J polyps had high risk potential to cancer and should be precancerous lesions.