Significance of K-ras mutation, K-ras expression and p53 expression in pancreatic cancer

Kim, Young Chul; Choi, Kwang Ho; Kim, Han Gyum; Lee, Eung Seok; Son, Gil Soo

Abstract

BACKGROUND: Though K-ras mutation and aberrant p53 have been considered the event of the oncogenesis of pancreatic adenocarcinoma, it is controversial that these have been attributed to difference of survival in pancreatic adenocarcinoma. We investigated for presence of a K-ras mutation, K-ras expression and p53 expression in carcinogenesis of pancreatic adenocarcinoma. Also their correlation with tumor grade, stage and survival was investigated.
METHODS
We examined 48 patients surgically resected, formalin-fixed and paraffin-embedded pancreatic adenocarcinoma. By using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), we detected K-ras mutation at codon 12. An aberrant K-ras and p53 expression was stained using an immunohistochemical staining (IHC) method.
RESULTS
Thirty-one of 48 cases (64.6%) showed K-ras mutation. K-ras expression was showed in 68.8% (33/48). p53 expression was showed in 47.9% (23/48). There was no correlation between a presence of K-ras mutation or K-ras expression and tumor grade, lymph node metastasis, clinical stage or survival rate. A positive correlation between p53 expression and clinical stage was found (p<0.05). The patients with p53 expression had shorter survival than the patients without p53 expression (p>0.05).
CONCLUSION
Mutation of the K-ras gene and aberrant p53 might play an important role in pancreatic carcinogenesis. But mutation of K-ras gene and K-ras expression is not considered to relate to progression of pancreatic carcinoma. It is suggested that p53 expression seems to be associated with a progression of pancreatic carcinoma.