Patterns of K-ras codon 12 and 13 mutations found in pancreatic adenocarcinoma of 30 Chinese patients by microdissection, PCR and direct sequencing.
OBJECTIVE
To our knowledge there are few reports on the K-ras mutation pattern of pancreatic adenocarcinoma from Chinese mainland patients. We examined surgically resected formalin-fixed, paraffin-embedded primary pancreatic adenocarcinoma tissue blocks for the presence of activating point mutations at codon 12 and 13 of the K-ras gene.


METHODS
Mutations were detected through the use of microdissection, polymerase chain reaction (PCR) and direct sequencing. The results were confirmed by reverse sequencing.


RESULTS
The combination of microdissection, PCR and direct sequencing techniques resulted in a rapid and sensitive detection of K-ras mutations at codon 12 and 13. Twenty-five (83%) of the 30 pancreatic adenocarcinomas examined harbored K-ras mutation. Among the 25 pancreatic adenocarcinomas, 24 showed K-ras mutation at codon 12 (11 with GGT-GTT, seven with GGT-GAT, four with GGT-CGT, and two with GGT-TGT), and only one showed a GGC-TGC mutation at codon 13. In this study most of K-ras mutations at codon 12 were at the second base (72%, 18/25) with a transition/transversion ratio of 1 : 1.57 (7/11).


CONCLUSIONS
The mutation profiles of K-ras at codon 12 in our pancreatic adenocarcinoma samples were significantly different from those of European and Japanese samples.
Wei
Shuanzeng
S
Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Peking Union Medical College Beijing, China.
Liang
Zhiyong
Z
Gao
Jie
J
Wu
Shafei
S
Zhu
Hong
H
Liu
Hongrui
H
Liu
Tonghua
T
D000230:Adenocarcinoma / Q000235:genetics*; D000328:Adult; D000368:Aged; D002681:China; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA