Open AccessPoint Mutation of c‐Ki‐ras Oncogene in Gastric Adenoma and Adenocarcinoma with Tubular Differentiation
Author(s) -
Kihana Toshimasa,
Tsuda Hitoshi,
Hirota Teruyuki,
Shimosato Yukio,
Sakamoto Hiromi,
Terada Masaaki,
Hirohashi Setsuo
Publication year - 1991
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1991.tb01847.x
Subject(s) - point mutation , adenocarcinoma , adenoma , mutation , pathology , biology , oncogene , cancer , cancer research , carcinogenesis , microbiology and biotechnology , medicine , gene , genetics , cell cycle
The presence of point mutation at codons 12,13 and 61 of the c‐Ki‐ ras oncogene was investigated in 7 cases of gastric adenoma and 35 cases of gastric adenocarcinoma using DNA samples from formalin‐fixed and paraffin‐embedded tissues. Oligonucleotides encompassing the three codons were amplified by using the polymerase chain reaction (PCR), and then examined for point mutation by the selective oligonucleotide hybridization technique. Point mutation was detected in three of the 7 adenomas (43%) and three of the 35 carcinomas (9%). All the gastric adenomas showed the histology of tubular adenoma, being very similar to that of colonic adenoma. The 35 cases of gastric adenocarcinoma were classified into 17 cases of differentiated type and 17 cases of undifferentiated type including signet‐ring cell carcinoma. The point mutation of c‐Ki‐ ras oncogene was detected only in the differentiated type (3/17, 18%), and there was no case with point mutation in the undifferentiated type. These results suggest that the genetic mechanism of carcinogenesis differs between the differentiated type and the undifferentiated type of gastric adenocarcinoma, and also that c‐Ki‐ ros activation is possibly involved in a relatively early step of the “adenoma‐carcinoma sequence,” which leads to the development of a portion of differentiated adenocarcinomas in the stomach.