CLONAL ANALYSIS OF GLANDULAR STOMACH CARCINOGENESIS IN C3H HEN[--]BALB/C CHIMERIC MICE TREATED WITH N-METHYL-N-NITROSOUREA/

The clonal growth of gastric carcinomas was investigated immunohistoch emically in C3H <-> BALB/c chimeras using a strain specific antibody. C3H, BALB/c and chimeric mice were given N-methyl-N-nitrosourea 0.5 mg /mice once a week for a total of 10 times by intragastric intubation a nd observed until week 50. In normal gastric mucosa of the chimeras, e ach gland was composed entirely of C3H strain specific antigen (CSA)-p ositive or -negative cells and no mixed glands were found. Cells of al l adenomatous hyperplasias and adenocarcinomas in chimeric mice were, in each case, homogeneous for one or other of the parental types, whil e comprising both surface mucous cell and pyloric gland cell forms. Th e results clearly suggest that individual cancers are derived from sin gle cells with multi-potential activities and that cellular differenti ation of gastric cancer cells occurs secondarily.