Relationship of ornithine decarboxylase activity and human colon tumorigenesis.

Ornithine decarboxylase (ODC) activity was determined in tumorous lesions of the human colon, and the possibility of ODC acting as a marker of colon tumorigenesis investigated. In adenoma, ODC activity, in pmoles/h/mg protein, was 164 +/- 82 in tumorous tissue, which was higher than the 19.6 +/- 10.5 in macroscopically normal mucosa (control tissue) around the tumorous tissue, while 8.7 +/- 4.1 in normal colon mucosa. In carcinoma-in-adenoma and carcinoma, ODC activities in the control tissue were 15.3 +/- 11.9 and 27.5 +/- 15.0, respectively. The levels were respectively higher than in normal tissue. These results suggest ODC to be a potential indicator of colon tumorigenesis.