[Ornithine decarboxylase activity and polyamine levels in human thyroid tumor tissue]

Production of polyamines such as putrescine (PUT), spermidine (SPD) and spermine (SPM) primarily from ornithine by ornithine decarboxylase (ODC) is correlated with cell proliferation. Polyamine levels and ODC activities were measured to determine the degree of biological malignancy in 186 thyroid tumor tissues. Carcinoma showed significantly higher ODC activity and higher levels of PUT, SPD and SPM than benign tumors. PUT levels showed 2.28 nmol/mg protein in anaplastic carcinoma, 0.66 in papillary carcinoma, 0.11 in follicular adenoma, 0.06 in adenomatous goiter and 0.04 in normal thyroid tissue. Anaplastic and papillary carcinomas showed higher PUT/SPD and SPD/SPM ratios than benign tumors. Poorly differentiated carcinoma showed significantly higher PUT level and PUT/SPD and SPD/SPM ratios than well differentiated carcinoma. No correlation was found among polyamine levels, ages and sex in papillary carcinoma. In female patients with papillary carcinoma, no significant difference in polyamine levels was observed between patients above and below 50 years old. These results suggest that ODC activity and polyamine levels may provide useful information to determine the degree of biological malignancy of thyroid tumors.