Abnormal accumulation of proteoglycan in human thyroid adenocarcinoma tissue.

Glycosaminoglycan (GAG) was extracted from thyroid tissue obtained at surgery for thyroid adenoma and adenocarcinoma and compared with that extracted from the thyroid tissue obtained at autopsy of non-thyroid disease. The amount of GAG was almost doubled in thyroid adenoma and increased from 6 to 15 fold in adenocarcinoma when compared with that of apparently normal thyroid tissue. Analysis by Sepharose 2B or 6B column chromatography revealed that at least a part of the GAG in thyroid carcinoma tissue was present in macromolecule form and the molecular size became smaller when treated with papain or alkaline borohydride. The results indicated that those fractions of GAG were present as proteoglycans. The GAG was composed of a mixture of heparan sulfate and chondroitin sulfate or dermatan sulfate in one carcinoma tissue and mainly composed of chondroitin sulfate or dermatan sulfate in the other. The mechanism of the increase in proteoglycan and GAG remains to be elucidated.