APOPTOSIS IN THYROID-DISEASES - A HISTOCHEMICAL-STUDY

Recent studies demonstrate that apoptosis is an important process in physiological and pathological cell death. We examined the apoptotic phenomena in thyroid tissues by two methods: immuno-histological and in situ end-labeling of fragmented DNA (ISEL). In thyroid tissues from patients with Hashimoto's thyroiditis and thyroid cancer, fragmented nuclear DNA and Le(Y) (apoptosis associated antigen) were observed. In tissues from patients with Graves' disease, Le(Y) and bcl-2 oncoprotein were expressed, but no ISEL positive cells were observed. In contrast, thyrocytes in normal thyroid tissues were not stained with ISEL or anti-Le(Y) antibodies (Abs). Fas antigen (Ag) was expressed in various thyroid tissues, including normal subjects. The clinical meaning of this was not determined. These results suggest that the apoptotic process takes place in Hashimoto's thyroiditis and thyroid cancer, and is overcome in Graves' disease by bcl-2 expression.