Expression of bcl-2, Bax and Fas in oxyphil cells of Hashimoto thyroiditis.
Immunoreactivity for bcl-2, Bax and Fas was analysed in 16 cases with Hashimoto thyroiditis. Bcl-2-expression was constantly seen in regular thyrocytes and in the mantle-zone of lymphofollicular infiltrates. However, thyrocytes in the vicinity of lymphoid infiltrates and, especially, mitochondria-rich oxyphil cells exhibited reduced staining or none at all for bcl-2. Bax was found to be weakly reactive or negative in normal thyrocytes and was not up-regulated in bcl-2-deficient epithelial cells. In contrast, expression of Fas was markedly increased both in typical thyrocytes and in oxyphil cells within areas of lymphocytic infiltration. In conclusion, focal lack of bcl-2 expression together with up-regulation of Fas is a constant feature of Hashimoto thyroiditis. The reaction pattern of oxyphil cells is identical to that of affected typical thyrocytes without proliferation of mitochondria. Loss of bcl-2 with up-regulation of Fas is therefore likely to precede oncocytic change. Whether these alterations are involved in the process of oncocytic transformation remains to be clarified, however.
Pathologisches Institut der Ludwig-Maximilians-Universität, München, Germany.
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Müller-Höcker
D000328:Adult; D000368:Aged; D053222:Fas Ligand Protein; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008679:Metaplasia; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D013961:Thyroid Gland / Q000473:pathology*; D013967:Thyroiditis, Autoimmune / Q000473:pathology*; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein