MATRIX METALLOPROTEINASES AND TISSUE INHIBITORS OF METALLOPROTEINASESIN THYROID C-CELLS AND MEDULLARY-THYROID CARCINOMAS

Aims: Hyperplastic C-cells of the thyroid and medullary thyroid carcin omas (MTCs) were studied immunocytochemically for calcitonin, carcinoe mbryonic antigen (CEA), chromogranin A, matrix metalloproteinase (MMP) -2 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 and -2. Methods and results: Nonneoplastic C-cells were positive for all these substances whereas MTC tumour cells were relatively weaker stained, a nd thyroid follicular cells were negative for all the substances studi ed, We have recently reported that pancreatic islet cells and islet ce ll tumours were positive for MMPs anti TIMPs, and, in addition, anteri or pituitary cells and pituitary adenomas and parathyroid gland and it s adenomas were also positively stained, The MMP- and TIMP-positive en docrine cells correspond to Pearse's APUD cells, derived from neural c rest and endodermal cells, Conclusions: MMPs and TIMPs may well be add ed as newly recognized markers for neuroendocrine cells. The possible function of MMP-TIMP homeostasis in C-cells and MTCs is discussed.