[Expression of matrix metalloproteinases 2 and 9 and their tissue inhibitors 1 and 2 in papillary thyroid cancer: an association with the clinical, morphological and ultrastructural characteristics of a tumor].

Papillary thyroid cancer (PTC) was ascertained to be characterized by a significant expression of matrix metalloproteinases (MMP-2 and 9) and a TIMP-2 inhibitor and decreased TIMP-1 accumulation in the cytoplasm of tumor cells; at the same time a combination of high cytoplasmic MMP-9 expression with no TIMP-1, as well as triple positive co-expression of MMP-2, MMP-9, and TIMP-2 are poor immunohistochemical indicators. The results of the performed study suggest that the detection of the types of expression of MMP-9+/TIMP-1 and MMP-2+/MMP-9+/TIMP-2+ is associated with the possible progression of a tumor process and concurrent with poor clinical and morphological signs, such as the large size of the tumor, the presence of intravascular invasion and regional metastases, organ capsular invasion, and low ultrastructural tumor cell differentiation. Thus, changes in the tumor expression of the extracellular matrix enzymes MMR-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2 along with the major clinical, morphological, and ultrastructural signs of the disease are important additional indicators for analyzing the malignant potential of PTC.