OBJECTIVETo study the roles of matrix metalloproteinases-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), vascular endothelial growth factor (VEGF) and transforming growth factor β-1 (TGFβ-1) in differentiation, invasiveness and metastatic potential of papillary carcinoma and follicular carcinoma of thyroid.

METHODSEighty-five cases of papillary thyroid carcinoma and 59 cases of follicular thyroid carcinoma were enrolled into the study. Immunohistochemistry using EnVision method was carried out for assessment of the expression of MMP-9, TIMP-1, VEGF and TGFβ-1 in the tumor tissue.

RESULTSMMP-9, TIMP-1, VEGF and TGFβ-1 were expressed in the cytoplasm of tumor cells. The positivity rates of MMP-9, TIMP-1, VEGF and TGFβ-1 in papillary thyroid carcinoma (83.5%, 81.2%, 90.6% and 75.3%, respectively) were similar to or lower than those in follicular thyroid carcinoma (93.2%, 86.4%, 89.9% and 78.0%, respectively). The expression rates in papillary thyroid carcinoma with lymph node metastasis were also higher than those in tumors without lymph node metastasis. The expression rates of MMP-9, VEGF and TGFβ-1 in poorly-differentiated follicular thyroid carcinoma were higher than those in well-differentiated follicular thyroid carcinoma. The expression of TIMP-1 however showed a negative correlation with the tumor cell differentiation. In general, the expression of VEGF and MMP-9 was higher than that of TIMP-1 and TGFβ-1 in papillary thyroid carcinoma and follicular thyroid carcinoma.

CONCLUSIONSImmunohistochemical detection of MMP-9, TIMP-1, VEGF and TGFβ-1 expression may carry clinical significance in evaluating the degree of differentiation, invasiveness, metastatic potential and prognosis of papillary thyroid carcinoma and follicular thyroid carcinoma.