TPS, Thymidine Kinase, VEGF and Endostatin in Cytosol of Thyroid Tissue Samples

The aim of the study was to determine whether VEGF, TPS, TK or Endostatin determination in tissue cytosol may have some additional value in distinguishing among different types of thyroid lesions. These markers were chosen as representatives of the 2 main pathways (angiogenesis and proliferation) involved in thyroid diseases. VEGF is the most potent angiogenic promoter and Endostatin plays an opposing role. Thymidine kinase (TK) is a marker of DNA synthesis and TPS, cytokeratin 18 fragments, is a marker of the rate of proliferation. We determined qualitatively all four markers in tissue extracts: cytosol from 157 tissue specimens (93 goitre,12 Hashimoto's thyroiditis, 39 adenomas and 13 carcinomas). In 6 cases we were able to compare both normal and pathological tissue samples from a single patient. Statistically significant differences were found in the measured markers, but outliers were present in all groups. This fact does not permit their use in differential diagnosis. The highest levels of all markers were reached in adenomas, being higher than in carcinomas, probably explained by the higher overall metabolic rate in adenomas. The thyroid gland is well-vascularised, with one of the highest blood flow rates per unit weight of tissue in the body. Pathological conditions such as Grave's Disease, thyroid enlargement and Hashimoto's thyroiditis are accompanied by a markedly increased blood flow. In cancers of the thyroid, microvessel density has been shown to correlate with disease-free survival in papillary carcinoma of the thyroid (1) and in intrathyroid tumours spread in follicular carcinoma (2). Experimental models of goitre have