Papillary thyroid cancer with Hashimoto’s thyroiditis attenuates the tumour aggressiveness through the up-regulation of E-cadherin and TGF-β expression

Human papillary thyroid cancer (PTC) is often associated with Hashimoto’s thyroiditis (HT), and their coexistence improves the prognosis of PTC. Aim of the study . The objective of our study is to investigate the expression of cadherins and TGF-β which are regulators in the tumour aggressiveness with metastatic spread in PTC patients and its relationship with HT. The expression of E-cadherin and N-cadherin was measured in thyroid tissues of healthy volunteers and PTC patients with HT (PTC/HT) or without. The E-cadherin expression was also determined in thyroid cancer cells (TPC1, SNU373, SNU790, 8505C, CAL62, and FTC133). Cell migration was measured by wound healing assay. The expression of N-cadherin, ICAM1, and TGF-β was measured in thyroid tissues and plasma. The E-cadherin expression was significantly increased in PTC/HT patients compared with PTC alone. Meanwhile, the N-cadherin expression was significantly decreased in PTC/HT patients. The E-cadherin expression was only observed in FTC cells, and the overexpression of E-cadherin inhibited cancer cell migration. The TGF-β expression was significantly increased in PTC/HT patients, and the plasma levels were higher in PTC/HT patients than in PTC alone. The expression of N-cadherin and ICAM-1 was significantly decreased in PTC/HT patients. Our results indicate that the expression of E-cadherin and TGF-β was higher in PTC/HT patients than in PTC alone. This suggests that the presence of PTC with HT may attenuate the tumour aggressiveness and metastasis through the up-regulation of E-cadherin and TGF-β expression.