Expression Of Estrogen Receptor α36in Papillary Thyroid Carcinoma And Its Correlation With Clinical Features

Background:Thyroid carcinoma ranks top of endocrine malignancies, and accounts for over1%of all human malignant tumors, its incident rate increasing every year. Women are3-5times more likely to develop such disease, and estrogen has been proposed to play an important role in this process. By binding to its receptor, estrogen is involved in a variety of biological functions, including the regulation of cell growth, proliferation and differentiation, which result in a series of pathophysiological processes including angiogenesis as well as tumorogenesis. Besides acting as a nuclear receptor, estrogen receptors (ERs) also take part in membrane-initiated pathways which is of special importance in the development of cancers. However, much has been left open to dispute in the study of ERs. ERa36is a variant of ERa which was newly isolated and cloned. It mainly exists in the cytoplasm and plasma membrane, thus mediates the membrane-initiated pathways and may be responsible for tamoxifen resistance in certain cases of breast cancers. Also, it has been identified in endometrial cancer, colorectal cancer and gastric cancer, with a relation to both pathology and lymph node metastasis of tumors. Its expression in thyroid carcinoma has never been studied.Objectives:In this study, we examined ERa36in human papillary thyroid carcinoma (PTC) tissues with comparison to ERa66, and primarily investigated its relation to certain clinical features.Materials and methods:68cases of PTC that underwent thyroidectomy in Shandong Provincial Hospital from2010to2011were chosen at random and their specimens were collected. ERa36and ERa66were examined by the method of immunohistochemistry (S-P). SPSS.16was used for the result analyses. Values of P <0.05were considered significant.Results:Both ERa36and ERa66were identified in the tissues of PTC. The expression level of ERa36was significantly higher than that of ERa66(67.6%vs.20.6%, P=0.000). The high expression rate of ERa36and ERa66were greater in patients over45years old (ERa36:95.2%vs.55.3%, P=0.001; ERa66:38.1%vs.12.8%, P=0.025).Conclusion:The expression of ERa36is significantly higher than that of ERa66in PTC and showed a close relation to the age of patient, which indicates that ERa36may take an active part in the development of PTC.