Study of autophagy-related protein light chain 3 (LC3)-II expression levels in thyroid diseases

Abstract

Thyroid cancers are the most common malignant tumors of the endocrine system. The survival-promoting role of autophagy in tumor cells has been received universally. This study aimed to explore autophagy-related protein light chain 3 (LC3)-II expression levels in thyroid diseases including papillary thyroid cancer. A total of 45 thyroid samples, including 19 samples of papillary thyroid cancer, 7 samples of nodular goiter, 8 samples of Hashimoto thyroiditis and 11 samples of normal thyroid tissue resected during surgery, were selected and divided into pathological groups using light microscope. Levels of autophagy-related protein LC3-II in four different types of thyroid tissue were tested through Western blot. SPSS19 software was utilized to analyze the research data statistically. LC3-II protein levels in papillary thyroid cancer tissues were lower than that in normal thyroid tissues significantly (P<0.05). Compared with normal thyroid tissue, expression levels of LC3-II protein were higher in samples of Hashimoto thyroiditis and nodular goiter (P<0.05). Multi-factor analysis of variance showed that there was no significant correlation between LC3-II protein levels and patients' gender of thyroid cancer, while there was significant variation between patients with and without lymph node metastasis. Compared with patients of thyroid cancer without lymph node metastasis, the level of LC3-II protein was lower in patients of thyroid cancer with lymph node metastasis (P<0.05). Detection of LC3-II protein expression levels in thyroid diseases may contribute to the clinical diagnosis and provide theoretic basis for the therapy.

Keywords: Autophagy; Autophagy-related protein light chain 3 (LC3)-II; Papillary thyroid cancer.