Expression of Autophagy-Related Proteins in Hürthle Cell Neoplasm Is Different from That in Follicular Neoplasm

Purpose. We aimed to evaluate expression of autophagy-related proteins in Hürthle cell neoplasm (HCN) and follicular neoplasm (FN) and assess the clinical implications. Methods. 265 FNs (112 follicular carcinomas and 153 follicular adenomas) and 108 HCNs (27 Hürthle cell carcinomas and 81 Hürthle cell adenomas) were made into a tissue microarray. Immunohistochemical staining and Western blot for autophagy-related proteins (beclin-1, light chain (LC) 3A, LC3B, p62, and BNIP3) were performed, and the results were statistically analyzed. Results. A higher expression rate of beclin-1, LC3B, p62, and BNIP3 was found in HCN than in FN (P<0.001). The expression rate of beclin-1, LC3B, p62, and BNIP3 was the highest in HCCs followed by HCAs, FCs, and FAs in that order (P<0.001). HCCs were positive for the largest number of autophagy-related proteins followed by HCAs, FCs, and FAs (P<0.001), and most of the positive markers identified in HCCs were the high autophagy type (P<0.001), defined by positive staining for three or more of the five autophagy-related proteins. Conclusion. The autophagy-related proteins, beclin-1, LC3A, LC3B, p62, and BNIP3, were more frequently expressed in HCNs than in FNs, and HCCs showed the highest expression rate.