NEXT GENERATION SEQUENCING FOR DETECTION OF MUTATIONS IN THYROID HURTHLE CELL CARCINOMAS

Abstract

The Hürthle cell carcinoma is considered a variant of the follicular thyroid carcinoma, despite distinct clinical behavior. Genetic abnormalities associated to thyroid carcinogenesis have been studied, mainly in papillary and follicular carcinomas. A few gene mutations were identified in Hürthle cell carcinoma, involving mitochondrial genes, RAS e MEN1. However, they were restricted to a small percentage of cases. Nevertheless, gene expression analysis revealed activation of the intracellular signaling pathways, PI3K-AkT-mTOR and Wnt/²-catenina, in extensively invasive Hürthle cell carcinomas. The aims of this study are identify genetic abnormalities associated to Hürthle cell carcinomas using next generation sequencing and analyze their connection with clinical and histological features associated to poor prognosis. Genomic DNA extraction will be performed in paraffin-embedded samples of 48 Hürthle cell carcinomas and respective normal thyroid tissues. One hundred selected genes will be simultaneously sequenced. They are involved in intracellular signaling pathways - Wnt/²-catenina, mTOR, MAPK and Notch-, some are related to follicular cell function and others associated to carcinogenesis. Next generation sequencing will be performed in the sequencing system of large-scale genomics, HiSeq 2500 (Illumina), belonging to the Laboratório de Sequenciamento em Larga Escala (SELA) and acquired with FAPESP grants (2014/50137-5). Finally, the identified abnormalities will be studied in 30 Hürthle cells adenomas in order to elucidate their association with malignant transformation. (AU)