PP22-2 Comprehensive Analysis of Transcriptional and Mutational Landscape of Follicular and Papillary Thyroid Cancers

Program: Abstracts - Orals, Poster Previews, and Posters
Session: SAT 270-310-Thyroid Neoplasia (posters)
Saturday, April 2, 2016: 1:15 PM-3:15 PM
Exhibit/Poster Hall (BCEC)

Poster Board SAT 286
Seong-Keun Yoo*1, Seungbok Lee1, Su-jin Kim2, Hyeon-Gun Jee3, Kyu Eun Lee2 and Jeong-Sun Seo1
1Genomic Medicine Institute, Seoul, South Korea, 2Seoul National University College of Medicine, Seoul, South Korea, 3Research Institute, National Medical Center, Seoul, South Korea
Thyroid cancer is the most common endocrine malignancy derived from the follicular cells of the thyroid gland, which includes classical papillary thyroid carcinoma (cPTC), follicular variant of papillary thyroid carcinoma (FVPTC), and follicular thyroid carcinoma (FTC). The similar histological feature of FTC compare to FVPTC or benign follicular adenoma (FA) often results in diagnostic difficulties in clinics. However, the genomic differences among them are still unclear. Here, we firstly performed comprehensive genomic and transcriptomic study on 31 FTCs and 25 FAs by RNA sequencing together with 77 cPTCs and 49 FVPTCs. The FTC and cPTC had substantially different mutational profiles but that of FVPTC represented intermediate status. However, in the context of transcriptional landscape, 182 tumors were classified as BRAF–like, RAS–like, and non–BRAF–non–RAS (NBNR) regardless of their histological subtypes. The novel molecular subtype, NBNR, was mainly associated with tumors which were driven by DICER1, EIF1AX, and PAX8–PPARG. Follicular-patterned thyroid tumors, FVPTC, FTC, and FA, characterized homogeneous transcriptome when they have same mutational status, although we identified some differentially expressed genes between FVPTC and FTC. In addition, we elucidated that the changes of genes which are related to mitochondrial biogenesis such as ESRRA and PPARGC1A were prominent in oncocytic follicular thyroid neoplasm. Our results broaden the transcriptional and mutational landscape of thyroid cancer by adding FTC to current understanding on PTC. We propose re-classification of thyroid cancer based on molecular subtypes providing novel diagnostic and prognostic implications.

Nothing to Disclose: SKY, SL, SJK, HGJ, KEL, JSS

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo

Sources of Research Support: This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI13C1927).