Telomerase reverse transcriptase mutations are independent predictor of disease-free survival in middle eastern papillary thyroid cancer

Abstract

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Tumor recurrence occurs in approximately 20% of PTCs and some reach advanced stages. Promoter mutation in the telomerase reverse transcriptase (TERT) gene is identified to be a prognostic marker in PTC. However, the contribution of TERT promoter mutation to cancer progression in PTC patients is still not fully understood. In this study we investigated the incidence of TERT promoter mutations and TERT protein expression and their association with clinicopathological outcomes in a large cohort of PTC samples using direct sequencing technology and immunohistochemistry. Furthermore, two PTC cell lines were utilized to investigate role of TERT mutations in mediating metastasis. Two promoter hotspot mutations C228T and C250T were identified in 18.0% (167/927) of our cohort and were significantly associated with poor 5 years disease-free survival and distant metastasis of PTC. TERT protein over-expression was noted in 20.1% of our PTC cohort and was significantly associated with poor prognostic markers such as older age, extra-thyroidal extension and Stage IV tumors. A significant association was also found between TERT over-expression and epithelial–mesenchymal transition (EMT) markers. Functional analysis showed that TERT inhibition reduced cell growth, invasion, migration and angiogenesis in PTC via suppression of EMT in PTC cells. Our results suggest TERT promoter mutation is an independent predictor of disease-free survival and might drive the metastasis, and downregulation of TERT could potentiate anti-tumor and anti-metastatic activities in PTC. This article is protected by copyright. All rights reserved.

http://ift.tt/2BPNGx8