Phosphorylated telomerase reverse transcriptase contributes to the progression of papillary thyroid carcinoma

Somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) occur at a high frequency in several cancer types and are associated with malignancy potential and prognosis. Protein levels of TERT and phosphorylated TERT (p-TERT) are related to malignancy potential. To explore the association of TERT phosphorylation and malignancy or prognosis of thyroid cancer, we analyzed the expression of p-TERT and the clinical features of papillary thyroid carcinoma (PTC) in a cohort of 120 patients. We found that TERT and p-TERT were more abundant in tumors harboring TERT promoter mutations. During the 5-year follow-up period, nine patients experienced disease recurrence. The hazard ratio for recurrence was higher in those with abundant TERT and p-TERT levels. The Kaplan–Meier analysis indicated that the recurrence-free survival was significantly worse in TERT-positive/p-TERT-positive patients than TERT-positive/p-TERT-negative and TERT-negative/p-TERT-negative patients. Higher p-TERT levels correlated with malignant clinicopathologic features and were an independent risk factor for PTC recurrence. These findings indicated the potential role of p-TERT level as a clinically prognostic biomarker in PTC.