Prognostic Significance of Sirtuins Expression in Papillary Thyroid Carcinoma

ABSTRACT

BACKGROUND AND OBJECTIVES: Sirtuins (SIRTs) play important roles in cellular and organismal homeostasis. They have distinct gene expression patterns in various cancers; however, the relationship between SIRT expression and the progression of thyroid cancer is unclear. We investigated the expression of SIRTs in patients with papillary thyroid carcinoma (PTC) and their role as biomarkers for predicting the aggressiveness of this disease. MATERIALS AND METHODS: We used immunohistochemical staining to evaluate the expression of SIRT1 and SIRT3 in tumor specimens from 270 patients with PTC. We also evaluated the potential association between SIRT expression and diverse clinicopathological features. RESULTS: High SIRT1 expression was negatively correlated with lymphovascular invasion, central lymph node metastasis, and lateral lymph node metastasis. Multivariate analyses revealed that high SIRT1 expression was a negative independent risk factor for lateral lymph node metastasis. By contrast, high SIRT3 expression was positively correlated with locoregional recurrence. Interestingly, when patients were grouped by tumor SIRT expression patterns, the group with low SIRT1 expression and high SIRT3 expression was correlated with more aggressive cancer phenotypes including central lymph node metastasis and lateral lymph node metastasis. CONCLUSION: Our results suggest that SIRTs play dual roles in tumor progression, and the combination of decreased SIRT1 expression and increased SIRT3 expression is significantly associated with a poor prognosis in patients with PTC.