Clinicopathological and predictive significance of SIRT1 and peroxisome proliferator-activated receptor gamma in esophageal squamous cell carcinoma: The correlation with EGFR and Survivin.

SIRT1 (silent mating type information regulation 2 homolog 1) is an enzyme that deacetylates proteins that contributes to cell survival and angiogenesis. Peroxisome proliferator-activated receptor Ƴ (PPAR Ƴ) is a member of the nuclear steroid hormone receptor superfamily and regulates cell apoptosis and proliferation. The functional roles of SIRT1 and PPAR Ƴ in tumor progression remain controversy. This study aims to investigate the roles of SIRT1 and PPAR Ƴ in esophageal squamous cell carcinoma (ESCC), as well as correlation with expression of EGFR and Survivin. Here, we analyzed the protein expression of SIRT1 and PPAR Ƴ in tumor microarray with ESCC and its associations with clinicopathological parameters and overall survival. Both SIRT1 and PPAR Ƴ were highly expressed in tumor tissues comparing with non-cancerous epithelium. High expression of SIRT1 was positively correlated with advanced TNM stage and poor outcome, while high expression of PPAR Ƴ was positively related with tumor grading, not with patients' prognosis. In addition, the high expression of SIRT1 was positively correlated with overexpression of EGFR, not related with PPAR Ƴ or Survivin expression status. These data suggests SIRT1 may serve as a predictor of poor prognosis in ESCC, and its mediated tumor-promoting role might be associated with the overexpression of EGFR protein in ESCC.