Prognostic and Predictive Role of Sirtuin1 Expression in Lung Adenocarcinoma

SIRT1 is the homologue of sir2 in mammals, which is a nicotinamide adenine dinucleotide (NAD+) dependent histone deacetylase. Several studies have reported that the overexpression of Sirtuin1 (SIRT1) was associated with poor prognosis in various human cancers. However, little is known regarding the prognostic value of SIRT1 in lung adenocarcinoma.

SIRT 1 expression in tissues of 60 lung adenocarcinoma (LAC) patients was evaluated using immunohistochemistry. The staining results were compared with clinicopathological characteristics and to the outcome of patients.

The intensity of SIRT1 staining was remarkably higher in LAC tissues than in matched non-tumor lung tissues; high levels of SIRT1 expression were found in 40 of 60 (66.7%) LAC and 5 of 60 (8.3%) non-tumor tissues (p < 0.05). SIRT1 expression displayed a significant correlation with histological grade (p = 0.01). According to the Kaplan-Meier survival analysis, median OS was 49.0 months (95% confidence interval (CI), 39.139 - 58.861) in the SIRT1-low group and 22.0 months (CI: 14.572 - 29.428) in the SIRT1-high group. Compared with SIRT1-high expression patients, SIRT1-low expression patients had higher 5-year OS, and the difference was significant (p < 0.01). Multivariate analyses revealed that SIRT1-low expression was a significant prognostic factor.

Taken together, our findings suggest that high expression of SIRT1 might be a potential unfavorable prognostic factor for patients with LAC.