Sirtuin 1 in malignant transformation: Friend or foe?

In the past decade, great interest has been shown in the role of sirtuin 1 (SIRT1) in tumorigenesis. The published data show SIRT1 can function as both a tumor promoter and tumor suppressor. In this review, we summarize the available data regarding the role of SIRT1 in tumorigenesis, with a focus on the potential mechanisms. The seemingly controversial role of SIRT1 in tumorigenesis suggests that SIRT1 might play a dual role in different tissue contexts depending on the temporal and special distribution of different SIRT1 upstream and downstream factors. Clearly, the role of SIRT1 in tumorigenesis is poorly understood and more research is necessary to elucidate its function in the malignant process.