Abstract 2056: SIRT1 silencing suppresses prostate cancer growth and metastasis in an orthotopic prostate cancer mouse model

Abstract

Abstract Tumor environment is critical for tumor growth and progression, and orthotopic mouse model allows accurately study tumor development in an appropriate tumor environment. SIRT1, a class III histone deacetylase, has been shown overexpressed in prostate cancer and is a biomarker for prostate cancer recurrence. Although these data have suggested the importance of the role SIRT1 plays in prostate cancer progression, the role of SIRT1 in tumor growth and progression within, specifically, a prostate tumor environment has not been established. In this study, we established an advanced prostate cancer PC3MM2 orthotopic mouse model to study the effects of SIRT1 silencing on prostate cancer growth and progression. Our data has shown that SIRT1 knockdown greatly suppresses tumor formation within a prostate tumor environment, along with an inhibition of metastasis to bone and liver. To further study the mechanism by which SIRT1 controls tumor growth and progression, we demonstrated that SIRT1 silencing reduces prostate cancer cell adhesion to cell matrix, and that this silencing also suppresses cancer cell growth and colony formation in a cell matrix dependent manner. Moreover, our data showed that SIRT1 regulates integrin expression and focal adhesion complex formation. Furthermore, we shows that SIRT1 silencing from prostate cancer cell significantly inhibited human umbilical vein endothelial cell (HUVEC) tube formation, suggests an important role of SIRT1 in prostate cancer angiogenesis. Thus, we have reported for the first time that SIRT1 plays a critical role in prostate cancer growth and progression using orthotopic mouse model, and demonstrated for the first time that SIRT1 regulates integrin expression, focal adhesion formation, tumor cell and matrix interaction, and angiogenesis. These results suggest SIRT1 regulates prostate cancer growth and progression through multiple mechanisms and that SIRT1 is a potential target in prostate cancer treatment. Citation Format: Yan Dai, Lijia Zhu, Elizabeth Cho, Audrey Hagiwara, Douglas Faller, Sun-Jin Kim, Isaiah J. Fidler, Marina Amaro. SIRT1 silencing suppresses prostate cancer growth and metastasis in an orthotopic prostate cancer mouse model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2056. doi:10.1158/1538-7445.AM2015-2056