Abstract 574: α-santalol induces caspase-dependent apoptosis and G2/M phase cell cycle arrest in human breast cancer cells

Abstract

Abstract Alpha-santalol, an active component of sandalwood oil, has been shown to have chemopreventive effects on skin cancer both in vitro and in vivo. However, effects of alpha-santalol on other types of cancer have not been studied. In this study, we examine the effects and mechanisms of action of alpha-santalol on human breast cancer cells using estrogen receptor (ER)- positive (MCF-7) and estrogen receptor- negative (MDA-MB-231) breast cancer cell lines. MTT and BrdU cell proliferation ELISA results showed inhibition of cell viability and proliferation in a time and dose-dependent manner in both cell lines. Alpha-santalol at 25-150 µM concentration decreased cell viability after 12h treatment. In addition, TUNEL assay and flow cytometry results revealed that alpha-santalol significantly induced apoptosis in MCF-7 and MDA-MB-231 cells. Further, immunoblotting and caspase activity assays showed involvement of caspase-3, caspase-8 and caspase-9 in apoptotic cell death. Induction of apoptosis by alpha-santalol was further confirmed by detecting the cleavage of Poly (ADP-ribose) Polymerase (PARP) through western blotting. Cell cycle distribution of alpha-santalol treated MFC-7 and MDA-MB-231 cells were analyzed by fluorescence- activated cell sorting (FACS) analysis of propidium iodide staining. We observed that alpha-santalol treatment arrests cell cycle at G2/M phase at 25µM −75µM concentration in both cell lines. Taken together, our studies reveal a potential mechanism for the chemopreventive effect of alpha-santalol on ER- positive and ER- negative breast cancer cells through induction of apoptosis and cell cycle arrest at G2/M phase. Alpha-santalol could be effective for the prevention and treatment of breast cancer. (Supported by Translational Cancer Research Center funded by South Dakota, Governors Office of Economic Development) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 574. doi:1538-7445.AM2012-574