Colon cancer is the third most lethal cancer worldwide, and is estimated to cause 49,190 cancer-related deaths in the U.S. in 2016 alone. Current treatments for colon cancer are limited in their capacity to target tumor cells employing adaptive mechanisms necessary for survival and proliferation, often resulting in poor prognosis. Therefore, it is critical to develop novel target-specific therapeutic approaches with minimal cytotoxicity to normal cells, in order to mitigate potential side effects. Proanthocyanidins represent a subclass of flavonoids, which have been widely investigated for their chemopreventive and therapeutic potential. Cinnamtannin B-1 (CTB-1) is a proanthocyanidin shown to have anti-cancer effects in several cancers, but its anti-cancer potential in colon cancer has not been tested. Hence, the focus of this study was to determine the anticancer effects of CTB-1 in colon cancer. Our results show that CTB-1 treatment significantly decreases the cell viability and proliferation of DLD-1 and COLO 201 human colon cancer cells in a time and dose-dependent manner. In addition, CTB-1 treatment modulated the cell cycle progression of colon cancer cells via G2/M arrest, coupled with a reduction of cells in the S phase. The expression and/or phosphorylation of key molecules involved in apoptosis and cell cycle progression were also modulated in response to CTB-1 treatment. Collectively, these findings, for the first time, shed light on the anti-proliferative effects of CTB-1 in colon cancer, and further demonstrate its potential as a novel therapeutic/preventive agent.

Citation Format: Patrick P. Carriere, Hina Mir, Neeraj Kapur, Clarence E. Clark, Shailesh Singh. Anti-proliferative effects of cinnamon extract in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 312. doi:10.1158/1538-7445.AM2017-312