Oral cancer is a prevalent type of cancer in many countries. Although studies indicated that garlic extracts such as diallyl disulfide and diallyl trisulfide have anti-cancer effects, the chemopreventive effects of aqueous garlic extracts, S-allylcysteine (SAC), on oral cancer have not been studied yet. To this specific aim, we investigated the inhibitory effects of SAC on the proliferation and progression of oral cancer cells in both in vitro and in vivo models. In the present study, our results demonstrated that SAC dose-dependently inhibited the proliferation of human oral squamous cancer CAL-27 cells in vitro. The results indicated that SAC stabilized the adherent junction complex of E-cadherin/β-catenin and suppressed epithelial-mesenchymal transition (EMT) in oral cancer cells through suppression of MAPK/ERK signaling pathways. By study end (4th week), consumption of SAC (at doses of 5 and 40 mg / kg of body weight per day) significantly prevented tumor growth of oral cancer in a mouse xenograft model. Histopathological and immunohistochemical (IHC) staining results indicated that SAC could effectively suppress tumor progression including EMT of oral cancer in vivo. The chemopreventive effects of SAC were associated with decreases in cyclin D1 expression and suppression of Akt, mTOR, IκBα, and ERK 1/2 signaling cascades in tumor tissues. SAC consumption could inhibit the expression of cyclooxygenase-2 (COX-2), Vimentin, and nuclear NF-κB p65 (RelA) proteins. These results suggested that SAC could act as an effective agent to prevent tumor growth, progression, and EMT of oral cancer.

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 5428. doi:1538-7445.AM2012-5428