Abstract 1253: Dual PI3K/mTOR inhibitor NVP-BEZ235 in combination with AKT inhibitor MK2206 in esophageal carcinoma cells

Abstract

Abstract The long-term goal of our research is to investigate the molecular carcinogenesis of esophageal squamous cell carcinoma and to develop strategies for esophageal cancer prevention. Previous studies in our laboratory demonstrated an association between activation of PI3K/AKT/mTOR pathways and the development of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus. The objective of current study is to evaluate the effects of NVP-BEZ235, a dual PI3K/mTOR inhibitor, and MK2206, an AKT inhibitor, alone or in combination in esophageal cancer cell lines, KYSE-70, -150, -270 and -410. The cancer cell lines were treated with different doses of NVP-BEZ235 (1, 10, 50, 100, 1000 nMol/L) and MK2206 (0.5, 1, 3, 10, 20 uMol/L), or NVP-BEZ235 100 nMol/L plus MK2206 3 uMol/L. Western blot was performed to assess the activation of PI3K/AKT/mTOR pathways. Cell proliferation, apoptosis and cell cycle were analyzed by WST1 and flow cytometry. We found that the combination of NVP-BEZ235 and MK2206 significantly reduced the phosphorylation of p-AKTT308, p-AKTS473, p-mTORS2448, p-S6S235/236 and p-4EBP1T37/46, when compared to NVP-BEZ235 (1000 nMol/L) and MK2206 (20 uMol/L) alone (p<0.05). The cell proliferation rate was reduced by NVP-BEZ235 1000 nMol/L, MK2206 20 uMol/L, or NVP-BEZ235 plus MK2206 to 20% (p<0.01), 24% (p<0.01) and 17% (p<0.01), respectively. The NVP-BEZ235 1000 nMol/L and MK2206 10 uMol/L induced apoptosis in esophageal cancer cells to 30% and 20% (p<0.01), respectively. NVP-BEZ235 plus MK2206 induced apoptosis in esophageal cancer cells to 45% (p<0.01). The combination treatment increased the proportion of cells at G0/G1 phase compared to cells treated with NVP-BEZ235 or MK2206 alone. Our results indicate that co-targeting the PI3K/mTOR and AKT signaling pathways produces synergistic activity against esophageal carcinoma cell growth. This in-vitro study provides evidence to test the efficacy of NVP-BEZ235 in combination with MK2206 in inhibition of esophageal tumor development in vivo. (Supported by NIH/NCI R01 CA131073-01A1). Citation Format: Hao Yu, Ni Shi, Zui Pan, Tong Chen. Dual PI3K/mTOR inhibitor NVP-BEZ235 in combination with AKT inhibitor MK2206 in esophageal carcinoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1253. doi:10.1158/1538-7445.AM2014-1253