Abstract 3084: The effects of NT-1044, a novel AMPK activator, on endometrial cancer cell proliferation, apoptosis, cell stress, and tumor growth

Abstract

Abstract Objectives: Obesity and diabetes are associated with increased risk and worse outcomes in endometrial cancer (EC). Anti-diabetic biguanide drugs such as metformin may have anti-tumorigenic effects by behaving as AMPK activators and mTOR inhibitors. Metformin requires organic cation transporters (OCTs) for entry into cells, and NT-1044 (NovaTarg Therapeutics) is an AMPK activator designed to have greater affinity for two of these transporters, OCT1 and 3. We sought to compare the effects of NT-1044 on cell proliferation in human EC cell lines and on tumor growth in an endometrioid EC mouse model. Methods: Cell proliferation was assessed in two EC cell lines, ECC-1 and Ishikawa, by MTT assay after exposure to NT-1044. Apoptosis was analyzed by Annexin V-FITC assay. Cell cycle progression was evaluated by flow cytometry. Reactive oxygen species (ROS) were measured using a DCFH-DA assay. Western immunoblotting was performed to evaluate the effects of NT-1044 on the downstream targets of the AMPK/mTOR pathway and proteins related to cell cycle and cellular stress. For in vivo studies, we utilized the LKB1f/f/p53f/f mouse model of endometrioid endometrial cancer. Mice were treated with placebo or NT-1044 (200 mg/kg/day, oral gavage) following tumor onset for 4 weeks. Results: NT-1044 significantly inhibited proliferation in a dose-dependent manner in both EC cell lines after 72 hours of exposure (IC50 218 uM for ECC-1; 87 uM for Ishikawa). Treatment with NT-1044 resulted in G1 cell cycle arrest, induced apoptosis and increased ROS production in both cell lines. NT-1044 increased phosphorylation of AMPK and decreased phosphorylation of S6, a key downstream target of the mTOR pathway. Expression of the cell cycle proteins CDK4, CDK6 and cyclin D1 decreased in a dose dependent-fashion while cellular stress protein expression was induced in both cell lines. As compared to placebo, NT-1044 inhibited endometrial tumor weight in the LKB1f/f/p53f/f mice by 56% (p = 0.031). Conclusions: NT-1044 suppressed EC cell growth through G1 cell cycle arrest, induction of apoptosis, cellular stress and inhibition of the AMPK/mTOR pathway. In addition, NT-1044 inhibited EC tumor growth in vivo. More work is needed to determine if this novel biguanide will be beneficial in the treatment of women with EC, a disease strongly impacted by obesity and diabetes. Citation Format: Dario R. Roque, Weiya Z. Wysham, Chunxiao Zhou, Ken W. Batchelor, Wendy R. Brewster, Victoria L. Bae-Jump. The effects of NT-1044, a novel AMPK activator, on endometrial cancer cell proliferation, apoptosis, cell stress, and tumor growth. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3084.