Abstract 1839: LKB1 deficiency enhances sensitivity to energetic stress induced by erlotinib treatment in non-small cell lung cancer (NSCLC) cells

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA The tumor suppressor LKB1 is inactivated in 20-30% of non-small cell lung cancer (NSCLC) patient tumors. Because LKB1 is the master kinase phosphorylating the energy-sensing kinase AMPK, dysregulation of the LKB1-AMPK signaling axis causes loss of cellular homeostasis in response to metabolic inhibition or external stress-induced mitochondrial insults. Erlotinib is used clinically in NSCLC patients to target mutationally activated EGFR and is known to induce mitochondrial-mediated apoptosis. We investigated the metabolic response and mitochondrial function of LKB1-deficient NSCLC cells treated with erlotinib. LKB1-deficient cells exhibited enhanced sensitivity to erlotinib treatment in vitro and in vivo despite having wild-type EGFR. We found that this enhanced response was due to altered energetic metabolism and mitochondrial dysfunction in LKB1-deficient cells, which prevents homestatic maintenance of ATP and reactive oxygen species (ROS) levels in response to erlotinib treatment. Despite negative regulation of mTOR activity by LKB1-AMPK signaling, erlotinib effectively blocked mTOR signaling in LKB1-deficient cells, resulting in inhibition of cell growth, as well as activation of apoptosis. These findings will be important for designing targeted treatments for LKB1-deficient NSCLC patient tumors harboring wild-type EGFR, which disrupt metabolic and signaling pathways known to regulate energy metabolism in these cells. Citation Format: Young Mi Whang, Serk In Park, Irina A. Trenary, Changki Lee, Jacob M. Kaufman, David P. Carbone, Jamey D. Young. LKB1 deficiency enhances sensitivity to energetic stress induced by erlotinib treatment in non-small cell lung cancer (NSCLC) 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 1839. doi:10.1158/1538-7445.AM2014-1839