Abstract 702: Kinetic analysis identifies determinants of sensitivity to MEK inhibitor-induced cell death

Abstract

Abstract Successful identification of the genetic determinants of drug sensitivity has been a long-standing goal of cancer research and, more recently, of precision medicine. In cancer cells, drug treatment can induce both growth arrest and death. The distinction between these outcomes is important but can be overlooked in large-scale analyses that rely on traditional metabolism-based methods for quantifying cell viability. We recently demonstrated that Scalable Time-Lapse Analysis of Cell Death Kinetics (STACK) effectively quantifies cell death in response to diverse lethal stimuli. We investigated cases in which this approach captured drug-induced lethality more effectively than traditional assays. We found that inhibitors of mitogen activated protein kinase 1 and 2 (MEK1/2) arrested proliferation in diverse cancer cell lines, but induced cell death in only a subset of these lines. We sought to identify the factors that determine whether a cancer cell will undergo growth arrest or death in response to MEK inhibition. MAP kinase pathway activation has previously been reported as a determinant of MEK inhibitor sensitivity; we determined that the dynamics of Bcl-2 family proteins in response to MEK inhibitor treatment correlate with death sensitivity independent of pathway activation. In a genome-wide CRISPR screen, we identified a lipid metabolic enzyme that is a novel modulator of MEKi sensitivity. Our results suggest new approaches for predicting and enhancing sensitivity to cancer therapeutics in tumors and demonstrate that direct measurement of cell death provides clear advantages over proliferation-based metrics. Citation Format: Zintis Inde, Kyuho Han, Michael C. Bassik, Scott J. Dixon. Kinetic analysis identifies determinants of sensitivity to MEK inhibitor-induced cell death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 702.