October 1, 2019
ell) in 100 mL complete medium and treated using a TECAN D300e digital dispenser (HP). After 72 hours of treatment, relative cell viability was assessed by measuring the ATP content in each well. Therefore, CellTiter-Glo Reagent (Promega, catalog no. G7573) was added 1:1. Upon 10 minutes of incubation, luminescence intensity was measured with a plate reader (Tecan Infinite M1000 Pro) and normalized to intensities of control wells
The advent of molecularly targeted therapeutic agents has opened a new era in cancer therapy. However, many tumors rely on nondruggable cancer-driving lesions. In addition, long-lasting clinical benefits from single-agent therapies rarely occur, as most of the tumors acquire resistance over time. The identification of targeted combination regimens interfering with signaling through oncogenically rewired pathways provides a promising approach to enhance efficacy of single-agent-targeted treatments. Moreover, combination drug therapies might overcome the emergence of drug resistance. Here, we performed a focused flow cytometry-based drug synergy screen and identified a novel synergistic interaction between GLUT1-mediated glucose transport and the cell-cycle checkpoint kinases ATR and CHK1. Combined inhibition of CHK1/GLUT1 or ATR/GLUT1 robustly induced apoptosis, particularly in RAS-mutant cancer cells. Mechanistically, combined inhibition of ATR/CHK1 and GLUT1 arrested sensitive cells in S-phase and led to the accumulation of genotoxic damage, particularly in S-phase. In vivo, simultaneous inhibition of ATR and GLUT1 significantly reduced tumor volume gain in an autochthonous mouse model of KrasG12D -driven soft tissue sarcoma. Taken together, these findings pave the way for combined inhibition of GLUT1 and ATR/CHK1 as a therapeutic approach for KRAS-driven cancers. SIGNIFICANCE: Dual targeting of the DNA damage response and glucose transport synergistically induces apoptosis in KRAS-mutant cancer, suggesting this combination treatment for clinical validation in KRAS-stratified tumor patients. Š2019 American Association for Cancer Research.
Erber, J; Steiner, JD; Isensee, J; Lobbes, LA; Toschka, A; Beleggia, F; Schmitt, A; Kaiser, RWJ; Siedek, F; Persigehl, T; Hucho, T; Reinhardt, HC;
Journal: Cancer Res. Pages: 4855-4868