Abstract C040: Discovery and development of novel ATG13 degrading compounds that inhibit autophagy and treat Non-Small Cell Lung Cancer

Abstract

Abstract Autophagy is the process by which a cell maintains homeostasis by removing and recycling cytoplasmic debris. Autophagy provides lung cancer cells with essential nutrients for their increased proliferation and metabolism and aids in survival during anti-cancer treatments. CRISPR knockout or siRNA knockdown of the autophagy protein ATG13 inhibits autophagy and reduces viability of non-small cell lung cancer (NSCLC) cell lines. These data show that ATG13 is essential for autophagy and essential for lung cancer cell survival, making it a viable therapeutic target for cancer treatment. To identify compounds that degrade ATG13 and inhibit autophagy, we established a high-throughput screening (HTS) compatible Nano-Glo HiBiT assay where endogenous ATG13 was labeled on the C-terminus with HiBiT peptide via CRISPR. Optimization of this assay allowed for a signal to background Z’ factor of 0.71 and confirmed a positive control compound that induced up to 50% ATG13 degradation, thus indicating that this assay was suitable for compound screening. Currently, over 50,000 compounds from a variety of libraries have been screened in 1536-well format and 15 positive hits for ATG13 degradation have been identified. A series of counter-screens and secondary assays including In Cell Western Blot and Protein Thermal Shift assays will be used to confirm these hits. At the end of this testing funnel, we will have characterized novel compounds that degrade ATG13 and inhibit autophagy. These hits will provide a starting point for further chemical optimization to provide lead ATG13 degraders to evaluate in advanced preclinical proof-of concept studies of lung cancer. Citation Format: Patrick M Hagan, Atoosa Emami, Hilarie Austin, Ian Pass, Allison Limpert, Douglas Sheffler, Nicholas Cosford. Discovery and development of novel ATG13 degrading compounds that inhibit autophagy and treat Non-Small Cell Lung Cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C040.