Abstract 6316: High throughput small molecule screening with synthetic 3D lung-mimetic hydrogels in the rare lung cancer lymphangioleiomyomatosis

Abstract

Abstract Lymphangioleiomyomatosis (LAM) is a rare lung cancer characterized by immature smooth muscle-like cell invasion of the lung parenchyma, leading to cystonodular destruction and respiratory decline. Interestingly, LAM is a monogetic disease caused by loss of TSC2, conferring constitutive mTORC1 activation. Currently, there are no approved therapeutics which exhibit LAM cell-specific cytotoxicity. Here, we describe a novel 3D drug screening platform which couples a rationally designed, synthetic, lung-mimetic hydrogel to high content imaging. We have designed and synthesized a hyaluronic acid-based hydrogel which mimics endogenous lung tissue. Human LAM cell models maintain mTORC1 activation in the hydrogel compared to matched controls, reflective of human LAM lesions. We observe LAM cells to exhibit both protease-dependent and independent modes of invasion: the former imparted by gel crosslinking with an MMP-cleavable peptide, the latter enabled by methylcellulose conjugation. Proliferation is inhibited as LAM cells actively invade through the gel. We coupled our culture system to high content confocal microscopy, permitting measurements of cell viability and invasion depth in response to therapeutic screening. We subsequently tested an 800-drug library of Health Canada-approved small molecule cancer therapeutics on LAM cells and matched controls. Surprisingly, LAM cells exhibited pan-therapeutic resistance as measured by both invasion and viability metrics. Enrichment analysis revealed categories of therapeutics which demonstrated LAM-selective cytotoxicity and/or anti-invasiveness. We performed a refinement screen on select therapeutics and identified AURA inhibition as an effective LAM cell-specific therapeutic avenue. Work is ongoing to establish the most efficacious small molecule inhibitor. In conclusion, we describe a novel drug screening platform which enables high content measurements of viability and invasion in response to drug screening in a lung-mimetic system. We have identified AURA inhibition as a potential therapeutic avenue for LAM patients using this screening platform. Future work will involve target validation, elucidation of the mechanism of action, and testing in a pre-clinical mouse model. As these small molecules are Health Canada-approved, we anticipate rapid clinical translation of our preferred candidate. Citation Format: Adam Pietrobon, Julien Yockell-Lelievre, Carole Doré, Roger Y. Tam, Sean P. Delaney, Molly Shoichet, William L. Stanford. High throughput small molecule screening with synthetic 3D lung-mimetic hydrogels in the rare lung cancer lymphangioleiomyomatosis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6316.