LAUSR

Background: Organotypic models have emerged as an important preclinical model for developmental therapeutics in pancreatic and biliary cancer. Naturally derived cardiac glycoside in 2D monoculture exquisite potency, here we describe their activity in cancer and normal liver with patient-derived cancer organoids (PCOs). Methods: PCOs of pancreatic and ampullary cancers and normal hepatic tissues were generated. Response was assayed with four structurally different cardiac glycoside (cerberin, neriifolin, digitoxin, digoxin; 72h). Response was characterized by growth inhibition (GI50) using 3D CellTiterGlo (CTG) and subclonal population response by high content imaging using normalized change in diameter (n=1038). Results: Dose response revealed improved potency for cerberin and neriifolin, versus digoxin and digitoxin across models (see table). In a normal liver organoid model, there was no convergence in dose response observed when extended to 1uM of each cardiac glycoside. Ampullary PCO response was assayed using subclonal population analysis. Cerberin at 10nM achieved growth arrest across the population as assayed by median Δ diameter (growth +4.0±32.0, GΔ=0.94, p<0.005). Neriifolin at 10nM had subclonal with residual growth representing 72% of overall population as assayed by Δ diameter (growth +18.3%, GΔ=0.65). Traditional cardiac glycosides of digoxin and digitoxin at 10nM had significant portions with residual growth (94.9% and 84.7%, respectively) as well as did not achieve meaningful effect (GΔ=-0.10 and GΔ=0.05, respectively). Conclusions: CGs have varied potency for anticancer activity between different structural motifs. Cerberin induce population growth arrest in cancer models which differed from normal liver. This work requires dedicated mechanistic modeling to explain differences in anti-cancer activity that may confer sensitivity and in considering models of cardiac toxicity. Potency of Cardiac Glycosides in Organoid Models. GI50 (nM) Ampullary GI50 (nM) Pancreatic GI50 (nM) Normal Liver Cerberin 7.4 7.20 71.0 (NC) Neriifolin 10.2 7.4 62.0 (NC) Digoxin 29.6 47.9 55.5 (NC) Digitoxin NC 40.0 85.5 (NC) Citation Format: Md Shahadat Hossan, Ethan Lin, Austin Stram, Jamie Warner, Luke Koeppel, Ellie Riedl, Jeremy Kratz. Potency of cardiac glycosides by structure in organotypic models of pancreatic and ampullary carcinomas. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3826.