LAUSR

Introduction: Despite major progress in its diagnosis, and treatment, lung cancer remains one of the deadliest cancers in the world. Patient-derived tumoroids offers unique advantage to integrate patients’ heterogeneity, and the diversity of resistance mechanisms in the drug discovery and development pathway. Organization of the tumor microenvironment both at the tissue, and at the molecular levels, is another critical factor that regulate drug response, in particular for immunotherapy. In this study, we have focused on oncolytic virotherapy, a promising concept that still deserves optimization. Different physiological barriers might limit the efficacy of oncolytic viruses (OVs): (i) mutations limiting viral replication and spreading, (ii) structure of the tumor tissue (basement membrane, vasculature, immune cells among other actors), (iii) physical parameters (therapeutic pressure, physical barriers), and iv) anti-viral vector response (reticulo-endothelial system, neutralizing antibodies, complement). Purpose of the Study: Development of an advanced in vitro model for NSCLC that would recapitulate major physical and biological barriers to the action of Vaccinia-based oncolytic vectors. Identification of major determinants of activity, and of R&D axes for the design of improved OVs. Experimental Approach: Lung tumor biopsies, and healthy tissues were obtained from the CRB of Strasbourg, and organoids were generated after an enzymatic treatment. Dissociated cells were mixed with exogenous microvessels derived from the adipose tissue. At day seven of the culture, patient-derived tumoroids and organoids (PDTs/PDOs) were transferred and embedded in a hydrogel mimicking the extracellular matrix. OVs were applied in fluidic to mimic intravenous perfusion, and viral properties were analyzed at 24h and 96h timepoints. Specificity was demonstrated by direct comparison of PDTs and PDOs from the same patient. Addition of circulating PBMCs after 24h of infection allowed us to analyze the interaction of OV with immune effectors. Results: Under fluidic conditions, mimicking intravenous infusion, we could confirm infection at the periphery of the lung PDT after only one hour of perfusion. IL-6 was significantly increased compared to IL-10, TNF-α and IL-1β (seven times more than the untreated condition). Compared to a passive diffusion mode (static conditions) infection was lower, suggesting the laminar flow and the matrix become efficacy-limiting factors. Indeed, under fluidic conditions, infection and replication were observed one day later than passive diffusion mode. The contribution of endothelial cells, and of immune cells was also characterized. Some experiments are still ongoing, and results on neutralizing antibodies will be presented in the poster. Citation Format: Le Hélène. Advanced patient-derived lung tumoroids to identify limiting factors for oncolytic virotherapy [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 5967.