Abstract LBA012: Engineered mini-livers for high-throughput tumor organoid screening of prodrugs

Abstract

Abstract Several anti-cancer compounds, including chemotherapy and targeted agents such as ifosfamide, cyclophosphamide, and imatinib, are administered as prodrugs which are metabolized to become pharmacologically active. Prodrugs are particularly difficult to study in vitro or ex vivo as many are activated in the liver by Cytochrome P450 enzymes. Preclinical studies of these compounds are restricted to in vivo models, as cancer cells typically do not express the enzymes required to transform prodrugs into their active form. While animal models effectively recapitulate the complexity of systemic drug metabolism and distribution, in vivo studies are time-consuming, expensive, and unsuitable for high-throughput drug screening studies. In previous work, we have developed a platform for screening patient-derived tumor organoids that yields results within a week of surgery (Phan et al, Commun Biol 2, 78, 2019; Nguyen and Soragni, STAR Protoc 1, 2, 2020; Al Shihabi et al, bioRxiv, 2021). Tumor organoids are promising pre-clinical models as they closely recapitulate features of the parent tumor, including drug responses. Here, we expand the physiological relevance of tumor organoid screenings by including mini-livers to metabolize prodrugs of interest. To retain the ability to perform automated, high-throughput screenings, we engineered a miniature liver insert (MLI). The MLI is a removable system that facilitates the addition of liver organoids to specific wells of 96-well plates in which prodrugs are tested. The MLI is designed to integrate with our existing tumor organoid screening platform (Phan et al, Commun Biol 2, 78, 2019; Nguyen and Soragni, STAR Protoc 1, 2, 2020; Al Shihabi et al, bioRxiv, 2021), and allows for simultaneous monitoring of tumor organoids and hepatocytes with brightfield and fluorescent imaging. Hepatocytes seeded in the MLI are viable and maintain their expression of the key Cytochrome P450 enzymes responsible for the metabolism of many clinically used prodrugs. Finally, we demonstrate that incorporating the MLI into prodrug screening experiments sensitizes tumor organoids to treatment with chemotherapeutic and targeted agents. Due to the facile integration with existing screening protocols, the MLI is a simple and effective system for studying anti-cancer prodrugs ex vivo. The MLI is a novel tool that facilitates the co-culture of functional liver organoids with clinically relevant tumor organoid models for drug discovery studies and precision medicine applications. Citation Format: Peyton J Tebon, Alice Soragni. Engineered mini-livers for high-throughput tumor organoid screening of prodrugs [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr LBA012.