Abstract 3737: Use of intestinal organoids as a preclinical screen for agents modulating epithelial regeneration and gastrointestinal toxicity

The mouse small intestinal in vitro organoid model was first described by Sato et al in 2009. We have further developed this model as a robust screening tool to aid the selection of lead candidates that may have efficacy preventing or treating GI toxicity, and to allow early identification of candidate toxicity. More specifically, we have been assessing the model9s potential to progress the development of novel therapeutic agents to treat the GI mucositis, a common toxicity associated with cancer therapy. The intestinal organoid culture conditions were designed to mimic the stem cell niche allowing cell differentiation and proliferation to occur. Indeed all intestinal lineages are present in the organoids and the epithelial hierarchy closely resembles that observed in vivo. Alteration of these organoid culture conditions allows identification of proliferative or cytotoxic effects, changes in differentiation and gene expression profiling of target pathways. Sub-optimal culture conditions reduce the background level of branching within an organoid population, allowing the quantification of proliferative effects through an increase in branching above the background upon agent exposure. Examples of agents inducing branching of organoids include Wnt pathway modulators. Optimal culture conditions allow assessment of toxicity caused by agents such as chemotherapy drugs. Organoid viability can be assessed either visually or with MTS techniques. In addition, differentiation by agents such as the Notch pathway inhibitor DAPT can be assessed by histological examination of the organoids. All of these cultures can undergo gene expression profiling forming links to the observed biological observations. Proof of concept gene expression data has been generated using known GI growth factors and modulators, which have been linked to in vivo gene expression profiling to demonstrate PD linkages. In addition, we have developed a model using APCMin+/- mice, which develop a phenotype in culture more consistent with a deregulated adenoma. Parallel assessment of agents on this model and the organoids has been useful for discriminating normal vs tumour responses, identifying agents with differential activities. Our intestinal organoid models allow screening of multiple agents, with over 5000 screened to date including Wnt pathway regulators, cytokines, growth factor, chemotherapy drugs, steroids and lectins. Citation Format: Sarah Hoyle, Shaun Ainsworth, Aude-Marine Bonavita, Jo Read, Alan Murdoch, Lorna Woolford, Elliott Harrison, Gino Miele, Cath Booth. Use of intestinal organoids as a preclinical screen for agents modulating epithelial regeneration and gastrointestinal toxicity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3737. doi:10.1158/1538-7445.AM2014-3737