Objective

In vitro cell culture techniques are rapidly moving towards three-dimensional (3D) models to better mimic the tissue architecture and environment in vivo. These physiologically relevant models such as mouse and patient cells derived organoids provide a platform for understanding behaviour of cells in various physiological and perturbed conditions. However, appropriate imaging technology, to visualise and understand the dynamic interactions of cells within organoids in 3D, is still lacking. Therefore, alongside rapid advancements in the field of organoid technology, there is a need for parallel development of imaging techniques that enable long-term imaging of living samples. In recent years, light sheet microscopy has proved to be an excellent technique for fast volume imaging of growing tissues, organs and embryos of model organisms. Owing to its capability to image large samples with minimal phototoxicity, visualisation of dynamic biological processes across spatio-temporal scales has become possible, revolutionising the fields of cell and developmental biology. Despite the wide applicability of light sheet microscopy, cancer research still relies on conventional imaging techniques using fixed and sectioned tissues, primarily due to the challenges posed by samples used to study cancer biology. In contrast to robustly developing embryos, 3D cell culture and organoids are very fragile and susceptible to contamination, challenging their long-term survival during the course of imaging. With my background in developing customised light sheet microscopes, I have established light sheet imaging at the Cancer Research UK Cambridge Institute, where we are working towards developing dedicated experimental setups and image processing workflows for live organoid imaging. In collaboration with several groups, we have established novel ways of growing the organoids and cells directly inside polymer tubes used for light sheet imaging. We have successfully imaged co-cultures of tumour cells, growing organoids and whole mouse embryos for over 24-48 hours of development at high resolution, tracking the dynamics and division of individual cells therein. Further, to understand the structure and organisation of cells within large tumours, we use clearing techniques to make the samples transparent and image whole tissues using light sheet microscopy. Our dedicated image-processing and analysis pipelines are used to reconstruct 3D models. I will present our on-going efforts and discuss the prospects light sheet microscopy brings to the cancer biology and translational research communities at large.