Organoids: technology refining, current applications and future directions

Organoids are derived from pluripotent stem cells or tissue stem cells, progenitor cells, or differentiated cells from healthy or diseased tissues (e.g., tumors). Numerous organoid engineering strategies have been tested to support the culture, growth, proliferation, differentiation, and maturation of organoids. A variety of organoids and organoid-on-chips have also been constructed to reflect real environments of human and mouse organs. Currently, four major areas of potential application for organoids include disease modeling, anticancer drug screening, drug toxicology testing, and gene/cell therapy. For cancer immunotherapy, immune organoids based on co-culturing human tumor cells have been used as a critical platform for drug screening and targeted therapy. This review summarizes recent advances in organoid culture, lists the methods for constructing organoids and their main applications, and highlights its value as a tool for precise cancer modeling. Given the enormous potential of organoids as an in vitro culture model in cancer treatment, we also discussed organoid-based methods for angiogenesis and immune microenvironment modeling, and analyzed the wide range of applications of immune organoids, such as testing treatment response, exploring mechanisms of drug resistance, optimizing treatment strategies, and guiding drug development. Finally, we attempt to look into the critical challenges and bright prospects for cancer organoid research.