Organoid Coculture Models for Cancer Research and Immunotherapy

ABSTRACT Three‐dimensional cancer organoids cultured in vitro closely recapitulate the phenotypic and genetic features of parental tumor tissues, making them powerful tools for cancer research, drug screening, and personalized medicine. However, traditional organoid cultures lack key components of the tumor microenvironment (TME), including cancer‐associated fibroblasts, immune cells, vascular networks, and dynamic physicochemical cues, such as fluid flow and oxygen gradients. These deficiencies limit the ability to study tumor–stroma crosstalk, model immunotherapy responses, and predict clinical drug efficacy, particularly for agents that function through intercellular interactions. To address these limitations, a range of organoid coculture strategies has been developed. Submerged Matrigel coculture enables the systematic reconstitution of specific TME components, facilitating the dissection of defined cell–cell interactions. Air–liquid interface culture uniquely preserves the native, unmanipulated TME, retaining resident immune cells, and fibroblasts for physiologically relevant studies of immune infiltration and checkpoint blockade. Microfluidic culture and organoid‐on‐a‐chip platforms introduce dynamic control over fluid flow, oxygen gradients, and shear stress, overcoming the static nature of traditional cultures and enabling vascularization, perfusion modeling, and high‐throughput drug screening. Three‐dimensional bioprinting offers unparalleled spatial precision in constructing multilayered heterogeneous tumor architectures, allowing for the recreation of complex TME structures such as vascular networks and tumor–stroma interfaces. This review synthesizes recent progress in these organoid coculture systems and their applications in immunotherapy optimization, adoptive cell therapy, and personalized medicine, while also analyzing the advantages and limitations of each model and offering perspectives on future developments toward more physiologically relevant preclinical platforms.