Modelling glioblastoma with organoids and assembloids: Opportunities and challenges

Glioblastoma (GBM) is the most common malignant tumor of the adult central nervous system and is associated with an extremely poor prognosis. Despite standard-of-care treatment, including surgery, radiotherapy, and chemotherapy, mortality rates remain high, highlighting the urgent need for more effective therapeutic strategies. The pronounced intratumoral heterogeneity, highly invasive growth behavior, and strong dependence on the tumor microenvironment complicate both the biological understanding of glioblastoma and the management of therapy resistance. Conventional two-dimensional culture systems and simplified three-dimensional models fail to adequately capture these complex disease characteristics. Recent advances in three-dimensional organoid and assembloid technologies provide physiologically relevant platforms that preserve patient-specific molecular profiles, spatial organization, and tumor-microenvironment interactions. In particular, assembloid systems integrating multiple cellular components enable the investigation of glioblastoma invasion, microenvironment-driven cellular plasticity, and mechanisms of therapeutic resistance. This review provides a critical overview of current two- and three-dimensional in vitro models used in glioblastoma research, with a focus on emerging organoid and assembloid platforms. Their strengths, limitations, and recent innovations are discussed, highlighting their potential to advance translational research and support personalized therapeutic strategies for glioblastoma.