Modeling the metastatic tumor microenvironment: a co-culture platform of lung cancer and blood vessel organoids for drug evaluation.

Tumor cell-vasculature interactions play a crucial role in lung cancer progression and metastasis; however, traditional cell culture models rarely capture these complex dynamics. We developed a vascularized lung cancer organoid (VLCO) model by coculturing lung cancer organoids (LCOs) with blood vessel organoids (BVOs) to recreate the tumor-vasculature niche in a three-dimensional in vitro system. During coculture, LCOs migrated along BVO-formed vascular networks and invaded vessel-like structures, mimicking intravasation. The organoid types interacted via secretory factors, including TGF-β and PDGF-BB, inducing epithelial-mesenchymal transition (EMT) in LCOs and pericyte-to-fibroblast transition in BVOs. We also developed a scalable drug response assay for vasculature-induced EMT, enabling targeted therapeutic screening. The VLCO model provides a robust platform for studying tumor-endothelial crosstalk and testing antimetastatic therapies targeting tumor-vasculature interactions.