A Microcavity-Based Sarcoma Spheroid Model for Drug Efficacy and Mechanism Analysis Using Cost-effective 3D Printing Technology

Ewing sarcoma is a pediatric bone cancer with poor survival in relapsed cases, highlighting the need for better preclinical models. Here, we developed a scalable 3D spheroid platform using SLA-printed microcavity arrays to generate uniform Ewing sarcoma spheroids. High-throughput screening of 11 compounds identified Torin 2, Talazoparib, and Trabectedin as potent inhibitors. Incorporating lung fibroblasts into hybrid spheroids revealed fibroblast-induced drug resistance, mimicking the metastatic tumor microenvironment. Transcriptomic analysis identified activation of NF-κB and TGF-β signaling pathways as key mediators of this resistance. This platform offers a cost-effective, biologically relevant system for drug testing and mechanistic studies in Ewing sarcoma and other stromal-influenced cancers.