Treatment Response to Oncolytic Virus in Patient-Derived Breast Cancer and Hypopharyngeal Cancer Organoids: Evaluation via a Microfluidics Organ-on-a-Chip System

In this study, we present an oncolytic virus (OV) evaluation system established using microfluidic organ-on-a-chip (OOC) systems and patient-derived organoids (PDOs), which was used in the development of a novel oncolytic virus, AD4-GHPE. An OV offers advantages such as good targeting ability and minimal side effects, and it has achieved significant breakthroughs when combined with immunotherapy in recent clinical trials. The development of OVs has become an emerging research focus. PDOs can preserve the heterogeneity of in situ tumor tissues, whereas microfluidic OOC systems can automate and standardize various experimental procedures. These systems have been applied in cutting-edge drug screening and cell therapy experiments; however, their use in functionally complex oncolytic viruses remains to be explored. In this study, we constructed a novel recombinant oncolytic adenovirus, AD4-GHPE, and evaluated OOC systems and PDOs through various functional validations in hypopharyngeal and breast cancer organoids. The results confirmed that AD4-GHPE exhibits three antitumor mechanisms, namely, tumor-specific cytotoxicity, a reduction in programmed death ligand 1 (PD-L1) expression in tumor cells to increase CD8⁺ T-cell activity, and granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. The evaluation system combining OOC systems and PDOs was efficient and reliable, providing personalized OV treatment recommendations for patients and offering industrialized and standardized research ideas for the development of OVs.