A facile automated multiple-well platform of immunized tumor organoid cultures in ECM-mimicked hydrogels for chem-immunotherapy evaluation

Abstract

Breast cancer often develops drug resistance during chemotherapy, and immunotherapeutic agents always exhibit ineffectiveness when used as a single treatment; thus, it is necessary to develop a chemo-immunotherapy strategy in clinics. However, there is still a challenge to evaluate the chemo-immunotherapy efficacy by conventional 2D cell culture and animal models. In this study, we developed a facile automated multiple-well platform for fabricating tumor associated macrophages (TAMs)-immunized breast cancer organoids in alginate hydrogels. An automated robotic microinjection system was used for building alginate hydrogels in situ and seeding mixed cell suspensions of breast cancer cells and TAMs into hydrogels to form organoids. The induced drug resistance to epirubicin was observed in breast cancer organoids with TAMs, but it could be inhibited by targeted immunotherapy PLX3397. The synergistic effects were also evaluated in several co-administration strategies of PLX3397 in combination with epirubicin. The RNA-seq and quantitative polymerase chain reaction were further used to examine gene transcription levels in the co-administration and find out three genes (IL6, CD37, and GLS2) with significant differences, which were involved in the tumor necrosis factor signaling, PI3K-Akt signaling and epidermal growth factor receptor tyrosine kinase inhibitor resistance pathway. The results demonstrated that the automated multiple-well platform showed the potential to replace the conventional bulk culture method in evaluating the therapeutic effects of chem-immunotherapy.