ROR1-CAR T-cells are effective against lung and breast cancer in advanced microphysiologic 3D tumor models

Solid tumors impose immunological and physical barriers to the efficacy of chimeric antigen receptor (CAR) T-cell therapy that are not reflected in conventional pre-clinical testing against singularized tumor cells in two-dimensional culture. Here, we established microphysiologic three-dimensional (3D) lung and breast cancer models that resemble architectural and phenotypical features of primary tumors, and evaluated the anti-tumor function of ROR1-specific CAR T-cells. 3D tumors were established from A549 (non-small cell lung cancer) and MDA-MB-231 (triple-negative breast cancer) cell lines on a biological scaffold with intact basement membrane (BM) under static and dynamic culture conditions, which resulted in progressively increasing cell mass and invasive growth phenotype (dynamic>static; MDA-MB-231>A549). Treatment with ROR1-CAR T-cells conferred potent anti-tumor effects. In dynamic culture, CAR T-cells actively entered arterial medium flow, adhered to and infiltrated the tumor mass. ROR1-CAR T-cells penetrated deep into tumor tissue and eliminated multiple layers of tumor cells located above and below the BM. The microphysiologic 3D tumor models developed in this study are standardized scalable test systems that can be used either in conjunction with or in lieu of animal testing to interrogate the anti-tumor function of CAR T-cells, and to obtain proof-of-concept for their safety and efficacy prior to clinical application.