Establishment of a three­dimensional triculture model on the novel AXTEX­4D™ platform.

Cancer can be fatal if it is not treated in a timely manner; therefore, there is a high demand for more specific oncology drugs. Unfortunately, drugs showing positive responses on a two­dimensional (2D) culture platform do not often show the same effect in clinical trials. Therefore, three­dimensional (3D) culture platforms are garnering attention since they more closely mimic the tumor microenvironment (TME). The TME stimulates metastasis and drug resistance, and serves an essential role in tumor formation. An accurate understanding of tumor­stroma interactions is undoubtedly required to improve the response of patients to therapeutic strategies, and cancer therapeutic strategies that do not account for the stroma are considered inadequate. It should be noted that 3D monoculture systems do not completely mimic the TME since other cells in the 3D culture are missing, such as fibroblast or endothelial cells, which are essential components of the stroma; therefore, it is essential to develop advanced 3D culture systems. The present study aimed to develop a versatile triculture model that mimics the native TME; therefore, it could aid in high­throughput screening of chemotherapeutic drugs against cancer by evaluating their effects on tumor progression and cell cytotoxicity. The present study demonstrated the use of the AXTEX­4D™ platform in developing triculture tissueoids composed of MCF­7, human umbilical vein endothelial cells and MRC5 cells, and compared it with a 3D monoculture model (MCF­7) and a 2D culture model. The triculture model was validated for proliferation, ECM markers and T­cell infiltration by confocal microscopy. Alamar Blue assay demonstrated that triculture tissueoids exhibited higher drug resistance than the other two models, thus demonstrating their use in the screening of oncology drugs.

AXTEX-4D: A Three-Dimensional Ex Vivo Platform for Preclinical Investigations of Immunotherapy Agents.

The latest advancements in oncology are majorly focused on immuno-oncology (I-O) therapies. However, only ∼7% of drugs are being approved from the preclinical discovery phase to phase 1. The most challenging issues in I-O are the development of active and efficient drugs in an economically feasible way and in a comparatively short time for testing and validation. This mandates an urgent need for the upgradation of preclinical screening models that closely mimic the in vivo tumor microenvironment (TME). The established and most common methods for investigating the tumoricidal activity of I-O drugs are either two-dimensional systems or primary tumor cells in standard tissue culture vessels. Unfortunately, they do not mimic the TME. Consequently, the more in vivo-like three-dimensional (3D) multicellular tumor spheroids are quickly becoming the favored model to examine immune cell-mediated responses in reaction to the administration of I-O drugs. Despite many advantages of multicellular spheroids, challenges (e.g., incompatibility of quantitative assays with spheroid platforms) are still involved in the tedious procedures required for the spheroid culture that is holding back the biological community from adapting the well-recognized spheroid tissue models for studying drug delivery more widely. To this end, we have demonstrated the utility of the 3D ex vivo oncology model, developed on our novel AXTEX-4D™ platform to assess therapeutic efficacies of I-O drugs by investigating immune cell proliferation, migration, infiltration, cytokine profiling, and cytotoxicity of tumor tissueoids. The platform eliminates the need for additional biomolecules such as hydrogels and instead relies on the cancer cells themselves to create their own gradients and microenvironmental factors. In effect, the more comprehensive and ex vivo-like immune-oncology model developed on AXTEX-4D platform can be utilized for high-throughput screening of immunotherapeutic drugs.