Abstract 4565: Drug screening by layered 3D co-cultured tumor model including vascularized stromal tissue
Authors: Takahashi Yuki , Nomura Yumi , Yokokawa Yuma , Kitano Shiro , Nagayama Satoshi , Shinozaki Eiji , Katayama Ryohei , Fujita Naoya 
Published: April 2023

Abstract
Introduction: In vivo, tumor microenvironments consist of not only cancer cells but also extracellular matrix and stromal tissues, such as fibroblasts, blood vessels, and so on. The interactions between cancer cells and stromal tissue have been reported to affect the behavior of cancer cells. So that ex vivo model recapturing the tumor microenvironment is needed to evaluate the efficacy of drugs under the condition mimicking the patient tumor tissue. Here, we developed the unique tissue engineering technique, which easily enables the construction of cell - stacked three dimensional (3D) tissue, and co-culture of 3D stromal tissues and patient-derived cancer cells (PDCs). We investigated drug sensitivity in conventional 2D culture, our 3D co-cultured model and in vivo tumor.
Methods: Fibroblasts and vascular endothelial cells were suspended in a buffer solution containing heparin and collagen to support cell aggregation. The heparin/collagen-treated cells were seeded in culture-inserts in over-confluent manner, and 3D layered stromal tissue called were constructed. PDCs established from colorectal cancer (CRC) and non-small cell lung cancer (NSCLC) patients in the Cancer Institute Hospital of JFCR were co-cultured with the 3D stromal tissue. The 3D co-cultured model applied to drug screening, and the results were compared with those of 2D culture model. In vivo drug evaluations were performed with the compounds in which marked differences were observed between 2D and 3D models.
Results: In our 3D model, drug sensitivities to most of the tested compounds tended to be decreased in comparison with those in 2D culture condition. Interestingly, a part of drugs did not effective in 2D showed marked tumor growth inhibition in our 3D model. The compounds that showed favorable efficacy in 3D rather than 2D in multiple PDCs were accounted for about 5% of tested compounds. At least half of these drugs showed significant tumor growth suppression or tumor regression in vivo. On the contrary, in the case of drug sensitivities were considerably fallen in our 3D model, most of the evaluated compounds represented almost no anti-tumor effect in vivo. Results from gene and protein expression analyses supported that cancer cells co-cultured in our 3D stromal tissue have some similar profiles to in vivo tumor rather than 2D culture condition.
Conclusion: Our study proposed the unique 3D co-cultured tumor model. The model may enable more accurate drug screening reflecting the in vivo circumstances. Further studies are needed to confirm the model’s predictability of clinical outcomes.
Citation Format: Yuki Takahashi, Yumi Nomura, Yuma Yokokawa, Shiro Kitano, Satoshi Nagayama, Eiji Shinozaki, Ryohei Katayama, Naoya Fujita. Drug screening by layered 3D co-cultured tumor model including vascularized stromal tissue. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4565.