Abstract 5016: A unique ex vivo drug evaluation model: 3D co-cultured system with tumor, stroma and blood microvessels

Background; Two dimensional single-layer culture still remains the preferred platform for most laboratory preclinical studies, although interaction between cancer and stromal cells has been well reported to be important in tumor progression and resistance against therapies. In order to mimic the patient tumor tissues, ex vivo model which recaptures the tumor microenvironment is required. Methods; Layered 3D stromal tissues were produced by culturing normal human dermal fibroblasts (NHDFs) and human umbilical vein endothelial cells (HUVECs) coated with extra-cellular matrix (ECM) and natural polysaccharide, namely collagen and heparin. The layered 3D stromal tissues and overlaid tumors were morphologically characterized by HE stain, immunohistochemistry (IHC) and immunofluorescence (IF). Furthermore, drug sensitivity assays were conducted using popular colorectal cancer cell lines, and patient-derived cell lines (PDCs) established in the laboratory of Japanese Foundation for Cancer Research. Cancer cell viability was evaluated by fluorescent labeling, enzymatic dissociation and cell counting analysis. IF with cancer specific markers and imaging analyses were also performed. Results; The 3D stromal tissues including CD31 positive luminal structure were multi-layered (approximately 20 layers), and formation of microvascular network was observed within several days. In comparison with 2D mono-culture or 3D mono/co-cultured spheroid model, decreased drug sensitivities were represented in our 3D co-cultured model. In the simultaneous treatment with cytotoxic anticancer agents and molecular targeted drugs, dose-responses were significantly different between the2D and 3D models. Conclusion; We developed the layered 3D stromal tissue culture system including blood micro-vessels. Drug evaluation with the co-cultured tumors may reflect the drug sensitivity of cancer cells in vivo. Our unique 3D ex vivo model represents a valuable tool for drug development in a fully human cell and matrix microenvironment, and thus testing patient-derived cells and approved compounds also enable better prediction their efficacy. Citation Format: Yuki Takahashi, Kei Tsukamoto, Shiro Kitano, Shinji Irie, Michiya Matsusaki, Satoshi Nagayama, Ryohei Katayama, Eiji Shinozaki, Naoya Fujita. A unique ex vivo drug evaluation model: 3D co-cultured system with tumor, stroma and blood microvessels [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5016.