Abstract 4264: Engineered in vitro models of cancer metastasis using decellularized biomatrix

Background: Metastasis contributes to majority of death in cancer patients. However, cancer metastasis is difficult to study due to the lack of experimental models that can fully recapitulate the biological process, especially the organ specificity of cancer metastasis. Recent advances in tissue engineering demonstrated that decellularized tissue, organs that are denuded of cells, are excellent scaffolds for tissue engineering of complex organs, such as liver and lung. These decellularized organs preserve the organ microenvironment, which is critical in cancer metastasis. We hypothesized that we can utilize decellularized organ and engineer in vitro models of cancer metastasis that can recapitulate the organ specificity of cancer metastasis. Here we report the proof-of-principle of this approach by employing colorectal cancer as a disease model. Since the primary cause of morbidity and mortality in colorectal patients is liver and lung metastasis, we aimed to engineer in vitro models of colorectal cancer lung and liver metastasis. Methods: Decellularized biomatrix was prepared by sodium deoxycholate based perfusion decellularization of rat liver or lung. We compared the growth factors on the biomatrix scaffold to that of normal rat liver and lung using semi-quantitative ELISA. We cultured colorectal cancer cell lines: HT-29, SW480 and Caco2, on tissue culture dishes coated with liver and lung decellularized biomatrix scaffolds. Cell colony morphology and structure was examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and hematoxylin and eosin stain. Therapeutic response (chemotherapy and radiation) for cells grown on biomatrix was also examined. Results: Decellularized organs preserved 92% growth factors bound to biomatrix scaffold at near physiological levels. HT-29, SW480 and Caco2 were able to proliferate on dishes coated with biomatrix scaffold and spontaneously formed three-dimensional (3D) colonies when maintained at higher levels. These tumor colonies are millimeter in size and are spherical in shape, similar to in vivo metastases. SEM showed cells on the tumor surface appeared to form tight junctions with each other. TEM images further confirmed that these 3D tumor colonies contain areas of necrosis, consistent existing literature 3D colonies and in vivo metastasis. Importantly, we identified signet ring cell formation in the engineered 3D metastases. We also found the cells in engineered liver and lung metastasis responded to chemotherapy treatment differently than the cells cultured under standard conditions or on collagen or on matrigel. Interestingly, cells in both engineered liver and lung metastasis are more sensitive to radiotherapy than standard condition. Conclusions: Our engineered in vitro tumor metastasis models closely mimic the in vivo metastasis phenotypically, histologically, and biologically. Citation Format: XI TIAN, Michael E. Werner, Henry P. Foote, Ariel D. Hanson, Lola M. Reid, Andrew Z. Wang. Engineered in vitro models of cancer metastasis using decellularized biomatrix. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4264.