Abstract A069: Microscale modeling of the human prostate bone metastatic niche
Authors: Ding Adeline , de Diego Cristina Sanchez , Kerr Sheena C. , Yada Ravi Chandra , Heninger Erika , Sethakorn Nan , Reese Shannon , Virumbrales-Muñoz Maria , Geiger Pete , Hazelberg Xavier , Lang Joshua M. , Beebe Dave 
Published: June 2023

Abstract
Difficulties in modeling the human bone metastasis microenvironment (BMME) niche contribute to limitations in our understanding of the cellular interactions that promote treatment resistance in prostate cancer. To address this, we have developed a multicellular, vascularized, and fully humanized 3D tissue chip model of bone metastases that will allow us to identify drivers of treatment resistance and test emerging cancer therapies in the context of multicellular networks. We utilized LumeNEXT, a closed microfluidics platform with a removable center rod allowing vessel formation, to create this bone microenvironment. To obtain major stromal and bone cell types found in the BMME, we differentiated primary bone marrow-derived mesenchymal stem cells (MSCs) into osteoblasts, fibroblasts, and adipocytes and differentiated patient-derived monocytes from peripheral blood into M2-polarized macrophages and osteoclasts. The primary stromal and bone cells were seeded into LumeNEXT devices and combined in co-cultured with primary prostate cancer tumor organoids in a collagen-based matrix. and deposited into LumeNEXT devices. After polymerization of the hydrogel, the center rod in each device was removed and the tunnels were seeded with endothelial cells to create functional microvasculature. We successfully differentiated the patient-derived cell types, optimized a novel multi-phenotype media (MPM) for co-culture, and maintained greater than 80% viability of all seven cell types in co-culture for at least 14 days in the LumeNEXT platform. qPCR analysis of the model confirmed that expression of differentiation marker genes was maintained after 14 days of co-culture for all cell types. Viability assays and time-lapse microscopy of cell tracker staining also showed viability and growth of prostate cancer organoids in co-culture. Integrated multi-analyte assay platforms were developed for cellular and molecular analysis of patient-derived primary tumor organoids including assessment of cellular phenotype, transcriptomic and epigenetic patterns in the context of multicellular networks. Additionally, we have aimed to develop assays to test emerging cancer-targeting therapies, such as antibody-drug conjugate (ADC). Functional testing of this model using ADC has demonstrated drug perfusion into the stroma through the microvessels, and ADC-specific tumor killing. In summary, we created a multicellular microfluidics model of human bone metastases. High viability of all seven cell types included in our model was maintained for 14 days and early ADC testing demonstrates functional microvasculature and tumor cell killing. The duration of viable co-culture multicellular cultures and promising functional testing demonstrates the suitability of this model for rapid drug testing. Future studies will focus on testing novel chemo-, hormone, and radiation therapies in this multicellular BMME model to determine mechanisms of microenvironment-mediated treatment resistance in prostate cancer.
Citation Format: Adeline Ding, Cristina Sanchez de Diego, Sheena C. Kerr, Ravi Chandra Yada, Erika Heninger, Nan Sethakorn, Shannon Reese, Maria Virumbrales-Muñoz, Pete Geiger, Xavier Hazelberg, Joshua M. Lang, Dave Beebe. Microscale modeling of the human prostate bone metastatic niche [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A069.