Abstract 2988: Characterization of 3D models of human breast, prostate and colorectal cancer

Abstract

Abstract Tumorigenic expression of programmed death-ligand 1 (PD-L1) and its receptor PD-1 is found in many cancers, though the intrinsic roles of these proteins and how immunotherapy treatment may affect these pathways needs to be fully explored across human cancers. One platform to assess the expression and regulation of these proteins is 3D cell culture, which is thought to more closely mimic the architecture of solid tumors and more closely recapitulate in vivo human tumors in terms of cell heterogeneity, immunological and tumorigenic marker expression and treatment response, to investigate PD-L1/PD-1 signaling in cancer cells. Human breast (MDA-MB-231 and MCF-7), prostate (LNCaP and PC3) and colorectal (SW480 and SW620) cancer cell lines were cultured in both scaffold-free and scaffold-based 3D cell culture models to facilitate the formation of spheroids that display cell heterogeneity. 3D cancer models were analyzed by microscopy, qPCR and flow cytometry to assess the viability of spheroids, and measure any alterations in immunological and tumorigenic markers at mRNA and protein level, respectively, compared to their 2D monolayer counterparts. Breast, prostate and colorectal cancer cells cultured in 3D were highly viable over time and displayed significantly altered levels of immunological and tumorigenic marker expression at mRNA and/or protein level compared to their 2D monolayer counterparts. Importantly, PD-L1 expression changed in a 3D environment which may be linked to the increased cell-cell and cell-ECM interactions; increased expression of PD-L1 regulatory genes/proteins; or hypoxic regions that establish in 3D spheroids. The significantly altered expression levels of immunological and tumorigenic markers in a 3D cell culture environment is more likely to mimic that of an in vivo human tumor than standard 2D cell culture; allowing for optimized in vitro evaluation of the role of tumorigenic PD-L1/PD-1 and how immunotherapy treatment may affect these pathways. Citation Format: Katie Hudson, Neil Cross, Nicola Jordan-Mahy, Rebecca Leyland. Characterization of 3D models of human breast, prostate and colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2988.