Abstract 5108: Investigation of how extracellular matrix composition affects pancreatic cancer chemoresistance through the use of biomimetic models

Abstract

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal and malignant type of cancer with few effective treatments. Despite recent advancement in knowledge of cancer treatment, median survival of PDAC patients remains within 2 years, and less than 8% patients live beyond 5 years after diagnosis. The main factor that drives PDAC lethality is the development of chemoresistance in nearly all clinical PDACs. While intrinsic factors that facilitates chemoresistance have been studied extensively, few studies have illustrated how complex and unique microenvironment surrounding the PDAC tumor affects therapeutic responses. Moreover, a physiologically relevant co-culture model of PDAC and stromal cells remained challenging. To address this issue, we have developed a Matrigel-based, orthogonally tunable 3-dimensional (3D) culture system to culture established human PDAC cell lines, cancer-associated fibroblast (CAF) cells and mouse model-derived organoids. Individual matrix parameters can be customized to mimic actual tumor matrix composition and mechanical properties. Moreover, we have optimized a co-culture medium to maintain viability of both organoid tumor and cancer associated fibroblasts. Through our 3D culture system, our data suggests that matrix-induced exosome secretion directly facilitate gemcitabine resistance in PDAC cells. By directly increasing stiffness of our 3D culture platform, we have observed that PDAC cells potentially display more invasive phenotype. Moreover, in the co-culture systems, we have seen that CAF cells cultured in different stiffness substrates affect PDAC drug response in organoid cultures. Our investigation provides insight into how matrix composition and stiffness together affect therapeutic outcome in PDAC. We believe that specific therapeutic strategies aimed at targeting the matrix microenvironment will be instrumental in order to overcome matrix-mediated chemoresistance in PDAC. Citation Format: Weikun Xiao, Chae-Young Eun, Charlene Dekalb, Kexin Zhang, Reginald Hill. Investigation of how extracellular matrix composition affects pancreatic cancer chemoresistance through the use of biomimetic models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5108.