Abstract 3958: Establishment of an in vitro model to study cancer associated fibroblasts and their direct effect on desmoplasia

Abstract

Abstract Background: The extracellular matrix (ECM) and desmoplasia is emerging as key components in defining prognosis and response to treatment. Cancer associated fibroblasts (CAFs) are vital contributors to the desmoplastic reaction and novel ambitious therapies targeting tumor specific ECM and CAFs are being developed. However, it is still debated whether in fact desmoplasia acts as a barrier to- or promoter of - tumor growth. Therefore, there is a need to establish novel models of desmoplasia to improve the understanding of CAFs and associated cancer specific ECM alterations in order to be successful in drug development and prediction of treatment success. By applying the “Scar-in-a-jar” (SiaJ) model, we established an in vitro model including healthy fibroblasts and CAFs derived from the pancreas to study ECM changes and desmoplasia. Methods: Primary healthy fibroblasts and CAFs were cultured for up to 12 days in the presence or absence of TGF-β. Type I (PRO-C1), type III (PRO-C3) and type VI (PRO-C6) collagen formation were quantified in cell supernatant using enzyme-linked immunosorbent assays. Metabolic activity was evaluated by AlamarBlue. Results: In healthy fibroblasts no collagen formation could be detected without TGF-β. However, the presence of TGF-β induced PRO-C1, PRO-C3 and PRO-C6 formation with levels increasing up to 20-fold (p<0.0001). Furthermore, PRO-C1, PRO-C3 and PRO-C6 levels where significantly increased in CAFs compared to healthy fibroblasts independent of TGF-β stimulation. There was no difference in metabolic activity across cell line. Conclusions: TGF-β stimulation led to increased ECM protein expression in healthy fibroblasts but not in CAFs. However, CAFs expressed higher levels of collagens than healthy fibroblasts independent of TGF-β. These results suggest a distinct role of CAFs in their contribution to desmoplasia compared to healthy fibroblasts. The “Scar-in-a-Jar” model can provide a novel in vitro tool to study CAF activity and their direct effect on desmoplasia. Citation Format: Neel Ingemann Nissen, Morten Karsdal, Nicholas Willumsen. Establishment of an in vitro model to study cancer associated fibroblasts and their direct effect on desmoplasia [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 3958.