Abstract A003: Deep functional characterization of donor and patient-derived pancreatic normal and cancer associated fibroblasts and their responses to pan-RAS inhibition
Farrah AliAbstract
Introduction:
Cancer-associated fibroblasts (CAFs) are a major cellular component of the pancreatic ductal carcinoma (PDAC) tumor microenvironment and play critical roles in tumor progression, extracellular matrix (ECM) deposition and remodeling, and therapeutic resistance. However, CAF functional heterogeneity remains understudied. Systematic functional characterization of patient-derived CAFs relative to bona-fide normal pancreatic fibroblasts (NF), along with their response to clinically relevant therapies such as pan-RAS inhibitors, are essential for better understanding of their phenotypic and functional changes associated with tumor progression. Therefore, this study aimed to functionally characterize PDAC CAFs, and normal fibroblasts from healthy donor pancreata, using our established 3D culturing system to identify phenotypic differences and better define fibroblast heterogeneity within the pancreatic tumor microenvironment.
Methods:
CAFs were isolated from PDAC tumor resections and NFs were obtained from healthy donor pancreata. Cells were cultured to produce their own ECM, creating a 3D environment. Cells were exposed to a variety of relevant PDAC tumor microenvironmental conditions, including Pan-RAS inhibition with RMC-7977, as well as classical TGFβ signaling agonists and antagonists. Functional assessment included protein signaling, bulk transcriptome profiling, chemokine and cytokine profiling, ECM characterization, intracellular lipid accumulation, and tumor cell survival within CAF and NF derived 3D ECM.
Results and Conclusion
s: Our findings demonstrate that while CAFs and NFs exhibit shared classical myofibroblasts signaling programs, CAFs displayed a much greater degree of inflammatory signaling and cytokine production. Furthermore, CAFs and NFs presented distinct functional outcomes, where NFs produce disorganized ECM, generated lower levels of cytokines and chemokines, and generated ECMs that were less supportive of tumor cell survival under nutrient stress, compared to CAFs. Interestingly, each normal and cancer associated fibroblast line had a distinct response to pan-RAS inhibition, with certain cells having a more pronounced functional shift under inhibition, while others were minimally affected. On the other hand, modulation of TGFβ signaling in fibroblasts and CAFs resulted in a much more uniform response, with similar functional profiles, regardless of the individual. Overall, this study highlights the inherent heterogeneity of fibroblast populations across individuals and provides a framework to deeply assess fibroblast functionality.
Citation Format:
Farrah Ali. Deep functional characterization of donor and patient-derived pancreatic normal and cancer associated fibroblasts and their responses to pan-RAS inhibition [abstract]. In: Proceedings of the AACR Conference on Pancreatic Cancer: New Frontiers in Biology and Therapeutic Development; 2026 Sep 25-28; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(18_Suppl_2):Abstract nr A003.