Abstract A008: Patient-matched tumor organoid and fibroblast pairs from endoscopic ultrasound-guided fine-needle aspiration and surgical specimens of pancreatic ductal adenocarcinoma reconstitute stroma-driven chemoresistance
Kyung Min Lee, Jin Ho Choi, Sang Hyub LeeAbstract
Background:
Most patients with pancreatic ductal adenocarcinoma (PDAC) present with unresectable disease, are diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), and are treated with FOLFIRINOX. Yet cancer-associated fibroblast (CAF) biology and patient-derived organoid (PDO) platforms have been built almost exclusively from surgical specimens, and PDO drug screening is performed in stroma-free monoculture that omits the CAF compartment driving desmoplasia and resistance. We asked whether tumor organoids and their autologous CAFs can both be recovered from a single diagnostic EUS-FNA pass, and whether the resulting co-cultures reconstitute stromal-driven resistance to FOLFIRINOX.
Methods:
Patient-matched PDO and CAF pairs were co-derived from PDAC patients using two tissue sources: diagnostic EUS-FNA biopsies and surgical resection specimens. PDO identity was confirmed by CK19 and F-actin staining, and CAF identity by alpha-SMA, FAP, and vimentin expression. CAF transcriptional states were profiled by single-cell RNA sequencing. Autologous PDO-CAF co-cultures were assembled by direct contact and evaluated for extracellular matrix deposition (collagen I, fibronectin immunofluorescence), morphology, secreted cytokines by multiplex immunoassay, and sensitivity to FOLFIRINOX in matched mono- versus co-culture.
Results:
More than 10 patient-matched PDO-CAF pairs were established across both tissue sources, showing that a single diagnostic needle biopsy can yield both the epithelial and stromal compartments from the same patient. FNA- and surgery-derived CAFs were comparable by marker expression and growth characteristics, supporting EUS-FNA as a valid stromal source for the unresectable population. Single-cell profiling showed that expanded CAFs adopted a predominantly myCAF-like, ECM-producing state. Autologous co-cultures deposited more collagen I and fibronectin than PDO monoculture and adopted a distinct morphology. Multiplex profiling showed induction of IL-6/IL-8 axis cytokines, with the dominant cytokine differing between pairs, indicating patient-specific stromal crosstalk detectable only in autologous co-culture. Critically, co-cultured PDOs were consistently less sensitive to FOLFIRINOX than matched monocultures, consistent with the known role of CAF-derived IL-6/IL-8 in PDAC chemoresistance.
Conclusions:
PDAC organoids and their autologous CAFs can be co-derived from a single diagnostic EUS-FNA biopsy, yielding tumor-stroma pairs comparable to those from resected tumors and extending autologous co-culture modeling to the unresectable majority of patients. These co-cultures recapitulate desmoplastic matrix deposition, induce patient-specific IL-6/IL-8 axis activation, and reconstitute stroma-driven FOLFIRINOX resistance that monoculture fails to capture, indicating that stroma-free PDO screening may overestimate sensitivity to standard-of-care therapy. Quantitative analysis across the full cohort is ongoing. This platform offers a clinically accessible route to stroma-inclusive precision drug testing in PDAC.
Citation Format:
Kyung Min Lee, Jin Ho Choi, Sang Hyub Lee. Patient-matched tumor organoid and fibroblast pairs from endoscopic ultrasound-guided fine-needle aspiration and surgical specimens of pancreatic ductal adenocarcinoma reconstitute stroma-driven chemoresistance [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 A008.