OBJECTIVE Pancreatic ductal adenocarcinoma (PDAC), a lethal cancer in need of new, effective therapies, has a unique tumor microenvironment characterized by a dense fibrotic stroma (desmoplasia) that is generated by pancreatic cancer- associated fibroblasts (PCAFs) derived from pancreatic stellate cells (PSCs) and pancreatic fibroblasts (PFs). METHEDS and RESULTS Hypothe?sizing that G protein-coupled receptors (GPCRs) may regulate PCAFs, we used an unbiased GPCRomic array approach to compare GPCR expression in PCAFs, PFs and PSCs and identified 82 GPCRs commonly expressed by PCAFs derived from primary tumors of five PDAC patients. We discovered that PCAFs have increased expression of numerous GPCRs, in particular aGPCR with much higher expression in PCAFs compared to both PFs and PSCs. Immunohistochemistry revealed increased expression of this GPCR in PDAC tumors. Co- culture of PSCs with PDAC cells or incubation with TNFα induced its expression. Activation of the GPCR in PCAF sincreased expression of interleukin-6 (IL-6) via a cAMP/PKA/CREB signaling pathway. GPCR knockdown with siRNA diminished IL-6 production and secretionby PCAFs and ability of PCAF conditioned media to enhance proliferation of PDAC cells. CONCLUSION We conclude that PDAC cells induce expression by PCAFs of a novel GPCR, resulting in increased IL-6 production by PCAFs and promotion of PDAC cell proliferation. This PCAF-expressed GPCR thus contributes to PDAC cell-PCAF interaction and as such, may be a novel therapeutic target for PDAC tumors.

Background/Aims: Three-dimensional cultures of human pancreatic cancer tissue also known as “organoids” have largely been developed from surgical specimens. Given that most patients present with locally advanced and/or metastatic disease, such organoids are not representative of the majority of patients. Therefore, we used endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) to collect pancreatic cancer tissues from patients with advanced pancreatic cancer to create organoids, and evaluated their utility in pancreatic cancer research. Methods: Single-pass EUS-FNA samplings were employed to obtain the tissue for organoid generation. After establishment of the organoid, we compared the core biopsy tissues with organoids using hematoxylin and eosin staining, and performed whole exome sequencing (WES) to detect mutational variants. Furthermore, we compared patient outcome with the organoid drug response to determine the potential utility of the clinical application of such organoid-based assays. Results: Organoids were successfully generated in 14 of 20 tumors (70%) and were able to be passaged greater than 5 times in 12 of 20 tumors (60%). Among them, we selected eight pairs of organoid and core biopsy tissues for detailed analyses. They showed similar patterns in hematoxylin and eosin staining. WES revealed mutations in KRAS, TP53, CDKN2A, SMAD4, BRCA1, and BRCA2 which were 93% homologous, and the mean nonreference discordance rate was 5.47%. We observed moderate drug response correlations between the organoids and clinical outcomes in patients who underwent FOLFIRINOX chemotherapy. Conclusions The established organoids from EUS-FNA core biopsies can be used for a suitable model system for pancreatic cancer research