Abstract 6565: <i>In-vitro</i> assessment of the effect of peri-pancreatic adipose tissue derived extracellular vesicles on the tumorigenicity of pancreatic cancer

Abstract Background: Pancreatic cancer (PC) is an aggressive malignancy marked by highinvasiveness, metastasis, and resistance to chemotherapy, presenting a significant global healthchallenge. Visceral obesity has been identified as key risk factors of PC. Significant progresshas been made in understanding the relation between visceral obesity and PC, particularly incontext of pro-inflammatory cytokines and adipokines secreted by surrounding adipose tissue.However, various aspects mediating this relationship remain unclear. Recent studiesilluminated the multifaceted role of extracellular vesicles (EVs) as key communicatorsregulating physiological and pathological processes. Despite their recognised significance, nostudy has yet unveiled the specific contribution of peri-pancreatic adipose tissue (PAT) derivedEVs in driving pancreatic tumorigenesis. The aim of this study is to assess the tumorigenicpotential of PAT-EVs in PC. Methods: The peri-pancreatic adipose tissue was collected from patients undergoing pancreatictumor surgical resection followed by EVs isolation via differential ultracentrifugation andcharacterization using DLS, TEM, Western blot and flow cytometry following MISEV 2023guidelines. Subsequently, the tumorigenic effect of PAT-EVs were determined by treatingPANC-1 cells (pancreatic cancer cell line) with PAT-EVs. The effect on proliferative potentialwas assessed by Colony formation and BrdU assay, while migration potential by Scratch assay. Further, effect on stemness, ECM modulation, EMT and chemoresistance was assessed viaqRT-PCR and western-blot. Results: The size (50-1000 nm), morphology (round and bilayer) and specific proteins (CD63,CD9, TSG101, Flotilin-1) observed through DLS, TEM, Western blot and flow cytometryrespectively confirmed the presence of EVs. Through in-vitro experiments, we observed asignificant increase in cell viability of PC cells with increasing EVs concentration (0, 10, 25,50, 100, 200 µg/mL). Further, we check the effect of 100 µg/mL and 200 µg/mL dose of EVson tumorigenicity of PANC-1 cells. The colony forming assay revealed that surviving fractionof PANC-1 cells increased by 34.5% and 69.13% at 100 µg/mL and 200 µg/mL doses of EVsrespectively. Additionally, the wound closure percentage increased by 62.3 % in 100 µg/mLEV treated PC cells and 74.9% in 200 µg/mL EV treated PC cells. The qRT-PCR analysisshowed an increase in fold change of markers related to stemness (Oct 4, Sox 2, Nanog); ECMmodulation (MMP 2, MMP 9); EMT (N-Cad, Vimentin); proliferation (p53, Ki67);angiogenesis (VEGF) and chemoresistance (ABCA7). Conclusion: Our results indicate that peri-pancreatic adipose tissue enhances the tumorigenicpotential of PC cells via EVs. The evaluation of PAT-EVs cargo molecules can further elaboratethe molecular-mechanism behind the interactions between PAT and PC cells. Citation Format: Ankita Arora, Vinit Sharma, Rajesh Gupta, Shalmoli Bhattacharya, Smita Pattanaik, Anjali Aggarwal. In-vitro assessment of the effect of peri-pancreatic adipose tissue derived extracellular vesicles on the tumorigenicity of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6565.