Abstract 3386: Changes in extracellular vesicle miRNAs from three-dimensional ovarian cancer cell models reflect physiological changes and cancer survival

Abstract Ovarian Cancer (OC) is the most common gynaecological malignancy and the eighth most diagnosed cancer in females worldwide. Currently, it is the fifth leading cause of cancer-related mortality among patients globally, largely due to delayed diagnosis, chemotherapy resistance, high metastasis rates, and subtype heterogeneity. Recent OC research highlights extracellular vesicles (EVs) as pivotal contributors to intercellular communication and disease progression, elucidating the intricacies of OC pathology. EVs, diverse membrane-derived vesicles released by most cells, carry molecular cargoes containing proteins and nucleic acids. Studies indicate that the biogenesis, packaging, and release of EVs are highly dependent and sensitive to the cellular microenvironment and depend on the in-vitro and in-vivo modelling systems. Labs use varied model systems—2D monolayers, animal models, and innovative 3D models—to investigate EVs' ovarian cancer roles. Therefore, in this study we aimed to compare the miRNA profiles associated with EVs in 3D ovarian cancer cell models, and to identify the pathophysiological relevance of the EVs isolated from these models to the patient derived EVs. In this study, two OC epithelial cell lines, SKOV-3 and OVCAR-, were initially cultured as 2D monolayers and embedded within Gelatin Methacryloyl hydrogels. Over nine days, multiple assays observed spheroid formation within the cell-laden hydrogels. EVs isolated from the cell-conditioned media were characterized per MISEV 2018 guidelines. Small RNA sequencing identified statistically significant miRNAs, subject to gene ontology and gene rank analyses. EVs from a cohort of 60 OC patients were used to identify survival-associated miRNA profiles. Our findings in the cell-laden hydrogels demonstrated OC cell growth, proliferation, and aggregation into spheroidal structures, establishing an ideal 3D model. The isolated EVs were characterized for size, concentration, morphology, and surface markers. Small RNA sequencing revealed 18 significantly different EV-associated miRNA species across 3D vs 2D models, influencing apoptosis, angiogenesis, migration, and proliferation in ovarian cancer. Notably, 3D model-derived EV-associated miRNAs mirrored patient-derived EV-associated miRNA profiles, indicating their pathophysiological relevance. This study establishes a robust 3D OC model in hydrogels, showcasing growth, proliferation, and aggregation capabilities. Differential miRNA profiles between 3D and 2D model EVs highlight the critical roles of these miRNAs in essential ovarian cancer processes. Moreover, similarities between 3D model and patient-derived EV-associated miRNA profiles emphasize the clinical relevance of our model. Citation Format: Nihar Godbole, Akhilandeshwari Ravichandran, Dominic Guanzon, Andrew Lai, Flavio Carrion, Priyakshi Kalita de Croft, Lewis Perrin, John Hooper, Laura Bray, Carlos Salomon. Changes in extracellular vesicle miRNAs from three-dimensional ovarian cancer cell models reflect physiological changes and cancer survival abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 3386.