Abstract 3077: Integrin expression during ovarian cancer progression

Abstract During peritoneal dissemination, ovarian cancer cells exfoliate from the primary tumor and aggregate in the peritoneal fluid. This elicits survival signals via changes in mitochondrial morphology and function. As spheroids adhere to secondary sites, mitochondrial function is restored in the form of recovery of mitochondrial morphology, increased mitochondrial membrane potential, glucose uptake and increased proliferation. These findings suggested a mitochondrial phenotypic switch from mitophagy in spheroids to upregulation of mitobiogenesis upon spheroids adhesion to secondary sites. Hence, our objective was to identify critical receptors that facilitate the adhesion of spheroids to secondary sites, focusing on integrins that facilitate cell-extracellular matrix (ECM) attachment and activate downstream signaling cascades. To investigate changes in integrin expression, we mimicked three major stages of ovarian cancer progression by developing adherent stage, spheroid stage and adherent spheroid stage using our mouse ovarian surface epithelial (MOSE) cell lines representing benign (MOSE-E) stage as well as slow-developing (MOSE-L) and fast-developing disease (MOSE-LTICv) in biologically relevant conditions. Using RT qPCR and Western blotting, we determined gene and protein expression levels of integrins and adhesion related genes. Confocal microscopy was used to determine protein localization during ovarian cancer progression. RT qPCR result indicated differential up-regulated expression of integrins in both spheroid and adherent spheroid stage, suggesting the role of different integrins during the stages of ovarian cancer progression. Specifically, we observed a decrease (integrin ɑ5, ɑ6) or increase (ɑ2𝛃;1) of integrins after aggregation and an upregulation of 𝛃;1, α2, αV, α3, α5 and immunomodulatory integrins such as αE and αM in adherent spheroids, indicating their role in mediating specific steps during progression of ovarian cancer from tumorigenesis to metastatic implantation. We also observed increased expression levels of extracellular matrix proteins and their modulators, and cell-to-cell adhesion genes during ovarian cancer progression that was more pronounced in the MOSE-LTICv cells which suggests their association with an aggressive cancer phenotype. Overall, this project will aid in the identification of adhesion targets to develop new anti-metastatic treatments that will reduce mortality in women with ovarian cancer. Citation Format: Nazia Bano, Eva M. Schmelz. Integrin expression during ovarian cancer progression 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 3077.