ABSTRACT | FULL RESEARCH PROJECT 2 Growing evidence indicates that the biological response to chronic stress and subsequent distress can promote the progression of epithelial ovarian cancer via prolonged activation of the sympathetic nervous system and sustained norepinephrine release. Downstream consequences of norepinephrine exposure include increased prostaglandin-related inflammation and an immunosuppressive landscape. Conversely, increasing evidence supports the role of aspirin use in ovarian cancer prevention and survival. Yet, key questions remain about the underlying biological mechanism of action of chronic stress/distress and aspirin use (considering low and standard doses separately) and their interrelationship with ovarian cancer biology. Specifically, we propose to evaluate the hypothesis that distress enhances ovarian cancer progression by promoting inflammatory and immune processes and that aspirin abrogates these effects. Our innovative study uses unique population-based and experimental resources. Aim 1 will use data from four long-term prospective cohorts in diverse populations, a population-based case-control study, a hospital case series that collected self-reported measures of chronic stress and distress (e.g., depression), and ovarian tumor tissue. Aim 1 will measure gene expression in bulk high grade serous tumor samples (to capture the full tumor microenvironment) using whole exome RNASeq. We hypothesize that distress is associated with the up- regulation of inflammation-related and immune suppression gene expression pathways that is normalized among aspirin users. We will also assess if the association of distress with ovarian cancer risk is attenuated among aspirin users. Notably, we are leveraging racially and ethnically diverse studies that have highly characterized ovarian cancer cases, allowing assessment of differences in association by race (Black, White) and ethnicity (Hispanic, non-Hispanic), as well as the examination of associations between distress- related gene expression profiles and clinical outcomes. Using an orthogonal and interactive approach, Aim 2 will use experimental ovarian cancer mouse models to characterize the progressive effect over time of daily restraint stress on tumor inflammation and immunity as well as ovarian tumor growth, using RNASeq and stress hormones measured via ELISA assays. We also will examine if aspirin (recapitulating equivalents of low and standard dose aspirin in humans) counteracts the effects of chronic stress on tumor progression and inflammatory and immune gene expression networks. This project will leverage the scientific services of several cores, including the Puerto Rico BioBank (PRBB) and the Quantitative Science Core (QSC), with substantial interaction with the Outreach Core, the Planning and Evaluation Core, and working with trainees in the Research Education Core. This innovative application will inform future work to develop novel immuno- preventive strategies, p...