Abstract 3590: Tumor intrinsic production of glucocorticoids in ovarian carcinoma

Abstract

Abstract Background: Cortisol is a glucocorticoid (GC) known to be produced by the hypothalamic-pituitary-adrenal (HPA) axis. Dysregulation of the HPA axis is prevalent in patients with ovarian cancer. These patients have elevated nighttime levels of cortisol and increased tumoral expression of the glucocorticoid receptor (GR); both of which correlate with shortened overall survival (OS). We hypothesize that outside the HPA axis, ovarian cancer may have tumor-intrinsic production of GC. In this study, we examined whether 11 beta-hydroxysteroid dehydrogenase 1 (11β-HSD1; enzyme which activates cortisone to cortisol) has steroidogenic activity in the ovarian cancer tumor microenvironment (TME). Methods: We used the Genotype-Tissue Expression (GTex) Portal and the Cancer Cell Line Encyclopedia (CCLE) to determine expression of steroidogenic enzymes in the ovary and ovarian cancer cell lines. We further performed UMAP analysis of a single-cell RNA-seq dataset of tumor samples from patients with ovarian carcinoma to cluster for cell type. ELISAs were performed to quantify cortisol production and secretion by cells stimulated with metabolite, cortisone. Subcellular fractionation and Western blotting were performed to measure protein expression of 11β-HSD1, GR, and phospho-Ser 211 GR. Results: HSD11B1 mRNA (which encodes 11β-HSD1) is detectable in bulk ovarian tissue at a median expression of 78.19 transcripts per million (TPM) as measured in the GTex data. In vitro, primary human ovarian fibroblasts express functional 11β-HSD1 and produce and secrete cortisol upon cortisone stimulation in a time-dependent manner, with a mean total secretion of 17.91 ± 0.21 ng/ml at 12 hours. Analysis of scRNA-seq data identifies that cancer-associated fibroblasts (CAFs) may be a source of HSD11B1 in the ovarian TME, with roughly 9% of CAFs expressing HSD11B1. In HeyA8 ovarian cancer cells (positive for 11β-HSD1), cortisone stimulation in vitro results in cortisol production with a mean total secretion of 22.04 ± 5.46 ng/ml at 12 hours. Moreover, this cortisol results in GR activation in an 11β-HSD1-dependent manner. Discussion: We identify 11β-HSD1 as a potential mechanism of GC production within ovarian cancer, with CAFs being a putative source. We further show that 11β-HSD1 activity can lead to activation of the GR within cancer cells. Citation Format: Pahul Hanjra, Elaine Stur, Steven Cole, Susan Lutgendorf, Anil Sood. Tumor intrinsic production of glucocorticoids in ovarian carcinoma [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(6_Suppl):Abstract nr 3590.