Abstract B006: Investigating the role of soluble metabolites in primary high grade serous ovarian cancer
Authors: Bergsten Tova M. , Levy Sarah , Lusk Hannah , Sanchez Laura , Burdette Joanna E. 
Published: January 2023

Abstract
Ovarian cancer is the fifth leading cause of cancer death in women. High grade serous ovarian cancer (HGSOC), the most common and lethal histotype, can originate from fallopian tube epithelial (FTE) cells. Research has not historically focused on the metabolites involved in the migration of transformed FTE cells from the fallopian tube to the ovary. Co-culture of murine FTE and ovaries enabled identification of several significantly upregulated soluble metabolites via imaging mass spectrometry (IMS), including norepinephrine (NE). Therefore, we set out to determine the effect of norepinephrine on FTE and ovarian cancer cell lines. Clinical data analysis revealed that human HGSOC cell lines express the β-adrenergic receptor through which norepinephrine signals, called ADRβ2, and HGSOC patients with increased ADRβ2 expression have worse survival outcomes (p&lt;0.05), suggesting that signaling through ADRβ2 plays a role in HGSOC. When we examined phenotypic changes following NE treatment (10 µM), tumorigenic MOE PTENshRNA p53 cells showed increased invasion in a Boyden chamber (N≥3, p&lt;0.05). Interestingly, in terms of mechanistic pathways, NE enhanced pSRC expression in MOE PTENshRNA p53 cells, which has been linked to invasion in the literature (N≥3, p&lt;0.05). NE treatment also increased N-Cad and C-Myc expression, but did not cause any phenotypic changes, in OVCAR4 cells (N≥3, p&lt;0.05). These data suggest that NE drives alterations in protein expression, which, depending on the cell line, may also induce oncogenic phenotypic changes. Given the above data, we also sought to understand the factors that drive ovarian NE release. Conditioned media from cultured MOE PTENshRNA cells was found to induce ovarian NE release. Further, we determined that only the protein fraction of this conditioned media (3-50kDa) was responsible for NE induction. Therefore, we conducted comparative proteomic analysis using non-tumorigenic tubal cells, MOE SCRshRNA, identifying a uniquely abundant protein potentially responsible for the NE release: SPARC (secreted protein acidic and rich in cysteine). Using our IMS/co-culture paradigm, we have seen that knockdown of SPARC in MOE PTENshRNA cells decreases levels of ovarian-derived NE and that overexpressing SPARC in MOE WT cells increases levels of ovarian-derived NE. To date, this work has identified two key molecules, NE and SPARC, involved in primary metastasis of HGSOC from fallopian tube to ovary. Future studies will focus on effects of blocking NE signaling in vivo and broadening our understanding of the role of SPARC in this signaling pathway. We are also studying effects of the other soluble metabolites identified in the initial IMS studies on ovarian cancer progression, including progesterone and testosterone. Ultimately, we hope that our integration of mass spectrometry techniques with phenotypic and mechanistic readouts will elucidate the signals involved in early ovarian cancer progression to enable more effective therapeutic targets for HGSOC.
Citation Format: Tova M. Bergsten, Sarah Levy, Hannah Lusk, Laura Sanchez, Joanna E. Burdette. Investigating the role of soluble metabolites in primary high grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B006.