Interferon Beta Drives Therapy Resistance in a Patient Derived Model of High Grade Serous Ovarian Cancer

Cancer cell-autonomous type 1 interferon (IFN-1) production and signaling is frequently activated in response to DNA damage and has been associated with the development of therapy resistance in several cancer types. However, its cell-autonomous role in driving resistance in high-grade serous ovarian cancer (HGSOC), a disease defined by near-universal exposure to genotoxic therapy as frontline treatment, remains unclear. Specifically, whether IFN-1 functions in HGSOC as only a response to genotoxic stress or can independently act in driving resistance phenotypes has not been studied. Utilizing a syngeneic patient-derived model of cisplatin-sensitive (SE) and -resistant (CR) HGSOC, we demonstrate that chronic cisplatin exposure is associated with enrichment of IFN-1 signaling and the interferon-related DNA damage resistance signature (IRDS). Acute cisplatin treatment elicited dynamic, temporal IFN-1 signaling and responses in both sensitive and resistant cells, indicating a conserved stress response in resistant cells. Chronic, low-level exposure to exogenous IFN{beta}, in the absence of a DNA-damaging agent, was sufficient to phenocopy several features of chronic cisplatin driven resistance, including reduced therapeutic sensitivity, cell cycle arrest, and decreased proliferation. Notably, IFN{beta} driven resistance occurred without sustained IRDS or canonical interferon stimulated gene (ISG) induction, revealing alternative mechanisms for IFN-1 mediated therapy resistance. Together, these findings identify IFN{beta} as a functional driver of the development of resistance-associated phenotypes and highlight cell-autonomous IFN-1 signaling as a potential biomarker for resistance and a therapeutic target in platinum-resistant disease.