ZNFX1 Functions as a Master Regulator of Epigenetically Induced Pathogen Mimicry and Inflammasome Signaling in Cancer.

DNA methyltransferase and poly (ADP-ribose) polymerase inhibitors (DNMTis, PARPis) induce a stimulator of interferon genes (STING)-dependent pathogen mimicry response (PMR) in ovarian and other cancers. Here, we showed that combining DNMTis and PARPis upregulates expression of the nucleic-acid sensor NFX1-type zinc finger-containing 1 protein (ZNFX1). ZNFX1 mediated induction of PMR in mitochondria, serving as a gateway for STING-dependent interferon/inflammasome signaling. Loss of ZNFX1 in ovarian cancer cells promoted proliferation and spheroid formation in vitro and tumor growth in vivo. In patient ovarian cancer databases, expression of ZNFX1 was elevated in advanced stage disease, and ZNFX1 expression alone significantly correlated with an increase in overall survival in a phase 3 trial for therapy-resistant ovarian cancer patients receiving bevacizumab in combination with chemotherapy. RNA-sequencing revealed an association between inflammasome signaling through ZNFX1 and abnormal vasculogenesis. Together, this study identified that ZNFX1 as a tumor suppressor that controls PMR signaling through the mitochondria and may serve as a biomarker to facilitate personalized therapy in ovarian cancer patients.