Emergent role of the fractalkine axis in dissemination of peritoneal metastasis from epithelial ovarian carcinoma.

Epithelial ovarian carcinoma is the most common cause of death from gynecologic cancers largely due to advanced, relapsed and chemotherapy-resistant peritoneal metastasis, which is refractory to the currently used treatment approaches. Mechanisms supporting advanced and relapsed peritoneal metastasis are largely unknown, precluding development of more effective targeted therapies. In this study, we investigated the function of a potentially targetable fractalkine axis in the formation and the development of advanced and relapsed peritoneal metastasis and its impact on patients' outcomes. Our mouse model studies support a role for the fractalkine receptor (CX3 CR1) in the initiation of peritoneal adhesion important for recolonization of relapsed peritoneal metastasis. We show that downregulation of CX3 CR1 results in reduction of metastatic burden at several peritoneal sites commonly colonized by advanced and relapsed metastatic ovarian carcinoma. We show that the chemokine fractalkine (CX3 CL1), an activating ligand of CX3 CR1, regulates organ-specific peritoneal colonization. High expression of CX3 CR1 correlates with significantly shorter survival, specifically in post-menopausal patients with advanced and terminal stages of the disease. Taken together, our studies support a key regulatory role for the fractalkine axis in advanced and relapsed peritoneal metastasis in epithelial ovarian carcinoma.