Modification of intrinsic ovarian cancer tumor factors by Wnt-pathway agents influences macrophage recruitment and activity.

Abstract

e14514 Background: The Wnt/B-catenin pathway is associated with a “cold” phenotype in the gynecologic malignancy tumor microenvironment (TME), resulting in immunosuppression. Research is limited regarding this pathway’s effects on TME myeloid cell populations. We aimed to characterize the impact of Wnt pathway modulation on macrophage activity in ovarian cancer. Methods: Syngeneic murine models harboring ID8 parental (ID8par) tumors were treated with DKN-01 and CGX-1321 as single agents or in sequence (DKN-01 followed by CGX-1321.) Flow cytometry analyses were performed on harvested omenta and blood. Ascites from 10 high grade serous epithelial ovarian cancer patients were treated with DKN-01 (Wnt activator) or CGX-1321 (Wnt inhibitor) for 48 hours; multiplex cytokine array was performed to determine changes in cytokine/chemokine expression. Lastly, we performed co-culture analyses on the effects of ID8par and ID8p53-/- isolated cell media on murine macrophage (RAW264.7) activity. Results: In the ID8par model, sequential DKN-01/CGX-1321 resulted in the greatest macrophage influx into the TME. CGX-1321 monotherapy increased the M2:M1 macrophage ratio (pro-tumor) while DKN-01 monotherapy resulted in decreased M2:M1 ratio (anti-tumor.) In human ascites, DKN-01 increased macrophage colony stimulating factor (M-CSF) expression. Of note, ascites from a patient harboring a p53 mutation demonstrated an increase in M1 polarization cytokines IFNy and TNFa in response to DKN-01; CGX-1321 treatment resulted in increased M2 polarization cytokines IL-4 and IL-13. In co-culture analysis, ID8par isolated media increased RAW264.7 migration and polarization towards an M2 phenotype; ID8p53-/- isolated media polarized towards an M1 phenotype. Conclusions: Macrophage activity influences immune responses and tumor behavior. For example, M2 macrophages are pro-tumor and can enhance tumor growth and immune evasion. In our studies, we demonstrated that macrophage recruitment and polarization (M1 vs M2) are influenced by genetic alterations that can be modified by treatment. The ID8par model positively influenced M2 macrophage activity; ID8p53-/- cells positively influenced M1 macrophage activity. Importantly, DKN-01 treatment reverses the M2-dominant phenotype in ID8par model towards M1. These results suggest that p53 mutation and/or DKN-01 treatment in ovarian cancer influences M1 anti-tumor macrophage activity, and posits a novel targetable pathway. Further studies should investigate Wnt/B-catenin modulation on macrophage activity for immunotherapy in gynecologic malignancies.