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Abstract Adhesion to and clearance of the mesothelial monolayer are key events in the early metastatic seeding of ovarian cancer. To identify mediators of ovarian cancer cell adhesion and invasion, we developed and conducted a cellular, high-throughput genetic screen using a human kinome siRNA library. Through this screen, we identified ROR2 as a driver of ovarian cancer adhesion and invasion. ROR2 is a receptor tyrosine kinase that interacts with Wnt5a ligand to activate non-canonical Wnt signaling and has been previously shown to be upregulated in ovarian cancer tissue. However, no prior study has evaluated the mechanistic role of ROR2 in ovarian cancer. Using in vitro adhesion and mesothelial clearance assays, we show that ROR2 promotes ovarian cancer cell adhesion and clearance of the mesothelial monolayer, key early steps in ovarian cancer metastasis. Further, we show that depletion of ROR2 reduces metastatic tumor burden in a syngeneic mouse model of ovarian cancer. Additionally, using a microfluidic device capable of producing stable fluid gradients, we demonstrate that ROR2 expression in ovarian cancer cells serves to drive directed cell migration of tumor cells, preferentially to areas of high Wnt5a ligand. As Wnt5a has been previously shown to be produced and upregulated in the mesothelial cells of the ovarian cancer microenvironment, these findings represent a novel role for ROR2 to promote the homing of ovarian tumor cells to the mesothelial lined metastatic niche by using Wnt5a as a chemotactic cue. These findings support the role of ROR2 as a critical factor contributing to the steps of ovarian cancer metastasis. Therapeutic targeting of the ROR2/Wnt5a signaling axis could provide a means of improving treatment for patients with advanced ovarian cancer. Citation Format: Whitney R. Grither, Breanna Baker, Vasilios A. Morikis, Katherine C. Fuh, Gregoery D Longmore. ROR2/Wnt5a signaling regulates directional cell migration and early tumor cell invasion in ovarian cancer abstract. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84 (5 Suppl₂): Abstract nr A102.
Grither et al. (Mon,) studied this question.