Targeting LRRC15 inhibits metastatic dissemination of ovarian cancer.

Dissemination of ovarian cancer (OC) cells can lead to inoperable metastatic lesions in the bowel and omentum that cause patient death. Here we show that LRRC15, a type-I 15-leucine-rich repeat-containing membrane protein, highly overexpressed in OC bowel metastases compared to matched primary tumors and acts as a potent promoter of omental metastasis. Complementary models of OC demonstrated that LRRC15 expression leads to inhibition of anoikis-induced cell death and promotes adhesion and invasion through matrices that mimic omentum. Mechanistically, LRRC15 interacted with β1-integrin to stimulate activation of focal adhesion kinase (FAK) signaling. As a therapeutic proof of concept, targeting LRRC15 with the specific antibody-drug conjugate ABBV-085 in both early and late metastatic OC cell line xenograft models prevented metastatic dissemination, and these results were corroborated in metastatic patient-derived OC xenograft models. Furthermore, treatment of 3D-spheroid cultures of LRRC15-positive patient-derived ascites with ABBV-085 reduced cell viability. Overall, these data uncover a role for LRRC15 in promoting OC metastasis and suggest a novel and promising therapy to target OC metastases.