Targeting AXL in PIK3R2-amplified ovarian cancer

Abstract

The p85 regulatory subunit and its associated p110 catalytic subunit are components of the class IA PI3K that mediates the downstream signal of receptor tyrosine kinases. PIK3R2 (encoding p85β, one of the p85 isoforms) is commonly amplified in ovarian cancer patients. Importantly, high PIK3R2 expression significantly correlated with worse patient survival. Here, we showed that p85β promoted tumorigenic properties of ovarian cancer cells. The protein expression of a receptor tyrosine kinase AXL was positively regulated by p85β. AXL is a member of the TAM receptor family. The regulation was specific to AXL because the other two members (Tyro3 and MERTK) were not altered by p85β. Drug sensitivity assays suggested that inhibition of AXL reduced oncogenic activities of p85β in vitro and in vivo. Together, we propose p85β as a potential therapeutic target in ovarian cancer and therapeutic blockade of AXL signaling may be an effective strategy for ovarian cancer with PIK3R2 amplification.