CD93 regulates breast cancer growth and vasculogenic mimicry through the PI3K/AKT/SP2 signaling pathway activated by integrin β1.

Abstract

In women, breast cancer (BC) accounts for 7%-10% of all cancer cases and is one of the most common cancers. To identify a new method for treating BC, the role of CD93 and its underlying mechanism were explored. MDA-MB-231 cells were used in this study and transfected with si-CD93, si-MMRN2, oe-CD93, si-integrin β1, or oe-SP2 lentivirus. After MDA-MB-231 cells were transfected with si-NC or si-CD93, they were injected into nude mice by subcutaneous injection at a dose of 5 × 106/mouse to construct a BC animal model. The expression of genes and proteins and cell migration, invasion and vasculogenic mimicry were detected by RT‒qPCR, western blot, immunohistochemistry, immunofluorescence, Transwell, and angiogenesis assays. In pathological samples and BC cell lines, CD93 was highly expressed. Functionally, CD93 promoted the proliferation, migration, and vasculogenic mimicry of MDA-MB-231 cells. Moreover, CD93 interacts with MMRN2 and integrin β1. Knockdown of CD93 and MMRN2 can inhibit the activation of integrin β1, thereby inhibiting the PI3K/AKT/SP2 signaling pathway and inhibiting BC growth and vasculogenic mimicry. In conclusion,the binding of CD93 to MMRN2 can activate integrin β1, thereby activating the PI3K/AKT/SP2 signaling pathway and subsequently promoting BC growth and vasculogenic mimicry.