ILT4 reprograms glucose metabolism to promote tumor progression in triple negative breast cancer.

Abstract

Triple negative breast cancer (TNBC) is the most aggressive and poorly-treated subtype of breast cancer. Identifying novel drivers and mechanisms for tumor progression is quite essential for precise targeted therapy of TNBC. Immunoglobulin-like transcript (ILT) 4 is a classic myeloid suppressor for their activation and immune response. Our recent results found that ILT4 is also high expressed in lung cancer cells where has a role in promoting immune evasion and thus tumor formation. However, the expression and function of ILT4 in breast cancer remains elusive. Here, using our patient cohort and public database analysis, we found that TNBC displayed the most abundant ILT4 expression among all breast cancer subtypes. Functionally, enriched ILT4 promoted TNBC cell proliferation, migration and invasion in vitro, as well as tumor growth and metastasis in vivo. Further mechanistic analysis revealed that ILT4 reprogrammed aerobic glycolysis of tumor cells via AKT/mTOR signaling-mediated glucose transporter 3 (GLUT3) and Pyruvate kinase muscle 2 (PKM2) overexpression. ILT4 inhibition in TNBC reduced tumor progression and GLUT3/PKM2 expression in vivo. Our study identified a novel driver for TNBC progression and proposed a promising strategy to combat TNBC by targeting ILT4.