FABP4 facilitates epithelial-mesenchymal transition via elevating CD36 expression in glioma cells

Abstract

Glioblastoma multiforme (GBM) is the most aggressive brain tumor with poor prognosis. A better understanding of mechanisms concerned in glioma invasion might be critical for treatment optimization. Given that epithelial-mesenchymal transition in tumor cells is closely associated with glioma progression and recurrence, identifying pivotal mediators in GBM EMT process is urgently needed. As a member of Fatty acid binding protein (FABP) family, FABP4 serves as chaperones for free fatty acids and participates in cellular process including fatty acid uptake, transport, and metabolism. In this study, our data revealed that FABP4 expression was elevated in human GBM samples and correlated with a mesenchymal glioma subtype. Gain of function and loss of function experiments indicated that FABP4 potently rendered glioma cells increased filopodia formation and cell invasiveness. Differential expression genes analysis and GSEA in TCGA dataset revealed an EMT-related molecular signature in FABP4-mediated signaling pathways. Cell interaction analysis suggested CD36 as a potential target regulated by FABP4. Furthermore, in vitro mechanistic experiments demonstrated that FABP4-induced CD36 expression promoted EMT via non-canonical TGFβ pathways. An intracranial glioma model was constructed to assess the effect of FABP4 on tumor progression in vivo. Together, our findings demonstrated a critical role for FABP4 in the regulation invasion and EMT in GBM, and suggest that pharmacological inhibition of FABP4 may represent a promising therapeutic strategy for treatment of GBM.