FTO-induced APOE promotes the malignant progression of pancreatic neuroendocrine neoplasms through FASN-mediated lipid metabolism.

Abstract

N6-methyladenosine (m6A) is considered the most prevalent RNA epigenetic regulator in cancer. FTO, an m6A demethylase, has been implicated in contributing to the progression of various cancers by up-regulating the expression of multiple oncogenes. However, studies exploring its impact on lipid metabolism in cancer, especially in pNENs, remain scarce. In this study, we demonstrated that FTO was up-regulated in pNENs and played a critical role in tumor growth and lipid metabolism. Mechanistically, we discovered that FTO over-expression increased the expression of APOE in an m6A-IGF2BP2-dependent manner, leading to dysregulation of lipid metabolism. Furthermore, we found APOE could activate the PI3K/AKT/mTOR signaling pathway, thereby enhancing lipid metabolism and proliferative capabilities, by orchestrating the state of FASN ubiquitination. In conclusion, our study reveals the FTO/IGF2BP2/APOE/FASN/mTOR axis as a mechanism underlying aberrant m6A modification in lipid metabolism and provides new insights into the molecular basis for developing therapeutic strategies for pNENs treatment.