m6A reader IGF2BP2-stabilized CASC9 accelerates glioblastoma aerobic glycolysis by enhancing HK2 mRNA stability

N-6-methyladenosine (m(6)A) has been identified to exert critical roles in human cancer; however, the regulation of m(6)A modification on glioblastoma multiforme (GBM) and long non-coding RNA (lncRNA) CASC9 (cancer susceptibility 9) is still unclear. Firstly, MeRIP-Seq revealed the m(6)A profile in the GBM. Moreover, the m(6)A-related lncRNA CASC9 expression was significantly elevated in the GBM tissue and its ectopic high expression was associated with poor survival, acting as an independent prognostic factor for GBM patients. Functionally, the aerobic glycolysis was promoted in the CASC9 overexpression transfection, which was inhibited in CASC9 knockdown in GBM cells. Mechanistically, m(6)A reader IGF2BP2 (insulin-like growth factor 2 mRNA binding protein 2) could recognize the m(6)A site of CASC9 and enhance its stability, then CASC9 cooperated with IGF2BP2, forming an IGF2BP2/CASC9 complex, to increase the HK2 (Hexokinase 2) mRNA stability. Our findings reveal that CASC9/IGF2BP2/HK2 axis promotes the aerobic glycolysis of GBM.