NSUN2-mediated m5C modification of PGK1 mRNA promotes cell growth, invasion, stemness and glycolysis in gastric cancer

To explore functions and mechanisms in gastric cancer (GC) progression. The mRNA and protein levels of NSUN2 and phosphoglycerate kinase 1 (PGK1) were determined by qRT-PCR and western blot. Cell proliferation, apoptosis, invasion and stemness were examined using CCK8 assay, EdU assay, flow cytometry, transwell assay and sphere formation assay. Cell glycolysis was evaluated by detecting glucose consumption, lactate production and ATP/ADP ratio. The interaction between PGK1 and NSUN2 or YBX1 was evaluated using MeRIP assay or RIP assay. Actinomycin D treatment assay was used to detect the effect of NSUN2 or YBX1 knockdown on PGK1 mRNA stability. The protein levels of p-PI3K/PI3K and p-AKT/AKT were tested by western blot. Animal study was performed to confirm the effect of NSUN2/PGK1 axis on GC tumorigenesis. NSUN2 was confirmed to be upregulated in GC tissues and cells. NSUN2 silencing could repress GC cell growth, invasion, stemness and glycolysis. NSUN2 enhanced PGK1 mRNA stability through promoting its m5C modification, and this modification could be recognized by YBX1. Besides, PGK1 overexpression reversed the inhibitory effect of NSUN2 knockdown on GC cell growth, invasion, stemness and glycolysis. In addition, NSUN2/PGK1 axis increased the activity of PI3K/AKT pathway. Animal study revealed that interference of NSUN2 reduced GC tumorigenesis via inactivating the PGK1/PI3K/AKT pathway. NSUN2/PGK1 axis might play a vital role in GC development.