METTL16 Promotes Lipid Metabolic Reprogramming and Colorectal Cancer Progression.

Background: Lipid reprogramming represents a pivotal stage in tumor progression. N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotic cells, plays a significant role in colorectal cancer (CRC) development, though its specific involvement in lipid reprogramming remains unclear. Methods: Bioinformatics analysis of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases revealed differential expression of METTL16 (M16), which was further validated through qRT-PCR and Western blotting in CRC tissues and cell lines. The impact of M16 on CRC proliferation, metastasis, invasion, and lipid reprogramming was evaluated using both in vivo and in vitro approaches. Regulatory mechanisms underlying M16's role in CRC progression were explored using immunofluorescence (IF) staining, RNA immunoprecipitation (RIP), MERIP assay, RNA pull-down assay, total m6A measurement, RNA stability assay, protein stability analysis, and luciferase reporter assays. Results: Analysis results demonstrated a significant upregulation of the m6A methyltransferase METTL16 in CRC, closely associated with poor prognosis and abnormal lipid droplet accumulation. Functional assays revealed that M16 overexpression markedly promotes CRC cell proliferation, migration, and invasion both in vitro and in vivo, primarily by enhancing lipid reprogramming. Mechanistically, M16 induces m6A modification of TM7SF2 mRNA, stabilizing it via an IGF2BP1- and IGF2BP2-dependent pathway, thereby upregulating TM7SF2 expression and driving lipid reprogramming in CRC. Conclusion: In conclusion, these findings highlight the critical role of the M16/m6A/TM7SF2 axis in lipid metabolic reprogramming in CRC, offering potential therapeutic targets for its treatment.