No abstract

No abstract

No abstract

BACKGROUND & AIMS: RNA N 6-methyladenosine (m 6 A) modification has recently emerged as a new regulatory mechanism in cancer progression. We aimed to explore the role of the m 6 A regulatory enzyme METTL3 in colorectal cancer (CRC) pathogenesis and its potential as a therapeutic target. METHODS: The expression and clinical implication of METTL3 were investigated in multiple human CRC cohorts. The underlying mechanisms of METTL3 in CRC were investigated by integrative m 6 A sequencing, RNA sequencing, and ribosome profiling analyses. The efficacy of targeting METTL3 in CRC treatment was elucidated in CRC cell lines, patient-derived CRC organoids, and Mettl3-knockout mouse models. RESULTS: Using targeted clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 dropout screening, we identified METTL3 as the top essential m 6 A regulatory enzyme in CRC. METTL3 was overexpressed in 62.2% (79/127) and 88.0% (44/50) of primary CRCs from 2 independent cohorts. High METTL3 expression predicted poor survival in patients with CRC (n ¼ 374, P < .01). Functionally, silencing METTL3 suppressed tumorigenesis in CRC cells, human-derived primary CRC organoids, and Mettl3-knockout mouse models. We discovered the novel functional m 6 A methyltransferase domain of METTL3 in CRC cells by domain-focused CRISPR screening and mutagenesis assays. Mechanistically, METTL3 directly induced the m 6 A-GLUT1-mTORC1 axis as identified by integrated m 6 A sequencing, RNA sequencing, ribosome sequencing,