N7-methylguanosine tRNA modification promotes tumorigenesis and chemoresistance through WNT/β-Catenin pathway in nasopharyngeal carcinoma

Treatment selections are very limited for patients with advanced nasopharyngeal carcinoma (NPC) experiencing disease progression. Uncovering the potential mechanism underlying NPC progression is crucial for identify novel treatments. Here we show that N7-methylguanosine (m7G) tRNA modification enzyme METTL1 and its partner WDR4 are significantly elevated in NPC and associated with poor prognosis. Loss-of-function and gain-of-function assays demonstrated that METTL1/WDR4 mediated m7G tRNA modification promotes NPC growth and metastasis in vitro and in vivo. Mechanistically, m7G tRNA modification selectively regulates the translation of transcripts with higher percentage of m7G tRNA decoded codons. Moreover, further analysis revealed that METTL1-mediated m7G tRNA modification activates WNT/β-Catenin signaling pathway to promote NPC cell epithelial-mesenchymal transition (EMT) and chemoresistance to cisplatin and docetaxel in vitro and in vivo. Our work uncovers a novel layer of mRNA translation regulation mechanism at codon recognition step mediated by tRNA modification and reveals the critical function of tRNA modification in cancer progression.