Conclusion
METTL3 is highly expressed in OS and enhances TRAF6 expression through m6A modification, thereby promoting the metastases of OS cells.
Methods
The expression differences of METTL3 between metastatic and non-metastatic OS tissues and patients with different Enneking stages were detected using RT-qPCR. METTL3 was artificially downregulated in the cells, followed by wound healing assay, Matrigel assay, immunofluorescence, in vivo tumorigenic assay, HE staining, and western blot. Transcriptome sequencing and m6A-seq was conducted to identify the downstream genes of METTL3, and RIP and dual-luciferase assays were performed for validation. The expression of TRAF6 in OS tissues was detected using RT-qPCR. Finally, the rescue experiments were conducted.
Results
METTL3 was overexpressed in metastatic OS tissues, and downregulation of METTL3 decreased cell migration, invasion, epithelial-mesenchymal transition, and tumorigenic and metastatic activities. The m6A site was highly enriched in cells poorly expressing METTL3, and the m6A peak was mainly enriched in the exon region. METTL3 was positively correlated with TRAF6 in metastatic OS, and depletion of METTL3 resulted in the loss of TRAF6 expression in OS cells. Upregulation of TRAF6 contributed to metastases in vitro and in vivo.