m6A mRNA methylation initiated by METTL3 directly promotes YAP translation and increases YAP activity by regulating the MALAT1-miR-1914-3p-YAP axis to induce NSCLC drug resistance and metastasis

Background METTL3 is an RNA methyltransferase that mediates m(6)A modification and is implicated in mRNA biogenesis, decay, and translation. However, the biomechanism through which METTL3 regulates MALAT1-miR-1914-3p-YAP axis activity to induce NSCLC drug resistance and metastasis is not very clear. Methods The expression of mRNA was analyzed by qPCR assays. Protein levels were analyzed by western blotting and immunofluorescent staining. Cellular proliferation was detected by CCK8 assays. Cell migration and invasion were analyzed by wound healing and transwell assays, respectively. Promoter activities and gene transcription were analyzed by luciferase reporter assays. Finally, m(6)A modification was analyzed by MeRIP. Results METTL3 increased the m(6)A modification ofYAP. METTL3, YTHDF3, YTHDF1, and eIF3b directly promoted YAP translation through an interaction with the translation initiation machinery. Moreover, the RNA level ofMALAT1was increased due to a higher level of m(6)A modification mediated by METTL3. Meanwhile, the stability ofMALAT1was increased by METTL3/YTHDF3 complex. Additionally,MALAT1functions as a competing endogenous RNA that sponges miR-1914-3p to promote the invasion and metastasis of NSCLC via YAP. Furthermore, the reduction of YAP m(6)A modification by METTL3 knockdown inhibits tumor growth and enhances sensitivity to DDP in vivo. Conclusion Results indicated that the m(6)A mRNA methylation initiated by METTL3 promotes YAP mRNA translation via recruiting YTHDF1/3 and eIF3b to the translation initiation complex and increases YAP mRNA stability through regulating the MALAT1-miR-1914-3p-YAP axis. The increased YAP expression and activity induce NSCLC drug resistance and metastasis.

Automated summary

The study demonstrated that METTL3 promotes YAP mRNA translation by increasing m(6)A modification, and enhances YAP mRNA stability through regulating the MALAT1-miR-1914-3p-YAP axis, leading to the promotion of invasion and metastasis in NSCLC.