Research Paper Volume 13, Issue 3 pp 4357—4369

The hepatic microenvironment promotes lung adenocarcinoma cell proliferation, metastasis, and epithelial–mesenchymal transition via METTL3-mediated N6-methyladenosine modification of YAP1

METTL3 elevated YAP1 expression in A549 and H1975 lung adenocarcinoma (LUAD) cells via m6A methylation. (A) RIP experiment showing that the hepatic inflammatory microenvironment significantly increased the m6A methylation of YAP1 in A549 and H1975 LUAD cells. (B) TEAD luciferase reporter assays showed that the inflammatory microenvironment of the liver significantly increased YAP1 signaling in A549 and H1975 cells. (C) RIP experiment showing that METTL3 gene silencing significantly inhibited the m6A methylation of YAP1, and METTL3 overexpression significantly increased the m6A methylation of YAP1. However, mutating a critical active site in METTL3 (W397A) had no effect on the m6A methylation of YAP1. (D) Western blot experiment showing that METTL3 gene silencing significantly inhibited the nuclear expression level of YAP1 protein, and the overexpression of METTL3 significantly increased the nuclear expression level of YAP1 protein. However, mutating the key active site of METTL3 (W397A) had no effect on YAP1 protein expression levels. (E) The hepatic inflammatory microenvironment significantly increased the stability of YAP1 mRNA in A549 and H1975 cells (*P

Figure 4. METTL3 elevated YAP1 expression in A549 and H1975 lung adenocarcinoma (LUAD) cells via m6A methylation. (A) RIP experiment showing that the hepatic inflammatory microenvironment significantly increased the m6A methylation of YAP1 in A549 and H1975 LUAD cells. (B) TEAD luciferase reporter assays showed that the inflammatory microenvironment of the liver significantly increased YAP1 signaling in A549 and H1975 cells. (C) RIP experiment showing that METTL3 gene silencing significantly inhibited the m6A methylation of YAP1, and METTL3 overexpression significantly increased the m6A methylation of YAP1. However, mutating a critical active site in METTL3 (W397A) had no effect on the m6A methylation of YAP1. (D) Western blot experiment showing that METTL3 gene silencing significantly inhibited the nuclear expression level of YAP1 protein, and the overexpression of METTL3 significantly increased the nuclear expression level of YAP1 protein. However, mutating the key active site of METTL3 (W397A) had no effect on YAP1 protein expression levels. (E) The hepatic inflammatory microenvironment significantly increased the stability of YAP1 mRNA in A549 and H1975 cells (*P<0.05, **P<0.01 versus the control group).