mA mRNA methylation regulates the ERK/NF-κB/AKT signaling pathway through the PAPPA/IGFBP4 axis to promote proliferation and tumor formation in endometrial cancer.

N6-methyladenosine (mA) mRNA methylation has been considered a gene modulatory mechanism involved in disease progression and carcinogenesis. Herein, we aimed to explore the specific mechanism of mA mRNA methylation in endometrial cancer. RT-qPCR was implemented to test the clinical correlation between mA methylation and endometrial cancer. Bioinformatics analysis was performed to screen the genes related to endometrial cancer, and SRAMP was utilized for the prediction of mA targets. Western blot assay and MeRIP-qPCR experiments were conducted to verify the effect of mA methylation on the candidate genes and the signaling pathways involved in the occurrence of endometrial cancer. mA-seq, RT-qPCR, and polysome profiling were used to confirm the mechanisms of mA methylation in modulating related genes and pathways. The levels of mA methylation, METTL3, and IGFBP4 were reduced in tumor tissues of patients with endometrial cancer, and SRAMP analysis confirmed that IGFBP4 and PAPPA had mA methylation sites. Reduced m6A methylation promoted endometrial cancer cell progression and tumor formation in vivo. mA methylation of RNA in endometrial cancer cells directly modulated IGFBP4 and PAPPA expression. mA methylation regulated the PAPPA/IGFBP4 axis, thereby influencing endometrial cancer through the NF-κB and ERK signaling pathways. Knockdown of PAPPA or overexpression of IGFBP4 in endometrial cancer cells partially reduced disease progression caused by reduced mA methylation. This research suggests that mA mRNA methylation modulates the ERK/NF-κB/AKT signaling pathway through the PAPPA/IGFBP4 axis to induce cell proliferation and tumor formation in endometrial cancer. 1. METTL3 expressed modestly and mA methylation of IGFBP4 and PAPPA mRNAs decreased in endometrial cancer; 2. YTHDF1-mediated IGFBP4 translation was reduced in HEC-1-A and AN3CA cells, and YTHDF2-mediated PAPPA mRNA degradation was blunted but its protein expression increased; 3. Increased PAPPA and reduced IGFBP4 activated IGF1-induced ERK, AKT, and NF-κB pathways by binding IGFR, thereby promoting cancer cell malignancy.