METTL3 and METTL14-mediated N6-methyladenosine modification promotes cell proliferation and invasion in a model of endometriosis.

RESEARCH QUESTION: Could METTL3 and METTL14-mediated N6-methyladenosine (m6A) modification play possible cooperative roles in pathogenesis and progression of endometriosis? DESIGN: An investigation into m6A methylation profiles and the roles of METTL3 and METTL14 in the m6A regulation and pathogenesis of endometriosis. The m6A methylation and mRNA levels in paired ectopic endometrium and eutopic endometrium were measured using m6A-mRNA epitranscriptomic microarrays. The functions of m6A methylation in mRNAs were predicted using bioinformatics analysis. The levels of m6A methyltransferases were detected using quantitative polymerase chain reaction. The role of METTL3 and METTL14 in endometriosis was explored using eutopic endometrium stromal cells. RESULTS: The m6A methylation levels were decreased in 1312 mRNAs and increased in 518 mRNAs; 1797 mRNAs were increased and 2580 mRNAs were reduced in the ectopic endometrium compared with the eutopic endometrium. Pathway analysis found that the genes with hypo-methylated m6A were significantly associated with important pathways in endometriosis, including oestrogen, Hippo, and PI3K-Akt signalling and cell-cell adhesion. Furthermore, METTL3 and METTL14 were downregulated in the ectopic endometrium compared with the eutopic endometrium (P < 0.001). Simultaneous METTL3 and METTL14 knockdown increased cell proliferation and invasion. CONCLUSION: Taken together, these data reveal a differential m6A epitranscriptomic pattern in endometriosis. The N6-methyladenosine modification mediated by METTL3 and METTL14 play a cooperative role in promoting cell proliferation and invasion in a model of endometriosis. Therefore, METTL3 and METTL14 may be a novel treatment target of the disease.