Quercetin Suppresses Uterine Leiomyoma Progression by Modulating METTL3-Mediated MAPK Signaling.

Uterine leiomyoma (UL) is characterized by excessive proliferation, extracellular matrix accumulation, and inflammatory activation, yet its upstream regulatory mechanisms remain incompletely defined. Here, we investigated the role of METTL3-associated signaling in mediating the anti-leiomyoma effects of quercetin. Quercetin significantly inhibited proliferation and induced apoptosis in UL cells, accompanied by suppression of inflammatory cytokine production. Transcriptomic profiling revealed that METTL3 silencing was associated with enrichment of MAPK and inflammation-related pathways. Mechanistically, quercetin downregulated METTL3 expression and suppressed phosphorylation of MEK, ERK, JNK, and p38, whereas METTL3 overexpression partially reversed these effects, supporting a functional role of METTL3 in mediating MAPK pathway activation. Consistently, METTL3 knockdown recapitulated the anti-proliferative, pro-apoptotic, and anti-inflammatory effects of quercetin. In a hormone-induced UL rat model, quercetin attenuated uterine enlargement, fibrosis, and proliferative activity, accompanied by decreased METTL3 expression and MAPK activation. Collectively, these findings demonstrate that quercetin suppresses UL progression, at least in part, through modulation of METTL3-mediated MAPK signaling, highlighting METTL3 as a critical regulatory node and a potential therapeutic target in UL.