m6A epitranscriptomic regulation of KRAS by METTL3 promotes EMT and stromal remodeling through TGF-β/SMAD signaling in cervical cancer

KRAS N6-methyladenosine (m⁶A) modification has emerged as a crucial epigenetic regulator in Cancer progression, but its role in cervical Cancer epithelial-mesenchymal transition (EMT) and stromal remodeling remains unclear. This study explored how METTL3-dependent m⁶A methylation of KRAS influences metastasis through the TGF-β/SMAD/SNAIL pathway. RNA Sequencing (RNA-seq) and MeRIP-seq revealed that METTL3 knockdown significantly reduces KRAS m⁶A levels and suppresses TGF-β/SMAD pathway activation. Functional assays, including Western blot, immunofluorescence, Transwell, and scratch tests, demonstrated that METTL3 depletion inhibits cell migration, invasion, and EMT marker expression. Co-immunoprecipitation confirmed that m⁶A modification facilitates interactions between KRAS, SMAD2/3, and SNAIL. In vivo models showed reduced tumor growth and pulmonary metastasis upon METTL3 silencing. These findings define a novel METTL3-KRAS-TGF-β/SMAD/SNAIL axis in cervical Cancer, offering new insights into m⁶A-mediated metastasis and potential therapeutic targets. Schematic Illustration of the Molecular Mechanism by Which KRAS m⁶A Modification Regulates SNAIL-Mediated EMT and Stromal Remodeling in Cervical Cancer Cells via the TGF-β/SMAD Signaling Axis (created by BioRender). Note: sh-METTL3(-) indicates METTL3 knockdown; oe-METTL3(+) indicates METTL3 overexpression. Upon extracellular signal stimulation, under METTL3 knockdown or overexpression conditions, KRAS m⁶A modification alters the expression of core molecules in the TGF-β/SMAD signaling axis and the EMT-related transcription factor SNAIL, subsequently modulating the expression of EMT markers (E-cadherin, Vimentin) in the nucleus. "↑" denotes activation or upregulation; "↓" denotes inhibition or downregulation.