Targeting the METTL14/Wnt9a/β-catenin pathway with pharmacological inhibitors enhances radiotherapy and immunotherapy efficacy in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer mortality, with its molecular heterogeneity posing a therapeutic challenge. This study investigates the pharmacologically targetable METTL14-mediated pathway in modulating cancer stemness and response to combined radiotherapy and PD-1 blockade. We performed single-cell RNA sequencing and m6A methylation sequencing on matched untreated and radiotherapy/anti-PD-1-treated NSCLC samples. ANALYSIS: of 21,019 cells revealed that combined treatment reduced cancer stem cells (CSCs) and exhausted CD8+ T cells, while increasing naïve CD8+ T cells. m6A sequencing identified METTL14 as a key regulator enhancing Wnt9a mRNA stability via m6A modification. In CSCs, Wnt9a activation stabilizes β-catenin by inhibiting its phosphorylation and degradation, promoting nuclear translocation and transcriptional activity through TCF/LEF, thereby driving malignancy. Pharmacologically, targeting METTL14 disrupts this axis and suppresses CSC stemness. Our findings establish METTL14 as a central pharmacological target whose inhibition suppresses the Wnt9a/β-catenin pathway, enhances radiotherapy and anti-PD-1 efficacy, and reduces CSC-driven progression in NSCLC.