Targeting WTAP sensitizes hepatocellular carcinoma to sorafenib by inhibiting the ERK signaling pathway

Hepatocellular carcinoma (HCC) often requires targeted therapy and immunotherapy due to frequent delayed diagnosis. Sorafenib, the first targeted drug applied to treat HCC, has demonstrated a remarkable therapeutic effect in the clinic. However, its clinical application has been limited by drug resistance and the insufficient understanding of the relevant mechanism. Wilms' tumor 1-associated protein (WTAP), associated with tumor progression, remains unstated in sorafenib resistance. In this study, <i>WTAP</i> expression patterns in HCC were systematically characterized through integrative analysis of The Cancer Genome Atlas (TCGA) datasets and spatial transcriptomic profiling. To delineate the potential mechanisms of <i>WTAP</i>-mediated sorafenib resistance in HCC, multimodal approaches integrating gene set enrichment analysis (GSEA), predictions from the "oncoPredict" package in vitro experiments, molecular docking simulations, and western blot validation were applied. To further investigate the role of <i>WTAP</i> in drug resistance, hydrodynamic tail vein injection (HTVi) mouse models and immunohistochemistry were utilized. Significant <i>WTAP</i> upregulation was identified in HCC tissues, showing strong associations with tumor progression and adverse clinical outcomes. The knockdown of <i>WTAP</i> sensitized HCC cells to sorafenib in vitro. GSEA, molecular docking analysis, and western blot analysis demonstrated that <i>WTAP</i> induces the activation of the extracellular signal-regulated kinase (ERK) signaling pathway, a critical link in chemoresistance mechanisms. In the HTVi HCC model, the combination of <i>WTAP</i> knockdown with sorafenib markedly suppressed tumor progression and boosted survival rates. These findings highlight that <i>WTAP</i> positively regulates the ERK pathway in HCC, promoting sorafenib resistance; therefore, targeting <i>WTAP</i> may represent a novel strategy to potentiate sorafenib responsiveness in HCC.