ABHD17C regulates the efficacy of lenvatinib in suppressing hepatocellular carcinoma

INTRODUCTION: Lenvatinib is a first-line therapy for hepatocellular carcinoma (HCC), but its clinical efficacy is limited by drug resistance. ABHD17C, a depalmitoylation enzyme involved in HCC progression, has not been investigated in lenvatinib response. This study aimed to determine whether ABHD17C regulates the anti-tumor efficacy of lenvatinib in HCC. METHODS: Published single-cell RNA sequencing (scRNA-seq) data were analyzed to characterize ABHD17C expression in the HCC tumor microenvironment. Functional assays were performed in HCC cell lines to evaluate the effects of lenvatinib and ABHD17C modulation. The findings were validated using HCC xenograft mouse models and patient-derived tumor organoids. RESULTS: scRNA-seq analysis showed that ABHD17C is associated with an immunosuppressive tumor microenvironment characterized by reduced CD8⁺ T cell infiltration, increased T cell exhaustion, and abnormal intercellular communication. In vitro, lenvatinib inhibited proliferation, migration, and invasion while inducing apoptosis and cell cycle arrest in HCC cells. These effects were significantly attenuated by ABHD17C overexpression but enhanced by ABHD17C depletion. In vivo, ABHD17C-overexpressing xenografts were less responsive to lenvatinib, exhibiting increased tumor growth and reduced apoptosis. Similarly, in patient-derived organoids, ABHD17C overexpression diminished lenvatinib efficacy. Notably, lenvatinib reduced ABHD17C expression in organoids, suggesting potential feedback regulation. CONCLUSION: ABHD17C promotes an immunosuppressive tumor microenvironment and attenuates the anti-tumor effects of lenvatinib in HCC. Targeting ABHD17C may represent a potential strategy to enhance lenvatinib sensitivity and improve therapeutic outcomes.