GALNT6 drives lenvatinib resistance in hepatocellular carcinoma through autophagy and cancer-associated fibroblast activation.

BACKGROUND: Hepatocellular carcinoma (HCC) remains a significant global health challenge with limited treatment options. Lenvatinib, a tyrosine kinase inhibitor, has shown promise but is often undermined by the development of drug resistance. METHODS: Utilizing high-throughput sequencing, we investigated the molecular mechanisms underlying lenvatinib resistance in HCC cells, with a focus on metabolic pathways. Key genes, including GALNT6, were validated through quantitative real-time PCR. The effects of GALNT6 knockdown on lenvatinib sensitivity were examined in vitro and in vivo. O-GalNAc glycosylation was assessed using Vicia Villosa Lectin. Immune cell infiltration and interactions were analyzed in the TCGA-LIHC cohort, with further validation by Western blotting and immunohistochemistry. RESULTS: Our findings indicate that lenvatinib resistance in HCC is driven by the mucin-type O-glycosylation pathway, with GALNT6 playing a critical role. Knockdown of GALNT6 led to reduced O-GalNAc glycosylation, including the modification of LAPTM5, resulting in decreased LAPTM5 activity and autophagy inhibition. Additionally, GALNT6 silencing disrupted the PDGFA-PDGFRB axis, impairing the activation of cancer-associated fibroblasts (CAFs) and reducing their secretion of SPP1, which collectively diminished lenvatinib resistance. CONCLUSIONS: GALNT6 is integral to the resistance mechanisms against lenvatinib in HCC by modulating autophagy and CAF activation. Targeting GALNT6 offers a promising strategy to enhance lenvatinib efficacy and improve therapeutic outcomes in HCC.