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

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. 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. 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. 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.