LRP4 mutations promote tumor progression and resistance to anti-PD-1 therapy in recurrent hepatocellular carcinoma

Background and Aims: HCC recurrence is a major factor limiting long-term survival and the cause of most deaths in patients with HCC. However, molecular characterization and potential therapeutic targets of recurrent HCC remain mostly unknown. Approach and Results: We performed whole-exome sequencing in 63 matched primary and recurrent HCC tumors and combined the data with whole-genome sequencing results in 43 paired samples from our previous study. Sanger sequencing was used to identify all low-density lipoprotein receptor-related protein 4 ( LRP4 ) coding exons in 203 additional patients with recurrent HCC. We identified LRP4 somatic mutations in 7.8% (24/309) of recurrent tumors and only 0.97% (3/309) of primary tumors ( p <0.001). Prognosis after the second liver resection was poorer in patients with an LRP4 mutation. Biofunctional investigations demonstrated that inactivating LRP4 mutations promoted tumor progression and immunosuppression. Mechanistically, mutated LRP4 reduced intratumoral conventional type 1 dendritic cell and CD8 + T cell infiltration by repressing C-C motif chemokine ligand 4 expression and secretion through activation of β-catenin signaling, resulting in resistance to anti-programmed cell death protein-1 therapy. Patients with recurrent HCC carrying an LRP4 mutation did not benefit from anti-programmed cell death protein-1 treatment after their second resection surgery. A β-catenin inhibitor–reversed LRP4-induced resistance to anti-programmed cell death protein-1 therapy in humanized tumor-bearing mice. Conclusions: Our results identified novel LRP4 mutations important in recurrent HCC. Inactivating LRP4 mutations were associated with resistance to anti-programmed cell death protein-1 therapy and could be useful biomarkers for precision therapy in patients with recurrent HCC.