FMO2+ cancer-associated fibroblasts sensitize anti-PD-1 therapy in patients with hepatocellular carcinoma
- J Immunother Cancer. 2025 May 2;13(5):e011648. doi: 10.1136/jitc-2025-011648.
- 1. Department of Liver Surgery & Transplantation, Liver Cancer Institute, Zhongshan Hospital Fudan University, Shanghai, China.
- 2. Department of Surgical Oncology, Zhejiang University, Hangzhou, Zhejiang, China.
- 3. The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
- 4. Department of Liver Surgery & Transplantation, Liver Cancer Institute, Zhongshan Hospital Fudan University, Shanghai, China [email protected].
Background: The efficacy of immune checkpoint inhibitors (ICIs) for hepatocellular carcinoma (HCC) is limited by heterogeneity in individual responses to therapy. The heterogeneous phenotypes and crucial roles of cancer-associated fibroblasts (CAFs) in immunotherapy resistance remain largely unclear.
Methods: A specific CAF subset was identified by integrating comprehensive single-cell RNA Sequencing, spatial transcriptomics and transcriptome profiling of patients with HCC with different responses to antiprogrammed cell death protein 1 (anti-PD-1) therapy. Mouse orthotopic HCC models and a coculture system were constructed, and cytometry by time-of-flight analysis was performed to investigate the functions and mechanisms of specific CAFs in the immune context of HCC.
Results: We identified a distinct flavin-containing monooxygenase 2 (FMO2)+ CAF subset associated with a favorable response to anti-PD-1 therapy and better clinical outcomes. FMO2+ CAFs increase anti-PD-1 treatment efficacy by promoting tertiary lymphoid structure formation and increasing the infiltration of CD8+ T cells and M1-like macrophages through the C-C motif chemokine ligand 19 (CCL19)-C-C motif Chemokine Receptor 7 axis. Mechanistically, FMO2 promotes nuclear factor kappa B/p65-mediated CCL19 expression by competitively binding to glycogen synthase 1 (GYS1) with praja ring finger ubiquitin Ligase 1 (PJA1), thereby suppressing the PJA1-mediated proteasomal degradation of GYS1. CCL19 treatment potentiated the therapeutic efficacy of anti-PD-1 therapy in mouse orthotopic HCC models. A favorable immunotherapy response was observed in patients with HCC with high serum levels of CCL19.
Conclusions: We identified a novel FMO2+ CAF subset that serves as a critical regulator of microenvironmental immune properties and a predictive biomarker of the immunotherapy response in patients with HCC. CCL19 in combination with anti-PD-1 therapy may constitute a novel therapeutic strategy for HCC.