CPNE1 promotes stemness and confers resistance to GPC3 CAR-T cell therapy in hepatocellular carcinoma via the STAT3-TGF-β signaling pathway.

backgroundHepatocellular carcinoma (HCC) remains a major global health burden with limited effective therapeutic strategies. Although chimeric antigen receptor (CAR) T-cell therapy has shown encouraging potential, its efficacy in HCC is profoundly constrained by the immunosuppressive tumor microenvironment.

methodsIn this study, we performed integrative analyses of HCC transcriptomic and clinical samples data to identify Copine-1 (CPNE1) as potential oncogenic drivers involved in tumor progression and immune suppression. Using functional and mechanistic assays in vitro with HCC cell line models and in vivo with mouse models, we examined the role of CPNE1 in regulating tumor proliferation, stemness, and its contribution to resistance against GPC3-targeted CAR-T cell therapy.

resultsWe found that CPNE1 is significantly overexpressed in HCC and correlates with poor patient prognosis. Functional assays revealed that CPNE1 enhances tumor proliferation and stemness by activating the STAT3-transforming growth factor beta (TGF-β) signaling pathway. Moreover, CPNE1-induced secretion of TGF-β promotes T-cell exhaustion, which impairs the efficacy of CAR-T cells. Knockdown of CPNE1 restored CAR-T cell function, enhanced T-cell infiltration into tumors, reduced exhaustion, and improved antitumor efficacy without causing systemic toxicity. Clinically, high CPNE1 expression was associated with lower T-cell infiltration and poor outcomes in HCC patients treated with immune checkpoint inhibitors.

conclusionsThese findings identify CPNE1 as a critical regulator of HCC progression and immune suppression, highlighting the CPNE1-STAT3-TGF-β axis as a promising therapeutic target in HCC.