Synergistic Antitumor Efficacy of Radiofrequency Ablation Combined With <scp>TROP2</scp> ‐ <scp>CAR</scp> ‐T Cells in a Xenograft Mouse Model of Lung Adenocarcinoma

ABSTRACT Background Lung adenocarcinoma (LUAD) is highly relapsed and responds poorly to chimeric antigen receptor (CAR)‐T therapy due to antigenic heterogeneity and the immunosuppressive microenvironment. Trophoblast cell‐surface antigen 2 (TROP2), overexpressed in LUAD and linked to poor prognosis, is a promising target. Radiofrequency ablation (RFA) can cause direct tumor necrosis, trigger immunogenic cell death, and enhance immune infiltration through antigen secretion; however, it often fails to eradicate residual tumors. Therefore, combining RFA with CAR‐T‐cell therapy may offer a new and synergistic therapy against LUAD. Objective This study examined the cytotoxicity of TROP2‐directed CAR‐T cells against LUAD in vitro and observed their therapeutic efficacy and safety in combination with RFA in vivo. Methods Third‐generation TROP2‐CAR‐T cells were developed and characterized for transduction efficiency, CD4/CD8 ratio, and proliferative capacity. Their antigen‐specific cytotoxicity against TROP2 + target cells was observed using a luciferase‐based assay and cytokine analysis. An A549‐TROP2‐Luc xenograft model was developed to examine the therapeutic effects of RFA, TROP2‐CAR‐T monotherapy, and their combination. Tumor suppression, Ki67/TUNEL assays, and immunohistochemical (IHC) analyses were performed to evaluate efficacy and safety. Results TROP2‐CAR‐T cells showed efficient transduction and potent, antigen‐dependent cytotoxicity with significant cytokine secretion in vitro. In vivo, both RFA and TROP2‐CAR‐T therapy suppressed tumor growth, and their combination showed a synergistic antitumor effect without hepatic or renal toxicity. Conclusion The combination of RFA and TROP2‐CAR‐T therapy demonstrates enhanced antitumor efficacy and improved safety profile in LUAD, highlighting a promising combinatorial immunotherapeutic approach.