Colorectal carcinoma (CRC) presents a formidable medical challenge, demanding innovative therapeutic strategies. Chimeric antigen receptor (CAR) natural killer (NK) cell therapy has emerged as a promising alternative to CAR T-cell therapy for cancer. A suitable tumor antigen target on CRC is carcinoembryonic antigen (CEA), given its widespread expression and role in tumorigenesis and metastasis. CEA is known to be prolifically shed from tumor cells in a soluble form, thus hindering CAR recognition of tumors and migration through the TME. We have developed a next-generation CAR construct exclusively targeting cell-associated CEA, incorporating a PD1-checkpoint inhibitor and a CCR4 chemokine receptor to enhance homing and infiltration of the CAR-NK-92 cell line through the TME, and which does not induce fratricidal killing of CAR-NK-92-cells. To evaluate this therapeutic approach, we harnessed intricate 3D multicellular tumor spheroid models (MCTS), which emulate key elements of the TME. Our results demonstrate the effective cytotoxicity of CEA-CAR-NK-92 cells against CRC in colorectal cell lines and MCTS models. Importantly, minimal off-target activity against non-cancerous cell lines underscores the precision of this therapy. Furthermore, the integration of the CCR4 migration receptor augments homing by recognizing target ligands, CCL17 and CCL22. Notably, our CAR design results in no significant trogocytosis-induced fratricide. In summary, the proposed CEA-targeting CAR-NK cell therapy could offer a promising solution for CRC treatment, combining precision and efficacy in a tailored approach.
结直肠癌（CRC）作为一种严峻的医学挑战，亟需创新的治疗策略。嵌合抗原受体（CAR）自然杀伤（NK）细胞疗法已成为癌症治疗中替代CAR T细胞疗法的有前景选择。癌胚抗原（CEA）因其在结直肠癌中广泛表达，并在肿瘤发生和转移中发挥关键作用，成为理想的靶向抗原。然而，CEA常以可溶性形式从肿瘤细胞大量脱落，从而阻碍CAR对肿瘤的识别及其在肿瘤微环境（TME）中的迁移。为此，我们开发了一种新一代CAR结构，专门靶向细胞膜结合型CEA，同时整合了PD1检查点抑制剂和CCR4趋化因子受体，以增强CAR-NK-92细胞系在TME中的归巢与浸润能力，且不会引发CAR-NK-92细胞间的自相残杀。为评估该疗法，我们构建了模拟TME关键特征的复杂三维多细胞肿瘤球体模型（MCTS）。实验结果表明，CEA-CAR-NK-92细胞在结直肠癌细胞系及MCTS模型中均展现出有效的细胞毒性。值得注意的是，该疗法对非癌细胞系的脱靶活性极低，凸显了其精准性。此外，CCR4迁移受体通过识别靶向配体CCL17和CCL22，进一步增强了细胞归巢能力。特别值得关注的是，我们的CAR设计未引发明显的胞啃作用导致的细胞自相残杀。综上所述，这种靶向CEA的CAR-NK细胞疗法结合了精准性与有效性，有望为结直肠癌治疗提供一种定制化的解决方案。
肿瘤(癌症)患者之家