Synergistic therapeutic combination with a CAF inhibitor enhances CAR-NK-mediated cytotoxicity via reduction of CAF-released IL-6

Abstract

BackgroundCancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) contribute to an impaired functionality of natural killer (NK) cells that have emerged as a promising therapeutic modality. The interaction between CAFs and NK cells within the TME exerts major inhibitory effects on immune responses, indicating CAF-targeted therapies as potential targets for effective NK-mediated cancer killing.MethodsTo overcome CAF-induced NK dysfunction, we selected an antifibrotic drug, nintedanib, for synergistic therapeutic combination. To evaluate synergistic therapeutic efficacy, we established an in vitro 3D Capan2/patient-derived CAF spheroid model or in vivo mixed Capan2/CAF tumor xenograft model. The molecular mechanism of NK-mediated synergistic therapeutic combination with nintedanib was revealed through in vitro experiments. In vivo therapeutic combination efficacy was subsequently evaluated. Additionally, the expression score of target proteins was measured in patient-derived tumor sections by the immunohistochemical method.ResultsNintedanib blocked the platelet-derived growth factor receptor β (PDGFRβ) signaling pathway and diminished the activation and growth of CAFs, markedly reducing CAF-secreted IL-6. Moreover, coadministration of nintedanib improved the mesothelin (MSLN) targeting chimeric antigen receptor-NK-mediated tumor killing abilities in CAF/tumor spheroids or a xenograft model. The synergistic combination resulted in intense NK infiltration in vivo. Nintedanib alone exerted no effects, whereas blockade of IL-6 trans-signaling ameliorated the function of NK cells. The combination of the expression of MSLN and the PDGFRβ+-CAF population area, a potential prognostic/therapeutic marker, was associated with inferior clinical outcomes.ConclusionOur strategy against PDGFRβ+-CAF-containing pancreatic cancer allows improvements in the therapy of pancreatic ductal adenocarcinoma.

Antitumor activity of genetically engineered NK-cells in non-hematological solid tumor: a comprehensive review

“…Moreover, significantly increased GSDME and Caspase 3 cleavage levels were observed in A549-hFAP, H226-hFAP, and CAF-hFAP cells, indicating that hFAP-CAR-NK-92 cells induced pyroptosis through caspase/GSDME activation. The findings collectively underscored that hFAP-CAR-NK-92 cells induce pyroptosis through caspase/GSDME activation ( 85 , 129 ).…”

“…However, the exact pathway and direct impact on NK cells have been explored only in a handful of studies. On a parallel note, CAR-NK therapy targeting MSLN has demonstrated strong cytotoxicity in pancreatic cancer cells ( 85 – 89 ).…”

Empowering pancreatic tumor homing with augmented anti-tumor potency of CXCR2-tethered CAR-NK cells

“…To evaluate NK-mediated cancer killing, cancer cells were genetically engineered to overexpress NanoLuc luciferase, as described previously. 45 Cancer cells expressing NanoLuc luciferase were then co-cultured with genetically engineered pNK cells at designated effector:target (E:T) ratios for 24 h. Following the co-culture period, luminescence signals were measured using the Nano-Glo luciferase assay system (N1120; Promega, Madison, WI, USA) in accordance with the manufacturer’s instructions. This assay system allows the quantification of luciferase activity and serves as an indicator of NK cell-mediated cancer cell death.…”

“…The shuttle vector, psPAX2 packaging vector, and baboon envelope vector were transfected into the cells using PEI transfection reagent as described previously. 45 Lentivirus-containing media were collected 24 and 48 h post-transfection. The harvested viruses were filtered through a 0.45-μm filter (Minisart 16533-K; Sartorius, Göttingen, Germany) and subsequently concentrated using the Lenti-X concentrator (631232; Takara, Tokyo, Japan).…”

Chimeric antigen receptor-natural killer cell therapy: current advancements and strategies to overcome challenges

“…transduced NK cells with anti-CD73 single chain fragment variable (scFv) CAR and successfully eliminated overexpressed CD73 lung cancer cells under hypoxic condition ( 101 ). Moreover, a drug such as nintedanib reduced IL-6 produced by cancer-associated fibroblasts (CAFs), thus enhancing the cytotoxicity of CAR-NK cells against mesothelin-positive cancer by increasing NK cell activating receptors ( 102 ).…”