Abstract 6360: A novel CAR-NK cell therapy to target lung adenocarcinoma cells

Abstract

Abstract Cell Adhesion Molecule (CADM1) is a Bonafede tumor suppressor with 40% of NSCLC tumors lose CADM1 expression either by loss of heterozygosity or promoter hypermethylation. The tumor suppressive ability of CADM1 is attributed to its cell adhesion function. However, we previously demonstrated that CADM1 also mediates its tumor suppression through regulation of NK-mediated immunosurveillance. In tumors that do not lose CADM1, it is expressed on cell surface and up regulated during TGF-β-induced EMT making it a biomarker for potential therapeutic targeting. Here we report the design and development of T and NK specific CAR that would specifically target lung cancer cells in CADM1 dependent manner. Anti-CADM1 single chain variable fragment (CADM1-scFv) was fused to NK or T cell specific transmembrane and co-stimulatory domains. The resulting CAR constructs were cloned into a retroviral vector, from which viral stocks were generated to transduce human and mouse cells. Next, we introduced anti-CADM1-CAR-NK construct into NK92 cell line and tested it in a cytotoxicity assay using A549-GFP-ffluc cell line as a target. We observed a significant increase in the killing of target cells with anti-CADM1-CAR-NK cells compared with non-transduced NK92 cells. This effect was significantly reduced when A549- GFP-ffluc-CADM1 KO cells were used as target. Next, we generated anti-CADM1-CAR-T cells by transducing human CD3+ T-cells purified from human PBMCs. Similar to anti -CADM1-CAR-NK, anti-CADM1-CAR-T cells showed increased T-cell specific cytotoxicity in a CADM1-dependent manner. Next, we evaluated the efficacy of anti-CADM1-CAR-T cells through adoptive transfer into NSG mice xenografted with human lung adenocarcinoma cells into mouse lungs. The administration of anti-CADM1-CAR-T cells markedly reduced tumor size and enhanced the survival rate of the mice. Importantly this effect was dependent on CADM1 expression, as mice xenografted with human CADM1 KO cells showed neither tumor size reduction nor increased survival. Finally, using IHC staining, we demonstrated that anti-CADM1-CAR-T cells directly target xenografted tumors in the mouse lungs. In conclusion, our findings indicate that CAR-NK and CAR-T cells targeting CADM1-expressing lung tumors have a significant therapeutic potential for the treatment of NSCLC. Citation Format: Sergey Zolov, Sergei Chuikov, Shiva Krishna Katkam, Delaney Shield, Venkateshwar G. Keshamouni. A novel CAR-NK cell therapy to target lung adenocarcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6360.