Cancer Biology Graduate Program, Ajou University School of Medicine, Suwon, Republic of Korea; Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
AI-Super Convergence KIURI Translational Research Center, Ajou University School of Medicine, Suwon, Republic of Korea; Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
Life Sci. 2023 Dec 15;335:122230. doi: 10.1016/j.lfs.2023.122230. Epub 2023 Nov 11.
Immunotherapy has shown remarkable effects on several malignancies; however, its impact on gastric cancers has been limited. Therefore, a novel strategy to overcome resistance to immunotherapy is required. In this study, we compared the gene expression profiles of two murine GC cell lines that exhibited different effects on tumor immunity. The functions of specific genes related to negative tumor immunity and the impact of a specific inhibitor were evaluated in syngeneic GC mouse models.
RT-PCR and Western blotting validated Gas6 and AXL expression in murine cell lines. RT-PCR compared YTN16 and YTN3 GC cell's impact on T cell activation. AXL, the receptor for GAS6 in YTN16, was validated by western blotting. Gas6 was inhibited in YTN16 cells using shRNA, and then the gene expression pattern, effects to T cell activation, and tumor growth were assessed. YTN16 cells were injected into mice and treated with CCB-3233, anti-PD-1 antibody, or both. Immunohistochemistry and flow cytometry evaluated tumor-infiltrating immune cells.
YTN16 cells expressed more Gas6 and had reduced T cell activation compared to YTN3 cells. AXL activation was higher in YTN16. CCB-3233 reduced AXL phosphorylation. Knocking down Gas6 in YTN16 reduced immunosuppression-related genes and increased tumor-infiltrating T cells. Combined CCB-3233 and anti-PD-1 treatment reduced tumor growth and increased T-cell infiltration. Human GC data revealed a negative correlation between GAS6 and immune activation-related genes.
The GAS6/AXL pathway contributes to immunotherapy resistance in GC. Targeting this pathway may be a novel therapeutic strategy.
免疫疗法已在多种恶性肿瘤中显示出显著疗效；然而，其对胃癌的影响有限。因此，需要一种新的策略来克服免疫治疗的耐药性。在这项研究中，我们比较了两种具有不同肿瘤免疫作用的鼠胃腺癌细胞系的基因表达谱。评估了与负性肿瘤免疫相关的特定基因的功能及其在同基因胃癌小鼠模型中的特异性抑制剂的影响。
通过 RT-PCR 和 Western blot 验证了 Gas6 和 AXL 在鼠细胞系中的表达。RT-PCR 比较了 YTN16 和 YTN3 胃腺癌细胞对 T 细胞激活的影响。Western blot 验证了 YTN16 中的 AXL，即 GAS6 的受体。用 shRNA 抑制 YTN16 细胞中的 Gas6，然后评估基因表达谱、对 T 细胞激活的影响和肿瘤生长。将 YTN16 细胞注入小鼠体内，并给予 CCB-3233、抗 PD-1 抗体或两者联合治疗。免疫组织化学和流式细胞术评估肿瘤浸润免疫细胞。
与 YTN3 细胞相比，YTN16 细胞表达更多的 Gas6，且 T 细胞激活减少。AXL 激活在 YTN16 中更高。CCB-3233 降低了 AXL 磷酸化。在 YTN16 中敲低 Gas6 减少了免疫抑制相关基因并增加了肿瘤浸润 T 细胞。CCB-3233 联合抗 PD-1 治疗减少了肿瘤生长并增加了 T 细胞浸润。人胃癌数据显示 GAS6 与免疫激活相关基因呈负相关。
GAS6/AXL 通路促进了胃癌的免疫治疗耐药。靶向该通路可能是一种新的治疗策略。
