基于免疫检查点抑制剂（ICIs）的疗法是转移性黑色素瘤（MM）患者的标准护理治疗。干扰素基因刺激剂 (STING) 信号通路对于控制 ICI 的免疫反应至关重要。干扰素 (IFN)-γ 诱导蛋白 16 (IFI16) 是一种胞质 DNA 传感器，可激活 STING 信号通路。 IFI16 和 STING 信号通路对 IFN-γ 刺激的联系以及与 ICI 反应的联系尚未完全了解。使用 TCGA-SKCM、GSE91061 和 PRJEB23709 公共 RNA 测序 (RNA-seq) 数据集进行解卷积分析，其中包含MM 患者的 RNA-seq。使用 MM 细胞系进行与细胞因子阵列相结合的功能测定，以在计算机数据中进行验证。对来自 MM 患者的未经治疗或预处理的肿瘤样本进行多重免疫荧光。去卷积分析显示，黑色素瘤细胞中高 IFI16 水平与 MM 患者的良好预后相关，并与 M1 巨噬细胞浸润呈正相关。使用 MM 细胞系的功能测定表明，IFI16 是感知胞质 DNA 并激活 STING 和核因子 kappa B (NF-κB) 信号通路的关键分子，独立于环 GMP-AMP 合酶或在黑色素瘤 2 中不存在，在 IFN-γ 上刺激。 IFI16 敲低显着降低了 CXCL10 和 ICAM1 的分泌。 EZH2 抑制剂逆转了对 IFI16 的抑制性表观遗传控制，以促进 IFN-γ 刺激下的 STING 和 NF-κB 信号通路。 MM 患者肿瘤样本中 IFI16、ICAM1 和 CXCL10 水平升高与 M1 巨噬细胞浸润以及对 ICI 的显着更好的反应呈正相关。这项研究确定 IFI16 是与 ICI 反应相关的 IFN-γ 刺激过程中的关键传感器，并且它提出表观遗传 EZH2 抑制剂作为克服 MM 患者 ICI 耐药性的替代治疗策略。© 作者（或其雇主）2024。在 CC BY-NC 下允许重复使用。禁止商业再利用。请参阅权利和权限。英国医学杂志出版。

Immune checkpoint inhibitor (ICIs)-based therapies are the standard of care treatment for patients with metastatic melanoma (MM). The stimulator of interferon genes (STING) signaling pathway is critical in controlling immune responses to ICIs. Interferon (IFN)-γ-inducible protein 16 (IFI16) is a cytosolic DNA sensor that activates the STING signaling pathway. The link between IFI16 and STING signaling pathway on IFN-γ stimulation and the connection to ICIs response remains not completely understood.Deconvolution analyses were performed using the TCGA-SKCM, GSE91061, and PRJEB23709 public RNA sequencing (RNA-seq) data sets that contained RNA-seq for patients with MM. Functional assays combined with cytokine arrays were performed using MM cell lines to validate in silico data. Multiplex immunofluorescence was performed on untreated or pretreatment tumor samples from patients with MM.Deconvolution analysis showed that high-IFI16 levels in melanoma cells were associated with a good prognosis in patients with MM and positively correlated with M1-macrophage infiltration. Functional assays using MM cell lines demonstrated that IFI16 is a key molecule to sense cytosolic DNA and activate STING and nuclear factor kappa B (NF-κB) signaling pathways, independent of cyclic GMP-AMP synthase or absent in melanoma 2, on IFN-γ stimulation. IFI16 knockdown significantly decreased CXCL10 and ICAM1 secretion. EZH2 inhibitor reversed the repressive epigenetic control on IFI16 to promote STING and NF-κB signaling pathways on IFN-γ stimulation. Increased IFI16, ICAM1, and CXCL10 levels in tumor samples from patients with MM were positively correlated with M1-macrophage infiltration and a significantly better response to ICIs.This study identifies IFI16 as a key sensor during IFN-γ stimulation associated with ICI response, and it proposes the epigenetic EZH2 inhibitor as an alternative treatment strategy to overcome ICI resistance in patients with MM.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.