理解癌症信号通路如何促进免疫抑制性程序，以维持对免疫检查点阻滞（ICB）的获得性或原发性抵抗，是提高免疫疗法效果的关键一步。干扰素（IFN）通路是影响ICB应答的一种通路，可能既有害又有益。免疫感受器基因RIG-I通过扰乱肌动蛋白细胞骨架而激活，诱导IFN活化和分泌。肿瘤细胞的肌动蛋白细胞骨架调控蛋白hMENA以及其亚型是不同实体肿瘤中的一个关键信号中心，最近提出其作为调控编码免疫调节性分泌蛋白基因的转录因子的作用。当hMENA在表达具有低水平上皮特异性hMENA11a亚型的肿瘤细胞时，标识出非小细胞肺癌（NSCLC）患者的预后差。目标是确定由hMENA11a下调调控的与NSCLC中ICB应答相关的癌症内在和外在通路。在这里，我们提出了一种由hMENA11a下调驱动的ICB抵抗的潜在新机制。通过RNA-Seq，ATAC-Seq，流式细胞仪和生化检测对hMENA11a下调的效应进行了测试。使用富含hMENA定制探针的Nanostring IO 360面板对接受ICB治疗的患者肿瘤组织进行了分析。使用OAK和POPLAR数据集对我们的发现队列进行了验证。转录组和生化分析表明，hMENA11a的耗竭导致IFN通路激活，通过RIG-I产生不同的炎症介质，包括IFNβ，维持肿瘤PD-L1水平增加，并激活肿瘤细胞与特定巨噬细胞亚群之间的旁分泌循环，促进上皮间质转化（EMT）。值得注意的是，当我们将结果转化到NSCLC ICB治疗患者的临床环境中时，转录组分析显示hMENA11a的低表达，IFN靶基因的高表达以及高巨噬细胞评分可识别出对ICB治疗耐药的患者。总的来说，这些数据确定了肌动蛋白细胞骨架调控蛋白hMENA11a在调节癌细胞内部I型IFN信号和促进肿瘤相关巨噬细胞以及有利于EMT的外部机制方面的新功能。这些数据突出了肌动蛋白细胞骨架扰动在激活免疫抑制性通路方面的作用，该通路可能参与NSCLC对ICB的耐药性。© 作者（或其雇主）2023。在CC BY-NC许可下允许复用。不可商业复用。由BMJ出版。

Understanding how cancer signaling pathways promote an immunosuppressive program which sustains acquired or primary resistance to immune checkpoint blockade (ICB) is a crucial step in improving immunotherapy efficacy. Among the pathways that can affect ICB response is the interferon (IFN) pathway that may be both detrimental and beneficial. The immune sensor retinoic acid-inducible gene I (RIG-I) induces IFN activation and secretion and is activated by actin cytoskeleton disturbance. The actin cytoskeleton regulatory protein hMENA, along with its isoforms, is a key signaling hub in different solid tumors, and recently its role as a regulator of transcription of genes encoding immunomodulatory secretory proteins has been proposed. When hMENA is expressed in tumor cells with low levels of the epithelial specific hMENA11a isoform, identifies non-small cell lung cancer (NSCLC) patients with poor prognosis. Aim was to identify cancer intrinsic and extrinsic pathways regulated by hMENA11a downregulation as determinants of ICB response in NSCLC. Here, we present a potential novel mechanism of ICB resistance driven by hMENA11a downregulation.Effects of hMENA11a downregulation were tested by RNA-Seq, ATAC-Seq, flow cytometry and biochemical assays. ICB-treated patient tumor tissues were profiled by Nanostring IO 360 Panel enriched with hMENA custom probes. OAK and POPLAR datasets were used to validate our discovery cohort.Transcriptomic and biochemical analyses demonstrated that the depletion of hMENA11a induces IFN pathway activation, the production of different inflammatory mediators including IFNβ via RIG-I, sustains the increase of tumor PD-L1 levels and activates a paracrine loop between tumor cells and a unique macrophage subset favoring an epithelial-mesenchymal transition (EMT). Notably, when we translated our results in a clinical setting of NSCLC ICB-treated patients, transcriptomic analysis revealed that low expression of hMENA11a, high expression of IFN target genes and high macrophage score identify patients resistant to ICB therapy.Collectively, these data establish a new function for the actin cytoskeleton regulator hMENA11a in modulating cancer cell intrinsic type I IFN signaling and extrinsic mechanisms that promote protumoral macrophages and favor EMT. These data highlight the role of actin cytoskeleton disturbance in activating immune suppressive pathways that may be involved in resistance to ICB in NSCLC.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.