Dadey Rebekah E, Li Ruxuan, Griner Jake, Chen Jie, Singh Arjun, Isett Brian, Newman Sarah, Augustin Ryan, Li Aofei, Manning Joseph A, Monga Satdarshan P, Singhi Aatur, Geller David A A, Krieg Carsten, Zervantonakis Ioannis K, Luke Jason John, Bao Riyue
UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, USA.
Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
J Immunother Cancer. 2025 Jun 15;13(6):e011537. doi: 10.1136/jitc-2025-011537.
Immune checkpoint inhibitors (ICI) have improved patient outcomes in hepatocellular carcinoma (HCC); however, most patients do not experience durable benefit. The non-T cell-inflamed tumor microenvironment, characterized by limited CD8 T-cell infiltration, reduced dendritic cell function, and low interferon-γ-associated gene expression, is associated with a lower likelihood of response to ICI. To nominate new therapeutic targets for overcoming ICI resistance in HCC, we conducted a large-scale multiomic analysis on 900+human specimens (RNA sequencing (RNA-seq), proteomics) and 31 tumor single-cell (sc) RNA-seq samples, with tissue validation through imaging mass cytometry (IMC) and spatial lipidomics by matrix-assisted laser desorption/ionization (MALDI), with experimental investigation by in vitro CD8 T-cell recruitment and macrophage polarization functional assays using three-dimensional (3D) co-culture models. We discovered 32 oncogenic pathways associated with immune exclusion, with sterol regulatory element binding protein 1 (SREBP1, encoded by ) as a hub regulator. scRNA-seq analysis showed that SREBP1 signaling is associated with enriched lipid biogenesis pathways in tumor cells, elevated immunosuppressive markers in macrophages, and diminished CD8 T-cell infiltration. Integration of IMC and MALDI images revealed distinct lipid species differentially abundant in tumor regions with low versus high CD8 T cell infiltration. Functional studies in a 3D in vitro tumor-immune co-culture system demonstrated that CRISPR-mediated knockout (KO) in HepG2 cells reduced monocyte recruitment, decreased expression of the protumorigenic CD206 marker in macrophages, and enhanced CD8 T-cell migration compared with wild-type (WT) (p<0.0001). RNA-seq of KO versus WT tumor cells confirmed suppression of lipid biosynthesis genes.Our findings nominate an atlas of tumor-intrinsic drivers of immune exclusion, particularly SREBP1 via pro-tumorigenic macrophage (M2-like) reprogramming. These pathways may represent novel therapeutic targets to enhance antitumor immunity and deserve further study as targeted therapy candidates to enhance ICI in HCC.
免疫检查点抑制剂（ICI）已改善了肝细胞癌（HCC）患者的预后；然而，大多数患者并未获得持久的益处。以CD8 T细胞浸润受限、树突状细胞功能降低和干扰素-γ相关基因表达低下为特征的非T细胞炎性肿瘤微环境，与对ICI产生应答的可能性较低相关。为了确定克服HCC中ICI耐药性的新治疗靶点，我们对900多个人类标本（RNA测序（RNA-seq）、蛋白质组学）和31个肿瘤单细胞（sc）RNA-seq样本进行了大规模多组学分析，并通过成像质谱流式细胞术（IMC）和基质辅助激光解吸/电离（MALDI）进行空间脂质组学的组织验证，同时使用三维（3D）共培养模型通过体外CD8 T细胞募集和巨噬细胞极化功能试验进行实验研究。我们发现了32条与免疫排斥相关的致癌途径，其中固醇调节元件结合蛋白1（SREBP1，由[具体基因名称]编码）作为核心调节因子。scRNA-seq分析表明，SREBP1信号传导与肿瘤细胞中丰富的脂质生物合成途径、巨噬细胞中免疫抑制标志物升高以及CD8 T细胞浸润减少相关。IMC和MALDI图像的整合揭示了在CD8 T细胞浸润低与高的肿瘤区域中差异丰富的不同脂质种类。在3D体外肿瘤-免疫共培养系统中的功能研究表明，与野生型（WT）相比，HepG2细胞中CRISPR介导的[基因名称]敲除（KO）减少了单核细胞募集，降低了巨噬细胞中促肿瘤性CD206标志物的表达，并增强了CD8 T细胞迁移（p<0.0001）。KO与WT肿瘤细胞的RNA-seq证实了脂质生物合成基因的抑制。我们的研究结果确定了免疫排斥的肿瘤内在驱动因素图谱，特别是通过促肿瘤性巨噬细胞（M2样）重编程的SREBP1。这些途径可能代表增强抗肿瘤免疫力的新治疗靶点，作为增强HCC中ICI的靶向治疗候选物值得进一步研究。
