PO.TB10.12 · 肿瘤生物学
肿瘤微环境的机械重塑通过EGR3-ALOX5信号通路促进乳腺癌及中性粒细胞相关免疫抑制
Mechanical remodeling of the tumor microenvironment promotes breast cancer and neutrophil-ssociated immunosuppression through ERG3-ALOX5 signaling
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摘要 Abstract
中文摘要
背景：肿瘤细胞外基质（ECM）硬度与乳腺癌进展和免疫逃逸相关。机械信号如何通过免疫微环境影响肿瘤免疫逃逸的机制尚不清楚。本研究探讨ECM硬度如何通过"机械信号-基质-中性粒细胞重编程-肿瘤免疫逃逸"轴影响免疫格局和肿瘤进展。
方法：采用超声弹性成像评估乳腺癌患者的ECM硬度，并与预后相关联。在临床前模型中，采用小鼠异种移植和三维细胞培养研究ECM硬度对肿瘤生长和免疫细胞浸润的影响。通过单细胞RNA测序（scRNA-seq）和多色免疫荧光分析不同硬度微环境下的免疫细胞组成。通过基因干扰、Ca²⁺信号阻断和ChIP-seq调控Piezo1-Ca²⁺-EGR3通路，研究基质机械信号在中性粒细胞趋化中的作用。在小鼠模型中评估EGR3抑制联合PD-L1治疗的疗效。
结果：单细胞RNA测序显示高硬度微环境中肿瘤相关中性粒细胞（TANs）和调节性T细胞（Tregs）显著富集，而CD8⁺ T细胞减少。这种重塑与PD-L1、Arg1和TGF-beta的上调相关，提示免疫逃逸。高硬度环境中的TANs表现出增强的免疫抑制特性，与肿瘤免疫逃逸相关。ECM硬度升高通过Piezo1介导的Ca²⁺内流提高肿瘤细胞组蛋白乙酰化，促进EGR3转录。ChIP-seq分析显示EGR3激活ALOX5，驱动LTB4合成并增强肿瘤细胞向TANs的趋化。本研究揭示ECM硬度通过Piezo1-Ca²⁺-EGR3-ALOX5-LTB4通路调控中性粒细胞趋化，促进免疫逃逸。功能实验表明，抑制EGR3或ALOX5/LTB4可损害中性粒细胞趋化和免疫逃逸。在小鼠模型中，PD-L1治疗联合抑制EGR3或ALOX5/LTB4通路可显著抑制肿瘤生长。
结论：ECM硬度通过Piezo1-Ca²⁺-EGR3-ALOX5-LTB4轴促进乳腺癌免疫逃逸，形成驱动肿瘤进展的免疫抑制微环境。这些发现为乳腺癌免疫治疗提示了新的治疗靶点。
查看英文原文 English abstract
Background: Tumor extracellular matrix (ECM) stiffness is linked to breast cancer progression and immune evasion. The mechanisms by which mechanical signals influence tumor immune evasion through the immune microenvironment remain unclear. This study explores how ECM stiffness impacts the immune landscape and tumor progression via the “mechanical signal-matrix-neutrophil reprogramming-tumor immune escape” axis.
Methods: ECM stiffness in breast cancer patients was assessed using ultrasound elastography, with correlation to prognosis. In preclinical models, a mouse xenograft and 3D cell cultures were used to investigate the effects of ECM stiffness on tumor growth and immune cell infiltration. Single-cell RNA sequencing (scRNA-seq) and multicolor immunofluorescence analyzed immune cell composition in varying stiffness microenvironments. The role of stromal mechanical signals in neutrophil chemotaxis was studied using Piezo1-Ca²⁺-EGR3 pathway modulation through gene interference, Ca²⁺ signaling blockade, and ChIP-seq. The efficacy of combined EGR3 inhibition and PD-L1 therapy was evaluated in a mouse model.
Results: Single-cell RNA sequencing revealed significant enrichment of tumor-associated neutrophils (TANs) and regulatory T cells (Tregs) in high-stiffness microenvironments, with a reduction in CD8⁺ T cells. This remodeling was linked to upregulation of PD-L1, Arg1, and TGF-beta, suggesting immune escape. TANs in high-stiffness environments exhibited enhanced immunosuppressive traits, correlating with tumor immune evasion. Increased ECM stiffness elevated tumor cell histone acetylation via Piezo1-mediated Ca²⁺ influx, promoting EGR3 transcription. ChIP-seq analysis showed that EGR3 activates ALOX5, driving LTB4 synthesis and enhancing tumor cell chemotaxis toward TANs. The study reveals that ECM stiffness regulates neutrophil chemotaxis via the Piezo1-Ca²⁺-EGR3-ALOX5-LTB4 pathway, promoting immune evasion. Functional assays demonstrated that inhibiting EGR3 or ALOX5/LTB4 impaired neutrophil chemotaxis and immune evasion. In a mouse model, combining PD-L1 therapy with inhibition of the EGR3 or ALOX5/LTB4 pathways significantly suppressed tumor growth.
Conclusion: ECM stiffness promotes immune evasion in breast cancer via the Piezo1-Ca²⁺-EGR3-ALOX5-LTB4 axis, creating an immunosuppressive microenvironment that drives tumor progression. These findings suggest new therapeutic targets for breast cancer immunotherapy.
利益披露 Disclosure
L. Tang, None..
L. Wei, None..
J. Lu, None..
S. Wu, None.