PO.TB10.12 · 肿瘤生物学
基质硬度通过PIEZO1-DCLK1-STAT5B通路重塑免疫抑制性肿瘤微环境
Matrix stiffness remodels the immunosuppressive tumor microenvironment via the PIEZO1-DCLK1-STAT5B pathway
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景 胰腺导管腺癌（PDAC）的5年生存率极低（8%），这在很大程度上归因于其致密的纤维化基质，形成高硬度的微环境。这一生物力学特征加剧免疫抑制并促进免疫逃逸，但基质硬度衍生的机械信号转化为免疫抑制线索的分子机制仍未明确。本研究旨在揭示PDAC中关键的机械转导-免疫串扰通路，并提供新的治疗靶点。
方法 我们利用已建立的可调节细胞外基质（ECM）硬度模型（体外3D培养和体内原位移植）作为核心研究平台。采用包括CRISPR-Cas9基因编辑、多组学（蛋白修饰组学、CUT&Tag-seq）、单细胞RNA测序和光谱流式细胞术在内的整合方法，以剖析机械转导通路及其对肿瘤微环境的调控作用。
结果 我们确定了一条介导硬度诱导免疫抑制的新型PIEZO1-Ca²⁺-DCLK1-STAT5B轴。高基质硬度特异性激活机械敏感离子通道PIEZO1，触发Ca²⁺内流。细胞内Ca²⁺通过双重机制上调并激活DCLK1：抑制ANAPC5/PSMA7介导的泛素化并促进HPCAL1依赖的丝氨酸磷酸化。激活的DCLK1通过其富含丝氨酸/脯氨酸的连接结构域（DCLK1）和SH2结构域（STAT5B）与STAT5B结合，诱导STAT5B磷酸化和核转位。核内STAT5B在超级增强子（以H3K27ac/H3K4me1标记）的调控下，转录激活免疫抑制基因（TGF-beta、PD-L1、KRAS），最终塑造出以Tregs、MDSCs和M2巨噬细胞浸润增加以及效应T细胞功能受损为特征的免疫抑制微环境。初步数据证实，高硬度上调了该轴的所有组分，而抑制STAT5B显著降低了TGF-beta/PD-L1/KRAS表达和免疫抑制细胞浸润。
结论 本研究首次揭示了PDAC中一条生物力学驱动的免疫抑制通路，在基质硬度和免疫逃逸之间建立了直接联系。PIEZO1-Ca²⁺-DCLK1-STAT5B轴为逆转免疫抑制和提高PDAC治疗疗效提供了新的治疗靶点。
查看英文原文 English abstract
Background Pancreatic ductal adenocarcinoma (PDAC) has an abysmal 5-year survival rate (8%), largely attributed to its dense fibrotic stroma that forms a high-stiffness microenvironment. This biomechanical feature exacerbates immunosuppression and promotes immune escape, but the molecular mechanism by which matrix stiffness-derived mechanical signals convert into immunosuppressive cues remains undefined. This study aims to uncover the key mechanotransduction-immunity crosstalk pathway in PDAC and provide novel therapeutic targets.
Methods We utilized our established adjustable extracellular matrix (ECM) stiffness models (in vitro 3D culture and in vivo orthotopic transplantation) as core research platforms. Integrated approaches including CRISPR-Cas9 gene editing, multi-omics (protein modification omics, CUT&Tag-seq), single-cell RNA sequencing, and spectral flow cytometry were employed to dissect the mechanotransduction pathway and its regulatory effect on the tumor microenvironment.
Results We identified a novel PIEZO1-Ca²⁺-DCLK1-STAT5B axis mediating stiffness-induced immunosuppression. High matrix stiffness specifically activated the mechanosensitive ion channel PIEZO1, triggering Ca²⁺ influx. Intracellular Ca²⁺ upregulated and activated DCLK1 via dual mechanisms: inhibiting ANAPC5/PSMA7-mediated ubiquitination and promoting HPCAL1-dependent serine phosphorylation. Activated DCLK1 bound to STAT5B through its serine/proline-rich linker domain (DCLK1) and SH2 domain (STAT5B), inducing STAT5B phosphorylation and nuclear translocation. Nuclear STAT5B, under the regulation of super-enhancers (marked by H3K27ac/H3K4me1), transcriptionally activated immunosuppressive genes (TGF-beta, PD-L1, KRAS), ultimately shaping an immunosuppressive microenvironment characterized by increased infiltration of Tregs, MDSCs, and M2 macrophages, and impaired effector T cell function. Preliminary data confirmed that high stiffness upregulated all components of this axis, and STAT5B inhibition significantly reduced TGF-beta/PD-L1/KRAS expression and immunosuppressive cell infiltration.
Conclusion This study is the first to uncover a biomechanics-driven immunosuppression pathway in PDAC, establishing a direct link between matrix stiffness and immune escape. The PIEZO1-Ca²⁺-DCLK1-STAT5B axis provides a novel therapeutic target for reversing immunosuppression and improving PDAC therapeutic efficacy.
利益披露 Disclosure
L. Wei, None..
L. Tang, None..
J. Lu, None..
T. Hu, None..
S. Chen, None..
Z. Wang, None..
H. Zhang, None.