PO.TB10.02 · 肿瘤生物学
利用单细胞与空间转录组学解析食管鳞状细胞癌肿瘤发生和淋巴结转移中的肿瘤微环境动态
Deciphering tumor microenvironment dynamics in tumorigenesis and lymph node metastasis of esophageal squamous cell carcinoma using single-cell and spatial transcriptomics
该海报暂无可下载的资料
AACR 官方页面
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
食管鳞状细胞癌（ESCC）是一种侵袭性恶性肿瘤，诊断较晚且淋巴结（LN）转移倾向高。鉴于淋巴结受累对预后和治疗的重大影响，明确区分转移性淋巴结与原发肿瘤的细胞和分子特征至关重要。我们旨在整合单细胞RNA/TCR测序（scRNA/TCR-seq）与高分辨率空间转录组验证，描绘原发肿瘤与转移性淋巴结之间的肿瘤微环境（TME）动态。
我们对18例T1-2N0-1M0期ESCC患者的58份初治手术标本中的344,790个细胞进行了scRNA-seq。样本包括配对的肿瘤黏膜（TM）、正常黏膜（NM）、肿瘤相关淋巴结（TLN）和正常淋巴结（NLN）。对8例患者进行的scTCR-seq描绘了克隆轨迹和功能性T细胞状态。此外，使用CosMx 6K平台的空间转录组学分析了来自13例患者的34份标本（NLN、TLN和TM）中的3,493,957个细胞，实现了对特定区室细胞相互作用的原位验证。
我们的分析揭示了TM与TLN免疫格局之间的显著差异。TM表现出以调节性T细胞（TREGs）为主导的免疫抑制环境，以及CD8耗竭T细胞（TEXHs）中细胞毒性的急剧丧失。相比之下，TLN保留了部分功能性的TEXHs，其遵循两条轨迹：一条为前耗竭/中间耗竭路径，持续表达GZMB和PRF1；另一条为终末耗竭路径，表现出功能的陡然下降——这在TM中突出，但在TLN中减弱。TCR克隆型分析支持了这一点，因为TM-TLN共享克隆保留了细胞毒性，而TLN限定克隆则显示出较弱的效应程序，提示存在由抗原驱动、从原发肿瘤而来的迁移。髓系分析显示TREM2高表达巨噬细胞（M）在TLN中富集，而TM则以TREG-树突状细胞（DC）相互作用为特征。空间转录组学验证了这些区室化的抑制性回路，证实了TREM2高表达M与TREGs或TEXHs在TLN中的共定位。SPP1介导的这些细胞群之间的信号传导仅出现在TLN中，凸显了转移部位内生态位特异性的免疫调节相互作用。
这项整合的单细胞与空间转录组学研究凸显了驱动ESCC进展和LN转移的不同免疫调节程序。TLN中包含保留细胞毒性和再激活潜能的TEXHs，而TM则表现出功能的骤然崩溃。我们鉴定出区室特异性的抑制网络——TLN中TREM2高表达M介导的轴和TM中DC介导的轴——并经空间分析验证。这些发现为LN转移提供了机制性见解，并可能为ESCC的生物标志物开发、新辅助治疗优化和个体化免疫治疗提供参考。
查看英文原文 English abstract
Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with late diagnosis and high propensity for lymph node (LN) metastasis. Given the major prognostic and therapeutic impact of LN involvement, defining the cellular and molecular features distinguishing metastatic LNs from primary tumors is imperative. We aimed to delineate tumor microenvironment (TME) dynamics between primary tumors and metastatic LNs integrating single-cell RNA/TCR sequencing (scRNA/TCR-seq) with high-resolution spatial transcriptomic validation.
We performed scRNA-seq on 344,790 cells from 58 upfront surgical specimens of 18 stage T1-2N0-1M0 ESCC patients. Samples included paired tumor mucosa (TM), normal mucosa (NM), tumor-associated LNs (TLN), and normal LNs (NLN). scTCR-seq in 8 patients delineated clonal trajectories and functional T-cell states. Additionally, spatial transcriptomics using the CosMx 6K platform profiled 3,493,957 cells across 34 specimens (NLN, TLN, and TM) from 13 patients, enabling in situ validation of compartment-specific cellular interactions.
Our analysis revealed marked divergence between TM and TLN immune landscapes. TM showed an immunosuppressive milieu dominated by regulatory T cells (T REG s) and sharp loss of cytotoxicity in CD8 exhausted T cells (T EXH s). In contrast, TLN retained partially functional T EXH s following two trajectories: a pre/intermediate-exhausted path with sustained GZMB and PRF1 expression, and a terminally-exhausted path showing steep functional decline-prominent in TM but attenuated in TLN. TCR clonotype analysis supported this, as shared TM-TLN clones preserved cytotoxicity whereas TLN-restricted clones displayed weaker effector programs, suggesting antigen-driven trafficking from primary tumor. Myeloid profiling showed TREM2 high macrophages (M) enrichment in TLN, while TM featured T REG -dendritic cell (DC) interactions. Spatial transcriptomics validated these compartmentalized suppressive circuits, demonstrating colocalization of TREM2 high Ms with T REG s or T EXH s in TLN. SPP1-mediated signaling between these populations appeared exclusively in TLN, highlighting niche-specific immunoregulatory interactions within metastatic sites.
This integrated single-cell and spatial transcriptomic study highlights distinct immunoregulatory programs driving ESCC progression and LN metastasis. While TLNs contained T EXH s with preserved cytotoxicity and reinvigoration potential, TMs exhibited abrupt functional collapse. We identified compartment-specific suppressive networks-TREM2 high M-mediated axes in TLN and DC-mediated axes in TM-validated by spatial analysis. These findings offer mechanistic insight into LN metastasis and may inform biomarker development, neoadjuvant treatment optimization, and tailored immunotherapy in ESCC.
利益披露 Disclosure
T. Hong, None..
H. Na, None..
C. Lee, None..
Y. Yang, None..
H. Kim, None..
B. Park, None..
M. Hong, None..
H. Kim, None..
H. Kim, None..
D. Kim, None.