PO.EN01.01 · 内分泌肿瘤
空间免疫分析揭示甲状腺乳头状微小癌中不同的肿瘤微环境
Spatial immune profiling reveals varying tumor microenvironments in papillary thyroid microcarcinoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
引言：甲状腺乳头状微小癌（PTMC）通常呈惰性，但高达10%可出现具有临床意义的淋巴结转移，极少数出现远处转移（M1）。本研究分析转移性与非转移性PTMC的转录组学特征和空间解析的肿瘤微环境图谱，以完善风险分层。
方法：选取诊断为惰性非转移性（N0/Nx）PTMC和原发肿瘤（PT）转移至颈侧淋巴结或远处部位（N1b/M1）的患者，对PT及相邻正常组织进行RNA测序。使用CD8a和CD20抗体进行多重免疫荧光染色。图像以单盲方式使用HALO（Indica Labs）进行分析，根据数据分布采用t检验或Mann-Whitney检验测试差异空间表达。使用NanoString（Bruker）GeoMX®平台进行空间蛋白质组学分析，包括用于nCounter分析的人类免疫细胞图谱、分型与激活状态以及MAPK信号蛋白模块。蛋白表达数据经log2转换，组间差异表达采用Welch双样本t检验并进行Benjamini-Hochberg校正。校正后p<0.05且绝对log2倍数变化>0.5的蛋白被视为显著。
结果：N0/Nx和N1b/M1研究队列分别包含17例和19例患者。两组间临床特征无差异，即年龄（p=0.64）、性别（p=0.24）和PT中位大小（p=0.27）。转录组分析表明，与N0/Nx组相比，N1b/M1组中参与B细胞激活的通路显著下调，而PT中（p=0.43）及PT边缘（p=0.92）的B细胞（CD20+/CD8a−）浸润无显著差异。然而，与N0/Nx相比，细胞毒性T细胞（CD8a+/CD20-）显著聚集于N1b/M1组PT的边缘（p=0.007）。空间免疫分析显示，N1b/M1 PT的T细胞浸润（CD3；padj=0.02）显著高于N0/Nx肿瘤，并表现出免疫逃逸分子PD-L2的明显表达（padj=0.02）。N1b PT还显示出高干性（CD44，padj=0.001）。与N1b PT相比，M1显示出更高的免疫逃逸（PD-L1，padj=0.01；PD-L2，padj=0.049）。
结论：易转移的PTMC以增强的干性、T细胞浸润增加以及伴随的免疫逃逸分子上调为特征，提示免疫逃逸可能在转移的发病机制中发挥关键作用。
查看英文原文 English abstract
Introduction: Papillary thyroid microcarcinomas (PTMC) are usually indolent, but up to 10% present with clinically significant lymph node metastases or very rarely with distant metastases (M1). This study analyzes transcriptomic signatures and spatially resolved tumor microenvironment profiles in metastatic versus non-metastatic PTMC to refine risk stratification.
Methods: Patients diagnosed with indolent non-metastatic (N0/Nx) PTMCs and with primary tumors (PT) metastatic to the lateral neck lymph nodes or distant sites (N1b/M1) were selected, and RNA sequencing was done on PT and adjacent normal tissues. Multiplex immunofluorescence was performed, staining using CD8a and CD20 antibodies. Images were analyzed in a single-blinded manner using HALO (Indica Labs), and differential spatial expression was tested using a t-test or a Mann-Whitney test, depending on data distribution. Spatial proteomic profiling was performed using the NanoString (Bruker) GeoMX® platform, including Human Immune Cell Profiling, Typing and Activation Status, and MAPK Signaling Protein Modules for the nCounter analysis. Protein expression data were log2-transformed, and between-groups differential expression was assessed using Welch's two-sample t-tests with Benjamini-Hochberg adjustment. Proteins with adjusted p<0.05 and absolute log2 fold-change >0.5 were considered significant.
Results: The N0/Nx and N1b/M1 study cohorts consisted of 17 and 19 patients, respectively. No difference in the clinical characteristics, viz., age (p=0.64), sex (p=0.24), and median PT size (p=0.27), was found between the groups. Transcriptome analysis indicated significant downregulation of pathways involved in the B cell activation without a significant difference in B cell (CD20 + /CD8a ‑ ) infiltration in the PT (p=0.43) nor in the PT rims (p=0.92) from the N1b/M1 compared to N0/Nx group. However, cytotoxic T cells (CD8a + /CD20 - ) significantly populated the rims of the PT from N1b/M1 group compared to N0/Nx (p=0.007). Spatial immune profiling revealed that N1b/M1 PT had significantly higher T-cell infiltration (CD3; padj=0.02) than N0/Nx tumors and showed pronounced expression of the immune evasion molecule PD-L2 (padj=0.02). N1b PT also showed high stemness (CD44, padj=0.001). Compared to N1b PT, M1 showed higher immune evasion (PD-L1, padj=0.01; PD-L2, padj=0.049).
Conclusion: Metastasis-prone PTMC is characterized by enhanced stemness, and increased T cell infiltration, accompanied by upregulation of immune evasion molecules, suggesting that immune evasion may play a critical role in pathogenesis of metastases.
利益披露 Disclosure
R. Sarkar, None..
S. Thakur, None..
G. Fridell, None..
E. Edmondson, None.