PO.TB10.11 · 肿瘤生物学
肝外胆管癌中癌症相关成纤维细胞微龛的空间转录组学分析
Spatial transcriptomic profiling of cancer-associated fibroblast niches in extrahepatic cholangiocarcinoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景。胆管癌（CCA）是一种罕见且高度致死的恶性肿瘤，其特征为含有癌症相关成纤维细胞（CAF）的致密纤维增生性基质。虽然CAF在肝内CCA中已被广泛研究，但其对肝外（e）CCA中TME重塑及化学免疫治疗（CIT）疗效的影响仍大多未被探索。对eCCA中的CAF进行全面表征十分必要，以鉴定能够改善CIT疗效的治疗策略——迄今为止，CIT疗效在这些患者中仍然有限。
方法。对8例接受durvalumab + 顺铂/吉西他滨治疗的晚期eCCA患者的初治肿瘤标本进行空间转录组学分析。共采用GeoMx数字空间分析仪对126个微区域进行分析，并根据pan-CK和ACTA2/alphaSMA染色分类如下：肿瘤（CK+alphaSMA-）、远端和瘤周CAF富集基质（CK-alphaSMA+）或瘤周alphaSMA阴性基质（CK-alphaSMA-）。
结果。alphaSMA染色揭示所有eCCA中存在显著的基质异质性，在同一样本中一些肿瘤巢被致密的CAF富集基质包围，而另一些则被alphaSMA-细胞包围。根据CD45染色，所有样本均被分类为免疫荒漠型或免疫排斥型，无瘤内免疫浸润。GSEA显示，在CAF富集区域和被alphaSMA+细胞包围的肿瘤细胞中，上皮-间质转化（EMT）特征呈正富集，同时伴有免疫激活和IFN响应通路的下调。有趣的是，与远端CAF区域相比，编码基质金属蛋白酶11（MMP11）和分泌型磷蛋白1（SPP1）的基因在邻近肿瘤巢的CAF富集区域中过度表达，提示CAF是基质MMP11和SPP1的主要来源。最后，使用CellChat工具进行的受体-配体相互作用建模显示，CAF富集区域通过分泌参与EMT重塑、肿瘤进展和免疫抑制的因子（即POSTN、HGF、WNT5A、TGFB1、INHBA、SPP1）与相邻肿瘤细胞表现出显著的相互作用。
结论。我们的研究结果提示，MMP11+SPP1+CAF可能促进eCCA中纤维增生性屏障的形成，从而阻碍免疫细胞的瘤内募集并限制CIT疗效。正在进行的分析旨在进一步表征CAF状态和CAF-肿瘤串扰，以支持开发增强eCCA中CIT响应性的策略。
查看英文原文 English abstract
Background. Cholangiocarcinoma (CCA) is a rare and highly lethal malignancy characterized by a dense desmoplastic stroma containing cancer-associated fibroblasts (CAF). While CAF have been extensively studied in intrahepatic CCA, their impact on TME remodeling and chemo-immunotherapy (CIT) efficacy in extrahepatic (e) CCA remains largely unexplored. A comprehensive characterization of CAF in eCCA is needed to identify therapeutic strategies able to improve the CIT efficacy, that, so far, is limited in these patients.
Methods. Spatial transcriptomics was performed on treatment-naive tumor specimens from 8 patients with advanced eCCA treated with durvalumab + cisplatin/gemcitabine. A total of 126 microregions were profiled with the GeoMx Digital Spatial Profiler and classified based on pan-CK and ACTA2/alphaSMA straining, as follow: tumor (CK + alphaSMA - ), distant and peritumor CAF-enriched stroma (CK - alphaSMA + ) or peritumor alphaSMA-negative stroma (CK - alphaSMA - ).
Results. alphaSMA staining revealed marked stromal heterogeneity across all eCCA, with some tumor nests surrounded by a dense CAF-enriched stroma and others by alphaSMA - cells within the same sample. Based on CD45 staining all samples were classified as immune-desert or -excluded, with no intratumoral immune infiltration. GSEA showed a positive enrichment of epithelial-mesenchymal transition (EMT) signatures, coupled with the downregulation of immune activation and IFN response pathways, in both CAF-enriched regions and tumor cells surrounded by alphaSMA + cells. Interestingly, genes encoding matrix metalloproteinase 11 (MMP11) and secreted phosphoprotein 1 (SPP1) were found overrepresented in CAF-enriched regions adjacent to tumor nests, as compared to distant CAF regions, suggesting CAF as major source of stromal MMP11 and SPP1. Finally, receptor-ligand interaction modeling performed using the CellChat tool showed that CAF-enriched regions exhibited significant interactions with adjacent tumor cells, throughout the secretion of factors involved in EMT-remodeling, tumor progression and immunosuppression (i.e., POSTN, HGF, WNT5A, TGFB1, INHBA, SPP1).
Conclusions. Our findings suggest that MMP11 + SPP1 + CAF may promote desmoplastic barrier formation in eCCA, thereby hindering intratumoral recruitment of immune cells and limiting CIT efficacy. Ongoing analyses aim to further characterize CAF states and CAF-tumor crosstalk to support the development of strategies to enhance CIT responsiveness in eCCA.
利益披露 Disclosure
G. Petroni, None..
S. Romagnoli, None..
D. Lavacchi, None..
G. Massaro, None..
F. Rizzo, None..
E. Alexandrova, None..
C. Winchler, None..
A. Carleo, None..
G. Grazi, None..
D. Rossini, None..
L. Messerini, None..
M. Benelli, None..
S. Pillozzi, None..
L. Antonuzzo, None.