颅底脊索瘤是一种罕见的侵袭性骨肿瘤，复发的可能性很高。原发性和复发性病变之间单细胞的根本差异仍然知之甚少，阻碍了有效治疗方法的开发。为了了解原发性和复发性脊索瘤之间单细胞的差异，我们进行了单细胞 RNA 测序和 T 细胞/ B 细胞受体 (BCR) 测序。这使我们能够描绘出两种类型的肿瘤细胞（肿瘤浸润淋巴细胞、骨髓细胞、成纤维细胞和 B 细胞）之间的差异。检测并比较肿瘤类型之间的拷贝数变异（CNV）以评估异质性。对选定的样品进行免疫组织化学分析以验证蛋白质表达。荧光原位杂交实验、Transwell 检测和异种移植小鼠模型有助于验证纤连蛋白 1 (FN1) 在脊索瘤中的作用。促进自然杀伤 (NK) 细胞和 CD8_GZMK T 细胞功能或抑制 CD8_GZMK T 细胞向 CD8_ZNF683 T 细胞的转化促进自然杀伤 T (NKT) 细胞向 NK 细胞的转化是预防脊索瘤复发的有前景的策略。此外，抑制肿瘤相关巨噬细胞 (TAM) 的 M2 样活性可能是一种有效的方法。具有高度富集的抗原呈递特征的抗原呈递癌症相关成纤维细胞（apCAF）和树突状细胞（DC）在原发性脊索瘤中富集。复发性脊索瘤中浆细胞和 BCR 克隆型较少。值得注意的是，与原发性脊索瘤相比，复发性脊索瘤中的 FN1 表达上调，具有更多的 CNV，并且由肿瘤、巨噬细胞、CD4 T 细胞、CD8 T 细胞和成纤维细胞高度分泌。最后，FN1在体内和体外增强了脊索瘤的侵袭和增殖。我们对原发性和复发性脊索瘤的微环境的全面了解为脊索瘤复发的机制提供了深入的见解。 FN1 是脊索瘤治疗的重要靶点。© 2023 作者。约翰·威利出版的《临床与转化医学》

Skull base chordoma is a rare and aggressive tumour of the bone that has a high likelihood of recurrence. The fundamental differences in single cells between primary and recurrent lesions remain poorly understood, impeding development of effective treatment approaches.To obtain an understanding of the differences in single cells between primary and recurrent chordomas, we performed single-cell RNA sequencing and T-cell/B-cell receptor (BCR) sequencing. This allowed us to delineate the differences between the two types of tumour cells, tumour-infiltrating lymphocytes, myeloid cells, fibroblasts and B cells. Copy number variants (CNVs) were detected and compared between the tumour types to assess heterogeneity. Selected samples were subjected to immunohistochemistry to validate protein expression. Fluorescence in situ hybridisation experiments, Transwell assays and xenograft mouse models helped verify the role of fibronectin 1 (FN1) in chordoma.Promoting natural killer (NK) cell and CD8_GZMK T-cell function or inhibiting the transformation of CD8_GZMK T cells to CD8_ZNF683 T cells and promoting the transformation of natural killer T (NKT) cells to NK cells are promising strategies for preventing chordoma recurrence. Additionally, inhibiting the M2-like activity of tumour-associated macrophages (TAMs) could be an effective approach. Antigen-presenting cancer-associated fibroblasts (apCAFs) and dendritic cells (DCs) with high enrichment of the antigen-presenting signature were enriched in primary chordomas. There were fewer plasma cells and BCR clonotypes in recurrent chordomas. Remarkably, FN1 was upregulated, had more CNVs, and was more highly secreted by tumours, macrophages, CD4 T cells, CD8 T cells and fibroblasts in recurrent chordoma than in primary chordoma. Finally, FN1 enhanced the invasion and proliferation of chordomas in vivo and in vitro.Our comprehensive picture of the microenvironment of primary and recurrent chordomas provides deep insights into the mechanisms of chordoma recurrence. FN1 is an important target for chordoma therapy.© 2023 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.