Unravelling the role of immune cells and FN1 in the recurrence and therapeutic process of skull base chordoma

Abstract

BackgroundSkull 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.MethodsTo 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.ResultsPromoting 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.ConclusionOur 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.

MicroRNA‑1224 inhibits cell proliferation by downregulating CBX3 expression in chordoma

“…However, chordoma has a complex local anatomy near important neural vasculature, so surgical removal is difficult. Therefore, chordoma has a poor prognosis, with a postoperative recurrence rate as high as 30-85% (22). It is estimated that ~20% of chordomas will relapse within 1 year after surgery and 40-60% of patients will have distant metastasis.…”

Fibroblast-based FN1CFD contributes to parathyroid cancer identification using integrated analysis

“…Gene FN1 encodes glycoprotein and has been demonstrated as an extracellular matrix protein, involved in cell adhesion and migration process [37][38][39]. The adverse role of FN1 in promoting the invasion and metastasis ability of cancer cells has been veri ed in vivo and in vitro [39].…”

“…Gene FN1 encodes glycoprotein and has been demonstrated as an extracellular matrix protein, involved in cell adhesion and migration process [37][38][39]. The adverse role of FN1 in promoting the invasion and metastasis ability of cancer cells has been veri ed in vivo and in vitro [39]. Also, recent sc-RNAseq analysis reported that FN1 bridged the crosstalk between macrophage [40] or tumor epithelial cell [41] and broblast, indicating that FN1 was a pivotal medium that controls the TME cell-cell network.…”