Single-cell landscape of undifferentiated pleomorphic sarcoma

Area of Science:

• Oncology
• Genomics
• Cell Biology

Background:

• Undifferentiated pleomorphic sarcoma (UPS) is an aggressive soft tissue tumor with poor prognosis.
• The cellular identity and heterogeneity within UPS tumors remain largely unknown.
• Understanding UPS heterogeneity is crucial for developing effective therapies.

Purpose of the Study:

• To comprehensively characterize the cellular landscape and heterogeneity of Undifferentiated Pleomorphic Sarcoma (UPS).
• To identify potential therapeutic targets within UPS tumors.
• To investigate the role of the tumor microenvironment in UPS progression.

Main Methods:

• Single-cell RNA sequencing of 79,569 individual UPS cells.
• Bioinformatic analysis to identify cell clusters and predict prognostic value.
• Ligand-receptor interaction analysis to map cellular communication.
• In vitro and in vivo studies using patient-derived xenografts and EGFR blockade.

Main Results:

• Eight major cell clusters were identified, revealing UPS originates from mesenchymal stem cells (MSCs) with undifferentiated subclusters.
• Functional heterogeneity in malignant cells and the immune microenvironment was characterized.
• Fused cells expressing monocyte/macrophase markers were detected.
• Abundant cellular interactions involving EGFR and VEGFR were identified.
• Positive EGFR expression (73% of patients) correlated with poor prognosis.
• EGFR blockade with cetuximab inhibited tumor growth in a xenograft model.

Conclusions:

• Transcriptomic analysis provides a detailed map of UPS intratumor heterogeneity.
• Mesenchymal stem cell origin and distinct subclusters contribute to UPS complexity.
• EGFR signaling is a key pathway in UPS, presenting a potential therapeutic target.