Deciphering head and neck cancer microenvironment: Single-cell and spatial transcriptomics reveals human...

Area of Science:

• Oncology
• Virology
• Molecular Biology
• Immunology

Background:

• Human papillomavirus (HPV) is a significant cause of head and neck squamous cell carcinoma (HNSCC).
• The incidence of HPV-negative HNSCC is rising, necessitating a deeper understanding of its tumor microenvironment.
• The role of the tumor microenvironment in viral oncogenesis and metastasis requires further investigation.

Purpose of the Study:

• To investigate the molecular and cellular differences between primary tumors (PTs) and lymph node metastatic tumors (LNMTs) in HNSCC based on HPV status.
• To explore the impact of the tumor microenvironment on HPV-associated and HPV-negative HNSCC.
• To identify key molecular players and pathways involved in HNSCC progression and metastasis.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) were employed on matched PT and LNMT samples from HPV-negative and HPV-positive patients.
• Integrative analysis of scRNA-seq and ST data was performed.
• Experimental validation, including gene knockdown and immunohistochemistry, was used to confirm findings.

Main Results:

• HPV-positive tissues showed abundant lymphoid cells, while HPV-negative tissues exhibited altered macrophage and plasma cell populations, especially in LNMT.
• Pyruvate kinase muscle isoform 1/2 (PKM2) was identified as a key gene associated with cancer stemness in HPV-negative LNMT.
• Ectopic lymphoid structures were observed in HPV-positive tissues, and the ephrin-A (EPHA2) pathway was implicated in angiogenesis and cell migration in HPV-negative HNSCC.

Conclusions:

• Distinct cellular compositions and molecular alterations characterize primary and metastatic HNSCC based on HPV status.
• PKM2 and the EPHA2 pathway represent potential therapeutic targets for HPV-negative HNSCC.
• The findings provide crucial insights into HNSCC biology, highlighting the importance of the tumor microenvironment in HPV-driven and non-viral oncogenesis.