Targeting VEGF signaling and stromal remodeling enhances chemoimmunotherapy efficacy in esophageal cancer

Neoadjuvant chemoimmunotherapy (NACI) has shown promising results in treating esophageal squamous cell carcinoma (ESCC), yet the mechanisms driving its efficacy remain poorly defined, limiting further optimization of this regimen.

To investigate the dynamics of the tumor microenvironment (TME), we integrated single-cell RNA sequencing, immunorepertoire profiling, and spatial transcriptomics across 18 samples from nine patients with ESCC undergoing NACI. Computational workflows encompassed integrated clustering, gene set enrichment, T cell receptor repertoire characterization, copy number variation estimation, and cell-cell communication inference. Spatial mapping was performed using cytoSPACE. Key findings were validated via orthogonal spatial transcriptomics, multiplex immunohistochemistry, and in vivo preclinical models.

We identified distinct post-treatment accumulation of ACKR1+ endothelial cells (ECs) and CFD+ cancer-associated fibroblasts (CAFs) at tumor boundaries, potentially correlating with enhanced CD8+ T cell infiltration and improved clinical outcomes. Conversely, treatment-resistant tumors exhibited VEGFA-driven upregulation in malignant cells, promoting RGCC+ ECs with elevated VEGFR2 expression. These RGCC+ ECs synergized with MMP11+ CAFs to form a collagen-rich tumor niche that fostered malignancy and immunosuppression. Importantly, targeting VEGFR2 not only improved therapeutic response but also reversed immune suppression.

This study reveals that stromal cells such as CAFs and ECs within the TME collaboratively determine NACI efficacy in ESCC. These findings could offer novel theoretical insights and actionable strategies for enhancing treatment efficacy in ESCC.