Single-cell Deciphering of the Progression Trajectories of the Tumor Ecosystem in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is typically diagnosed at advanced stages, highlighting the critical need for early intervention. By integrating single-cell and bulk RNA-seq data from LSCC, vocal cord leukoplakia (VCL), and LSCC precursors, we characterized dynamic remodeling of the tumor microenvironment during LSCC pathogenesis. We identified transcriptional program gene modules that reflect malignant epithelial cells (maEpCs). The infiltration of POSTN⁺ fibroblasts progressively increases from normal tissue to VCL and further to LSCC, accompanied by enhanced intercellular communication. These fibroblasts interact with maEpCs and endothelial cells via ligands such as MIF, promoting epithelial-mesenchymal transition, cancer stemness, and angiogenesis. Blocking MIF reversed cancer-associated fibroblast-driven invasion and angiogenesis. Here, we further revealed that an immunosuppressive microenvironment arises as early as the precancerous stage, with VCL exhibiting CD8⁺ T cell exhaustion and abundant LAMP3⁺ dendritic cells that correlate positively with Tregs and exhausted CD8⁺ T cells, promoting early immune escape. Additionally, LSCC was uniquely enriched for a pro-tumor SPP1⁺ macrophage subset with low phagocytic activity and high angiogenic potential, linked to poor prognosis. Our findings uncover key mechanisms driving LSCC malignant progression, offer insights for early diagnosis and prognosis assessment, and highlight MIF as a promising therapeutic target.