MMP13- and COL11A1-expressing cancer-associated fibroblasts: key drivers of esophageal squamous cell carcinoma progression and prognostic indicators.

Abstract

The tumor microenvironment comprises various cell types, and cancer-associated fibroblasts are crucial contributors to cancer progression and metastasis. Cancer-associated fibroblasts also play an important role in esophageal squamous cell carcinoma and have been extensively studied in this context. However, the association between cancer-associated fibroblasts and progression across pathological stages has not yet been reported. To identify these specific cancer-associated fibroblasts, we used a case-oriented approach for single-cell RNA sequencing. Consequently, we identified three cancer-associated fibroblast clusters, classified as myofibroblastic cancer-associated fibroblasts, which increased in number as the cancer progressed. Pathway analysis revealed that the three cancer-associated fibroblast clusters had distinct properties. These cancer-associated fibroblasts were named MMP13⁺, COL11A1⁺, and SFRP4⁺ myofibroblastic cancer-associated fibroblasts based on their characteristic gene expression. We also investigated the distribution of various immune cells within the tumor microenvironment associated with the three different cancer-associated fibroblast clusters. The results revealed the presence of different types of immune cells, including M2 macrophages, regulatory T cells, and interferon-γ⁺ programmed death-1⁺ T cells and interferon-γ⁺ programmed death-1^- T cells. Next, we evaluated the presence of these three cancer-associated fibroblast subtypes in surgically resected specimens from patients with advanced esophageal squamous cell carcinoma using RNA in situ hybridization. Analysis of the association between these three cancer-associated fibroblast subtypes and prognosis showed that two subtypes (MMP13⁺ and COL11A1⁺ myofibroblastic cancer-associated fibroblasts) were associated with poor prognosis. MMP13⁺ myofibroblastic cancer-associated fibroblasts were associated with poorly differentiated infiltration patterns, whereas COL11A1⁺ myofibroblastic cancer-associated fibroblasts were associated with lymph node metastasis. These results suggest that future treatments targeting these cancer-associated fibroblasts and patient stratification based on these cancer-associated fibroblasts are warranted.