Periostin(+)cancer‐associated fibroblasts promote lymph node metastasis by impairing the lymphatic endothelial barriers in cervical squamous cell carcinoma

Lymph node metastasis (LNM), a critical prognostic determinant in cancer patients, is critically influenced by the presence of numerous heterogeneous cancer‐associated fibroblasts (CAFs) in the tumor microenvironment. However, the phenotypes and characteristics of the various pro‐metastatic CAF subsets in cervical squamous cell carcinoma (CSCC) remain unknown. Here, we describe a CAF subpopulation with elevated periostin expression (periostin(+)CAFs), located in the primary tumor sites and metastatic lymph nodes, that positively correlated with LNM and poor survival in CSCC patients. Mechanistically, periostin(+)CAFs impaired lymphatic endothelial barriers by activating the integrin‐FAK/Src‐VE‐cadherin signaling pathway in lymphatic endothelial cells and consequently enhanced metastatic dissemination. In contrast, inhibition of the FAK/Src signaling pathway alleviated periostin‐induced lymphatic endothelial barrier dysfunction and its related effects. Notably, periostin(‐)CAFs were incapable of impairing endothelial barrier integrity, which may explain the occurrence of CAF‐enriched cases without LNM. In conclusion, we identified a specific periostin(+)CAF subset that promotes LNM in CSCC, mainly by impairing the lymphatic endothelial barriers, thus providing the basis for potential stromal fibroblast‐targeted interventions that block CAF‐dependent metastasis.