Spatial profiling identified senescent cancer-associated fibroblasts localized in the border region of human pancreatic ductal adenocarcinoma.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by a fibroblast-rich tumor microenvironment. Cancer-associated fibroblasts (CAFs) closely interact with tumor cells and play a pivotal role in cancer pathogenesis. Single-cell analyses have identified distinct CAF subsets that exert either tumor-promoting or tumor-suppressive effects in PDAC. Senescent CAFs have recently been linked to poor prognosis through their senescence-associated secretory phenotype (SASP). However, the dynamics of senescent CAF induction and their spatial distribution in PDAC remain largely unclear. This study aimed to investigate the heterogeneity and spatial organization of CAFs in PDAC, with a specific focus on the induction and localization of senescent CAFs. METHODS: We performed immunostaining and spatial transcriptomic analyses covering unbiased regions of tumor architecture to map CAF subpopulations and characterize senescent CAF induction and localization. RESULTS: Senescent CAFs were found to accumulate preferentially at the gross tumor edge, and their abundance was associated with poor patient prognosis. Chemotherapy further promoted senescence in myofibroblastic CAFs within the tumor core, resulting in an increased population of senescent CAFs. Spatial transcriptomic profiling identified gene signatures specific to senescent CAFs and revealed their distinct interactions with neighboring cells. Notably, senescent CAFs exhibited enhanced TGFβ signaling activity and upregulation of downstream genes, such as CCN2 and PLAU, which may contribute to tumor proliferation and invasion. CONCLUSIONS: This study reveals that senescent CAFs preferentially localize near the gross tumor edge and could impact tumor progression through their SASP. These findings highlight the spatial plasticity of pancreatic CAFs and underscore the pathological significance of senescent CAFs in human PDAC.