Cancer-Associated Fibroblasts Expressing Sulfatase 1 Facilitate VEGFA-Dependent Microenvironmental Remodeling to Support Colorectal Cancer

Abstract Tumor stroma plays a critical role in fostering tumor progression and metastasis. Cancer-associated fibroblasts (CAFs) are a major component of the tumor stroma. Identifying the key molecular determinants for the pro-tumor properties of CAFs could enable the development of more effective treatment strategies. Herein, through analyses of single-cell sequencing data, we identified a population of CAFs expressing high levels of sulfatase 1 (SULF1), which was associated with poor prognosis in colorectal cancer (CRC) patients. CRC models using mice with conditional SULF1 knockout in fibroblasts revealed the tumor-supportive function of SULF1+ CAFs. Mechanistically, SULF1+ CAFs enhanced the release of vascular endothelial growth factor A (VEGFA) from heparan sulfate proteoglycan (HSPG). The increased bioavailability of VEGFA initiated the deposition of extracellular matrix (ECM) and enhanced angiogenesis. In addition, intestinal microbiota-produced butyrate suppressed SULF1 expression in CAFs through its HDAC inhibitory activity. The insufficient butyrate production in CRC patients increased the abundance of SULF1+ CAFs, thereby promoting tumor progression. Importantly, tumor growth inhibition by HDAC inhibition was dependent on SULF1 expression in CAFs, and CRC patients with more SULF1+ CAFs were more responsive to treatment with the HDAC inhibitor chidamide. Collectively, these findings unveil the critical role of SULF1+ CAFs in CRC and provide a strategy to stratify CRC patients for HDAC inhibitor treatment.