Cancer‐associated fibroblasts‐derived exosomal ZNF250 promotes the proliferation, migration, invasion, and immune escape of hepatocellular carcinoma cells by transcriptionally activating PD‐L1

Abstract Hepatocellular carcinoma (HCC) is a lethal form of liver cancer, and the tumor microenvironment, particularly cancer‐associated fibroblasts (CAFs), plays a critical role in its progression. This study aimed to elucidate the mechanism by which CAF‐derived exosomes regulate the development of HCC. The study employed quantitative real‐time polymerase chain reaction for mRNA expression analysis and western blot analysis for protein expression detection. Chromatin immunoprecipitation assay and dual‐luciferase reporter assay were performed to investigate the relationship between zinc finger protein 250 (ZNF250) and programmed cell death 1 ligand 1 (PD‐L1). Transmission electron microscopy and western blot analysis were used to characterize the isolated exosomes. The transferability of CAF‐derived exosomes and normal fibroblasts (NFs)‐derived exosomes into HCC cells was analyzed using a green fluorescent labeling dye PKH67. Cell proliferation was assessed via a 5‐Ethynyl‐2′‐deoxyuridine assay, while Transwell assays were conducted to evaluate cell migration and invasion. Flow cytometry was performed to measure cell apoptosis, while enzyme‐linked immunosorbent assays were used to assess the levels of tumor necrosis factor‐α and perforin. Finally, a xenograft mouse model was constructed to examine the effects of exosomes derived from ZNF250‐deficient CAFs on the tumor properties of HCC cells. The study revealed increased expression of ZNF250 in HCC tissues and cells, with ZNF250 transcriptionally activating PD‐L1 in HCC cells. ZNF250 expression was associated with HbsAg, clinical stage and tumor size of HCC patients. CAF‐derived exosomal ZNF250 can regulate PD‐L1 expression in HCC cells. Furthermore, exosomes derived from ZNF250‐deficient CAFs inhibited the proliferation, migration, invasion, and immune escape of HCC cells by downregulating PD‐L1 expression. Moreover, CAF‐derived exosomal ZNF250 promoted tumor formation in vivo. These findings provide insights into the role of CAF‐derived exosomes in the suppression of HCC development, highlighting the significance of ZNF250 and PD‐L1 regulation in tumor progression.