Interleukin‐17A educated hepatic stellate cells promote hepatocellular carcinoma occurrence through fibroblast activation protein expression

Abstract Background Liver cancer is typified by a complex inflammatory tumor microenvironment, where an array of cytokines and stromal cells orchestrate a milieu that significantly influences tumorigenesis. Interleukin‐17A (IL‐17A), a pivotal pro‐inflammatory cytokine predominantly secreted by Th17 cells, is known to play a substantial role in the etiology and progression of liver cancer. However, the precise mechanism by which IL‐17A engages with hepatic stellate cells (HSCs) to facilitate the development of hepatocellular carcinoma (HCC) remains to be fully elucidated. This investigation seeks to unravel the interplay between IL‐17A and HSCs in the context of HCC. Methods An HCC model was established in male Sprague–Dawley rats using diethylnitrosamine to explore the roles of IL‐17A and HSCs in HCC pathogenesis. In vivo overexpression of Il17a was achieved using adeno‐associated virus. A suite of molecular techniques, including RT‐qPCR, enzyme‐linked immunosorbent assays, Western blotting, cell counting kit‐8 assays and colony formation assays, was employed for in vitro analyses. Results The study findings indicate that IL‐17A is a key mediator in HCC promotion, primarily through the activation of hepatic progenitor cells (HPCs). This pro‐tumorigenic influence appears to be mediated by HSCs, rather than through a direct effect on HPCs. Notably, IL‐17A‐induced expression of fibroblast activation protein (FAP) in HSCs emerged as a critical factor in HCC progression. Silencing Fap in IL‐17A‐stimulated HSCs was observed to reverse the HCC‐promoting effects of HSCs. Conclusions The collective evidence from this study implicates the IL‐17A/FAP signaling axis within HSCs as a contributor to HCC development by enhancing HPC activation. These findings bolster the potential of IL‐17A as a diagnostic and preventative target for HCC, offering new avenues for therapeutic intervention.