Biejiajian pill inhibits progression of hepatocellular carcinoma by downregulating PDGFRβ signaling in cancer-associated fibroblasts

Abstract

Ethnopharmacological relevance: Biejiajian pill (BJJP) is a canonical formula that is clinically used to treat chronic liver disease, especially to decrease the incidence of hepatocellular carcinoma (HCC). However, the mechanisms underlying the prevention of HCC progression by BJJP remain unclear.

Aim of the study: This study aimed to determine whether BJJP inhibits HCC progression by downregulating platelet-derived growth factor receptor beta (PDGFRβ) signaling in cancer-associated fibroblasts (CAFs) in a mouse model of diethylnitrosamine (DEN)/carbon tetrachloride (CCl₄)-induced HCC.

Materials and methods: C57BL/6 male mice were intraperitoneally injected with DEN 2 weeks after birth, followed by repeated injections of CCl₄ weekly from 6 weeks of age onwards, to recapitulate features of HCC. At week 14, BJJP was orally administered to mice. The effects of BJJP on HCC progression were evaluated using histology, immunohistochemistry, and serum biochemical marker levels. Transcriptome analysis, molecular docking, quantitative real-time PCR, and Western blot were used to study the genes targeted by BJJP and the associated signaling pathway. The effects of BJJP on PDGFRβ signaling in CAFs and the underlying mechanism were demonstrated.

Results: BJJP treatment significantly suppressed carcinogenesis and cancer progression, and it ameliorated liver inflammation in mice with HCC. A total of 176 genes, including PDGFRβ, were significantly downregulated after BJJP treatment and five components of BJJP with high binding affinity to PDGFRβ were identified. BJJP inhibited the phosphorylation of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and glycogen synthase kinase 3 beta (GSK3β) by suppressing PDGFRβ expression in CAFs, and it also downregulated the expression of the downstream proteins hepatocyte growth factor (HGF) and vascular endothelial growth factor A (VEGF-A). Furthermore, BJJP-containing serum consistently reduced PDGFRβ, HGF, and VEGF-A expression levels in HSC-derived CAFs in vitro. Importantly, PDGF-BB induced PDGFRβ activation in CAFs and both BJJP and sunitinib (a kinase inhibitor) inhibited PDGF-BB/PDGFRβ signaling.

Conclusion: BJJP inhibits the progression of HCC through suppressing VEGF-A and HGF expression in CAFs by downregulating PDGFRβ signaling.

Keywords: Biejiajian pill; Cancer-associated fibroblasts; Hepatocellular carcinoma; Platelet-derived growth factor receptor beta.