Activated hepatic stellate cell-derived exosomal miR-23a-3p promotes hepatocellular carcinogenesis by regulating DUSP5/ERK signaling.

[INTRODUCTION] Activation of hepatic stellate cells (HSCs) is a core driver of liver fibrosis and may contribute to the evolution to hepatocellular carcinoma (HCC). Exosomes mediate intercellular signaling by transporting bioactive molecules, yet the role of activated HSC-derived exosomes in hepatocarcinogenesis remains unexplored.

[OBJECTIVES] This study aims to investigate whether and how activated HSCs induce hepatocarcinogenesis through the mediation of exosomes.

[METHODS] Exosomes from activated HSCs were isolated and applied to hepatocytes to assess malignant transformation via immunoblotting, soft-agar colony formation, and xenograft assays. Oncogenic miRNAs were screened by sequencing and validated by qPCR. Target genes and signaling pathways were identified through transcriptomics, bioinformatics, and dual-luciferase assays. Functional roles of miRNAs and downstream pathways were confirmed via gain/loss-of-function experiments. Clinical correlations and diagnostic potential of exosomal miRNAs were evaluated using patient samples.

[RESULTS] Exosomes from activated HSCs induced hepatocyte malignant transformation in vitro and tumorigenesis in vivo. MiR-23a-3p was markedly enriched in activated HSC-derived exosomes and exerted oncogenic effect upon delivery to recipient hepatocytes. Mechanistically, exosomal miR-23a-3p directly targeted DUSP5 in hepatocytes, thereby suppressing its expression and subsequently activating pro-oncogenic ERK signaling. Notably, the miR-23a-3p/DUSP5/ERK signaling axis exhibited progressive activation that paralleled histopathological transitions from fibrosis to HCC in both murine models and clinical specimens. Clinically, elevated plasma exosomal miR-23a-3p levels demonstrated significant diagnostic merit for detecting precancerous lesions and predicting HCC onset in patient cohorts.

[CONCLUSION] Our results indicate that activated HSCs secrete exosomes enriched with miR-23a-3p, which directly target to inhibit DUSP5, and subsequently activate ERK signaling in hepatocytes, leading to the initiation of cellular malignant transformation and tumorigenesis.