Exosomes secreted by chronic hepatitis B patients with PNALT and liver inflammation grade ≥ A2 promoted the progression of liver cancer by transferring miR‐25‐3p to inhibit the co‐expression of TCF21 and HHIP

OBJECTIVES: The current study aimed to investigate the mechanism by which exosomes secreted by CHB patients with PNALT and liver inflammation grade (≥A2) affected the development of liver cancer. MATERIALS AND METHODS: Gene expression was assessed by RT‐PCR, Western blotting and immunohistochemistry. CCK‐8, colony formation, transwell, scratch‐wound and flow cytometry assays were used to detect cell viability, proliferation, apoptosis and metastasis. The interaction of TCF21 and HHIP was assessed by co‐immunoprecipitation assay. Luciferase reporter was used to detect the combination of TCF21/HHIP and miR‐25‐3p. Xenograft studies in nude mice manifested tumour growth ability of miR‐25‐3p. Bioinformatics analyses were conducted using TargetScan, EVmiRNA, TCGA, GEO, DAVID, COEXPEDIA, UALCAN, UCSC and the Human Protein Atlas databases. RESULTS: CHB‐PNALT‐Exo (≥A2) promoted the proliferation and metastasis of HepG2.2.15 cells. miR‐25‐3p was upregulated in CHB‐PNALT‐Exo (≥A2). miR‐25‐3p overexpression promoted cell proliferation and metastasis and was related to poor survival in patients with CHB‐PNALT (≥A2). The cell proliferation‐ and metastasis‐promoting functions of CHB‐PNALT‐Exo (≥A2) were abolished by miR‐25‐3p inhibitors. TCF21 directly interacted with HHIP. Inhibition of TCF21 or HHIP promoted cell proliferation and metastasis. Knockdown of TCF21 or HHIP counteracted the effects of CHB‐PNALT‐Exo (≥A2) containing miR‐25‐3p inhibitor on cell proliferation, metastasis and the expression of Ki67, E‐cadherin and caspase‐3/‐9. CONCLUSIONS: Transfer of miR‐25‐3p by CHB‐PNALT‐Exo promoted the development of liver cancer by inhibiting the co‐expression of TCF21 and HHIP.