Hsa‐microRNA‐370‐3p targeting Snail and Twist1 suppresses IL‐8/STAT3‐driven hepatocellular carcinoma metastasis

The pro‐inflammatory factor interleukin‐8 (IL‐8) is related to poor prognosis in hepatocellular carcinoma (HCC) patients. Interleukin‐8 enhanced HCC invasion by upregulating Snail and Twist1, whether this modulation relies on microRNAs (miR) is unclear. In this study, hsa‐miR‐370‐3p was screened as candidate miRNA targeting Snail and Twist1, and its expression was downregulated by IL‐8. Luciferase assays and RNA electrophoretic mobility shift assays were used to evaluate the interaction between miR‐370‐3p and targeted mRNAs. Coimmunoprecipitation, luciferase, and ChIP assays were undertaken to investigate the mechanisms underlying IL‐8‐mediated modification of miR‐370‐3p. Gain‐ and loss‐of‐function studies, Transwell assays, and a xenograft nude mouse model were used to investigate pro‐ and antitumor activities. Interleukin‐8 and miR‐370‐3p levels were analyzed for clinical relevance in HCC patients. Our results showed that HCC patients with high levels of IL‐8 experienced more metastasis and shorter survival. Interleukin‐8 induced epithelial–mesenchymal transition and promoted liver cancer cell migration, invasion, and metastasis both in vitro and in vivo. MicroRNA‐370‐3p interacted with its cognate mRNA within the 3′‐UTR regions of Twist1 and Snail mRNA directly and specifically and attenuated IL‐8 protumoral effects on liver cancer cells. Interleukin‐8 negatively modulated miR‐370‐3p through signal transducer and activator of transcription 3 (STAT3) activation by recruiting histone deacetylase 1 (HDAC1) to miR‐370‐3p promoter. The STAT3 and HDAC antagonists inhibited liver cancer cell migration and invasion. Patients with high miR‐370‐3p and low IL‐8 levels had longer overall survival. In conclusion, our study elucidated a novel axis IL‐8/STAT3/miR‐370‐3p/Twist1 and Snail relying on HDAC1 recruitment, which showed both diagnostic and therapeutic potentials of miR‐370‐3p in HCC metastasis.