miR-203a-3p.1 targets IL-24 to modulate hepatocellular carcinoma cell growth and metastasis

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death. Cytokines, including interleukin 24 (IL-24), play an important role in HCC. IL-24 inhibits HCC metastasis but the molecular mechanism by which this occurs is still unknown. MicroRNAs (miRNAs) are regulators of cancers including hepatocellular carcinoma (HCC). However, the role that miRNAs play in the regulation of IL-24 in HCC is unclear. The aim of this study was to investigate the effects of regulation of IL-24 by miR-203a-3p.1 on liver cancer cell proliferation and metastasis. IL-24 mRNA and miR-203a-3p.1 were detected by real-time RT-PCR, and IL-24 protein in the cell growth medium was measured by ELISA. A luciferase assay was used to verify that the IL-24 gene was the target of miR-203a-3p.1. Cell survival ability was detected by the MTT assay and colony formation. Cell metastasis was assayed by the Transwell system. The results showed that IL-24 could be down-regulated by miR-203a-3p.1 in HCC cells and that miR-203a-3p.1 acted as an onco-miRNA by targeting IL-24. Inhibition of miR-203a-3p.1 in cells could lead to the reversal of HCC cell proliferation and metastasis. The study highlights a novel molecular interaction between miR-203a-3p.1 and IL-24, which indicates that IL-24 and miR-203a-3p.1 may constitute potential therapeutic targets for HCC.