MicroRNA-455-3p functions as a tumor suppressor by targeting HDAC2 to regulate cell cycle in hepatocellular carcinoma

Environ Toxicol. 2022 Jul;37(7):1675-1685. doi: 10.1002/tox.23516. Epub 2022 Mar 14.

Abstract

Hepatocellular carcinoma (HCC) is one of the most common cancers. MicroRNA has been studied more and more deeply and may become a new target for the treatment of HCC. Here, we investigated the role of miR-455-3p in HCC progression. Compared with non-tumor tissues and normal human hepatic cells, miR-455-3p expression was significantly downregulated in HCC tissues and cell lines. And overexpression of miR-455-3p inhibited cell proliferation and migration but promoted cell apoptosis in HCC cell lines HepG2 and Huh7. Mechanism studies displayed that miR-455-3p targeted HDAC2 and negatively regulated HDAC2 expression. Moreover, HDAC2 was highly expressed in HCC tissues and cell lines. Overexpression of HDAC2 reversed the inhibitory effects of miR-455-3p on cell proliferation, migration and cell cycle protein (CDK6 and cyclin D1) expression, and neutralized the promotion effects of miR-455-3p on cell apoptosis and the activation of p53 pathway. Furthermore, a p53 inhibitor Pifithrin-α (PFT-α) effectively abolished the effects of miR-455-3p on HCC cell behaviors. Additionally, the role of miR-455-3p in tumorigenesis was evaluated by using a mouse xenograft model, and the data showed that miR-455-3p suppressed tumor growth in vivo. In summary, our results suggested that miR-455-3p targeted HDAC2 to inhibit cell proliferation, migration and promote cell apoptosis via the activation of p53 pathway.

Keywords: HDAC2; cell cycle; hepatocellular carcinoma; microRNA-455-3p; the p53 pathway.

MeSH terms

  • Carcinoma, Hepatocellular* / pathology
  • Cell Cycle / genetics
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic / genetics
  • Histone Deacetylase 2 / genetics
  • Histone Deacetylase 2 / metabolism
  • Humans
  • Liver Neoplasms* / pathology
  • MicroRNAs* / genetics
  • MicroRNAs* / metabolism
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • MIRN455 microRNA, human
  • MicroRNAs
  • Tumor Suppressor Protein p53
  • HDAC2 protein, human
  • Histone Deacetylase 2