MiR-214 regulates oral cancer KB cell apoptosis through targeting RASSF5

Genet Mol Res. 2017 Mar 8;16(1). doi: 10.4238/gmr16019327.

Abstract

Ras association domain family member 5 (RASSF5), a member of the Ras association domain family, induces cell apoptosis by phosphorylating FOXO3a, which triggers target gene BIM (pro-apoptotic factor) activation. MiR-214 is overexpressed in oral cancer tissue, indicating its possible involvement in oral cancer pathogenesis. Bioinformatics analysis has revealed a complimentary sequence between miR-214 and the 3'-UTR of RASSF5 mRNA. However, whether miR-124 regulates RASSF5 in oral cancer remains poorly understood. We aimed to investigate the role of miR-214 in RASSF5 expression regulation in oral cancer. Tumor and paracarcinoma tissues were obtained from 48 oral cancer patients to examine miR-214 and RASSF5 expression. The relationship between miR-214 and RASSF5 was investigated by dual luciferase reporter gene assay. Oral cancer KB cells were cultured in vitro and divided into inhibitor NC, miR-214 inhibitor, Scramble-pMD18, RASSF5-pMD18, and miR-214 inhibitor + RASSF5-pMD18 groups. Caspase 3 activity, cell apoptosis, and total protein expression were measured by spectrophotometry, flow cytometry, and western blot, respectively. MiR-214 expression was significantly increased, while that of RASSF5 decreased in oral cancer tumor tissues compared to paracarcinoma tissues. Luciferase assay showed that miR-214 suppressed RASSF5 expression by targeting its 3'-UTR. Down-regulation of miR-214 and/or enhancement of RASSF5 expression markedly increased FOXO3a phosphorylation, BIM expression, caspase 3 activity, and apoptosis. In conclusion, miR-214 expression was elevated and RASSF5 was down-regulated in oral cancer. Moreover, miR-214 regulated KB cell apoptosis through targeted inhibition of RASSF5 expression, FOXO3a phosphorylation, and BIM expression, suggesting its possible application as a novel therapeutic oral cancer target.

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adult
  • Aged
  • Apoptosis / genetics*
  • Apoptosis Regulatory Proteins / genetics
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Down-Regulation
  • Female
  • Genes, Tumor Suppressor
  • Humans
  • KB Cells
  • Male
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Middle Aged
  • Monomeric GTP-Binding Proteins / genetics*
  • Monomeric GTP-Binding Proteins / metabolism
  • Mouth Neoplasms / genetics*
  • Mouth Neoplasms / metabolism
  • Mouth Neoplasms / pathology
  • RNA, Messenger / genetics

Substances

  • Adaptor Proteins, Signal Transducing
  • Apoptosis Regulatory Proteins
  • MIRN214 microRNA, human
  • MicroRNAs
  • RASSF5 protein, human
  • RNA, Messenger
  • Monomeric GTP-Binding Proteins