miR-15a induces cell apoptosis by targeting BCL2L2 and BCL2 in HPV-positive hypopharyngeal squamous cell carcinoma

Oncol Rep. 2016 Oct;36(4):2169-76. doi: 10.3892/or.2016.5049. Epub 2016 Aug 25.

Abstract

Aberrant expression of miR-15a was recently reported in several types of cancers; however, its role in HPV-positive hypopharyngeal squamous cell carcinoma (HSCC) remains obscure. In the present study, we investigated the mechanism by which miR-15a induces HPV-positive HSCC apoptosis. Synthetic miR-15a mimics were transfected into FaDu cells (HPV-negative), and the miR-15a inhibitor was transfected into HPV-positive HSCC cells. miR-15a expression was analyzed by RT-PCR, and BCL2L2 and BCL2 were analyzed by western blotting. The Hochest 33342/propidium iodide (PI) and caspase-3/-9 assays, and Annexin V staining were used to assess the effect of miR-15a on apoptosis. After transfection, overexpression of miR-15a in the FaDu cells was associated with significantly decreased BCL2L2 and BCL2 expression and a significant increase in the apoptosis rate. The opposite results were observed in HPV-positive HSCC, where downregulation of miR-15a suppressed apoptosis. These findings indicate that miR-15a acts as a tumor suppressor in HPV-positive HSCC.

MeSH terms

  • Apoptosis / genetics
  • Apoptosis Regulatory Proteins / biosynthesis*
  • Apoptosis Regulatory Proteins / genetics
  • Carcinoma, Squamous Cell / genetics*
  • Carcinoma, Squamous Cell / pathology
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Hypopharyngeal Neoplasms / genetics*
  • Hypopharyngeal Neoplasms / pathology
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis*
  • Proto-Oncogene Proteins c-bcl-2 / genetics

Substances

  • Apoptosis Regulatory Proteins
  • BCL2L2 protein, human
  • MIRN15 microRNA, human
  • MicroRNAs
  • Proto-Oncogene Proteins c-bcl-2