Proteasome beta-4 subunit contributes to the development of melanoma and is regulated by miR-148b

Tumour Biol. 2017 Jun;39(6):1010428317705767. doi: 10.1177/1010428317705767.


The proteasome beta-4 subunit is required for the assembly of 20S proteasome complex, forming a pivotal component for the ubiquitin-proteasome system. Emerging evidence indicates that proteasome beta-4 subunit may be involved in underlying progression and mechanisms of malignancies. However, the role of proteasome beta-4 subunit in melanoma is currently unknown. Here, we reported that proteasome beta-4 subunit was markedly upregulated in human melanoma tissues and cells, compared with normal skin samples. High proteasome beta-4 subunit levels were significantly associated with poor overall survival in patients with melanoma. Proteasome beta-4 subunit knockdown strongly decreased melanoma cell growth in vitro and in vivo. We further identified miR-148b as a negative regulator of proteasome beta-4 subunit. Enforced expression of miR-148b resulted in vitro growth inhibition of melanoma cells, whereas this inhibition was further abolished by enforced expression of proteasome beta-4 subunit. Our findings, for the first time, indicated that the miR-148b/proteasome beta-4 subunit axis contributed to the development of melanoma, revealing novel therapeutic targets for the treatment of melanoma.

Keywords: Proteasome beta-4 subunit; melanoma; miR-148b; targeted therapy.

MeSH terms

  • Adult
  • Aged
  • Carcinogenesis / genetics*
  • Cell Proliferation / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Humans
  • Male
  • Melanoma / genetics*
  • Melanoma / pathology
  • MicroRNAs / genetics*
  • Middle Aged
  • Proteasome Endopeptidase Complex / genetics*


  • MIRN148 microRNA, human
  • MicroRNAs
  • PSMB4 protein, human
  • Proteasome Endopeptidase Complex