Protein kinase C α is involved in the regulation of AXL receptor tyrosine kinase expression in triple-negative breast cancer cells

Mol Med Rep. 2016 Aug;14(2):1636-42. doi: 10.3892/mmr.2016.5424. Epub 2016 Jun 23.

Abstract

AXL receptor tyrosine kinase is overexpressed in triple-negative breast cancer (TNBC), and has a function in cancer progression and metastases. However, the mechanism underlying AXL gene regulation in TNBC remains unknown. In this study, the involvement of protein kinase C α (PKCα) in the expression of AXL was investigated in human TNBC cells. The microarray data from other studies showed that PKCα is significantly correlated with AXL expression in TNBC cell lines. Tissue array analysis also confirmed their correlation in TNBC. The PKCα inhibitor Go6976 was used to treat MDA‑MB‑231 and Hs578T TNBC cells, which resulted in decreased expression of AXL and epithelia-mesenchymal transition-related gene vimentin, and decreased cell proliferation. An MZF‑1 acidic domain fragment (MZF-1 peptide), which was designed to downregulate PKCα expression, was transfected into the cells and resulted in inhibition of AXL expression. This effect was reversed by co‑treatment with the constitutive form of PKCα. Moreover, the downregulation of PKCα was also confirmed by treatment with TAT‑fused MZF‑1 peptide. Thus, the current study proposes that AXL may be correlated with PKCα‑dependent TNBC cells, and could be modulated by MZF‑1 peptides.

MeSH terms

  • Adult
  • Aged
  • Axl Receptor Tyrosine Kinase
  • Cell Line, Tumor
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic* / drug effects
  • Humans
  • Kruppel-Like Transcription Factors / chemistry
  • Kruppel-Like Transcription Factors / metabolism
  • Middle Aged
  • Neoplasm Grading
  • Neoplasm Staging
  • Peptide Fragments / pharmacology
  • Protein Kinase C-alpha / genetics
  • Protein Kinase C-alpha / metabolism*
  • Proteome
  • Proteomics / methods
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Triple Negative Breast Neoplasms / genetics*
  • Triple Negative Breast Neoplasms / metabolism*
  • Triple Negative Breast Neoplasms / pathology

Substances

  • Kruppel-Like Transcription Factors
  • MZF1 protein, human
  • Peptide Fragments
  • Proteome
  • Proto-Oncogene Proteins
  • Receptor Protein-Tyrosine Kinases
  • Protein Kinase C-alpha
  • Axl Receptor Tyrosine Kinase
  • AXL protein, human