Suppression of iASPP-dependent aggressiveness in cervical cancer through reversal of methylation silencing of microRNA-124

Sci Rep. 2016 Oct 21:6:35480. doi: 10.1038/srep35480.

Abstract

Derepression of wild-type p53 by suppressing its negative inhibitor iASPP (Inhibitor of apoptosis-stimulating protein of p53) represents a potential therapeutic option for cervical cancer (CC). Here, we reported a novel functional significance of iASPP upregulation in cervical tumorigenesis: iASPP acts as a key promoter of CC cell proliferation, epithelial-mesenchymal transition, invasion and cancer stemness, by interacting with p53 to suppress p53-mediated transcription of target genes and reducing p53-responsive microRNA-34a levels. Moreover, we demonstrate that miR-124, directly targeting iASPP, reduces expression of iASPP and attenuates CC cell growth and invasiveness. Low miR-124 expression is inversely correlated with increased expression of iASPP mRNA in CC tissues. In a cohort of 40 patients with CC, the low miR-124 expression was correlated with poor 5-year overall survival (P = 0.0002) and shorter disease-free survival 5-year (P = 0006). Treatment with the DNA methyltransferase inhibitor Zebularine increases miR-124 expression and retards CC cell growth and invasion with minimal toxicity to normal cells. Even at a non-toxic concentration, Zebularine was effective in suppressing CC cell invasion and migration. Altogether, the restoration of miR-124 reduces iASPP expression and leads to p53-dependent tumor suppression, suggesting a therapeutic strategy to treat iASPP-associated CC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Proliferation / genetics
  • Cytidine / analogs & derivatives
  • Cytidine / pharmacology
  • DNA Methylation / genetics*
  • Epithelial-Mesenchymal Transition / drug effects
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Silencing*
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Models, Biological
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology
  • Oncogenes
  • Phenotype
  • Protein Binding / drug effects
  • Repressor Proteins / metabolism*
  • Transcription, Genetic / drug effects
  • Tumor Suppressor Protein p53 / metabolism
  • Uterine Cervical Neoplasms / genetics*
  • Uterine Cervical Neoplasms / pathology*

Substances

  • Intracellular Signaling Peptides and Proteins
  • MIRN124 microRNA, human
  • MicroRNAs
  • PPP1R13L protein, human
  • Repressor Proteins
  • Tumor Suppressor Protein p53
  • Cytidine
  • pyrimidin-2-one beta-ribofuranoside