Modulation of chemotherapeutic drug resistance in neuroblastoma SK-N-AS cells by the neural apoptosis inhibitory protein and miR-520f

Int J Cancer. 2015 Apr 1;136(7):1579-88. doi: 10.1002/ijc.29144. Epub 2014 Sep 2.


The acquisition of multidrug resistance is a major impediment to the successful treatment of neuroblastoma, a clinically heterogeneous cancer accounting for ∼15% of all pediatric cancer deaths. The MYCN transcription factor, whose gene is amplified in ∼30% of high-risk neuroblastoma cases, influences drug resistance by regulating a cadre of genes, including those involved with drug efflux, however, other high-risk subtypes of neuroblastoma lacking MYCN amplification, such as those with chromosome 11q deletions, also acquire multidrug resistance. To elucidate additional mechanisms involved with drug resistance in non-MYCN amplified tumour cells, an SK-N-AS subline (SK-N-AsCis24) that is significantly resistant to cisplatin and cross resistant to etoposide was developed through a pulse-selection process. High resolution aCGH analysis of SK-N-AsCis24 revealed a focal gain on chromosome 5 containing the coding sequence for the neural apoptosis inhibitory protein (NAIP). Significant overexpression of NAIP mRNA and protein was documented, while experimental modulation of NAIP levels in both SK-N-AsCis24 and in parental SK-N-AS cells confirmed that NAIP was responsible for the drug resistant phenotype by apoptosis inhibition. Furthermore, a decrease in the NAIP targeting microRNA, miR-520f, was also demonstrated to be partially responsible for increased NAIP levels in SK-N-AsCis24. Interestingly, miR-520f levels were determined to be significantly lower in postchemotherapy treatment tumours relative to matched prechemotherapy samples, consistent with a role for this miRNA in the acquisition of drug resistance in vivo, potentially through decreased NAIP targeting. Our findings provide biological novel insight into neuroblastoma drug-resistance and have implications for future therapeutic research.

Keywords: NAIP; cisplatin; drug-resistance; miR-520f; neuroblastoma.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use
  • Cell Line, Tumor
  • Cisplatin / pharmacology
  • Comparative Genomic Hybridization
  • Drug Resistance, Neoplasm / genetics*
  • Gene Expression
  • Gene Expression Regulation, Neoplastic
  • Genomics
  • Humans
  • MicroRNAs / genetics*
  • Neuroblastoma / drug therapy
  • Neuroblastoma / genetics*
  • Neuronal Apoptosis-Inhibitory Protein / genetics*
  • Phenotype
  • RNA Interference


  • Antineoplastic Agents
  • MIRN520 microRNA, human
  • MicroRNAs
  • Neuronal Apoptosis-Inhibitory Protein
  • Cisplatin