title: Modulation of chemotherapeutic drug resistance in neuroblastoma SK-N-AS cells by the neural apoptosis inhibitory protein and miR-520f.
abstract: 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.
authors.affiliation: Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland; National Children's Research Centre, Our Ladies Hospital for Sick Children, Dublin 12, Ireland.
authors.forename: Harry
authors.initials: H
authors.lastname: Harvey
authors.forename: Olga
authors.initials: O
authors.lastname: Piskareva
authors.forename: Laura
authors.initials: L
authors.lastname: Creevey
authors.forename: Leah C
authors.initials: LC
authors.lastname: Alcock
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Buckley
authors.forename: Maureen J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Miguel F
authors.initials: MF
authors.lastname: Segura
authors.forename: Soledad
authors.initials: S
authors.lastname: Gallego
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Stallings
authors.forename: Isabella M
authors.initials: IM
authors.lastname: Bray
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D055028:Comparative Genomic Hybridization; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D023281:Genomics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics*; D051616:Neuronal Apoptosis-Inhibitory Protein / Q000235:genetics*; D010641:Phenotype; D034622:RNA Interference
chemical_list: D000970:Antineoplastic Agents; C575048:MIRN520 microRNA, human; D035683:MicroRNAs; D051616:Neuronal Apoptosis-Inhibitory Protein; D002945:Cisplatin
keywords: NAIP; cisplatin; drug-resistance; miR-520f; neuroblastoma