title: Mesenchymal change and drug resistance in neuroblastoma.
abstract: BACKGROUND
  Metastatic initiation has many phenotypic similarities to epithelial-to-mesenchymal transition, including loss of cell-cell adhesion, increased invasiveness, and increased cell mobility. We have previously demonstrated that drug resistance is associated with a metastatic phenotype in neuroblastoma (NB). The purpose of this project was to determine if the development of doxorubicin resistance is associated with characteristics of mesenchymal change in human NB cells.
  
  
  METHODS
  Total RNA was isolated from wild type (WT) and doxorubicin-resistant (DoxR) human NB cell lines (SK-N-SH and SK-N-BE(2)C) and analyzed using the Illumina Human HT-12 version 4 Expression BeadChip. Differentially expressed genes (DEGs) were identified. Volcano plots and heat maps were generated. Genes of interest with a fold change in expression >1.5 and an adjusted P < 0.1 were analyzed. Immunofluorescence (IF) and Western blot analysis confirmed microarray results of interest. Matrigel invasion assay and migration wounding assays were performed.
  
  
  RESULTS
  Volcano plots and heat maps visually demonstrated a similar pattern of DEGs in the SK-N-SH and SK-N-BE(2)C DoxR cell lines relative to their parental WT lines. Venn diagramming revealed 1594 DEGs common to both DoxR cell lines relative to their parental cell lines. Network analysis pointed to several significantly upregulated epithelial-to-mesenchymal transition pathways, through TGF-beta pathways via RhoA, PI3K, and ILK and via SMADs, as well as via notch signaling pathways. DoxR cell lines displayed a more invasive phenotype than respective WT cell lines.
  
  
  CONCLUSIONS
  Human SK-N-SH and SK-N-BE(2)C NB cells display characteristics of mesenchymal change via multiple pathways in the transition to a drug-resistant state.
authors.affiliation: Department of Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, Illinois; Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Naiditch
authors.affiliation: Whole Genome Core Facility, Northwestern University, Chicago, Illinois.
authors.forename: Chunfa
authors.initials: C
authors.lastname: Jie
authors.affiliation: Department of Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, Illinois; Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Lautz
authors.affiliation: Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Songtao
authors.initials: S
authors.lastname: Yu
authors.affiliation: Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Sandra
authors.initials: S
authors.lastname: Clark
authors.affiliation: Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Dimitry
authors.initials: D
authors.lastname: Voronov
authors.affiliation: Department of Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, Illinois; Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois. Electronic address: fchu@luriechildrens.org.
authors.forename: Fei
authors.initials: F
authors.lastname: Chu
authors.affiliation: Department of Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University, Chicago, Illinois; Cancer Biology and Epigenomics, Stanley Manne Children's Research Institute, Chicago, Illinois.
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Madonna
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002465:Cell Movement; D004317:Doxorubicin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics / Q000556:secondary; D010641:Phenotype; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D000903:Antibiotics, Antineoplastic; D004317:Doxorubicin
keywords: Drug resistance; Long-term drug exposure; Mesenchymal change; Neuroblastoma