title: Microarray analysis reveals differential gene expression patterns and regulation of single target genes contributing to the opposing phenotype of TrkA- and TrkB-expressing neuroblastomas.
abstract: Expression of neurotrophin receptors of the tyrosine kinase receptor (Trk) family is an important prognostic factor in solid tumors including neuroblastoma. High expression of TrkA (NTRK1) is associated with a favorable biology and outcome of neuroblastoma, whereas TrkB (NTRK2) is expressed on aggressive neuroblastomas with unfavorable outcome. To gain new insights into the global gene expression program resulting in these divergent biological phenotypes, we stably expressed either TrkA or TrkB in the human SH-SY5Y neuroblastoma cell line. Gene expression profiles were obtained from parental cells and transfectants activated by their ligands in a time course over 24 h using oligonucleotide microarrays. Basal activation of Trk receptors in the absence of exogenous ligand was sufficient to induce broad and divergent genetic changes. Global gene regulation following external ligand stimulation was surprisingly similar in SY5Y-TrkA and SY5Y-TrkB cells except for the differential expression of distinct novel target genes. Consistent with their divergent biological phenotype, SY5Y-TrkA cells were characterized by upregulation of proapoptotic genes and angiogenesis inhibitors, whereas SY5Y-TrkB cells demonstrated upregulation of genes involved in invasion or therapy resistance. We suggest that the transcriptional program of neuroblastoma cells is modulated by Trk-receptor expression and basal activation rather than by ligand-induced activation. Fine-tuning of the malignant phenotype may be achieved by additional ligand stimulation with subsequent activation of a few specific genes.
authors.affiliation: University Children's Hospital of Essen, Germany.
authors.forename: Johannes H
authors.initials: JH
authors.lastname: Schulte
authors.forename: Alexander
authors.initials: A
authors.lastname: Schramm
authors.forename: Ludger
authors.initials: L
authors.lastname: Klein-Hitpass
authors.forename: Michael
authors.initials: M
authors.lastname: Klenk
authors.forename: Hendrika
authors.initials: H
authors.lastname: Wessels
authors.forename: Berthold P
authors.initials: BP
authors.lastname: Hauffa
authors.forename: Jürgen
authors.initials: J
authors.lastname: Eils
authors.forename: Roland
authors.initials: R
authors.lastname: Eils
authors.forename: Garrett M
authors.initials: GM
authors.lastname: Brodeur
authors.forename: Lothar
authors.initials: L
authors.lastname: Schweigerer
authors.forename: Werner
authors.initials: W
authors.lastname: Havers
authors.forename: Angelika
authors.initials: A
authors.lastname: Eggert
mesh_terms: D002455:Cell Division / Q000502:physiology; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D008024:Ligands; D009389:Neovascularization, Pathologic / Q000378:metabolism; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020917:Receptor, trkA / Q000235:genetics* / Q000378:metabolism; D020813:Receptor, trkB / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D008024:Ligands; D020917:Receptor, trkA; D020813:Receptor, trkB