title: [Neuronal differentiation and TrkA expression of neuroblastoma induced by the combination treatment of interferon-gamma and NGF].
abstract: OBJECTIVE
  Neuroblastoma (NB) is one of the most common solid tumors of early childhood. A small percentage of NB has been found to undergo spontaneous or chemotherapeutically induced regression or differentiation into benign ganglioneuromas. The differentiation therapy is a respective method in the clinical treatment of NB.
  
  
  OBJECTIVE
  Interferon-gamma (IFN-gamma), nerve growth factor (NGF), and combination of IFN-gamma and NGF were used as induction drugs respectively to induce the differentiation of human SMS-KCNR cells. The cells were observed for morphological differences, growth arrest, and the TrkA mRNA expression of the 10th day-cells.
  
  
  METHODS
  The human SMS-KCNR cell lines were cultured. The TrkA mRNA expression was detected by RT-PCR. Cell counts were measured by using a hemocytometer and the viability was assessed with the trypan blue exclusion. The morphological differentiation was observed under the phase-contrast microscope.
  
  
  RESULTS
  The simultaneous loading of NGF with IFN-gamma caused more prominent neurite outgrowth than independent treatment with either IFN-gamma or NGF in SMS-KCNR cells (P < 0.01). The cell proliferation was inhibited significantly in the former (P < 0.01). The TrkA mRNA level increased in the IFN-gamma group (P < 0.01). While there was no significant change of TrkA mRNA level in the NGF group (P > 0.05). The TrkA mRNA level was obvious decreased in the combination group (P < 0.01).
  
  
  CONCLUSIONS
  In human SMS-KCNR cells, the combination of IFN-gamma and NGF showed prominent effect on the cell differentiation. In contrast with the induction of TrkA mRNA expression by IFN-gamma, the combination treatment could decrease TrkA mRNA expression, which might indicate that a kind of negative feedback mechanism existed. These data suggest that using IFN-gamma and NGF together may be an appropriate strategy in the treatment of children with advanced neuroblastoma.
authors.affiliation: Department of Pediatrics, The Second Affiliated Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Jin-hua
authors.initials: JH
authors.lastname: Zhang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Mi
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics*; D020932:Nerve Growth Factor / Q000494:pharmacology*; D009447:Neuroblastoma / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020917:Receptor, trkA; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D007371:Interferon-gamma; D020932:Nerve Growth Factor; D020917:Receptor, trkA