title: N-myc amplification in multiple homogeneously staining regions in two human neuroblastomas.
abstract: Molecular characterization of two human neuroblastoma cell lines has revealed that both contain multiple homogeneously staining regions (HSRs), each representing a chromosome site of N-myc amplification. The newly established cell line CHP-382/JK had two cytogenetically distinct populations with several identical chromosomal abnormalities, indicating a common progenitor cell. Each population had one HSR, one on chromosome 5 at q31-34 and the other on chromosome 2 at q31-32. Chromosomal in situ hybridization with the N-myc probe pNb-1 demonstrated that both HSRs contained amplified copies of N-myc. Southern blot analysis confirmed amplification of N-myc sequences in genomic DNA of CHP-382/JK. Chromosomal features of CHP-382/JK shared with other neuroblastoma cell lines were the deletion of 1p and the presence of extra 17q material. In addition, the cells were highly reactive to monoclonal antibody PI 153/3 used to identify human neuroblastoma. CHP-382/JK cells were further characterized as neuronal cells by the expression of neurotoxin-responsive Na+ channels. Another neuroblastoma cell line, CHP-134, contained a single cell population with three HSRs, one in the short arm of each chromosome 7 and one in the long arm of a chromosome 6. All three HSRs contained amplified copies of N-myc as shown by in situ hybridization with the N-myc probe pNb-1. One of the 7p HSRs was acquired during culture of CHP-134 cells, whereas the 2q HSR of CHP-382/JK was lost. Such findings highlight the continued process of N-myc amplification and transposition in vitro. To our knowledge, amplification of N-myc in multiple HSRs has not been documented previously in neuroblastoma cell lines.
authors.forename: B S
authors.initials: BS
authors.lastname: Emanuel
authors.forename: G
authors.initials: G
authors.lastname: Balaban
authors.forename: J P
authors.initials: JP
authors.lastname: Boyd
authors.forename: A
authors.initials: A
authors.lastname: Grossman
authors.forename: M
authors.initials: M
authors.lastname: Negishi
authors.forename: A
authors.initials: A
authors.lastname: Parmiter
authors.forename: M C
authors.initials: MC
authors.lastname: Glick
mesh_terms: D000911:Antibodies, Monoclonal; D002460:Cell Line; D002871:Chromosome Banding; D005784:Gene Amplification; D006801:Humans; D007473:Ion Channels / Q000032:analysis; D007621:Karyotyping; D009447:Neuroblastoma / Q000235:genetics*; D009857:Oncogenes; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D000911:Antibodies, Monoclonal; D007473:Ion Channels; D012964:Sodium; D012413:Rubidium