Excision of N-myc from chromosome 2 in human neuroblastoma cells containing amplified N-myc sequences.
Amplification of one of three growth-stimulating myc genes is a common method by which many tumor types gain a proliferative advantage. In metastatic human neuroblastoma, the amplification of the N-myc locus, located on chromosome 2, is a dominant feature of this usually fatal pediatric cancer. Of the many models proposed to explain this amplification, all incorporate as the initial step either disproportionate overreplication of the chromosomal site or recombination across a loop structure. The original locus is retained within the chromosome in the overreplication models but is excised in the recombination models. To test these models, we have used somatic cell hybrids to separate and analyze the chromosomes 2 from a neuroblastoma cell line containing in vivo amplified N-myc. Our results demonstrate that N-myc is excised from one of the chromosomes, suggesting that deletion is a requisite part of gene amplification in a naturally occurring system.
Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
J D
JD
Hunt
M
M
Valentine
A
A
Tereba
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002889:Chromosomes, Human, Pair 2; D006224:Cricetinae; D015342:DNA Probes; D005784:Gene Amplification; D005838:Genotype; D006801:Humans; D006822:Hybrid Cells / Q000166:cytology; D007521:Isocitrate Dehydrogenase / Q000235:genetics; D007527:Isoenzymes / Q000235:genetics; D007621:Karyotyping; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000235:genetics*; D015345:Oligonucleotide Probes; D016274:Oncogene Protein p55(v-myc); D009857:Oncogenes; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D015183:Restriction Mapping; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics*
D015342:DNA Probes; D007527:Isoenzymes; D015345:Oligonucleotide Probes; D016274:Oncogene Protein p55(v-myc); D015682:Retroviridae Proteins, Oncogenic; D007521:Isocitrate Dehydrogenase; D011505:Protein-Tyrosine Kinases