N-myc amplification at chromosome band 1p32 in neuroblastoma cells as investigated by in situ hybridization.

Chromosome deletion at the short arm of one chromosome 1 (1p32)--the most common aberration in neuroblastoma cells--was found to be combined with the generation of a homogeneously staining region at this specific site in a newly established neuroblastoma cell line (GI-LI-N) from a stage IV neuroblastoma. By in situ hybridization this homogeneously staining region was shown to contain multiple copies of the proto-oncogene N-myc. This 30-fold oncogene amplification was confirmed by Southern-blot and DNA-dot-blot analyses. In two additional cell lines from children with stage IV neuroblastoma (GI-ME-N and GI-CA-N) N-myc amplification was not detected. Chromosome 1, however, was involved in a structural rearrangement in one cell line (GI-ME-N).