[Amplification of oncogene N-myc in human neuroblastomas]

The basic mechanisms of oncogene activation are gene amplification, increased expression of a single copy gene and somatic mutation, resulting in a genetic product with increased oncogenic potential. Gene amplification appears to be a more common mechanism of oncogene overexpression and its clinical significance is beginning to be appreciated. In human neuroblastomas, N-myc amplification is highly correlated with advanced stages of disease and rapid disease progression, suggesting that the N-myc gene plays a crucial part in determining the degree of malignancy of neuroblastomas. Chromosome aberrations such as double minutes and homogeneously staining region which observed frequently in neuroblastomas are the cytological manifestation of N-myc amplification and its surrounding DNA fragments.