Enhanced expression of the human gene N-myc consequent to amplification of DNA may contribute to malignant progression of neuroblastoma.
Previous studies had revealed that DNA with partial similarity to the myc oncogene (N-myc) is frequently amplified in human neuroblastoma cell lines and neuroblastoma tumors. We show here for one patient that N-myc amplification is confined to the neuroblastoma tumor and is not present in normal tissue. N-myc mRNA approximately equal to 4.0 kilobases in size is detectable in neuroblastoma cell lines and tumors and in a retinoblastoma cell line. By contrast, appreciable amounts of this RNA were not present in a number of cell lines derived from other human tumors and in fibroblasts from a normal individual and from a neuroblastoma patient. Low levels of N-myc RNA were found in human and murine neuroblastoma cell lines lacking amplification of this gene, up to 80-fold greater levels in all cell lines carrying amplified N-myc. In situ hybridization to sections of neuroblastoma tumors revealed high expression of N-myc predominantly in undifferentiated neuroblasts. We hypothesize that amplification and consequent elevated expression of N-myc may be related to malignant progression.
D002460:Cell Line; D005784:Gene Amplification; D005786:Gene Expression Regulation; D006801:Humans; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology; D009857:Oncogenes; D012333:RNA, Messenger / Q000235:genetics
D012333:RNA, Messenger