Increased N-myc mRNA expression associated with dibutyryl cyclic AMP induced neuroblastoma differentiation.
The N-myc cellular oncogene is frequently amplified and expressed at a high level in neuroectodermal tumor cells such as neuroblastoma and retinoblastoma. We examined N-myc expression in NCB-20 hybrid (N18TG2 neuroblastoma x embryonic Chinese Hamster brain) cells. After five days of culture, cells treated with 1 mM db cAMP show extensive neurite outgrowth and secrete acetylcholinesterase into the media at a level three times higher than untreated control. In situ hybridizations, dot blots, and Northern analyses reveal four- to eight-fold higher levels of N-myc mRNA in the treated, differentiated cells than in the untreated, undifferentiated controls. Our results show that the highly differentiated state is not incompatible with a high level of N-myc mRNA.
Berman
S A
SA
Department of Neurology, University of Chicago, Illinois 60637.
Bursztajn
S
S
Kinnard
R
R
Cashman
N
N
Arnason
B G
BG
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D003994:Bucladesine / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects*; D011905:Genes, ras / Q000187:drug effects; D009447:Neuroblastoma / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology
D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D003994:Bucladesine; D011505:Protein-Tyrosine Kinases; D000110:Acetylcholinesterase