The biological effects of antisense N-myc expression in human neuroblastoma.
Although N-myc amplification and overexpression are believed to play an important role in determining the clinical behavior of neuroblastoma (NB), the exact function of N-myc in NB cell growth and differentiation remains unknown. To better understand the function of N-myc, an established human NB cell line was transfected with N-myc antisense (AS) complementary DNA in an effort to down-regulate N-myc gene expression. Five clones expressing AS N-myc RNA have been maintained in culture for over 2 years. Compared to control cells, a 30-69% decrease in the quantity of N-myc protein was demonstrated by Western blot analysis in 4 of the 5 AS clones. All 5 of the AS clones exhibited a 50-75% decrease in colony formation in soft agar assays compared to control cells. In addition, all 5 AS clones expressed a 3.2-kilobase protein kinase C-alpha transcript, whereas this message was not detected by Northern blot analysis in any of the control clones. These results suggest that N-myc may play an important role in NB cell growth and that antisense N-myc expression is associated with an induction of protein kinase C-alpha RNA expression. Further characterization of the AS clones may provide insight into the function of N-myc and may thus lead to a better understanding of the role that N-myc plays in determining the clinical behavior of this childhood neoplasm.
Schmidt
M L
ML
Department of Pediatrics, University of Illinois, Chicago 60612.
Salwen
H R
HR
Manohar
C F
CF
Ikegaki
N
N
Cohn
S L
SL
D015152:Blotting, Northern; D015139:Blotting, Southern; D002455:Cell Division; D002460:Cell Line; D002999:Clone Cells; D016373:DNA, Antisense / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000032:analysis; D015870:Gene Expression; D016259:Genes, myc; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis; D009447:Neuroblastoma; D011493:Protein Kinase C / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D016373:DNA, Antisense; D004273:DNA, Neoplasm; D007527:Isoenzymes; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011493:Protein Kinase C