Schmidt M L, Salwen H R, Manohar C F, Ikegaki N, Cohn S L
Department of Pediatrics, University of Illinois, Chicago 60612.
Cell Growth Differ. 1994 Feb;5(2):171-8.
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.
尽管人们认为N - myc基因的扩增和过表达在决定神经母细胞瘤（NB）的临床行为中起重要作用，但N - myc在NB细胞生长和分化中的确切功能仍不清楚。为了更好地理解N - myc的功能，将已建立的人NB细胞系用N - myc反义（AS）互补DNA进行转染，以下调N - myc基因表达。五个表达AS N - myc RNA的克隆已在培养中维持了两年多。与对照细胞相比，通过蛋白质印迹分析在5个AS克隆中的4个中显示N - myc蛋白量减少了30 - 69%。在软琼脂试验中，所有5个AS克隆与对照细胞相比，集落形成减少了50 - 75%。此外，所有5个AS克隆都表达了一个3.2千碱基的蛋白激酶C - α转录本，而在任何对照克隆中通过Northern印迹分析都未检测到该信息。这些结果表明，N - myc可能在NB细胞生长中起重要作用，并且反义N - myc表达与蛋白激酶C - α RNA表达的诱导有关。对AS克隆的进一步表征可能会深入了解N - myc的功能，从而可能更好地理解N - myc在决定这种儿童肿瘤临床行为中所起的作用。
