N-myc and c-src genes are differentially regulated in PCC7 embryonal carcinoma cells undergoing neuronal differentiation.
N-myc and c-src genes are differentially regulated in PCC7 embryonal carcinoma cells undergoing neuronal differentiation.
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N-myc 和 c-src 基因在经历神经元分化的 PCC7 胚胎癌细胞中受到差异性调节。
DOI：
10.1002/jcp.1041270213
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发表时间：
1986
影响因子：
5.6
通讯作者：
Ringertz,NR
中科院分区：
文献类型：
--
作者：
Sejersen,T;Bjorklund,H;Sumegi,J;Ringertz,NR
我们检测了N-myc、c-myc和c-src在四种胚胎癌细胞系不同生长状态和体外诱导分化过程中的表达。在4株未分化的EC细胞系(PCC7、PCC3、PCC4、F9)的未分化细胞中均检测到N-myc基因的扩增。从小鼠神经母细胞瘤细胞系和小鼠成纤维细胞系制备的mRNA中未检测到N-myc转录产物。维甲酸和cAMP联合诱导PCC7 EC形成神经样细胞后，N-myc基因表达水平下降85%。诱导6天后，PCC7细胞转变为神经丝阳性细胞聚集体，并有大量突起生长。在这个阶段，DNA复制已经减少了95%以上。在诱导的PCC7细胞中，N-myc表达的降低与c-src表达的300-500%的增加是平行的。另一方面，血清饥饿减缓了细胞增殖，但不影响PCC7细胞中N-myc或c-src的mRNA水平。C-myc在除PCC7外的所有EC细胞中都有表达，令人惊讶的是，即使以指数级的增殖速度，PCC7也不表达c-myc。化学诱导F9 EC细胞形成内脏内胚层或壁层内胚层后，N-myc转录本水平显著降低(85%)。在分化的F9细胞中，c-myc的表达也有类似的下降。在增殖或分化的F9细胞中未检测到c-src转录本。这些结果表明，N-myc可能不仅在神经发育中表达，而且在非常早期的、未确定的胚胎细胞中也表达。当PCC7 EC分化为神经样细胞时，c-src的表达被激活，这表明原癌基因的表达模式在分化过程中可能会发生变化，一些原癌基因的表达增加，另一些在mRNA池中的表达减少。
We examined the expression of N‐myc, c‐myc, and c‐src in four embryonic carcinoma (EC) cell lines during different states of cell growth and following induction of in vitro differentiation. N‐myc mRNA was detected in undifferentiated cells of four EC cell lines (PCC7, PCC3, PCC4, F9) neither of which showed N‐myc gene amplification. No N‐myc transcripts could be detected in mRNA prepared from a murine neuroblastoma cell line and from a murine fibroblast line. The level of N‐myc mRNA decreased by 85% when PCC7 EC cells were induced by retinoic acid and cAMP treatment to form nerve‐like cells. Six days after induction, the PCC7 cells changed into aggregates of neurofilament positive cells with massive neurite outgrowths. At this stage DNA replication had been reduced by more than 95%. The decreased N‐myc expression in induced PCC7 cells was parallelled by 300–500% increase in c‐src expression. Slowing of cell multiplication by serum starvation, on the other hand, did not affect the level of N‐myc or c‐src mRNA levels in PCC7 cells. C‐myc was expressed in all EC lines except PCC7, which surprisingly did not express c‐myc even at an exponential rate of proliferation. Chemical induction of F9 EC cells to form visceral endoderm or parietal endoderm resulted in markedly reduced (85%) levels of N‐myc transcripts. A similar decline in c‐myc expression was found in differentiated F9 cells. No c‐src transcripts were detected in proliferating or differentiated F9 cells. These results suggest that N‐myc may be expressed not only in neural development, but also in very early, undetermined embryonic cells. The activation of c‐src expression when PCC7 EC cells differentiate into nerve‐like cells shows that the pattern of proto‐oncogene expression may change during a differentiation process, some proto‐oncogenes increasing, others decreasing their representation in the mRNA pool.