Griep A E, Westphal H
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Proc Natl Acad Sci U S A. 1988 Sep;85(18):6806-10. doi: 10.1073/pnas.85.18.6806.
Down-regulation of Myc expression is the earliest documented change in gene expression in retinoic acid-induced differentiation of murine F9 teratocarcinoma cells. F9 cells transfected with plasmids expressing antisense Myc sequences under control of the simian virus 40 (SV40) early promoter exhibit a decrease in Myc protein. The result of this decrease is the spontaneous differentiation into cells that resemble retinoic acid-treated F9 cells as judged by plasminogen activator assays. In contrast, when F9 cells are transfected with a plasmid expressing Myc under control of the SV40 early promoter, resulting cell clones are resistant to differentiation by retinoic acid as shown by the lack of induction of plasminogen activator. These results suggest that down-regulation of Myc is sufficient and necessary for F9 cell differentiation.
Myc表达的下调是视黄酸诱导小鼠F9畸胎瘤细胞分化过程中最早记录的基因表达变化。用在猴病毒40（SV40）早期启动子控制下表达反义Myc序列的质粒转染的F9细胞，Myc蛋白水平降低。这种降低的结果是自发分化为通过纤溶酶原激活物测定判断类似于视黄酸处理的F9细胞的细胞。相反，当用在SV40早期启动子控制下表达Myc的质粒转染F9细胞时，所产生的细胞克隆对视黄酸诱导的分化具有抗性，如缺乏纤溶酶原激活物的诱导所示。这些结果表明，Myc的下调对于F9细胞分化是充分且必要的。
