Edwards S A, Rundell A Y, Adamson E D
Cancer Research Center, La Jolla Cancer Research Foundation, California 92037.
Dev Biol. 1988 Sep;129(1):91-102. doi: 10.1016/0012-1606(88)90164-9.
To test the putative role of c-fos in F9 differentiation, we have attempted to inhibit c-fos expression in these cells using an SV40-based expression vector (pSVneo-sof) that programs expression of c-fos antisense (sof) sequences as a 3' extension of a neo mRNA transcript. Of six G418-resistant clones isolated in transfection experiments, five expressed neo-sof transcripts. Two clones synthesized polyadenylated mRNA of the expected size (3.8 kb), two were smaller than expected, and one was larger. Two clones that expressed reduced levels of c-fos protein were inhibited in the induction of laminin, type IV collagen, and proteoglycan-19 RNA transcripts measured after 4 days of differentiation induction with RA and dibutyryl cyclic AMP. Also inhibited was the induction of the differentiation markers, TROMA-1 and TROMA-3. Antisense-expressing cells were not inhibited in the differentiation pathway to visceral endoderm since the alpha-fetoprotein gene was activated normally. We conclude that c-fos antisense expression inhibits some aspects of differentiation in F9 cells.
为了测试c-fos在F9细胞分化中的假定作用，我们尝试使用基于SV40的表达载体（pSVneo-sof）抑制这些细胞中的c-fos表达，该载体可将c-fos反义（sof）序列作为neo mRNA转录本的3'延伸进行表达。在转染实验中分离出的6个G418抗性克隆中，有5个表达了neo-sof转录本。两个克隆合成了预期大小（3.8 kb）的多聚腺苷酸化mRNA，两个比预期的小，一个比预期的大。在用视黄酸（RA）和二丁酰环磷酸腺苷诱导分化4天后，两个表达c-fos蛋白水平降低的克隆在层粘连蛋白、IV型胶原蛋白和蛋白聚糖-19 RNA转录本的诱导中受到抑制。分化标志物TROMA-1和TROMA-3的诱导也受到抑制。由于甲胎蛋白基因正常激活，反义表达细胞在内胚层分化途径中未受到抑制。我们得出结论，c-fos反义表达抑制了F9细胞分化的某些方面。
