Glucocorticoid-stimulated accumulation of mouse mammary tumor virus RNA: increased rate of synthesis of viral RNA.
Glucocorticoid-stimulated accumulation of mouse mammary tumor virus RNA: increased rate of synthesis of viral RNA.
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糖皮质激素刺激小鼠乳腺肿瘤病毒 RNA 积累：病毒 RNA 合成率增加。
DOI：
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发表时间：
1977
影响因子：
11.1
通讯作者：
H. Varmus
中科院分区：
文献类型：
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作者：
G. Ringold;K. Yamamoto;J. Bishop;H. Varmus
糖皮质激素特异性地增加 GR 小鼠乳腺癌 (GR) 培养细胞系和 MMTV 感染的大鼠肝癌细胞系 (M1.19) 中小鼠乳腺肿瘤病毒 (MMTV) RNA 的细胞内浓度。相比之下，这些类固醇对 Balb/c 小鼠淋巴瘤系 S49 中 MMTV RNA 的浓度没有影响。使用分子杂交程序检测新合成的 RNA，我们直接测量了地塞米松（一种合成糖皮质激素）对 MMTV RNA 合成速率的影响。在 GR 细胞中，该激素可使病毒 RNA 合成速率提高 10 倍，而不会明显影响细胞 RNA 合成的总体速率。 MMTV RNA 合成从基础速率到最大刺激速率的转变发生在最早的标记期内，即添加激素后 0-15 分钟。因此，糖皮质激素似乎主要通过这种快速且特异性的转录速率改变来调节 MMTV 基因。在 M1.19 大鼠肝癌细胞中也获得了类似的结果。相反，地塞米松不影响 S49 淋巴瘤细胞中病毒 RNA 合成的速率。
Glucocorticoid hormones specifically increase the intracellular concentration of mouse mammary tumor virus (MMTV) RNA in a cultured cell line from a GR mouse mammary carcinoma (GR) and in an MMTV-infected rat hepatoma cell line (M1.19). In contrast, these steroids have no effect on the concentration of MMTV RNA in a lymphoma line, S49, from a Balb/c mouse. Using a molecular hybridization procedure to detect newly synthesized RNA, we have directly measured the effect of dexamethasone, a synthetic glucocorticoid, on the rate of MMTV RNA synthesis. In GR cells the hormone causes a 10-fold increase in the rate of synthesis of viral RNA without appreciably affecting the overall rate of cellular RNA synthesis. The transition from the basal to the maximally stimulated rate of MMTV RNA synthesis occurs within the earliest labeling period, 0-15 min after addition of the hormone. Thus, it appears that glucocorticoids regulate MMTV genes principally by this rapid and specific alteration of their rate of transcription. Similar results are obtained in M1.19 rat hepatoma cells. In contrast, dexamethasone does not affect the rate of viral RNA synthesis in S49 lymphoma cells.