Sustained mammary gland-directed, ponasterone A-inducible expression in transgenic mice
Sustained mammary gland-directed, ponasterone A-inducible expression in transgenic mice
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DOI：
10.1096/fasebj.14.7.877
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发表时间：
2000-05-01
期刊：
影响因子：
4.8
通讯作者：
Pestell, RG
中科院分区：
文献类型：
--
作者：
Albanese, C;Reutens, AT;Pestell, RG
在转基因小鼠中调节靶基因的时空特异性表达的能力将有助于基因功能的分析，并使建立人类疾病的小鼠模型成为可能。乳腺肿瘤发生的遗传学分析需要开发乳腺特异的转基因基因，这些转基因基因在整个成人乳腺上皮中受到严格调控。嵌合型转基因表达和几个候选基因(细胞周期蛋白D1、Stat5a、催乳素受体)的纯合缺失使乳腺正常发育受阻，阻碍了对乳腺肿瘤发生的基因分析。我们描述了转基因小鼠品系的发展，在这些品系中，成人乳腺上皮中持续的转基因表达受到诱导，既有特异性的，也有一致性的。使用了编码RXRα和嵌合蜕皮激素受体的转基因，在针对乳腺表达的改良MMTV-LTR的控制下。将这些转基因‘受体’系与转基因‘增强子’系杂交，在这些‘增强子’系中，蜕皮激素/RXR结合位点诱导了转基因β-半乳糖苷酶的配体依赖性表达。药代动力学分析表明，从当地植物中筛选出的蜕皮甾类化合物证明了一种具有高度生物活性的配基(巴那雄酮A)在体内的持续释放和转基因表达。这一转基因模型具有严格调控和均一的转基因表达，利用从当地菌群中提取的配基在体内维持，在乳腺疾病的遗传分析中具有广泛的实用价值。
The ability to regulate temporal- and spatial-specific expression of target genes in transgenic mice will facilitate analysis of gene function and enable the generation of murine models of human diseases. The genetic analysis of mammary gland tumorigenesis requires the development of mammary gland-specific transgenics, which are tightly regulated throughout the adult mammary epithelium. Analysis of genes implicated in mammary gland tumorigenesis has been hampered by mosaic transgene expression and the findings that homozygous deletion of several candidate genes (cyclin D1, Stat5A, prolactin receptor) abrogates normal mammary gland development. We describe the development of transgenic mouse lines in which sustained transgene expression was inducibly regulated, both specifically and homogeneously, in the adult mammary gland epithelium. Transgenes encoding RXR alpha and a chimeric ecdysone receptor under control of a modified MMTV-LTR, which targets mammary gland expression, were used. These transgenic 'receptor' lines were crossed with transgenic 'enhancer' lines in which the ecdysone/RXR binding site induced ligand-dependent expression of transgenic beta-galactoxidase. Pharmacokinetic analysis of a highly bioactive ligand (ponasterone A), identified through screening ecdysteroids from local plants, demonstrated sustained release and transgene expression in vivo. This transgenic model with both tightly regulated and homogeneous transgene expression, which was sustained in vivo using ligands readily extracted from local flora, has broad practical applicability for genetic analysis of mammary gland disease.