The epithelial-specific ETS transcription factor ESX/ESE-1/Elf-3 modulates breast cancer-associated gene expression
The epithelial-specific ETS transcription factor ESX/ESE-1/Elf-3 modulates breast cancer-associated gene expression
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DOI：
10.1089/104454903321515896
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发表时间：
2003-02-01
影响因子：
3.1
通讯作者：
Gutierrez-Hartmann, A
中科院分区：
文献类型：
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作者：
Eckel, KL;Tentler, JJ;Gutierrez-Hartmann, A
ETS转录因子家族的几个成员参与许多不同组织的肿瘤发生，包括乳腺上皮。ESX基因是上皮特异性的Ets成员，与乳腺癌特别相关。ESX在早期乳腺癌中扩增，在人乳腺导管原位癌中过表达，HER2/neu原癌基因与ESX之间可能存在正反馈回路。尽管我们对ESX的理解取得了进展，但其调节肿瘤相关基因表达和调节乳腺细胞存活的能力仍然未知。我们发现HA-ESX刺激胶原酶和HER2/neu启动子，但不能激活完整的基质溶解素启动子。然而，HA-ESX以剂量依赖的方式激活了一个异源启动子，该启动子含有来自基质溶解素基因（p8Xpal-CAT）的8个Ets结合位点拷贝。对编码9个Ets家族成员的构建体激活HER2/neu启动子的能力分析揭示了三种基因激活模式：(1)不影响或抑制启动子活性（Elk-1和NET）；(2)中间活性（ER81、GABP、ESX和HA-Ets-2）；(3)最大活动（Ets-1、VP-16-Ets-1和EHF）。基于这些观察结果，我们还确定了ESX是否能够赋予永生化但未转化且ESX阴性的MCF-12A人乳腺细胞存活表型。通过集落形成实验，我们发现HA-ESX和HA-Ets-2介导的MCF-12A细胞存活率接近致癌V12 Ras产生的细胞存活率，而空载体导致的集落形成可以忽略不计。相比之下，在永生化和转化的同时表达HER2/neu和ESX的T47D乳腺癌细胞中，我们发现反义和显性阴性HA-ESX抑制T47D集落的形成，而对照载体允许形成许多集落。这些结果具有重要意义，因为它们表明HA-ESX能够不同地激活几种恶性肿瘤相关基因启动子，并且ESX的表达对于未转化的MCF-12A和转化的T47D人乳腺细胞的细胞存活是必需的。
Several members of the ETS family of transcription factors contribute to tumorigenesis in many different tissues, including breast epithelium. The ESX gene is an epithelial-specific Ets member that is particularly relevant to breast cancer. ESX is amplified in early breast cancers, it is overexpressed in human breast ductal carcinoma in situ, and there may be a positive feedback loop between the HER2/neu proto-oncogene and ESX. Despite this progress in our understanding of ESX, its ability to regulate tumor-related gene expression and to modulate breast cell survival, remain unknown. Here we show that HA-ESX stimulates the collagenase and HER2/neu promoters, but fails to activate an intact stromelysin promoter. However, HA-ESX activates, in a dose-dependent manner, a heterologous promoter containing eight copies of the Ets binding site derived from the stromelysin gene (p8Xpal-CAT). Analysis of the ability of constructs encoding nine Ets family members to activate the HER2/neu promoter revealed three patterns of gene activation: ( 1) no effect or repressed promoter activity (Elk-1 and NET); ( 2) intermediate activity (ER81, GABP, ESX, and HA-Ets-2); and, ( 3) maximal activity (Ets-1, VP-16-Ets-1, and EHF). Based on these observations, we also determined whether ESX is capable of conferring a survival phenotype upon immortalized, but nontransformed and ESX negative MCF-12A human breast cells. Using a colony formation assay, we found that HA-ESX and HA-Ets-2, mediated MCF-12A cell survival rates that approached those generated by oncogenic V12 Ras, whereas empty vector resulted in negligible colony formation. By contrast, in immortalized and transformed T47D breast cancer cells, which express both HER2/neu and ESX, we found that antisense and dominant-negative HA-ESX inhibited T47D colony formation, whereas control vector allowed formation of many colonies. These results are significant because they show that HA-ESX is able to differentially activate several malignancy-associated gene promoters, and that ESX expression is required for cellular survival of nontransformed MCF-12A and transformed T47D human mammary cells.