转录组学和 ChIP-seq 分析揭示了 HER2+ 乳腺癌细胞中 EGFR 信号的动态染色质景观和 S100 基因作为靶点。
Transcriptomic and ChIP-sequence interrogation of EGFR signaling in HER2+ breast cancer cells reveals a dynamic chromatin landscape and S100 genes as targets.
机构信息
Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 East 120th Street, Los Angeles, CA, 90059, USA.
Jonsson Comprehensive Cancer Center and David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
出版信息
BMC Med Genomics. 2019 Feb 8;12(1):32. doi: 10.1186/s12920-019-0477-8.
BACKGROUND
The Human Epidermal Growth Factor Receptor (EGFR/HER1) can be activated by several ligands including Transforming Growth Factor alpha (TGF-α) and Epidermal Growth Factor (EGF). Following ligand binding, EGFR heterodimerizes with other HER family members, such as HER2 (human epidermal growth factor receptor-2). Previously, we showed that the EGFR is upregulated in trastuzumab resistant HER2 positive (HER2+) breast cancer cells. This study is aimed to determine the downstream effects on transcription following EGFR upregulation in HER2+ breast cancer cells.
METHODS
RNA-sequence and ChIP-sequence for H3K18ac and H3K27ac (Histone H3 lysine K18 and K27 acetylation) were conducted following an Epidermal Growth Factor (EGF) treatment time course in HER2+ breast cancer cells, SKBR3. The levels of several proteins of interest were confirmed by western blot analysis. The cellular localization of proteins of interest was examined using biochemically fractionated lysates followed by western blot analysis.
RESULTS
Over the course of 24 h, EGFR stimulation resulted in the modulation of over 4000 transcripts. Moreover, our data demonstrates that EGFR/HER2 signaling regulates the epigenome, with global H3K18ac and H3K27ac oscillating as a function of time following EGF treatment. RNA-sequence data demonstrates the activation of immediate early genes (IEGs) and delayed early genes (DEGs) within 1 h of EGF treatment. More importantly, we have identified members of the S100 (S100 Calcium Binding Protein) gene family as likely direct targets of EGFR signaling as H3K18ac, H3K27ac and pol2 (RNA polymerase II) increase near the transcription start sites of some of these genes.
CONCLUSIONS
Our data suggests that S100 proteins, which act as Ca2+ sensors, could play a role in EGF induced tumor cell growth and metastasis, contribute to trastuzumab resistance and cell migration and that they are likely drug targets in HER2+ breast cancer.
背景
人类表皮生长因子受体（EGFR/HER1）可被多种配体激活，包括转化生长因子α（TGF-α）和表皮生长因子（EGF）。配体结合后，EGFR 与其他 HER 家族成员（如 HER2）异二聚化。先前，我们发现曲妥珠单抗耐药的 HER2 阳性（HER2+）乳腺癌细胞中 EGFR 上调。本研究旨在确定 HER2+乳腺癌细胞中 EGFR 上调后对转录的下游影响。
方法
在 HER2+乳腺癌细胞 SKBR3 中进行表皮生长因子（EGF）处理时间过程的 RNA 测序和 H3K18ac 和 H3K27ac（组蛋白 H3 赖氨酸 K18 和 K27 乙酰化）的 ChIP-seq。通过 Western blot 分析证实了几个感兴趣蛋白的水平。使用生物化学分级裂解物后进行 Western blot 分析来检查感兴趣蛋白的细胞定位。
结果
在 24 小时的过程中，EGFR 刺激导致超过 4000 个转录本的调节。此外，我们的数据表明，EGFR/HER2 信号转导调节表观基因组，EGF 处理后，H3K18ac 和 H3K27ac 整体呈时间依赖性波动。RNA 测序数据表明，EGF 处理后 1 小时内立即早期基因（IEGs）和延迟早期基因（DEGs）的激活。更重要的是，我们已经确定 S100（钙结合蛋白 S100）基因家族的成员可能是 EGFR 信号的直接靶标，因为 H3K18ac、H3K27ac 和 pol2（RNA 聚合酶 II）在这些基因的一些转录起始位点附近增加。
结论
我们的数据表明，作为 Ca2+传感器的 S100 蛋白可能在 EGF 诱导的肿瘤细胞生长和转移中发挥作用，有助于曲妥珠单抗耐药和细胞迁移，并且它们可能是 HER2+乳腺癌的药物靶点。
Zotero 插件