Grainyhead like 2 (GRHL2) is an essential transcription factor for development and function of epithelial tissues. It has dual roles in cancer by supporting tumor growth while suppressing epithelial to mesenchymal transitions (EMT). GRHL2 cooperates with androgen and estrogen receptors (ER) to regulate gene expression. We explore genome wide GRHL2 binding sites conserved in three ER⍺/GRHL2 positive luminal breast cancer cell lines by ChIP-Seq. Interaction with the ER⍺/FOXA1/GATA3 complex is observed, however, only for a minor fraction of conserved GRHL2 peaks. We determine genome wide transcriptional dynamics in response to loss of GRHL2 by nascent RNA Bru-seq using an MCF7 conditional knockout model. Integration of ChIP- and Bru-seq pinpoints candidate direct GRHL2 target genes in luminal breast cancer. Multiple connections between GRHL2 and proliferation are uncovered, including transcriptional activation of ETS and E2F transcription factors. Among EMT-related genes, direct regulation of CLDN4 is corroborated but several targets identified in other cells (including CDH1 and ZEB1) are ruled out by both ChIP- and Bru-seq as being directly controlled by GRHL2 in luminal breast cancer cells. Gene clusters correlating positively (including known GRHL2 targets such as ErbB3, CLDN4/7) or negatively (including TGFB1 and TGFBR2) with GRHL2 in the MCF7 knockout model, display similar correlation with GRHL2 in ER positive as well as ER negative breast cancer patients. Altogether, this study uncovers gene sets regulated directly or indirectly by GRHL2 in luminal breast cancer, identifies novel GRHL2-regulated genes, and points to distinct GRHL2 regulation of EMT in luminal breast cancer cells.

中文翻译：

---

管腔乳腺癌中 GRHL2 控制的基因表达网络

Grainyhead like 2 (GRHL2) 是上皮组织发育和功能必需的转录因子。它在癌症中具有双重作用，支持肿瘤生长，同时抑制上皮间质转化 (EMT)。GRHL2 与雄激素和雌激素受体 (ER) 合作调节基因表达。我们通过 ChIP-Seq 探索了三种 ER⍺/GRHL2 阳性管腔乳腺癌细胞系中保守的全基因组 GRHL2 结合位点。然而，仅观察到一小部分保守 GRHL2 峰与 ER⍺/FOXA1/GATA3 复合物的相互作用。我们使用 MCF7 条件敲除模型，通过新生 RNA Bru-seq 确定了响应 GRHL2 丢失的全基因组转录动态。ChIP-和 Bru-seq 的整合可精确定位管腔乳腺癌中候选的直接 GRHL2 靶基因。GRHL2 与增殖之间的多重联系已被发现，包括 ETS 和 E2F 转录因子的转录激活。在 EMT 相关基因中，CLDN4 的直接调控得到了证实，但 ChIP-和 Bru-seq 都排除了在其他细胞（包括 CDH1 和 ZEB1）中鉴定的几个靶标，因为在管腔乳腺癌细胞中直接受 GRHL2 控制。在MCF7敲除模型中，与GRHL2呈正相关（包括已知的GRHL2靶标，如ErbB3、CLDN4/7）或负相关（包括TGFB1和TGFBR2）的基因簇，在ER阳性和ER阴性乳腺癌患者中显示出与GRHL2相似的相关性。总而言之，这项研究揭示了管腔乳腺癌中 GRHL2 直接或间接调节的基因组，鉴定了新的 GRHL2 调节基因，并指出了管腔乳腺癌细胞中 GRHL2 对 EMT 的独特调节。