Estrogen regulates Hippo signaling via GPER in breast cancer
Xin Zhou, Shuyang Wang, Zhen Wang, Xu Feng, Peng Liu, Xian-Bo Lv, Fulong Li, Fa-Xing Yu, Yiping Sun, Haixin Yuan, Hongguang Zhu, Yue Xiong, Qun-Ying Lei, Kun-Liang Guan
Xin Zhou, Shuyang Wang, Zhen Wang, Xu Feng, Peng Liu, Xian-Bo Lv, Fulong Li, Fa-Xing Yu, Yiping Sun, Haixin Yuan, Hongguang Zhu, Yue Xiong, Qun-Ying Lei, Kun-Liang Guan
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Research Article Oncology

Estrogen regulates Hippo signaling via GPER in breast cancer

Abstract

The G protein–coupled estrogen receptor (GPER) mediates both the genomic and nongenomic effects of estrogen and has been implicated in breast cancer development. Here, we compared GPER expression in cancerous tissue and adjacent normal tissue in patients with invasive ductal carcinoma (IDC) of the breast and determined that GPER is highly upregulated in cancerous cells. Additionally, our studies revealed that GPER stimulation activates yes-associated protein 1 (YAP) and transcriptional coactivator with a PDZ-binding domain (TAZ), 2 homologous transcription coactivators and key effectors of the Hippo tumor suppressor pathway, via the Gαq-11, PLCβ/PKC, and Rho/ROCK signaling pathways. TAZ was required for GPER-induced gene transcription, breast cancer cell proliferation and migration, and tumor growth. Moreover, TAZ expression positively correlated with GPER expression in human IDC specimens. Together, our results suggest that the Hippo/YAP/TAZ pathway is a key downstream signaling branch of GPER and plays a critical role in breast tumorigenesis.

Authors

Xin Zhou, Shuyang Wang, Zhen Wang, Xu Feng, Peng Liu, Xian-Bo Lv, Fulong Li, Fa-Xing Yu, Yiping Sun, Haixin Yuan, Hongguang Zhu, Yue Xiong, Qun-Ying Lei, Kun-Liang Guan

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Figure 3

GPER acts through Gαq/11, PLCβ-PKC, and Rho/ROCK to stimulate TAZ.

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GPER acts through Gαq/11, PLCβ-PKC, and Rho/ROCK to stimulate TAZ. (A) G...
(A) Gαq/11 was required for G1 to activate TAZ. ZR-75-30 cells were transfected with control or 2 different Gαq/11 siRNAs. After 8 hours of serum starvation, cells were treated with 100 nM G1 for 2 hours. The knockdown efficiency of Gαq/11, TAZ protein levels and phosphorylation, and CTGF expression were determined by immunoblotting. (B and C) PLCβ and PKC were required for G1-induced TAZ activation. Serum-starved ZR-75-30 cells were pretreated with PLCβ inhibitors (U73122 or ET-18-OCH3) or PKC inhibitors (enzastaurin or chelerythrin chloride) for 4 hours and then stimulated with 100 nM G1 for 2 hours. The lysates were subjected to immunoblot analysis with the indicated antibodies. (D) Inactivation of Rho prevented TAZ dephosphorylation and accumulation following G1 stimulation. Serum-starved ZR-75-30 cells were pretreated with C3 for 4 hours (left panel) or transfected with dominant-negative RhoN19 or Rho GDI (right panel) and then stimulated with 100 nM G1 for 2 hours. Cell lysates were subjected to immunoblotting with the indicated antibodies. (E) ROCK was required for G1-induced TAZ activation. After serum starvation, ZR-75-30 cells were pretreated with the ROCK inhibitor GSK429286 or Y27632 for 4 hours, followed by treatment with 100 nM G1 for 2 hours. Immunoblotting was performed. (F) Disruption of the actin cytoskeleton blocked G1-induced TAZ activation. Serum-starved ZR-75-30 cells were pretreated with Lat B or Cyto D for 15 minutes and then stimulated with 100 nM G1 for 2 hours. Immunoblotting was performed. Data are representative of at least 3 independent experiments.