Estrogen and its receptors are critical factors in the development, progression, metastasis and treatment of breast cancer. In addition to the classical nuclear estrogen receptors, ERalpha and ERbeta, the 7-transmembrane G protein-coupled estrogen receptor GPER is now recognized as mediating many of the rapid signaling events associated with estrogen action. Anti-estrogen therapies in the form of selective estrogen receptor modulators (SERMs, such as tamoxifen) and selective estrogen receptor down regulators (SERDs, such as Fulvestrant) have been highly successful in many ER-positive breast cancer patients;however, intrinsic and acquired resistance remains significant problems. Tamoxifen and Fulvestrant are agonists of GPER, suggesting that GPER may play a role in resistance to these drugs. We have identified both a selective agonist and antagonists of GPER that will allow us to test the hypothesis that GPER plays an important role in breast carcinogenesis and treatment efficacy.
Aim 1 will test whether GPER mediates cellular effects including proliferation, survival, transformation and migration in response to estrogen, anti-estrogens and GPER-selective ligands.
Aim 2 will test whether selective targeting of GPER activity modulates carcinogenesis and metastasis in a murine model of breast cancer.
Aim 3 will test whether selective activation and inhibition of GPER regulates proliferation and survival of cells in normal human breast tissue and human breast tumor explants. Significance: Completion of these aims will significantly advance our knowledge of and provide insight into the role of the novel estrogen receptor GPER in multiple aspects of breast cancer, from initiation to metastasis and drug resistance resulting in the identification of a novel therapeutic target for which highly selective antagonists exist. Further development of this antagonist could lead to a new drug for the treatment of GPER-expressing breast tumors.

Public Health Relevance

Estrogen and its receptors play important roles in breast cancer and are the targets of multiple therapies in breast cancer. Although often initially effective, resistance to drugs such as tamoxifen is a common problem. This study will determine the role of a novel estrogen receptor in breast cancer formation, progression and metastasis and test the ability of unique inhibitors of this receptor to prevent, cure or reduce the severity f this cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA163890-02
Application #
8517052
Study Section
Tumor Progression and Metastasis Study Section (TPM)
Program Officer
Sathyamoorthy, Neeraja
Project Start
2012-08-01
Project End
2017-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
2
Fiscal Year
2013
Total Cost
$294,526
Indirect Cost
$99,476
Name
University of New Mexico Health Sciences Center
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
829868723
City
Albuquerque
State
NM
Country
United States
Zip Code
87131
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Scaling, Allison L; Prossnitz, Eric R; Hathaway, Helen J (2014) GPER mediates estrogen-induced signaling and proliferation in human breast epithelial cells and normal and malignant breast. Horm Cancer 5:146-60
Marjon, Nicole A; Hu, Chelin; Hathaway, Helen J et al. (2014) G protein-coupled estrogen receptor regulates mammary tumorigenesis and metastasis. Mol Cancer Res 12:1644-54
Nayak, Tapan K; Ramesh, Chinnasamy; Hathaway, Helen J et al. (2014) GPER-targeted, 99mTc-labeled, nonsteroidal ligands demonstrate selective tumor imaging and in vivo estrogen binding. Mol Cancer Res 12:1635-43
Brunsing, Ryan L; Owens, Kristin S; Prossnitz, Eric R (2013) The G protein-coupled estrogen receptor (GPER) agonist G-1 expands the regulatory T-cell population under TH17-polarizing conditions. J Immunother 36:190-6
Sharma, Geetanjali; Hu, Chelin; Brigman, Jonathan L et al. (2013) GPER deficiency in male mice results in insulin resistance, dyslipidemia, and a proinflammatory state. Endocrinology 154:4136-45
Barton, Matthias; Meyer, Matthias R; Prossnitz, Eric R (2013) Alike but not the same: anatomic heterogeneity of estrogen receptor-mediated vasodilation. J Cardiovasc Pharmacol 62:22-5