Our overall objective is to elucidate how extracellular matrix (ECM) stimulates hormone production. Several estrogen-dependent pathological conditions including breast cancer, uterine fibroids, and endometriosis are associated with local overexpression of aromatase, a key enzyme in estrogen biosynthesis and important therapeutic target for postmenopausal ER+ breast cancer. In addition, excessive aromatase expression in adipose tissue at least partially accounts for obesity-associated breast cancer risk among postmenopausal women. While altered matrix homeostasis is associated with these aromatase- overexpressing tissues, little is known as to whether it can directly impact local steroidogenic gene expression and estrogen biosynthesis. A paucity of knowledge in this area is partly due to the lack of proper model systems that can recapitulate the mechanical properties of a cell's microenvironment. We hypothesize that ECM is a previously unappreciated critical determinant for local aromatase overexpression and estrogen production. In support of this hypothesis, our preliminary data indicate that matrix alone can significantly stimulate aromatase transcription in breast stromal cells (BSCs) via distinct signaling pathways. We have a repertoire of molecular and biophysical tools, in vitro and in vivo model systems, and cross-disciplinary expertise to further test the hypothesis. Specifically, we will first determine how ligand-receptor interactions rigidity, and three-dimensionality of a matrix affect aromatase expression;and how the matrix signals are sensed by cellular mechanosensory apparatus (Aim 1). We will then determine how the intracellular signaling cascades relay the matrix signals to the transcription machinery at the aromatase gene (Aim 2). Lastly, we will use in vitro co-culture systems, humanized animal models, and clinical samples to examine the functional consequences of matrix-induced stromal aromatase expression (Aim 3). The link between matrix homeostasis and hormone metabolism is a vastly under-explored topic. When successfully executed, the proposed work promises to fill a major gap of knowledge in this field. Findings from the study may also provide novel prognostic tools and markers, as well as new therapeutic targets for reducing local estrogen production, thus overcoming the side effects often associated with systemic inhibition of aromatase. In a broader sense, the conceptual and technical advances achieved in the current proposal may offer guidance to research on endocrine/paracrine dysfunction in a variety of tissues and organs.

Public Health Relevance

The proposed work promises to establish a novel paradigm for regulation of steroidogenic gene expression and estrogen production. The concept of ECM- influenced hormone metabolism may have a far-reaching impact on the etiology and treatment of endocrine diseases that are associated with altered matrix homeostasis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA161349-02
Application #
8464675
Study Section
Integrative and Clinical Endocrinology and Reproduction Study Section (ICER)
Program Officer
Sathyamoorthy, Neeraja
Project Start
2012-05-01
Project End
2017-03-31
Budget Start
2013-04-01
Budget End
2014-03-31
Support Year
2
Fiscal Year
2013
Total Cost
$289,862
Indirect Cost
$94,812
Name
University of Texas Health Science Center San Antonio
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229
Yuan, Bin; Cheng, Long; Chiang, Huai-Chin et al. (2014) A phosphotyrosine switch determines the antitumor activity of ER?. J Clin Invest 124:3378-90
Ghosh, Sagar; Hughes, Daniel; Parma, Dorothy Long et al. (2014) Association of obesity and circulating adipose stromal cells among breast cancer survivors. Mol Biol Rep 41:2907-16
Ghosh, Sagar; Gu, Fei; Wang, Chou-Miin et al. (2014) Genome-wide DNA methylation profiling reveals parity-associated hypermethylation of FOXA1. Breast Cancer Res Treat 147:653-9
Cuevas, Brandi T; Hughes, Daniel C; Parma, Dorothy Long et al. (2014) Motivation, exercise, and stress in breast cancer survivors. Support Care Cancer 22:911-7
Ghosh, Sagar; Ashcraft, Keith; Jahid, Md Jamiul et al. (2013) Regulation of adipose oestrogen output by mechanical stress. Nat Commun 4:1821