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.
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.
|Zhang, Xiaowen; Chiang, Huai-Chin; Wang, Yao et al. (2017) Attenuation of RNA polymerase II pausing mitigates BRCA1-associated R-loop accumulation and tumorigenesis. Nat Commun 8:15908|
|Nair, Sreejith J; Zhang, Xiaowen; Chiang, Huai-Chin et al. (2016) Genetic suppression reveals DNA repair-independent antagonism between BRCA1 and COBRA1 in mammary gland development. Nat Commun 7:10913|
|Parameswaran, Balaji; Chiang, Huai-Chin; Lu, Yunzhe et al. (2015) Damage-induced BRCA1 phosphorylation by Chk2 contributes to the timing of end resection. Cell Cycle 14:437-48|
|Long Parma, Dorothy; Hughes, Daniel C; Ghosh, Sagar et al. (2015) Effects of six months of Yoga on inflammatory serum markers prognostic of recurrence risk in breast cancer survivors. Springerplus 4:143|
|Chiang, Huai-Chin; Elledge, Richard; Larson, Paula et al. (2015) Effects of Radiation Therapy on Breast Epithelial Cells in BRCA1/2 Mutation Carriers. Breast Cancer (Auckl) 9:25-9|
|Pan, Haihui; Zhao, Xiayan; Zhang, Xiaowen et al. (2015) Translational Initiation at a Non-AUG Start Codon for Human and Mouse Negative Elongation Factor-B. PLoS One 10:e0127422|
|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; 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|
|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; 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|
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