Ginny L. Powers

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Estrogen receptor-alpha (ERalpha) is a major therapeutic target of hormonal therapies in breast cancer, and its expression in tumors is predictive of clinical response. Protein levels of ERalpha are tightly controlled by the 26S proteasome; yet, how the clinical proteasome inhibitor, bortezomib, affects ERalpha regulation has not been studied. Bortezomib(More)
Breast cancer cell growth and therapeutic response are manipulated extrinsically by microenvironment signals. Despite recognition of the importance of the microenvironment in a variety of tumor processes, predictive measures that incorporate the activity of the surrounding cellular environment are lacking. In contrast, tumor cell biomarkers are well(More)
Estrogen receptor-alpha (ERalpha) is essential in the maintenance of cellular responsiveness to estrogen in the reproductive system. It is established that ligand binding induces downregulation of ERalpha protein by targeting receptor for destruction by the 26S proteasome. However, ERalpha is preserved in cells chronically exposed to estrogen and it is(More)
The prostate is a branched ductal-acinar gland that is part of the male reproductive tract. Prostate development depends upon the integration of steroid hormone signals, paracrine interactions between the stromal and epithelial tissue layers, and the actions of cell autonomous factors. Several genes and signaling pathways are known to be required for one or(More)
UNLABELLED Phosphodiesterase 4D (PDE4D) has recently been implicated as a proliferation-promoting factor in prostate cancer and is overexpressed in human prostate carcinoma. However, the effects of PDE4D inhibition using pharmacologic inhibitors have not been examined in prostate cancer. These studies examined the effects of selective PDE4D inhibitors,(More)
BACKGROUND In vivo ectopic gene expression is a common approach for prostate research through the use of transgenes in germline transgenic mice. For some other organs, somatic transgenesis with the Sleeping Beauty transposon system has allowed in vivo ectopic gene expression with higher throughput and lower cost than germline transgenic approaches. (More)
Purpose To determine the binding specificity of 18F-16α-17β-fluoroestradiol (FES) in estrogen receptor (ER) α-positive breast cancer cells and tumor xenografts. Materials and Methods Protocols were approved by the office of biologic safety and institutional animal care and use committee. By using ER-negative MDA-MB-231 breast cancer cells, clonal lines were(More)
Expression of the estrogen receptor-α (ERα) gene, ESR1, is a clinical biomarker used to predict therapeutic outcome of breast cancer. Hence, there is significant interest in understanding the mechanisms regulating ESR1 gene expression. Proteasome activity is increased in cancer and we previously showed that proteasome inhibition leads to loss of ESR1 gene(More)