Genes targeted by the Hedgehog-signaling pathway can be regulated by Estrogen related receptor β

Additional file 1. Table S1: Known Hh-signaling pathway target genes. Table S2: Result of all pairwise comparisons of differentially expressed genes. Table S3: Hh-signaling differentially responsive genes

Messenger RNA profile analysis deciphers new Esrrb responsive genes in prostate cancer cells

Additional file 2: Table S1.  Gene ontology analysis result. Table S2. Esrrb expression with DY131 treatment (control vs. Esrrb + DY131)

Estrogen receptors in TRAMP C2 cells

Abstract only availableAccording to a 2005 study done by the American Cancer Society, prostate cancer is the second most common type of cancer among American men. It has been shown that estrogen receptors alpha and beta play significant roles in the development and inhibition of prostate cancer. To further understand the roles ERs play in prostate cancer, a Transgenic Adenocarcinogenic of the Mouse Prostate (TRAMP) model was utilized. Simply put, these DNA engineered mice are highly likely to develop a prostate cancer similar to the type experienced by humans. Similar to humans, in TRAMP mice there are different stages of prostate cancer; well differentiated carcinoma (WDC) and poorly differentiated carcinoma (PDC) are the stages being we study extensively. It has been shown that double transgenic ER alpha knockout/ TRAMP mice have decreased incidence of PDC, while ER beta knockout/ TRAMP mice have increased incidence of PDC, which implies different roles for ER α and ER β in prostate cancer. The TRAMP C2 cell line is derived from TRAMP mice and potentially serve as a good model for in vitro studies of prostate cancer. This cell line would be useful for studying estrogen effects on prostate cancer, if it contained ER α and β. Our hypothesis is that TRAMP C2 cells are ER α and ER β positive. The goal of this research is to test for the presence of these proteins in the TRAMP C2 cell line. To test for the presence of ER alpha and ER beta, the Western blot method was used. Western Blot is a widely accepted and efficient method for detecting a specific protein among a mixture of many different ones. In conclusion, both estrogen receptor α and β are present in TRAMP C2 cells. With this confirmation, the cure to prostate cancer is one step closer because this TRAMP C2 cell line will be well suited for determining the benefits of ER alpha and ER beta manipulation.NSF-REU Program in Biological Sciences & Biochemistr

Genistein Affects HER2 Protein Concentration, Activation and Promoter Regulation via Estrogen Receptor-and non-Estrogen Receptor-Mediated Mechanisms

The HER2 proto-oncogene, a member of the epidermal growth factor receptor family, is overexpressed in 20–30% of breast cancers. Genistein, the main soy isoflavone, interacts with estrogen receptors (ER) and it is also a potent tyrosine kinase inhibitor. Previously, our laboratory found that genistein delayed mammary tumor onset in transgenic mice that overexpress HER2 gene. Our goal was to define the mechanism through which genistein affects mammary tumorigenesis inHER2 overexpressing mice. We hypothesized that genistein inhibits HER2 activation and expression through ER-dependent and ER-independent mechanisms. Genistein inhibited total HER2 protein expression and tyrosine phosphorylation in BT-474, an ERα (−) and ERβ (+) human breast cancer cell line, however, E2 had no effect. Taken together, these data suggest that genistein has an ER-independent inhibitory effect, presumably, through tyrosine kinase inhibition activity. Genistein at 1.0 μM mimicked E2 and down-regulated HER2 protein phosphorylation when BT-474 was co-transfected with ERα, but not ERβ. Although E2 and overexpression of HER2 can promote mammary tumorigenesis, an inverse relationship between ER expression and HER2 overexpression has been found in human breast cancer. We cloned a 500-bp promoter region upstream of theHER2 transcription initiation site. Co-transfection with ERα, but not with ERβ, down-regulated HER2promoter reporter in BT-474. At concentrations ≥1 μM, genistein inhibited HER2 promoter reporter in the absence of ERα. In conclusion, genistein at ≥1 μM inhibited HER2 protein expression, phosphorylation, and promoter activity through an ER-independent mechanism. In the presence of ERα, genistein mimicked E2 and inhibited HER2 protein phosphorylation. These data support genistein’s chemo-prevention and potential chemo-therapeutic roles in breast cancer

Estrogen receptor-beta prevents cardiac fibrosis.

Development of cardiac fibrosis portends the transition and deterioration from hypertrophy to dilation and heart failure. Here we examined how estrogen blocks this important development. Angiotensin II (AngII) and endothelin-1 induce cardiac hypertrophy and fibrosis in humans. and we find that these agents directly stimulate the transition of the cardiac fibroblast to a myofibroblast. AngII and endothelin-1 stimulated TGFβ1 synthesis in the fibroblast, an inducer of fibrosis that signaled via c-jun kinase to Sma- and Mad-related protein 3 phosphorylation and nuclear translocation in myofibroblasts. As a result, mesenchymal proteins fibronectin and vimentin were produced, as were collagens I and III, the major forms found in fibrotic hearts. 17β-Estradiol (E2) or dipropylnitrile, an estrogen receptor (ER)β agonist, comparably blocked all these events, reversed by estrogen receptor (ER)β small interfering RNA. E2 and dipropylnitrile signaling through cAMP and protein kinase A prevented myofibroblast formation and blocked activation of c-jun kinase and important events of fibrosis. In the hearts of ovariectomized female mice, cardiac hypertrophy and fibrosis were induced by AngII infusion and prevented by E2 administration to wild type but not ERβ knockout rodents. Our results establish the cardiac fibroblast as an important target for hypertrophic/fibrosis-inducing peptides the actions of which were mitigated by E2/ERβ acting in these stromal cells

Studying DNA methylation changes of CpG islands in different stages of prostate cancer by pyrosequencing

Abstract only availableProstate cancer is one of the most common forms of cancer in men. Our lab is currently investigating changes in DNA methylation that occur during cancer progression, and in response to the soy phytoestrogen genistein treatment. We analyze genome-wide methylation differences by using the mouse DMH (mouse-Differential Methylation Hybridization) assay, a form of microarray. We are specifically looking at broad sets of CpG islands, areas rich in cytosine-guanine dinucleotides, that are subject to epigenetic modifications. The hypermethylation of CpG islands is correlated with the silencing of a gene while hypomethylation is correlated with a gene being actively transcribed. We were looking for potential new oncogenes or tumor suppressors. To study these genes we have a mouse model called TRAMP (TRansgenic Adenocarcinoma of the Mouse Prostate), which is a good model to study the progression of prostate cancer and metastasis because it is similar to human prostate cancer. We are using double transgenic mice that are WT or KO for the transcription factor estrogen receptor alpha, on a TRAMP background. The removal of ERα has been correlated with DNA methylation changes. These methylation changes showed up in our microarray screen that led us to find a set of genes that were differentially methylated across cancer progression. We selected one gene: Kinesin superfamily protein 9 (K3_E17) which has been shown on our microarrays to be methylated in well differentiated carcinoma and unmethylated in hyperplasia and poorly differentiated carcinoma. To confirm the methylation status we performed pyrosequencing, a new method to specifically study short sequences of DNA for methylation at specific CG sites. Our hypothesis is that in well differentiated carcinoma Kinesin 9 is hypermethylated, which will correlate with this gene being turned off. This would mean that Kinesin 9 might be acting as a tumor suppressor.Life Sciences Undergraduate Research Opportunity Progra

Phytosterol Pygeum africanum regulates prostate cancer in vitro and in vivo

Background Prostate cancer is an important public health problem. It is an excellent candidate disease for chemo-prevention because prostate cancer is typically slow growing and is usually diagnosed in elderly males. Pygeum africanum (Prunus africana or Rosaceae) is an African prune (plum) tree found in tropical Africa. An extract from the bark of Pygeum africanum has been used in Europe as a prevention and treatment of prostate disorders including benign prostatic hypertrophy (BPH). More recently in the USA, the phytotherapeutic preparations of Pygeum africanum and Saw palmetto have been marketed for prostate health including prostate cancer prevention and treatment. Methods The anti-cancer potential of Pygeum africanum has been tested both in vitro (PC-3 and LNCaP cells) and in␣vivo (TRAMP mouse model). Results In tissue culture, ethanolic extracts (30%) of Pygeum africanum inhibited the growth of PC-3 and LNCaP cells; induced apoptosis and altered cell kinetics; down regulated ERα and PKC-α protein, and demonstrated good binding ability to both mouse uterine estrogen receptors and LNCaP human androgen receptors. TRAMP mice fed Pygeum africanum showed a significant reduction (P = 0.034) in prostate cancer incidence (35%) compared to casein fed mice (62.5%). Conclusion Pygeum africanum, which is widely used in Europe and USA for treatment of BPH, has a significant role in regulation of prostate cancer both in␣vitro and in␣vivo and therefore may be a useful supplement for people at high risk for developing prostate cancer

Impaired cerebral autoregulation distal to carotid stenosis/occlusion is associated with increased risk of stroke at cardiac surgery with cardiopulmonary bypass

ObjectivesSevere carotid stenosis and occlusion are associated with an increased risk of stroke during and after cardiac surgery with cardiopulmonary bypass. Relevance of an impaired cerebral autoregulation caused by stenosis/occlusion is unknown.MethodsWe prospectively assessed the incidence of stroke in relation to severity of carotid disease and corresponding autoregulatory reserve in 2797 patients who had coronary artery bypass graft and/or valve surgery with cardiopulmonary bypass. Patients underwent preoperative carotid sonography and, in case of severe extracranial disease, transcranial Doppler sonography with carbon dioxide stimulation to assess cerebrovascular reserve capacity.ResultsSixty-seven (2.4%) patients had an ischemic stroke, which was fatal in 5. Anterior hemispheric stroke occurred in 42 (1.9%) patients with no/low-grade stenosis, 6 (1.8%) with medium-grade stenosis, 1 (0.6%) with high-grade stenosis/occlusion and normal autoregulation, and 3 (27.3%) with high-grade stenosis/occlusion and exhausted autoregulatory reserve. Increased risk was observed in patients with high-grade stenosis/occlusion and exhausted autoregulatory reserve also after adjustment for potential confounders (adjusted odds ratio [OR] 28.3, 95% confidence interval [CI] 5.8–139.1). Stroke risk was not increased in patients with stenosis/occlusion and normal autoregulation (1.5%, adjusted OR 0.6, 95% CI 0.2–1.6).ConclusionsCerebrovascular reserve capacity evaluated by preoperative transcranial Doppler carbon dioxide testing is a major determinant of stroke risk in patients with carotid artery stenosis/occlusion undergoing cardiac surgery with cardiopulmonary bypass. Its assessment facilitates identification of patients with an excess perioperative stroke risk

Improving mouse-DMH screening capability by adding 2000 mouse CpG islands

Abstract only availableDNA methylation alteration, in correlation with gene expression, is involved in development and progression of many cancers. Using a microarray based method, mouse-DMH (Differential Methylation Hybridization), our lab is able to study DNA methylation changes during prostate cancer progression in the TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mouse model. Currently, there are about 3000 CpG islands on the microarray, which were used as probes to detect DNA methylation changes. In order to improve our ability to screen for a larger number of CpG island methylation changes, we are working on adding about 2000 more mouse CpG islands onto the array. In addition, we have successfully designed primers and PCR amplified CpG islands for tumor suppressor genes and proto-oncogenes which have been previously reported in literature to be differentially methylated during development of human prostate cancer. These genes include AR (Androgen Receptor), ER (Estrogen Receptor alpha), ER(Estrogen Receptor beta) and GSTP1 (Glutathione S-Transferase PI). Primer design and PCR amplification for other known tumor suppressors/oncogenes is still in process. The microarray-based mouse-DMH is a tool of great potential. It can easily be adapted to screen for DNA methylation changes in other mouse cancer models and generate valuable data leading to understanding of the molecular mechanism behind cancer development, which will in turn contribute to treatment of human cancers.NSF-REU Biology & Biochemistr