Abstract P5-06-01: MTA2 and AR Overexpression in ER-Negative Breast Cancer Cells: Roles in Invasion and Metastasis

Background: We have previously shown that overexpression of metastasis associated protein 2 (MTA2) can render estrogen receptor (ER)-positive breast cancer cells hormone-independent through postranscriptional effects on ER acetylation and phosphorylation. Recently we discovered that MTA2 overexpression in ER-negative MDA-MB-231 breast cancer cells enhances invasion and metastasis in athymic nude mice which involves activation of the Rho pathway. It is also known that the androgen receptor (AR) is frequently expressed in breast tumors; however its role in proliferation, invasion, or breast cancer metastasis is poorly understood. Materials and Methods: MTA2 was stably overexpressed in MDA-MB-231 and its levels validated using Western blot analysis. To identify downstream effects due to MTA2 overexpression, we employed reverse phase protein arrays, and Affymetrix expression arrays. Significant changes in gene expression were identified using dCHIP software, and student t tests. Invasion was examined using modified Boyden chamber growth assays, proliferation was assayed using soft agar growth and MTT assays, and metastasis was measured as tumor growth in athymic nude mice. Results: MTA2 overexpression in ER-negative cells enhanced distant and skin metastases in athymic nude mice. In an attempt to identify effectors of MTA2-mediated metastasis, we used RNA microarray and protein array screens, and found that AR was significantly increased. As a control, we employed a rescue of the highly metastatic MTA2-MDA-MB-231 cell phenotype via stable transfection and add-back of Rho GDIa, a gene that was concomitantly down-regulated with MTA2 overexpression. AR levels were significantly reduced with Rho GDIa add-back. To determine if AR was functional in these cells, we used ARE-luciferase reporter assays and discovered that both basal, and agonist (R1881)-induced transcriptional activity were significantly enhanced. The AR antagonist, bicalutamide, was effective at significantly decreasing the invasive potential of MTA2- overexpressing MDA-MB-231 cells In vivo experiments in nude mice with bicalutamide treatment are underway.

Discussion: AR was significantly overexpressed with the aggressive phenotype conferred via MTA2 overexpression. This suggests that blockade of AR action might provide a new therapeutic target to inhibit metastasis of breast cancer cells.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-01.

Abstract S6-9: Expression of Hedgehog Proteins in the Epithelial and Stromal Compartments of Primary Breast Tumors and Its Prognostic Significance

Purpose: Aberrant hedgehog (Hh) signaling has been reported in various cancers including breast cancers and clinical trials targeting this pathway are currently ongoing. Preclinical evidence suggests that increased ligand-dependent Hh signaling in breast tumor epithelial (E) cells cross-talks and activates Hh pathway in the stroma (S) but the clinical implication of this E/S interaction is unknown. We sought to determine the expression of Hh proteins in the E and S compartments of primary breast tumor samples and correlate with clinical outcomes.

Methods: Using tissue microarray (TMA) of ∼500 primary breast cancer samples (OSU 2009C009 A) that includes both primary breast tumor and axillary metastasis, the expression pattern of the key Hh signaling proteins (Shh, Gli-1, SMO, Ptch1) and a target gene of the pathway (BMI1) was determined by immunohistochemistry (IHC) in both the epithelial and stromal tissues and compared to other known prognostic/predictive markers such as age, stage, estrogen/progesterone receptor (ER/PR)/HER2 status and to disease-free survival (DFS). IHC was performed using Benchmark LT automated system from Ventana Medical Systems using previously published methods (Nuovo GJ, Nature protocols, 2009). Scoring was done by combining the intensity and percentage of cells staining with respective antibodies by three independent measurements.

Results: Analysis of a total of 315 primary breast tumors revealed the following percentage of tumors with high expression of Hh proteins in the E/S compartments respectively: Shh (72/31%), Gli-1 (69/53%), SMO (40/64%), and Ptch-1 (93/74%). Analyzing the interaction between the epithelial and stromal expressions of these proteins, we found positive correlation between i) high Shh and SMO in the epithelial cells and Gli-1 in the stroma, and ii) high Gli-1 in the epithelial cells and target protein Bmi1 in the stroma. High intensity staining of Gli-1 in the tumor epithelial cells was significantly associated with higher stage, grade, ER negative status and worse DFS. Adjusting for stage and ER status, tumors with increased epithelial Gli-1 expression was still significantly associated with worse DFS (p=0.0131, survival analysis) when compared to tumors with low expression. In particular, among the ER negative and node positive patients higher Gli-1 expression in epithelial cells was very significantly associated with poor DFS (p= <0.0001). Staining for other target proteins in these tumors is currently ongoing.

Conclusions: We report here for the first time a positive correlation between expression of Hh proteins in the stromal and epithelial compartment of primary breast tumors. Furthermore, we observed that higher Gli-1 expression in the tumor epithelial cells was associated with worse DFS, particularly in the ER negative, node-positive tumors suggesting that aberrant Hh signaling may contribute to drug-resistance and hence a rationale therapeutic target. Further correlative studies between clinical parameters and additional Hh target genes in these tumors are in progress.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S6-9.

Search for dijet resonances in 7 TeV pp collisions at CMS

A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 pb⁻¹ collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E6 diquarks, in specific mass intervals. This extends previously published limits on these models.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Transgenic rescue of enamel phenotype in Ambn null mice

Ameloblastin null mice fail to make an enamel layer, but the defects could be due to an absence of functional ameloblastin or to the secretion of a potentially toxic mutant ameloblastin. We hypothesized that the enamel phenotype could be rescued by the transgenic expression of normal ameloblastin in Ambn mutant mice. We established and analyzed 5 transgenic lines that expressed ameloblastin from the amelogenin (AmelX) promoter and identified transgenic lines that express virtually no transgene, slightly less than normal (Tg+), somewhat higher than normal (Tg++), and much higher than normal (Tg+++) levels of ameloblastin. All lines expressing detectable levels of ameloblastin at least partially recovered the enamel phenotype. When ameloblastin expression was only somewhat higher than normal, the enamel covering the molars and incisors was of normal thickness, had clearly defined rod and interrod enamel, and held up well in function. We conclude that ameloblastin is essential for dental enamel formation.

Intradermal alpha1-antitrypsin therapy avoids fatal anaphylaxis, prevents type 1 diabetes and reverses hyperglycaemia in the NOD mouse model of the disease

AIMS/HYPOTHESIS

Human alpha1-antitrypsin (hAAT) gene therapy prevents type 1 diabetes in a NOD mouse model of diabetes. However, repeated i.p. injections of hAAT into NOD mice leads to fatal anaphylaxis. The aim of the study was to determine if an alternative route of administration avoids anaphylaxis and allows evaluation of hAAT's potential for diabetes prevention and reversal. We also sought to determine if the addition of granulocyte colony-stimulating factor (G-CSF), augments hAAT's capacity to prevent or reverse disease in the NOD mice.

METHODS

To evaluate hAAT pharmacokinetics, serum hAAT levels were monitored in NOD mice receiving a single dose (2 mg) of hAAT by i.p., s.c. or i.d. injection. For studies of type 1 diabetes prevention and reversal, mice received i.d. hAAT (2 mg/mouse/3 days) for 8 or 10 weeks or hAAT and G-CSF (i.p., 6 microg/day) for 6 weeks. Blood glucose determinations, glucose tolerance testing and insulin tolerance tests were performed.

RESULTS

Both i.p. and s.c. injections resulted in fatal anaphylaxis. The i.d. injection avoided anaphylaxis and i.d. injection of hAAT into 11-week-old NOD mice prevented disease (p = 0.005, AAT vs PBS at 40 weeks of age). Treatment of diabetic NOD mice with hAAT or hAAT plus G-CSF provided long-term (at least 100 days) reversal of diabetes in 50% of treated animals. G-CSF did not enhance the reversal rates of hAAT. Glucose tolerance and insulin levels were normalised in mice with hAAT prevention and reversal.

CONCLUSIONS/INTERPRETATION

Intradermal hAAT prevents and reverses disease in a NOD mouse model of type 1 diabetes without inducing anaphylaxis.

Protective effects of icariin on brain dysfunction induced by lipopolysaccharide in rats

In this study we examined the protective effects of icariin, a flavonol isolated from Herba epimedii, on learning and memory in a rat model with brain inflammation induced by lipopolysaccharide (LPS). Injecting LPS into the lateral ventricle caused rat brain dysfunction, as evidenced by deficits of spatial learning and memory in the Morris water maze. With administration of icariin (30, 60, 120mg/kg body wt./day) for 17 consecutive days, spatial learning and memory abilities were markedly altered. Escape latency and searching distance decreased, and the expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) of brain were significantly reduced as observed by real-time RT-PCR and immunohistochemistry. This study used ibuprofen (40mg/kg body wt./day) as positive control. In conclusion, this study suggested that icariin can improve spatial learning and memory abilities in rats with brain dysfunction induced by LPS, an effect which may be due to decreased expressions of TNF-α, IL-1β and COX-2 in the hippocampus.

Involvement of cysteinyl leukotriene receptors in angiogenesis in rat thoracic aortic rings

Cysteinyl leukotrienes (CysLTs) are potent inflammatory mediators that induce inflammation through the activation of CysLT1 and CysLT2 receptors. It has been reported that inflammatory mediators, such as prostaglandins, play an important role in angiogenesis. However, whether CysLTs and the receptor subtypes are involved in angiogenesis is not clarified. Here, we determined the effects of CysLT receptor agonist leukotriene D4 (LTD4) and antagonists on angiogenesis by rat thoracic aortic ring assay. We found that the microvessel growth in 25% serum-containing cultures was significantly inhibited by the CysLT1 receptor antagonist montelukast (0.1-1 microM), but not by the CysLT2 receptor antagonist BAY cyslt2 (0.1-1 microM). The microvessel growth in serum-free culture was affected neither by montelukast (0.01-1 microM) nor by BAY cyslt2 (0.1-1 microM). Furthermore, LTD4 at 100 nM significantly enhanced the microvessel growth in serum-free culture and LTD4 at 10-100 nM significantly enhanced the microvessel growth in 25% serum-containing cultures. The enhancement was abrogated by both montelukast and BAY cyslt2. Thus, CysLT1 receptors may mediate endogenously regulated microvessel growth in normal culture; whereas the exogenous agonist LTD4 induces angiogenesis through the activation of both CysLT1 and CysLT2 receptors. The CysLT receptor antagonists can be developed as angiogenesis inhibitors.

Reduced recombination in gynodioecious populations of a facultative apomictic orchid

Many plants combine sexual reproduction with some form of asexual reproduction to different degrees, and lower genetic diversity is expected with asexuality. Moreover, the ratios of sexual morphs in species with gender dimorphism are expected to vary in proportion to the reproductive success of the sexual process. Hence, sex ratios can directly influence the genetic structure and diversity of a population. We investigated genotypic diversity in 23 populations of a facultative, apomictic gynodioecious orchid, Satyrium ciliatum, to examine the effect on genotypic diversity of variation in the frequency of females and in the amount of sexual reproduction. The study involved one pure female, seven gynodioecious (both females and hermaphrodites present) and 15 hermaphroditic populations. Pollinia receipt was higher in hermaphroditic than in gynodioecious populations. Analyses of variation in ISSRs demonstrated that genotypic diversity was high in all populations and was not significantly different between hermaphroditic and gynodioecious populations. We used character compatibility analysis to determine the extent to which recombination by sexual reproduction contributed to genotypic diversity. The results indicate that the contribution of recombination to genotypic diversity is higher in hermaphroditic than in gynodioecious populations, consistent with the finding that hermaphroditic populations received higher amounts of pollinia. Our finding of reduced recombination in gynodioecious populations suggests that maintenance of sex in hermaphrodites plays an important role in generating genotypic diversity in this apomictic orchid.

Incorporation of the International Spinal Cord Injury Data Set elements into the National Institute of Neurological Disorders and Stroke Common Data Elements

OBJECTIVES

To develop consistent variable names and a common database structure for the data elements in the International Spinal Cord Injury (SCI) Data Sets.

SETTING

National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDE) Project and The Executive Committee of the International SCI Standards and Data Sets committees (ECSCI).

METHODS

The NINDS CDE team creates a variable name for each defined data element in the various International SCI Data Sets. Members of the ECSCI review these in an iterative process to make the variable names logical and consistent across the data sets. Following this process, the working group for the particular data set reviews the variable names, and further revisions and adjustments may be made. In addition, a database structure for each data set is developed allowing data to be stored in a uniform way in databases to promote sharing data from different studies.

RESULTS

The International SCI Data Sets variable names and database specifications will be available through the web sites of the International Spinal Cord Society (http://www.iscos.org.uk), the American Spinal Injury Association (http://www.asia-spinalinjury.org) and the NINDS CDE project web site (http://www.CommonDataElements.ninds.nih.gov).

CONCLUSION

This process will continue as additional International SCI Data Sets fulfill the requirements of the development and approval process and are ready for implementation.

Allergy and risk of glioma: a meta-analysis

We evaluated the association between allergic conditions and the risk of glioma in case-control and cohort studies published so far on this issue. A total of 12 studies (10 case-control and 2 cohort studies) were included in the analysis, involving 61 090 participants, of whom 6408 had glioma. When compared with non-allergic conditions, the pooled odds ratio (OR) with any allergic conditions for glioma was 0.60 (95% CI: 0.52-0.69, P<0.001), suggesting a significant negative association (protective effect) between allergy and glioma. Subgroup analysis showed that the ORs were 0.70 (95% CI: 0.62-0.79, P<0.001), 0.69 (95% CI: 0.62-0.78, P<0.001), and 0.78 (95% CI: 0.70-0.87, P<0.001) for asthma, eczema, and hay fever, respectively. The significant association remained even after excluding the bias of proxy reporting (OR=0.61; 95% CI: 0.50-0.75, P<0.001). We conclude that allergic conditions may significantly reduce the risk of glioma.

Synthesis and evaluation of chitosan-graft-polyethylenimine as a gene vector

The objective of this study was to prepare a series of chitosan-graft-polyethylenimine (chitosan-g-PEI) copolymers as gene carriers with high transfection efficiency and low cytotoxicity. Chitosan-g-PEIs with different molecular weights and segments were successfully synthesized by both oxidation and imine reactions and then characterized by 1H NMR, IR, UV and DSC. All types of Chitosan-g-PEIs prepared were found to interact efficiently with plasmid DNA (pIRES2-EGFP-p53) on DNA retardation assays. The Chitosan-g-PEI/DNA complex had a diameter of approximately 200 nm and a surface potential of zeta = +10.0 mV when the N/P ratio was 15/1. Optimal transfection efficiency of the chitosan-g-PEI/DNA complex was observed at N/P = 45/1 on HepG2 cells, with significantly lower toxicity compared with the gold standard PEI 25 kd. Moreover, the results showed that the toxicity increased with increasing molecular weight of the PEI segment in chitosan-g-PEI. Based on these results, chitosan-g-PEI with different chitosan and PEI segments of could be used for gene expression on different levels, and some of them may appear as potential candidates for gene delivery systems.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Using support vector regression coupled with the genetic algorithm for predicting acute toxicity to the fathead minnow

The potential toxicity of chemicals may present adverse effects to the environment and human health. The quantitative structure-activity relationship (QSAR) provides a useful method for hazard assessment. In this study, we constructed a QSAR model based on a highly heterogeneous data set of 571 compounds from the US Environmental Protection Agency, for predicting acute toxicity to the fathead minnow (Pimephales promelas). An approach coupling support vector regression (SVR) with the genetic algorithm (GA) was developed to build the model. The generated QSAR model showed excellent data fitting and prediction abilities: the squared correlation coefficients (r(2)) for the training set and the test set were 0.826 and 0.802, respectively. Only eight critical descriptors, most of which are closely related to the toxicity mechanism, were chosen by GA-SVR, making the derived model readily interpretable. In summary, the successful case reported here highlights that our GA-SVR approach can be used as a general machine learning method for toxicity prediction.

Does standardized BMD still remove differences between Hologic and GE-Lunar state-of-the-art DXA systems?

The standardized bone mineral density (sBMD) values, derived using universal standardized equations, were shown to be equivalent within 1.0% for hip but significantly different for spine for state-of-art fan-beam dual X-ray absorptiometry (DXA) Hologic and GE-Lunar systems. Spine L1-L4 and L2-L4 sBMD mean differences between the two systems were 0.042 g/cm(2) (4.1%) and 0.035 g/cm(2) (3.2%), respectively.

INTRODUCTION

The objective of this study is to validate the 1994 pencil-beam DXA "universal standardization equations" for state-of-the-art fan-beam DXA systems.

METHODS

The spine and bilateral femurs of 87 postmenopausal women were scanned on both Hologic Delphi and GE-Lunar Prodigy DXA systems at three different clinical centers. The scans were analyzed using Hologic Apex and GE-Lunar EnCore software. The BMD results were converted to sBMD using the equations previously developed. Linear regression analysis was used to describe the relationship of the two systems' BMD results. Bland-Altman analysis was used to assess the differences in measures.

RESULTS

The Apex and Prodigy sBMD values were highly correlated (r ranged from 0.92 to 0.98). Spine L1-L4 and L2-L4 sBMD values had significant intercepts and slopes for Bland-Altman regression, with mean differences of 0.042 g/cm(2) (4.1%) and 0.035 g/cm(2) (3.2%), respectively. The total hip and neck sBMD showed no significant intercept and slope, except left total sBMD had a significant difference between the two systems of 0.009 g/cm(2) (1.0%).

CONCLUSIONS

The sBMD values were shown to be equivalent within 1.0% for hip but were significantly different for spine on the two systems. Biases may persist in pooled sBMD data from different manufacturers, and further study is necessary to determine the cause.