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Find video protocols related to scientific articles indexed in Pubmed.
Haematopoietic stem cell induction by somite-derived endothelial cells controlled by meox1.
Nature
PUBLISHED: 08-13-2014
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Haematopoietic stem cells (HSCs) are self-renewing stem cells capable of replenishing all blood lineages. In all vertebrate embryos that have been studied, definitive HSCs are generated initially within the dorsal aorta (DA) of the embryonic vasculature by a series of poorly understood inductive events. Previous studies have identified that signalling relayed from adjacent somites coordinates HSC induction, but the nature of this signal has remained elusive. Here we reveal that somite specification of HSCs occurs via the deployment of a specific endothelial precursor population, which arises within a sub-compartment of the zebrafish somite that we have defined as the endotome. Endothelial cells of the endotome are specified within the nascent somite by the activity of the homeobox gene meox1. Specified endotomal cells consequently migrate and colonize the DA, where they induce HSC formation through the deployment of chemokine signalling activated in these cells during endotome formation. Loss of meox1 activity expands the endotome at the expense of a second somitic cell type, the muscle precursors of the dermomyotomal equivalent in zebrafish, the external cell layer. The resulting increase in endotome-derived cells that migrate to colonize the DA generates a dramatic increase in chemokine-dependent HSC induction. This study reveals the molecular basis for a novel somite lineage restriction mechanism and defines a new paradigm in induction of definitive HSCs.
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Retrograde and anterograde memory following selective damage to the dorsolateral entorhinal cortex.
Neurobiol Learn Mem
PUBLISHED: 08-07-2014
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Anatomical and electrophysiological evidence suggest the dorsolateral entorhinal cortex (DLEC) is involved in processing spatial information, but there is currently no consensus on whether its functions are necessary for normal spatial learning and memory. The present study examined the effects of excitotoxic lesions of the DLEC on retrograde and anterograde memory on two tests of allocentric spatial learning: a hidden fixed-platform watermaze task, and a novelty-preference-based dry-maze test. Deficits were observed on both tests when training occurred prior to but not following n-methyl d-aspartate (NMDA) lesions of DLEC, suggesting retrograde memory impairment in the absence of anterograde impairments for the same information. The retrograde memory impairments were temporally-graded; rats that received DLEC lesions 1-3days following training displayed deficits, while those that received lesions 7-10days following training performed like a control group that received sham surgery. The deficits were not attenuated by co-infusion of tetrodotoxin, suggesting they are not due to disruption of neural processing in structures efferent to the DLEC, such as the hippocampus. The present findings provide evidence that the DLEC is involved in the consolidation of allocentric spatial information.
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Methylation-capture and Next-Generation Sequencing of free circulating DNA from human plasma.
BMC Genomics
PUBLISHED: 03-25-2014
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Free circulating DNA (fcDNA) has many potential clinical applications, due to the non-invasive way in which it is collected. However, because of the low concentration of fcDNA in blood, genome-wide analysis carries many technical challenges that must be overcome before fcDNA studies can reach their full potential. There are currently no definitive standards for fcDNA collection, processing and whole-genome sequencing. We report novel detailed methodology for the capture of high-quality methylated fcDNA, library preparation and downstream genome-wide Next-Generation Sequencing. We also describe the effects of sample storage, processing and scaling on fcDNA recovery and quality.
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Direct crosstalk between cancer and osteoblast lineage cells fuels metastatic growth in bone via auto-amplification of IL-6 and RANKL signaling pathways.
J. Bone Miner. Res.
PUBLISHED: 03-13-2014
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The bone microenvironment and its modification by cancer and host cell interactions is a key driver of skeletal metastatic growth. Interleukin-6 (IL-6) stimulates receptor activator of NF-?B ligand (RANKL) expression in bone cells, and serum IL-6 levels are associated with poor clinical outcomes in cancer patients. We investigated the effects of RANKL on cancer cells and the role of tumor-derived IL-6 within the bone microenvironment. Using human breast cancer cell lines to induce tumors in the bone of immune-deficient mice, we first determined whether RANKL released by cells of the osteoblast lineage directly promotes IL-6 expression by cancer cells in vitro and in vivo. We then disrupted of IL-6 signaling in vivo either via knockdown of IL-6 in tumor cells or through treatment with specific anti-human or anti-mouse IL-6 receptor antibodies to investigate the tumor effect. Finally, we tested the effect of RANK knockdown in cancer cells on cancer growth. We demonstrate that osteoblast lineage-derived RANKL upregulates secretion of IL-6 by breast cancers in vivo and in vitro. IL-6, in turn, induces expression of RANK by cancer cells, which sensitizes the tumor to RANKL and significantly enhances cancer IL-6 release. Disruption in vivo of this auto-amplifying crosstalk by knockdown of IL-6 or RANK in cancer cells, or via treatment with anti-IL-6 receptor antibodies, significantly reduces tumor growth in bone but not in soft tissues. RANKL and IL-6 mediate direct paracrine-autocrine signaling between cells of the osteoblast lineage and cancer cells, significantly enhancing the growth of metastatic breast cancers within bone.
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Standardizing leucocyte PNH clone detection: an international study.
Cytometry B Clin Cytom
PUBLISHED: 02-13-2014
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Consensus and Practical Guidelines for robust high-sensitivity detection of glycophosphatidylinostitol-deficient structures on red blood cells and white blood cells in paroxysmal nocturnal hemoglobinuria (PNH) were recently published.
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Standardizing Leucocyte PNH clone detection: An international study.
Cytometry B Clin Cytom
PUBLISHED: 02-13-2014
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Background: Consensus and Practical Guidelines for robust high-sensitivity detection of glycophosphatidylinostitol (GPI)-deficient structures on Red Blood Cells (RBCs) and White Blood Cells (WBCs) in Paroxysmal Nocturnal Hemoglobinuria (PNH) were recently published. Methods: UK NEQAS LI issued 3 stabilized samples manufactured to contain no PNH cells (normal), approximately 0.1% and 8% PNH leucocyte populations, together with instrument-specific SOPs and pre-titered antibody cocktails to 19 international laboratories experienced in PNH testing. Samples were tested using both standardized protocol/reagents and in-house protocols. Additionally, samples were issued to all participants in the full PNH EQA programmes. Results: Expert laboratory results showed no difference in PNH clone detection rates when using standardized and their 'in-house' methods though lower variation around the median was found for the standardized approach compared to in-house methods. Neutrophil analysis of the sample containing an 8% PNH population, for example, showed an interquartile range of 0.48% with the standardized approach compared with 1.29% for in-house methods. Results from the full EQA group showed the greatest variation with an inter-quartile range of 1.70 and this was demonstrated to be significantly different (P<0.001) to the standardized cohort. Conclusions: The results not only demonstrate that stabilized whole PNH blood samples are suitable for use with currently recommended high-sensitivity reagent cocktails/protocols but also highlight the importance of using carefully selected conjugates alongside the standardized protocols. While much more variation was seen amongst the full UK NEQAS LI EQA group, the standardized approach lead to reduced variation around the median even for the experienced laboratories. © 2014 Clinical Cytometry Society.
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Recent memory for socially transmitted food preferences in rats does not depend on the hippocampus.
Neurobiol Learn Mem
PUBLISHED: 01-31-2014
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The standard model of systems consolidation holds that the hippocampus (HPC) is involved only in the initial storage and retrieval of a memory. With time hippocampal-neocortical interactions slowly strengthen the neocortical memory, ultimately enabling retrieval of the memory without the HPC. Key support for this idea comes from experiments measuring memory recall in the socially-transmitted food preference (STFP) task in rats. HPC damage within a day or two of STFP learning can abolish recall, but similar damage five or more days after learning has no effect. We hypothesize that disruption of cellular consolidation outside the HPC could contribute to the amnesia with recent memories, perhaps playing a more important role than the loss of HPC. This view predicts that intraHPC infusion of Tetrodotoxin (TTX), which can block conduction of action potentials from the lesion sites, will block the retrograde amnesia in the STFP task. Here we confirm the previously reported retrograde amnesia with neurotoxic HPC damage within the first day after learning, but show that co-administration of TTX with the neurotoxin blocks the retrograde amnesia despite very extensive HPC damage. These results indicate that HPC damage disrupts cellular consolidation of the recent memory elsewhere; STFP memory may not ever depend on the HPC.
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Temporary inactivation of the rodent hippocampus: an evaluation of the current methodology.
J. Neurosci. Methods
PUBLISHED: 01-14-2014
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Temporary cellular inactivation is a useful and increasingly popular approach in examining brain function. In general the methods allow for fast-acting manipulations that have the advantage of being reversible. However, there is significant variation in detailed procedures across experiments and most authors show very little evidence about the extent or duration of inactivation. Here we investigate a commonly used method of temporarily inactivating the hippocampus in rats. Using immediate early gene activation after electroconvulsive shock we measure the extent of inactivation using different lengths of infusion needles and one vs. two bilateral infusion sites. Our methods allowed us to uncover some possible confounding factors. We suggest specific variations in the procedures which decrease or eliminate these problems. We also investigate the properties of the sodium channel blocker ropivacaine and recommend this drug based on its functional profile and established low level of toxicity.
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Targeting cyclin-dependent kinase 1 (CDK1) but not CDK4/6 or CDK2 is selectively lethal to MYC-dependent human breast cancer cells.
BMC Cancer
PUBLISHED: 01-08-2014
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Although MYC is an attractive therapeutic target for breast cancer treatment, it has proven challenging to inhibit MYC directly, and clinically effective pharmaceutical agents targeting MYC are not yet available. An alternative approach is to identify genes that are synthetically lethal in MYC-dependent cancer. Recent studies have identified several cell cycle kinases as MYC synthetic-lethal genes. We therefore investigated the therapeutic potential of specific cyclin-dependent kinase (CDK) inhibition in MYC-driven breast cancer.
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ZNF300P1 encodes a lincRNA that regulates cell polarity and is epigenetically silenced in type II epithelial ovarian cancer.
Mol. Cancer
PUBLISHED: 01-02-2014
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We previously identified that the CpG island-associated promoter of the novel lincRNA ZNF300P1 (also known as LOC134466) is frequently hypermethylated and silenced in ovarian cancer tissues. However, the function of ZNF300P1 was unknown. In this report we demonstrate that ZNF300P1 is involved in the regulation of key cell cycle and cell motility networks in human ovarian surface epithelial cells, and may play a role in promoting metastasis in ovarian cancer cells.
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?-Catenin signaling is a critical event in ErbB2-mediated mammary tumor progression.
Cancer Res.
PUBLISHED: 05-29-2013
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Although ERBB2 amplification and overexpression is correlated with poor outcome in breast cancer, the molecular mechanisms underlying the aggressive nature of these tumors has not been fully elucidated. To investigate this further, we have used a transgenic mouse model of ErbB2-driven tumor progression (ErbB2(KI) model) that recapitulates clinically relevant events, including selective amplification of the core erbB2 amplicon. By comparing the transcriptional profiles of ErbB2(KI) mammary tumors and human ERBB2-positive breast cancers, we show that ErbB2(KI) tumors possess molecular features of the basal subtype of ERBB2-positive human breast cancer, including activation of canonical ?-catenin signaling. Inhibition of ?-catenin-dependent signaling in ErbB2(KI)-derived tumor cells using RNA interference impaired tumor initiation and metastasis. Furthermore, treatment of ErbB2(KI) or human ERBB2-overexpressing tumor cells with a selective ?-catenin/CBP inhibitor significantly decreased proliferation and ErbB2 expression. Collectively, our data indicate that ERBB2-mediated breast cancer progression requires ?-catenin signaling and can be therapeutically targeted by selective ?-catenin/CBP inhibitors.
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Global characterization of signalling networks associated with tamoxifen resistance in breast cancer.
FEBS J.
PUBLISHED: 04-18-2013
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Acquired resistance to the anti-estrogen tamoxifen remains a significant challenge in breast cancer management. In this study, we used an integrative approach to characterize global protein expression and tyrosine phosphorylation events in tamoxifen-resistant MCF7 breast cancer cells (TamR) compared with parental controls. Quantitative mass spectrometry and computational approaches were combined to identify perturbed signalling networks, and candidate regulatory proteins were functionally interrogated by siRNA-mediated knockdown. Network analysis revealed that cellular metabolism was perturbed in TamR cells, together with pathways enriched for proteins associated with growth factor, cell-cell and cell matrix-initiated signalling. Consistent with known roles for Ras/MAPK and PI3-kinase signalling in tamoxifen resistance, tyrosine-phosphorylated MAPK1, SHC1 and PIK3R2 were elevated in TamR cells. Phosphorylation of the tyrosine kinase Yes and expression of the actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) were increased two- and eightfold in TamR cells respectively, and these proteins were selected for further analysis. Knockdown of either protein in TamR cells had no effect on anti-estrogen sensitivity, but significantly decreased cell motility. MARCKS expression was significantly higher in breast cancer cell lines than normal mammary epithelial cells and in ER-negative versus ER-positive breast cancer cell lines. In primary breast cancers, cytoplasmic MARCKS staining was significantly higher in basal-like and HER2 cancers than in luminal cancers, and was independently predictive of poor survival in multivariate analyses of the whole cohort (P < 0.0001) and in ER-positive patients (P = 0.0005). These findings provide network-level insights into the molecular alterations associated with the tamoxifen-resistant phenotype, and identify MARCKS as a potential biomarker of therapeutic responsiveness that may assist in stratification of patients for optimal therapy.
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Transcription factor ATF3 links host adaptive response to breast cancer metastasis.
J. Clin. Invest.
PUBLISHED: 04-11-2013
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Host response to cancer signals has emerged as a key factor in cancer development; however, the underlying molecular mechanism is not well understood. In this report, we demonstrate that activating transcription factor 3 (ATF3), a hub of the cellular adaptive response network, plays an important role in host cells to enhance breast cancer metastasis. Immunohistochemical analysis of patient tumor samples revealed that expression of ATF3 in stromal mononuclear cells, but not cancer epithelial cells, is correlated with worse clinical outcomes and is an independent predictor for breast cancer death. This finding was corroborated by data from mouse models showing less efficient breast cancer metastasis in Atf3-deficient mice than in WT mice. Further, mice with myeloid cell-selective KO of Atf3 showed fewer lung metastases, indicating that host ATF3 facilitates metastasis, at least in part, by its function in macrophage/myeloid cells. Gene profiling analyses of macrophages from mouse tumors identified an ATF3-regulated gene signature that could distinguish human tumor stroma from distant stroma and could predict clinical outcomes, lending credence to our mouse models. In conclusion, we identified ATF3 as a regulator in myeloid cells that enhances breast cancer metastasis and has predictive value for clinical outcomes.
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Outcomes of transperineal template-guided prostate biopsy in 409 patients.
BJU Int.
PUBLISHED: 04-03-2013
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To present the template-guided transperineal prostate biopsy (TPB) outcomes for patients of two urologists from a single institution.
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Neither time nor number of context-shock pairings affect long-term dependence of memory on hippocampus.
Neurobiol Learn Mem
PUBLISHED: 02-28-2013
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There are still basic uncertainties concerning the role of the hippocampus (HPC) in maintaining long-term context memories. All experiments examining the effects of extensive HPC damage on context memory for a single learning episode find that damage soon after learning results in robust retrograde amnesia. Some experiments find that if the learning-to-damage interval is extended, remote context memories are spared. In contrast, other experiments fail to find spared remote context memory. One possible explanation for inconsistency might be the potency of the context memory conditioning procedure, as the experiments showing spared remote memory used a greater number of context-shock pairings, likely creating a stronger context fear memory. We designed an experiment to directly test the question: does increasing the number of context-shock pairings result in sparing of remote context memory after HPC damage? Six independent groups of rats received either 3 or 12 context-shock pairings during a single conditioning session and then either received extensive HPC damage or Control surgery at 1-week, 2-months, or 4-months after conditioning. 10days after surgery rats were tested for memory of the shock context. Consistent with all relevant studies, HPC damage at the shortest training-surgery interval produced robust retrograde amnesia for both 3- and 12-shock groups whereas the Control rats expressed significantly high levels of memory. At the longer training-surgery interval, HPC damage produced similarly robust retrograde amnesia in the rats in both the 3- and 12-shock groups. These results clearly demonstrate that increasing the number of context-shock pairings within a single learning session does not change the dependence of the memory on the HPC. Current evidence from our group on retrograde amnesia has now shown that partial damage, dorsal vs. ventral damage, discrete cue+context conditioning, time after training, and number of context-shock pairings do not affect HPC dependence of context fear memories. When taken together, the evidence strongly supports a permanent role of the HPC in context memory.
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Histomolecular phenotypes and outcome in adenocarcinoma of the ampulla of vater.
J. Clin. Oncol.
PUBLISHED: 02-25-2013
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Individuals with adenocarcinoma of the ampulla of Vater demonstrate a broad range of outcomes, presumably because these cancers may arise from any one of the three epithelia that converge at that location. This variability poses challenges for clinical decision making and the development of novel therapeutic strategies.
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Mental rotational ability is correlated with spatial but not verbal working memory performance and P300 amplitude in males.
PLoS ONE
PUBLISHED: 01-24-2013
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This study investigated how both sex and individual differences in a mental rotation test (MRT) influence performance on working memory (WM). To identify the neural substrate supporting these differences, brain electrical activity was measured using the event-related potential technique. No significant sex differences were observed in a test of verbal WM, however males were significantly faster than females to respond to probe stimuli in a test of spatial WM. This difference was no longer significant after controlling for differences in MRT score, suggesting that rotational ability mediates performance in the spatial memory task for both sexes. A posterior P300 was observed in both tasks as participants encoded information into memory, however the amplitude of the P300 correlated with RT in the spatial task but not in the verbal task. Individual differences in the MRT also correlated with RT and with the amplitude of the P300, but again only in the spatial task. After splitting the analysis by sex, partial correlations controlling for MRT revealed that for males, individual differences in rotational ability completely mediated the correlation between the P300 and RT in the spatial task. This mediating effect was not observed for the female participants. The results therefore suggest a relatively stronger association in males between innate mental rotational ability, spatial memory performance, and brain electrophysiological processes supporting spatial memory.
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Cyclin E2 induces genomic instability by mechanisms distinct from cyclin E1.
Cell Cycle
PUBLISHED: 01-16-2013
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Cyclins E1 drives the initiation of DNA replication, and deregulation of its periodic expression leads to mitotic delay associated with genomic instability. Since it is not known whether the closely related protein cyclin E2 shares these properties, we overexpressed cyclin E2 in breast cancer cells. This did not affect the duration of mitosis, nor did it cause an increase in p107 association with CDK2. In contrast, cyclin E1 overexpression led to inhibition of the APC complex, prolonged metaphase and increased p107 association with CDK2. Despite these different effects on the cell cycle, elevated levels of either cyclin E1 or E2 led to hallmarks of genomic instability, i.e., an increased proportion of abnormal mitoses, micronuclei and chromosomal aberrations. Cyclin E2 induction of genomic instability by a mechanism distinct from cyclin E1 indicates that these two proteins have unique functions in a cancer setting.
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Differences in degradation lead to asynchronous expression of cyclin E1 and cyclin E2 in cancer cells.
Cell Cycle
PUBLISHED: 01-16-2013
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Cyclin E1 is expressed at the G 1/S phase transition of the cell cycle to drive the initiation of DNA replication and is degraded during S/G2M. Deregulation of its periodic degradation is observed in cancer and is associated with increased proliferation and genomic instability. We identify that in cancer cells, unlike normal cells, the closely related protein cyclin E2 is expressed predominantly in S phase, concurrent with DNA replication. This occurs at least in part because the ubiquitin ligase component that is responsible for cyclin E1 downregulation in S phase, Fbw7, fails to effectively target cyclin E2 for proteosomal degradation. The distinct cell cycle expression of the two E-type cyclins in cancer cells has implications for their roles in genomic instability and proliferation and may explain their associations with different signatures of disease.
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Evaluation of 2009 pandemic H1N1 influenza vaccination in adults with lymphoid malignancies receiving chemotherapy or following autologous stem cell transplant.
Leuk. Lymphoma
PUBLISHED: 01-08-2013
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This is a randomized trial evaluating the safety and immunogenicity of one or two doses of 2009 pandemic H1N1 influenza vaccination in adults with lymphoid malignancies. Adults with a lymphoid malignancy receiving active systemic therapy, or within a year after autologous stem cell transplant, received one dose of AS03-adjuvanted A/California/7/2009 (H1N1) vaccine, and were randomized 21 days later to a second dose or no further vaccination. The primary outcomes were seroprotection and seroconversion rates by hemagglutination inhibition 21 and 42 days after initial vaccination. Twenty-two patients received one dose, and 20 patients received a second dose. Seroconversion rates at day 21 were 30% (one dose) and 5% (two doses), and subsequently 30% for both groups at day 42. Seroprotection rates at day 21 were 40% (one dose) and 15% (two doses), and subsequently 35% (one dose) and 40% (two doses) at day 42. Differences in serologic endpoints were not statistically significant between both study arms at day 42. Patients with low levels of B-cells (CD19-positive) had low seroconversion rates on days 21 (odds ratio [OR] 0.74, 95% confidence interval [CI] 0.59-0.93, p = 0.043) and 42 (OR 0.12, 95% CI 0.01-1.07, p = 0.058). Only three of the 14 patients who received rituximab achieved seroprotective titers by day 42. Patients with lymphoid malignancies did not achieve rates of seroconversion or seroprotection seen in healthy subjects despite a second dose and the use of an adjuvant. Notwithstanding suboptimal immunogenicity, seasonal and pandemic influenza vaccination should continue to be recommended.
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TLE3 expression is associated with sensitivity to taxane treatment in ovarian carcinoma.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 12-22-2011
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We have previously shown that transducin-like enhancer of split 3 (TLE3) is associated with outcome specifically in patients with taxane-treated breast cancer and not in patients treated with anthracycline-based regimens without a taxane. The purpose of this study was to assess the association between TLE3 expression and recurrence in patients with ovarian carcinoma treated with a taxane containing regimen as opposed to those treated with a platinum-based agent alone.
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Retinoid signaling in pancreatic cancer, injury and regeneration.
PLoS ONE
PUBLISHED: 10-24-2011
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Activation of embryonic signaling pathways quiescent in the adult pancreas is a feature of pancreatic cancer (PC). These discoveries have led to the development of novel inhibitors of pathways such as Notch and Hedgehog signaling that are currently in early phase clinical trials in the treatment of several cancer types. Retinoid signaling is also essential for pancreatic development, and retinoid therapy is used successfully in other malignancies such as leukemia, but little is known concerning retinoid signaling in PC.
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High Gleason grade carcinoma at a positive surgical margin predicts biochemical failure after radical prostatectomy and may guide adjuvant radiotherapy.
BJU Int.
PUBLISHED: 10-12-2011
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Study Type - Prognosis (case series) Level of Evidence 4 Whats known on the subject? and What does the study add? Only 30-35% of patients with positive surgical margins after radical prostatectomy develop recurrent disease. Adjuvant radiotherapy reduces the rate of biochemical relapse or metastasis and improves overall survival after radical prostatectomy. Various pathological factors, such as location and extent of positive margins, have been proposed as possible prognostic factors in men with margin-positive prostate cancer, however, the recent International Society of Urological Pathology consensus meeting in Boston noted that there is limited data on the significance of Gleason grade of the carcinoma at a positive margin. The present study shows that the presence of high grade prostate cancer, i.e. Gleason pattern 4 or 5, at a positive surgical margin is an independent predictor of biochemical recurrence after radical prostatectomy. Moreover, patients with lower grade carcinoma at the margin have a similar prognosis to men with negative margins. Hence, assessment of Gleason grade at the site of positive margin may aid optimal selection of patients for adjuvant radiotherapy.
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Suppression of neurotoxic lesion-induced seizure activity: evidence for a permanent role for the hippocampus in contextual memory.
PLoS ONE
PUBLISHED: 09-28-2011
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Damage to the hippocampus (HPC) using the excitotoxin N-methyl-D-aspartate (NMDA) can cause retrograde amnesia for contextual fear memory. This amnesia is typically attributed to loss of cells in the HPC. However, NMDA is also known to cause intense neuronal discharge (seizure activity) during the hours that follow its injection. These seizures may have detrimental effects on retrieval of memories. Here we evaluate the possibility that retrograde amnesia is due to NMDA-induced seizure activity or cell damage per se. To assess the effects of NMDA induced activity on contextual memory, we developed a lesion technique that utilizes the neurotoxic effects of NMDA while at the same time suppressing possible associated seizure activity. NMDA and tetrodotoxin (TTX), a sodium channel blocker, are simultaneously infused into the rat HPC, resulting in extensive bilateral damage to the HPC. TTX, co-infused with NMDA, suppresses propagation of seizure activity. Rats received pairings of a novel context with foot shock, after which they received NMDA-induced, TTX+NMDA-induced, or no damage to the HPC at a recent (24 hours) or remote (5 weeks) time point. After recovery, the rats were placed into the shock context and freezing was scored as an index of fear memory. Rats with an intact HPC exhibited robust memory for the aversive context at both time points, whereas rats that received NMDA or NMDA+TTX lesions showed a significant reduction in learned fear of equal magnitude at both the recent and remote time points. Therefore, it is unlikely that observed retrograde amnesia in contextual fear conditioning are due to disruption of non-HPC networks by propagated seizure activity. Moreover, the memory deficit observed at both time points offers additional evidence supporting the proposition that the HPC has a continuing role in maintaining contextual memories.
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Recruitment and activation of pancreatic stellate cells from the bone marrow in pancreatic cancer: a model of tumor-host interaction.
PLoS ONE
PUBLISHED: 09-19-2011
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Chronic pancreatitis and pancreatic cancer are characterised by extensive stellate cell mediated fibrosis, and current therapeutic development includes targeting pancreatic cancer stroma and tumor-host interactions. Recent evidence has suggested that circulating bone marrow derived stem cells (BMDC) contribute to solid organs. We aimed to define the role of circulating haematopoietic cells in the normal and diseased pancreas.
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Between-systems memory interference during retrieval.
Eur. J. Neurosci.
PUBLISHED: 09-08-2011
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Context memories normally depend on the hippocampus (HPC) but, in the absence of the HPC, other memory systems are capable of acquiring and supporting these memories. This suggests that the HPC can interfere with other systems during memory acquisition. Here we ask whether the HPC can also interfere with the retrieval of a context memory that was independently acquired by a non-HPC system. Specifically, we assess whether the HPC can impair the retrieval of a contextual fear-conditioning memory that was acquired while the HPC was temporarily inactive. Rats were infused with the ?-aminobutyric acid (GABA)(A) receptor agonist muscimol in the dorsal and ventral HPC either before acquisition, retrieval, or prior to both acquisition and retrieval, consistent with the effects of permanent HPC lesions on contextual fear conditioning, if the HPC was inactive at the time of acquisition and retention memory was intact. Thus, non-HPC systems acquired and supported this memory in absence of the HPC. However, if the HPC was inactive during acquisition but active thereafter, rats displayed severe deficits during the retention test. Moreover, when the same rats received a second retention test but with the HPC inactive at this time, the memory was recovered, suggesting that removal of a form of interference allowed the memory to be expressed. Combined, these findings imply that the HPC competes and/or interferes with retrieval of a long-term memory that was established in non-HPC systems.
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Prognostic and diagnostic significance of DNA methylation patterns in high grade serous ovarian cancer.
Gynecol. Oncol.
PUBLISHED: 09-01-2011
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Altered DNA methylation patterns hold promise as cancer biomarkers. In this study we selected a panel of genes which are commonly methylated in a variety of cancers to evaluate their potential application as biomarkers for prognosis and diagnosis in high grade serous ovarian carcinoma (HGSOC); the most common and lethal subtype of ovarian cancer.
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Integrative genome-wide expression and promoter DNA methylation profiling identifies a potential novel panel of ovarian cancer epigenetic biomarkers.
Cancer Lett.
PUBLISHED: 08-16-2011
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To identify epigenetic-based biomarkers for diagnosis of ovarian cancer we performed MeDIP-Chip in A2780 and CaOV3 ovarian cancer cell lines. Validation by Sequenom massARRAY methylation analysis confirmed a panel of six gene promoters (ARMCX1, ICAM4, LOC134466, PEG3, PYCARD & SGNE1) where hypermethylation discriminated 27 serous ovarian cancer clinical samples versus 12 normal ovarian surface epithelial cells (OSE) (ROC of 0.98). Notably, CpG sites across the transcription start site of a potential long-intergenic non-coding RNA (lincRNA) gene (LOC134466), was shown to be hypermethylated in 81% of serous EOC and could differentiate tumours from OSE (p<0.05). We propose that this potential biomarker panel holds great promise as a diagnostic test for high-grade (Type II) serous ovarian cancer.
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Synthesis and in vitro evaluation of analogues of avocado-produced toxin (+)-(R)-persin in human breast cancer cells.
Bioorg. Med. Chem.
PUBLISHED: 07-26-2011
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A structure-activity study of several new synthetic analogues of the avocado-produced toxin persin has been conducted, with compounds being evaluated for their cytostatic and pro-apoptotic effects in human breast cancer cells. A 4-pyridinyl derivative demonstrated activity comparable to that of the natural product, suggesting future directions for exploration of structure-activity relationships.
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Cyclin D as a therapeutic target in cancer.
Nat. Rev. Cancer
PUBLISHED: 07-07-2011
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Cyclin D1, and to a lesser extent the other D-type cyclins, is frequently deregulated in cancer and is a biomarker of cancer phenotype and disease progression. The ability of these cyclins to activate the cyclin-dependent kinases (CDKs) CDK4 and CDK6 is the most extensively documented mechanism for their oncogenic actions and provides an attractive therapeutic target. Is this an effective means of targeting the cyclin D oncogenes, and how might the patient subgroups that are most likely to benefit be identified?
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Stress precipitates functional deficits following striatal silent stroke: a synergistic effect.
Exp. Neurol.
PUBLISHED: 06-11-2011
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Stress has been linked to structural and functional outcomes after stroke. Moreover, the striatum, both dorsal and ventral, is a vital regulator of stress perception and associated physiological responses. This study investigates potential synergistic effects of focal stroke in the ventrolateral striatum and restraint stress on motor and spatial performance. Adult male Long-Evans rats were pre-trained in a skilled reaching task and randomly assigned to sham, stroke-only, stress-only and stroke+stress conditions. Ventrolateral striatal focal ischemia was induced by endothelin-1 (ET-1) infusion. Rats in stress-only and stroke+stress groups received 21 days of mild restraint stress after stroke. All rats were tested in the skilled reaching task and the ziggurat task (ZT) for post-stroke motor and spatial performance. There was no effect of ventrolateral striatal ischemia or stress alone on motor and spatial performance. Notably, stroke and stress interacted synergistically to reduce reaching success and to disrupt qualitative aspects of movement performance in the absence of histological differences in lesion size. Thus, stress can precipitate behavioural deficits after focal ischemia even in the absence of significant functional deficits on its own. These results emphasize the importance of prevention programmes to control post-stroke levels of stress in clinical populations.
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Hedgehog overexpression is associated with stromal interactions and predicts for poor outcome in breast cancer.
Cancer Res.
PUBLISHED: 06-03-2011
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Hedgehog (Hh) signaling plays an important role in several malignancies but its clinical significance in breast cancer is unclear. In a cohort of 279 patients with invasive ductal carcinoma of the breast, expression of Hh ligand was significantly associated with increased risk of metastasis, breast cancer-specific death, and a basal-like phenotype. A paracrine signature, encompassing high epithelial Hh ligand and high stromal Gli1, was an independent predictor for overall survival in multivariate analysis. In 2 independent histological progression series (n = 301), Hh expression increased with atypia. Hh ligand overexpression in a mouse model of basal breast cancer increased growth, induced a poorly differentiated phenotype, accelerated metastasis, and reduced survival. A stromal requirement for these effects was supported by the lack of similar Hh-mediated changes in vitro, and by stromal-specific expression of Hh target genes in vivo. Furthermore, inhibition of Hh ligand with a monoclonal antibody (5E1) inhibited tumor growth and metastasis. These data suggest that epithelial-stromal Hh signaling, driven by ligand expression in carcinoma cells, promotes breast cancer growth and metastasis. Blockade of Hh signaling to peritumoral stromal cells may represent a novel therapeutic approach in some basal-like breast cancers.
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Endocrine resistance in breast cancer: new roles for ErbB3 and ErbB4.
Breast Cancer Res.
PUBLISHED: 05-20-2011
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Endocrine resistance is a major limitation to the successful treatment of estrogen receptor-positive (ER(+)) breast cancer, and the EGFR (epidermal growth factor receptor) and ErbB-2 receptor tyrosine kinases are involved in this process. A recent study now implicates the other two ErbB family members, ErbB-3 and -4. Exposure of ER+ breast cancer cells to the pure antiestrogen, fulvestrant, increased levels of ErbB-3 or ErbB-4 and sensitivity to the growth-stimulatory effects of heregulin ?1, a potent ligand for these receptors. Thus, the initial growth-inhibitory effects of fulvestrant appear compromised by cellular plasticity that allows rapid compensatory growth stimulation via ErbB-3/4. Further evaluation of pan-ErbB receptor inhibitors in endocrine-resistant disease appears warranted.
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ISHAGE protocol: are we doing it correctly?
Cytometry B Clin Cytom
PUBLISHED: 03-18-2011
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Flow cytometric CD34(+) stem cell enumeration is routinely performed to optimize timing of peripheral blood stem cell collections and assess engraftment capability of the apheresis product. While a number of different flow methodologies have been described, the highly standardized ISHAGE protocol is currently the most widely employed, with 204/255 (81%) international participants in the UK NEQAS CD34(+) stem cell enumeration program indicating their use of this method. Recently, two laboratories were identified as persistent poor performers, a fact attributed to incorrect ISHAGE protocol usage/setup. This prompted UK NEQAS to question whether other laboratories were making similar errors and, if so, how this might affect individual EQA performance.
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Preclinical strategies to define predictive biomarkers for therapeutically relevant cancer subtypes.
Hum. Genet.
PUBLISHED: 03-10-2011
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Defining key driver mutations in cancer, the resulting aberrations in molecular mechanisms and the subsequent phenotype underpins the development and implementation of novel personalized medicine strategies. The literature is replete with biomarkers of prognosis and therapeutic responsiveness identified in single cohorts of patients that have not been independently validated and as a consequence, not developed. Integrating companion biomarker discovery with therapeutic development at the preclinical stage creates the opportunity to identify candidate biomarkers early, which would significantly facilitate both biomarker and therapeutic development. Advances in "-omic" technologies have led to large-scale efforts in characterizing and cataloguing the full range of aberrations in cancer. These include the International Cancer Genome Consortium and The Cancer Genome Atlas, which aim to comprehensively catalogue the range of genomic aberrations for large numbers of cancers for a progressively increasing range of cancer types and subtypes. The technical challenges associated with achieving these goals in some instances have required the generation of primary xenografts and cell lines. These extensively characterized model systems will provide an unprecedented resource for the discovery of biomarkers of therapeutic responsiveness for established therapies, and the development of companion biomarkers linked with preclinical novel therapeutic development in the future.
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Recruitment of regulatory T cells is correlated with hypoxia-induced CXCR4 expression, and is associated with poor prognosis in basal-like breast cancers.
Breast Cancer Res.
PUBLISHED: 03-07-2011
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Basal-like breast cancers behave more aggressively despite the presence of a dense lymphoid infiltrate. We hypothesised that immune suppression in this subtype may be due to T regulatory cells (Treg) recruitment driven by hypoxia-induced up-regulation of CXCR4 in Treg.
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Low AZGP1 expression predicts for recurrence in margin-positive, localized prostate cancer.
Prostate
PUBLISHED: 02-17-2011
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Men with positive margins after radical prostatectomy (RP) for localized prostate cancer (PC) have a 40-50% biochemical relapse rate at 5 years. Adjuvant radiotherapy improves biochemical progression-free and overall survival in men with positive margins, but is associated with increased toxicity. There is an urgent need to identify new prognostic markers to define the group of patients who would benefit from multimodality therapy.
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The expression of the ubiquitin ligase SIAH2 (seven in absentia homolog 2) is mediated through gene copy number in breast cancer and is associated with a basal-like phenotype and p53 expression.
Breast Cancer Res.
PUBLISHED: 02-09-2011
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The seven in absentia homolog 2 (SIAH2) protein plays a significant role in the hypoxic response by regulating the abundance of hypoxia-inducible factor-?; however, its role in breast carcinoma is unclear. We investigated the frequency and expression pattern of SIAH2 in two independent cohorts of sporadic breast cancers.
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Enhanced RAD21 cohesin expression confers poor prognosis and resistance to chemotherapy in high grade luminal, basal and HER2 breast cancers.
Breast Cancer Res.
PUBLISHED: 01-21-2011
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RAD21 is a component of the cohesin complex, which is essential for chromosome segregation and error-free DNA repair. We assessed its prognostic and predictive power in a cohort of in situ and invasive breast cancers, and its effect on chemosensitivity in vitro.
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A novel animal model of hippocampal cognitive deficits, slow neurodegeneration, and neuroregeneration.
J. Biomed. Biotechnol.
PUBLISHED: 01-19-2011
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Long-term adrenalectomy (ADX) results in an extensive and specific loss of dentate gyrus granule cells in the hippocampus of adult rats. This loss of granule cells extends over a period of weeks to months and ultimately results in cognitive deficits revealed in a number of tasks that depend on intact hippocampal function. The gradual nature of ADX-induced cell death and the ensuing deficits in cognition resemble in some important respects a variety of pathological conditions in humans. Here, we characterize behavioural and cellular processes, including adult neurogenesis, in the rat ADX model. We also provide experimental evidence for a neurogenic treatment strategy by which the lost hippocampal cells may be replaced, with the goal of functional recovery in mind.
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Chronic stress prior to hippocampal stroke enhances post-stroke spatial deficits in the ziggurat task.
Neurobiol Learn Mem
PUBLISHED: 01-12-2011
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Stress is one of the most important variables to determine recovery following stroke. We have previously reported that post-stroke exposure to either stress or corticosterone (CORT) alleviates hippocampal ischemic outcome. The present experiment expands previous findings by investigating the influence of exposure to stress prior to ischemic event. Rats received either daily restraint stress (1h/day; 16 consecutive days) or CORT (0.5mg/kg; 16 consecutive days) prior to focal ischemic stroke in the hippocampus induced by bilateral injection of endothelin-1 (ET-1). All experimental groups were then tested in the ziggurat task, a new task for spatial cognition. The stress+stroke group showed significant deficits in both hippocampal structure and function. No deleterious effect of pre-stroke exposure to CORT was found in the CORT+stroke group. Our results indicate that a history of chronic stress sensitizes hippocampal cells to the damaging consequences of focal ischemia. The opposing effects of CORT-related experiences in this study not only reflect the diversity of glucocorticoid actions in the stress response, but also provide evidence that elevated CORT in the absence of emotional disturbance is not sufficient to produce hippocampal deficit.
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The effect of local breast radiotherapy on circulating CD34(+) cells.
Radiother Oncol
PUBLISHED: 01-02-2011
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The number of circulating CD34(+) (hematopoietic stem) cells (HSCs) was observed to decline by 15% in breast cancer patients after starting adjuvant radiation therapy, regardless of age or preceding chemotherapy. These data demonstrate that local radiation therapy can profoundly affect HSC homeostasis, which might have a myriad of important implications.
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Pathways of chemotherapy resistance in castration-resistant prostate cancer.
Endocr. Relat. Cancer
PUBLISHED: 01-01-2011
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Chemotherapy remains the major treatment option for castration-resistant prostate cancer (CRPC) and limited cytotoxic options are available. Inherent chemotherapy resistance occurs in half of all patients and inevitably develops even in those who initially respond. Docetaxel has been the mainstay of therapy for 6 years, providing a small survival benefit at the cost of significant toxicity. Cabazitaxel is a promising second-line agent; however, it is no less toxic, whereas mitoxantrone provides only symptomatic benefit. Multiple cellular pathways involving apoptosis, inflammation, angiogenesis, signalling intermediaries, drug efflux pumps and tubulin are implicated in the development of chemoresistance. A thorough understanding of these pathways is needed to identify biomarkers that predict chemotherapy resistance with the aim to avoid unwarranted toxicities in patients who will not benefit from treatment. Until recently, the search for predictive biomarkers has been disappointing; however, the recent discovery of macrophage inhibitory cytokine 1 as a marker of chemoresistance may herald a new era of biomarker discovery in CRPC. Understanding the interface between this complex array of chemoresistance pathways rather than their study in isolation will be required to effectively predict response and target the late stages of advanced disease. The pre-clinical evidence for these resistance pathways and their progress through clinical trials as therapeutic targets is reviewed in this study.
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Inositol polyphosphate 4-phosphatase II regulates PI3K/Akt signaling and is lost in human basal-like breast cancers.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 12-02-2010
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Inositol polyphosphate 4-phosphatase-II (INPP4B) is a regulator of the phosphoinositide 3-kinase (PI3K) signaling pathway and is implicated as a tumor suppressor in epithelial carcinomas. INPP4B loss of heterozygosity (LOH) is detected in some human breast cancers; however, the expression of INPP4B protein in breast cancer subtypes and the normal breast is unknown. We report here that INPP4B is expressed in nonproliferative estrogen receptor (ER)-positive cells in the normal breast, and in ER-positive, but not negative, breast cancer cell lines. INPP4B knockdown in ER-positive breast cancer cells increased Akt activation, cell proliferation, and xenograft tumor growth. Conversely, reconstitution of INPP4B expression in ER-negative, INPP4B-null human breast cancer cells reduced Akt activation and anchorage-independent growth. INPP4B protein expression was frequently lost in primary human breast carcinomas, associated with high clinical grade and tumor size and loss of hormone receptors and was lost most commonly in aggressive basal-like breast carcinomas. INPP4B protein loss was also frequently observed in phosphatase and tensin homolog (PTEN)-null tumors. These studies provide evidence that INPP4B functions as a tumor suppressor by negatively regulating normal and malignant mammary epithelial cell proliferation through regulation of the PI3K/Akt signaling pathway, and that loss of INPP4B protein is a marker of aggressive basal-like breast carcinomas.
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Epigenetic deregulation across chromosome 2q14.2 differentiates normal from prostate cancer and provides a regional panel of novel DNA methylation cancer biomarkers.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 11-23-2010
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Previously, we showed that gene suppression commonly occurs across chromosome 2q14.2 in colorectal cancer, through a process of long-range epigenetic silencing (LRES), involving a combination of DNA methylation and repressive histone modifications. We now investigate whether LRES also occurs in prostate cancer across this 4-Mb region and whether differential DNA methylation of 2q14.2 genes could provide a regional panel of prostate cancer biomarkers.
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Tyrosine phosphorylation profiling reveals the signaling network characteristics of Basal breast cancer cells.
Cancer Res.
PUBLISHED: 09-21-2010
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To identify therapeutic targets and prognostic markers for basal breast cancers, breast cancer cell lines were subjected to mass spectrometry-based profiling of protein tyrosine phosphorylation events. This revealed that luminal and basal breast cancer cells exhibit distinct tyrosine phosphorylation signatures that depend on pathway activation as well as protein expression. Basal breast cancer cells are characterized by elevated tyrosine phosphorylation of Met, Lyn, EphA2, epidermal growth factor receptor (EGFR), and FAK, and Src family kinase (SFK) substrates such as p130Cas. SFKs exert a prominent role in these cells, phosphorylating key regulators of adhesion and migration and promoting tyrosine phosphorylation of the receptor tyrosine kinases EGFR and Met. Consistent with these observations, SFK inhibition attenuated cellular proliferation, survival, and motility. Basal breast cancer cell lines exhibited differential responsiveness to small molecule inhibitors of EGFR and Met that correlated with the degree of target phosphorylation, and reflecting kinase coactivation, inhibiting two types of activated network kinase (e.g., EGFR and SFKs) was more effective than single agent approaches. FAK signaling enhanced both proliferation and invasion, and Lyn was identified as a proinvasive component of the network that is associated with a basal phenotype and poor prognosis in patients with breast cancer. These studies highlight multiple kinases and substrates for further evaluation as therapeutic targets and biomarkers. However, they also indicate that patient stratification based on expression/activation of drug targets, coupled with use of multi-kinase inhibitors or combination therapies, may be required for effective treatment of this breast cancer subgroup.
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Stress after hippocampal stroke enhances spatial performance in rats.
Physiol. Behav.
PUBLISHED: 09-19-2010
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The nature of stress-related cognitive changes is still a matter of debate. Stress is often considered to be deleterious to cognitive function, despite many instances in which beneficial effects are evident in neural structure and cognition. Moreover, in some neuropathological conditions such as focal ischemia, stress exaggerates loss of cognitive function. The present experiments set out to investigate the effects of repeated restraint stress on spatial cognition in rats, and on recovery from a focal stroke induced by injection of endothelin-1 (ET-1) into the hippocampus (HPC). We did not observe a deleterious effect of stress on performance in the Morris water task (MWT). The HPC focal stroke induced by ET-1 produced lasting spatial learning impairments. Importantly, rats in the HPC stroke+stress group exhibited superior performance in the MWT compared with the HPC stroke-only group. No between-group structural difference was observed related to stress. These findings confirm that corticosterone-related experiences may be key factors influencing cognitive performance after HPC focal ischemic stroke.
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Global levels of specific histone modifications and an epigenetic gene signature predict prostate cancer progression and development.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 09-14-2010
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Epigenetic alterations are common in prostate cancer, yet how these modifications contribute to carcinogenesis is poorly understood. We investigated whether specific histone modifications are prognostic for prostate cancer relapse, and whether the expression of epigenetic genes is altered in prostate tumorigenesis.
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Comparative biomarker expression and RNA integrity in biospecimens derived from radical retropubic and robot-assisted laparoscopic prostatectomies.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 07-10-2010
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Knowledge of preanalytic conditions that biospecimens are subjected to is critically important because novel surgical procedures, tissue sampling, handling, and storage might affect biomarker expression or invalidate tissue samples as analytes for some technologies.
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Guidelines for the diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria and related disorders by flow cytometry.
Cytometry B Clin Cytom
PUBLISHED: 06-10-2010
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Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disorder characterized by a somatic mutation in the PIGA gene, leading to a deficiency of proteins linked to the cell membrane via glycophosphatidylinositol (GPI) anchors. While flow cytometry is the method of choice for identifying cells deficient in GPI-linked proteins and is, therefore, necessary for the diagnosis of PNH, to date there has not been an attempt to standardize the methodology used to identify these cells.
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Spatial memory: a Rosetta stone for rat and human hippocampal discourse: Theoretical comment on Goodrich-Hunsaker and Hopkins (2010).
Behav. Neurosci.
PUBLISHED: 06-10-2010
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The article by Goodrich-Hunsaker and Hopkins (2010, this issue) takes up an important place among in the recent contributions on the role of the hippocampus in memory. They evaluate the effect of bilateral damage to the hippocampus on performance by human participants in a virtual 8-arm radial maze. The hippocampal damage appears to be highly selective and nearly complete. Exactly as with selective hippocampal damage in rats, the human participants showed a deficit in accurately choosing rewarded versus never-rewarded arms and a deficit in avoiding reentering recently visited arms. The results are triply significant: (1) They provide good support for the idea that the wealth of neurobiological information, from network to synapse to gene, on spatial memory in the rat may apply as a whole to the human hippocampal memory system; (2) They affirm the utility of human virtual task models of rat spatial memory tasks; (3) They support one interpretation of the dampening of the hippocampal functional MRI (fMRI) blood oxygen level-dependent (BOLD) signal during performance of the virtual radial arm maze observed by Astur et al. (2005).
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Cell cycle proteins in epithelial cell differentiation: implications for breast cancer.
Cell Cycle
PUBLISHED: 05-15-2010
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Proliferation and differentiation are tightly coupled processes, so that a final cell cycle is often linked to the initiation of cell differentiation. The flux in cell cycle proteins during this process is commonly assumed to simply control the final cell cycle exit. However it now appears that cell cycle proteins can also play a role in the decision to continue cycling or to terminally differentiate. A subset of the G1 to S phase transition proteins, D-type cyclins, Rb family proteins and the CDK inhibitors, are particularly involved in the commitment to differentiation. Cell cycle proteins can sequester or modify activators of differentiation pathways, while simultaneously performing their cell cycle functions as illustrated by their roles in terminal differentiation in mammary epithelium. G1 to S phase cell cycle proteins, particularly cyclin D1, are commonly altered in breast cancer and contribute to breast tumorigenesis, presumably by increasing proliferation. However the capacity for cell cycle proteins to also influence differentiation may influence tumour progression, and may alter the efficacy of differentiation-based therapeutics.
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High Notch1 protein expression is an early event in breast cancer development and is associated with the HER-2 molecular subtype.
Histopathology
PUBLISHED: 05-13-2010
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Activation of Notch signalling results in hyperplasia and tumorigenesis in murine mammary epithelium. However, there is little information regarding the expression of Notch1 in premalignant lesions and early breast cancer. We investigated expression of Notch1 in breast cancer development and its association with molecular subtypes.
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International network of cancer genome projects.
, Thomas J Hudson, Warwick Anderson, Axel Artez, Anna D Barker, Cindy Bell, Rosa R Bernabé, M K Bhan, Fabien Calvo, Iiro Eerola, Daniela S Gerhard, Alan Guttmacher, Mark Guyer, Fiona M Hemsley, Jennifer L Jennings, David Kerr, Peter Klatt, Patrik Kolar, Jun Kusada, David P Lane, Frank Laplace, Lu Youyong, Gerd Nettekoven, Brad Ozenberger, Jane Peterson, T S Rao, Jacques Remacle, Alan J Schafer, Tatsuhiro Shibata, Michael R Stratton, Joseph G Vockley, Koichi Watanabe, Huanming Yang, Matthew M F Yuen, Bartha M Knoppers, Martin Bobrow, Anne Cambon-Thomsen, Lynn G Dressler, Stephanie O M Dyke, Yann Joly, Kazuto Kato, Karen L Kennedy, Pilar Nicolás, Michael J Parker, Emmanuelle Rial-Sebbag, Carlos M Romeo-Casabona, Kenna M Shaw, Susan Wallace, Georgia L Wiesner, Nikolajs Zeps, Peter Lichter, Andrew V Biankin, Christian Chabannon, Lynda Chin, Bruno Clément, Enrique De Alava, Françoise Degos, Martin L Ferguson, Peter Geary, D Neil Hayes, Amber L Johns, Arek Kasprzyk, Hidewaki Nakagawa, Robert Penny, Miguel A Piris, Rajiv Sarin, Aldo Scarpa, Marc van de Vijver, P Andrew Futreal, Hiroyuki Aburatani, Mònica Bayés, David D L Botwell, Peter J Campbell, Xavier Estivill, Sean M Grimmond, Ivo Gut, Martin Hirst, Carlos Lopez-Otin, Partha Majumder, Marco Marra, John D McPherson, Zemin Ning, Xose S Puente, Yijun Ruan, Hendrik G Stunnenberg, Harold Swerdlow, Victor E Velculescu, Richard K Wilson, Hong H Xue, Liu Yang, Paul T Spellman, Gary D Bader, Paul C Boutros, Paul Flicek, Gad Getz, Roderic Guigo, Guangwu Guo, David Haussler, Simon Heath, Tim J Hubbard, Tao Jiang, Steven M Jones, Qibin Li, Nuria López-Bigas, Ruibang Luo, Lakshmi Muthuswamy, B F Francis Ouellette, John V Pearson, Víctor Quesada, Benjamin J Raphael, Chris Sander, Terence P Speed, Lincoln D Stein, Joshua M Stuart, Jon W Teague, Yasushi Totoki, Tatsuhiko Tsunoda, Alfonso Valencia, David A Wheeler, Honglong Wu, Shancen Zhao, Guangyu Zhou, Mark Lathrop, Gilles Thomas, Teruhiko Yoshida, Myles Axton, Chris Gunter, Linda J Miller, Junjun Zhang, Syed A Haider, Jianxin Wang, Christina K Yung, Anthony Cros, Anthony Cross, Yong Liang, Saravanamuttu Gnaneshan, Jonathan Guberman, Jack Hsu, Don R C Chalmers, Karl W Hasel, Terry S H Kaan, William W Lowrance, Tohru Masui, Laura Lyman Rodriguez, Catherine Vergely, David D L Bowtell, Nicole Cloonan, Anna deFazio, James R Eshleman, Dariush Etemadmoghadam, Brooke B Gardiner, Brooke A Gardiner, James G Kench, Robert L Sutherland, Margaret A Tempero, Nicola J Waddell, Peter J Wilson, Steve Gallinger, Ming-Sound Tsao, Patricia A Shaw, Gloria M Petersen, Debabrata Mukhopadhyay, Ronald A DePinho, Sarah Thayer, Kamran Shazand, Timothy Beck, Michelle Sam, Lee Timms, Vanessa Ballin, Youyong Lu, Jiafu Ji, Xiuqing Zhang, Feng Chen, Xueda Hu, Qi Yang, Geng Tian, Lianhai Zhang, Xiaofang Xing, Xianghong Li, Zhenggang Zhu, Yingyan Yu, Jun Yu, Jörg Tost, Paul Brennan, Ivana Holcatova, David Zaridze, Alvis Brazma, Lars Egevard, Egor Prokhortchouk, Rosamonde Elizabeth Banks, Mathias Uhlén, Juris Viksna, Fredrik Ponten, Konstantin Skryabin, Ewan Birney, Ake Borg, Anne-Lise Børresen-Dale, Carlos Caldas, John A Foekens, Sancha Martin, Jorge S Reis-Filho, Andrea L Richardson, Christos Sotiriou, Giles Thoms, Laura van't Veer, Daniel Birnbaum, Hélène Blanché, Pascal Boucher, Sandrine Boyault, Jocelyne D Masson-Jacquemier, Iris Pauporté, Xavier Pivot, Anne Vincent-Salomon, Eric Tabone, Charles Theillet, Isabelle Treilleux, Paulette Bioulac-Sage, Thomas Decaens, Dominique Franco, Marta Gut, Didier Samuel, Jessica Zucman-Rossi, Roland Eils, Benedikt Brors, Jan O Korbel, Andrey Korshunov, Pablo Landgraf, Hans Lehrach, Stefan Pfister, Bernhard Radlwimmer, Guido Reifenberger, Michael D Taylor, Christof von Kalle, Partha P Majumder, Paolo Pederzoli, Rita A Lawlor, Massimo Delledonne, Alberto Bardelli, Thomas Gress, David Klimstra, Giuseppe Zamboni, Yusuke Nakamura, Satoru Miyano, Akihiro Fujimoto, Elias Campo, Silvia de Sanjosé, Emili Montserrat, Marcos Gonzalez-Díaz, Pedro Jares, Heinz Himmelbauer, Heinz Himmelbaue, Sílvia Beà, Samuel Aparicio, Douglas F Easton, Francis S Collins, Carolyn C Compton, Eric S Lander, Wylie Burke, Anthony R Green, Stanley R Hamilton, Olli P Kallioniemi, Timothy J Ley, Edison T Liu, Brandon J Wainwright.
Nature
PUBLISHED: 04-16-2010
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The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.
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MAL2 and tumor protein D52 (TPD52) are frequently overexpressed in ovarian carcinoma, but differentially associated with histological subtype and patient outcome.
BMC Cancer
PUBLISHED: 04-07-2010
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The four-transmembrane MAL2 protein is frequently overexpressed in breast carcinoma, and MAL2 overexpression is associated with gain of the corresponding locus at chromosome 8q24.12. Independent expression microarray studies predict MAL2 overexpression in ovarian carcinoma, but these had remained unconfirmed. MAL2 binds tumor protein D52 (TPD52), which is frequently overexpressed in ovarian carcinoma, but the clinical significance of MAL2 and TPD52 overexpression was unknown.
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Hippocampus and retrograde amnesia in the rat model: a modest proposal for the situation of systems consolidation.
Neuropsychologia
PUBLISHED: 03-30-2010
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The properties of retrograde amnesia after damage to the hippocampus have been explicated with some success using a rat model of human medial temporal lobe amnesia. We review the results of this experimental work with rats focusing on several areas of consensus in this growing literature. We evaluate the theoretically significant hypothesis that hippocampal retrograde amnesia normally exhibits a temporal gradient, affecting recent, but sparing remote memories. Surprisingly, the evidence does not provide much support for the idea that there is a lengthy process of systems consolidation following a learning episode. Instead, recent and remote memories tend to be equally affected. The extent of damage to the hippocampus is a significant factor in this work since it is likely that spared hippocampal tissue can support at least partial memory retrieval. With extensive hippocampal damage gradients are flat or, in the case of memory tasks with flavour/odour retrieval cues, the retrograde amnesia covers a period of about 1-3 days. There is consistent evidence that at the time of learning the hippocampus interferes with or overshadows memory acquisition by other systems. This contributes to the breadth and severity of retrograde amnesia relative to anterograde amnesia in the rat. The fact that multiple, distributed learning episodes can overcome this overshadowing is consistent with a parallel dual-store theory or a Distributed Reinstatement Theory in which each learning episode triggers a short period of memory replay that provides a brief hippocampal-dependent systems consolidation.
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Expression of a conditioned place preference or spatial navigation task following muscimol-induced inactivations of the amygdala or dorsal hippocampus: A double dissociation in the retrograde direction.
Brain Res. Bull.
PUBLISHED: 01-25-2010
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Previous work indicates an essential role of the basolateral amygdala in stimulus-reward learning and the dorsal hippocampus in spatial learning and memory. The goal of the present, experiments was to examine the involvement of the amygdala and hippocampus in performance of tasks requiring stimulus-reward and spatial/relational learning and memory processes in the retrograde direction. Accordingly, this series of experiments tested the effects of temporary, inactivations directed at the basolateral nucleus of the amygdala or dorsal hippocampus on the, expression of a conditioned place preference (CPP) task or a spatial navigation water task. The results, of Experiments 1a and b showed that inactivations of the amygdala impaired the expression of a, previously acquired CPP but did not impair the expression of a learned spatial response required for, accurate performance of a spatial navigation task. The results of Experiments 2a and b showed that, inactivations of the dorsal hippocampus impaired expression of a learned response required for the, accurate performance of a spatial navigation task but did not impair the learned response required for, the expression of a CPP. Taken together, the results showed a functional dissociation between the, effects of amygdala or hippocampal dysfunction on the expression of these different classes of tasks.
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Overexpression of the oncogenic signal transducer Gab2 occurs early in breast cancer development.
Int. J. Cancer
PUBLISHED: 01-21-2010
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Gab2, a docking-type signaling protein with demonstrated oncogenic potential, is overexpressed in breast cancer, but its prognostic significance and role in disease evolution remain unclear. Immunohistochemical detection of Gab2 in a large cohort of primary human breast cancers of known outcome revealed that while Gab2 expression was positively correlated with increased tumor grade, it did not correlate with disease recurrence or breast cancer-related death in the total cohort or in patients stratified according to lymph node, estrogen receptor (ER) or HER2 status. Interestingly, analysis of a "progression series" that included premalignant and preinvasive breast lesions as well as samples of metastatic disease revealed that Gab2 expression was significantly enhanced in the earliest lesion examined, usual ductal hyperplasia, with a further increase detected in ductal carcinoma in situ (DCIS). Furthermore, expression was less in invasive cancers and lymph node metastases than in DCIS, but still higher than in normal breast. These findings indicate that while Gab2 expression is not prognostic in breast cancer, its role in early disease evolution warrants further analysis, as Gab2 and its effectors may provide targets for novel strategies aimed at preventing breast cancer development.
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Gene based prediction of clinically localized prostate cancer progression after radical prostatectomy.
J. Urol.
PUBLISHED: 01-17-2010
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Accurate estimates of recurrence risk are needed for optimal treatment of patients with clinically localized prostate cancer. We combined an established nomogram and what to our knowledge are novel molecular predictors into a new prognostic model of prostate specific antigen recurrence.
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Cytoplasmic localization of beta-catenin is a marker of poor outcome in breast cancer patients.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 01-09-2010
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Beta-catenin is involved in cell adhesion through catenin-cadherin complexes and as a transcriptional regulator in the Wnt signaling pathway. Its deregulation is important in the genesis of a number of human malignancies, particularly colorectal cancer. A range of studies has been undertaken in breast cancer, with contradictory associations reported among beta-catenin expression, clinicopathologic variables, and disease outcome. We undertook an immunohistochemical study measuring the levels and subcellular localization of beta-catenin in 292 invasive ductal breast cancers with known treatment and outcome. No association with breast cancer-specific death was observed for cytoplasmic or membrane expression alone; however, a continuous score representing both locations (membrane minus cytoplasmic expression: MTC score) was associated with a worse outcome in univariate analysis (P = 0.004), and approached significance in a multivariate analysis model that included lymph node, progesterone receptor (PR), and HER2 status (P = 0.054). Therefore, the MTC score was used for further statistical analyses due to the importance of both the subcellular location and the levels of expression of beta-catenin. An association was identified between high cytoplasmic expression (low MTC score), and high tumor grade (P = 0.004), positive Ki67 (P = 0.005), negative estrogen receptor (ER) (P = 0.005), positive HER2 (P = 0.04) status, and an active phosphoinositide 3-kinase pathway (P = 0.005), measured as PIK3CA mutations (P = 0.05) or PTEN loss (P = 0.05). Low cytoplasmic expression (high MTC score) was associated with the luminal A subtype (P = 0.004). In conclusion, a low beta-catenin MTC score is associated with an adverse outcome in breast cancer, which may be of mechanistic significance in the disease process.
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Object/context-specific memory deficits associated with loss of hippocampal granule cells after adrenalectomy in rats.
Learn. Mem.
PUBLISHED: 01-01-2010
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Chronic adrenalectomy (ADX) causes a gradual and selective loss of granule cells in the dentate gyrus (DG) of the rat. Here, we administered replacement corticosterone to rats beginning 10 wk after ADX. We then tested them in three discrimination tasks based on object novelty, location, or object/context association. Only during testing of the object/context association did ADX rats demonstrate deficits. These findings add to a body of evidence that the hippocampus is necessary when contextual information is important. We also confirm that memory deficits after chronic adrenalectomy are not a result of loss of corticosterone per se.
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CDK inhibitors as potential breast cancer therapeutics: new evidence for enhanced efficacy in ER+ disease.
Breast Cancer Res.
PUBLISHED: 12-07-2009
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Loss of cell cycle control is a hallmark of cancer, and aberrations in the cyclin-CDK-RB (cyclin-dependent kinase-retinoblastoma protein) pathway are common in breast cancer. Consequently, inhibition of this pathway is an attractive therapeutic strategy, but results from clinical trials of CDK inhibitors in breast cancer have been disappointing. A recent study now shows that in cell culture a selective CDK4/6 inhibitor is preferentially effective in estrogen receptor-positive (ER(+)) disease and apparently acts synergistically with tamoxifen or trastuzumab. These exciting new preclinical data set the scene for a more targeted approach to further clinical evaluation wherein this class of drugs is targeted to subgroups of ER(+) patients, including those with resistance to endocrine therapy, alone or in combination with current standard therapies.
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Quantitative caveats of standard immunohistochemical procedures: implications for optical disector-based designs.
J. Histochem. Cytochem.
PUBLISHED: 12-07-2009
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Immunohistochemistry is a ubiquitous technique in histology. Often, the goal of such studies is the quantification of some parameter associated with a particular antigen. When used correctly, the optical disector offers a statistically relevant approach to achieve this goal without bias from cell size, shape, or orientation. This three-dimensional counting probe is virtually embedded within the depth of the tissue section, thus avoiding sampling near the cut surfaces of the section, where cells are often lost during the cutting and subsequent processing steps. It follows that the probability that a cell could be immunolabeled should be equal throughout the section depth to correctly employ the optical disector. In this report, we demonstrate that parameters commonly used in immunohistochemistry often leave the middle of the section unlabeled. Furthermore, the degree of incomplete penetration varies among antibodies but can be overcome in some cases by extending the incubation time of the secondary antibody. The detection of this phenomenon in immunofluorescence preparations and the implications of these findings for quantitative stereology using the optical disector are discussed.
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Identification of candidate biomarkers of therapeutic response to docetaxel by proteomic profiling.
Cancer Res.
PUBLISHED: 09-22-2009
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Docetaxel chemotherapy improves symptoms and survival in men with metastatic hormone-refractory prostate cancer (HRPC). However, approximately 50% of patients do not respond to Docetaxel and are exposed to significant toxicity without direct benefit. This study aimed to identify novel therapeutic targets and predictive biomarkers of Docetaxel resistance in HRPC. We used iTRAQ-mass spectrometry analysis to identify proteins associated with the development of Docetaxel resistance using Docetaxel-sensitive PC3 cells and Docetaxel-resistant PC3-Rx cells developed by Docetaxel dose escalation. Functional validation experiments were performed using recombinant protein treatment and siRNA knockdown experiments. Serum/plasma levels of the targets in patient samples were measured by ELISA. The IC(50) for Docetaxel in the PC3-Rx cells was 13-fold greater than the parent PC-3 cell line (P = 0.004). Protein profiling identified MIC-1 and AGR2 as respectively up-regulated and down-regulated in Docetaxel-resistant cells. PC-3 cells treated with recombinant MIC-1 also became resistant to Docetaxel (P = 0.03). Conversely, treating PC3-Rx cells with MIC-1 siRNA restored sensitivity to Docetaxel (P = 0.02). Knockdown of AGR2 expression in PC3 cells resulted in Docetaxel resistance (P = 0.007). Furthermore, increased serum/plasma levels of MIC-1 after cycle one of chemotherapy were associated with progression of the cancer (P = 0.006) and shorter survival after treatment (P = 0.002). These results suggest that both AGR2 and MIC-1 play a role in Docetaxel resistance in HRPC. In addition, an increase in serum/plasma MIC-1 level after cycle one of Docetaxel may be an indication to abandon further treatment. Further investigation of MIC-1 as a biomarker and therapeutic target for Docetaxel resistance in HRPC is warranted.
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Use of a FLAER-based WBC assay in the primary screening of PNH clones.
Am. J. Clin. Pathol.
PUBLISHED: 09-19-2009
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Diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) with flow cytometry traditionally involves the analysis of CD55 and CD59 on RBCs and neutrophils. However, the ability to accurately detect PNH RBCs is compromised by prior hemolysis and/or transfused RBCs. Patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS) can also produce PNH clones. We recently described a multiparameter fluorescent aerolysin (FLAER)-based flow assay using CD45, CD33, and CD14 that accurately identified PNH monocyte and neutrophil clones in PNH, AA, and MDS. Here, we compared the efficiency of this WBC assay with a CD59-based assay on RBCs during a 3-year period. PNH clones were detected with the FLAER assay in 63 (11.8%) of 536 samples tested, whereas PNH RBCs were detected in only 33 (6.2%), and always with a smaller clone size. The FLAER assay on WBCs is a more sensitive and robust primary screening assay for detecting PNH clones in clinical samples.
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Stage migration in localized prostate cancer has no effect on the post-radical prostatectomy Kattan nomogram.
BJU Int.
PUBLISHED: 09-14-2009
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To investigate the effect of prostate-specific antigen (PSA) testing on stage migration in an Australian population, and its consequences on the prognostic accuracy of the post-radical prostatectomy (RP) Kattan nomogram, as in North America widespread PSA testing has resulted in prostate cancer stage migration, questioning the utility of prognostic nomograms in this setting.
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Prediction of local recurrence, distant metastases, and death after breast-conserving therapy in early-stage invasive breast cancer using a five-biomarker panel.
J. Clin. Oncol.
PUBLISHED: 08-31-2009
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To determine the clinical utility of intrinsic molecular phenotype after breast-conserving therapy (BCT) with lumpectomy and whole-breast irradiation with or without a cavity boost.
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Cyclin D1 splice variants: polymorphism, risk, and isoform-specific regulation in prostate cancer.
Clin. Cancer Res.
PUBLISHED: 08-25-2009
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Alternative CCND1 splicing results in cyclin D1b, which has specialized, protumorigenic functions in prostate not shared by the cyclin D1a (full length) isoform. Here, the frequency, tumor relevance, and mechanisms controlling cyclin D1b were challenged.
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Biological determinants of endocrine resistance in breast cancer.
Nat. Rev. Cancer
PUBLISHED: 08-25-2009
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Endocrine therapies targeting oestrogen action (anti-oestrogens, such as tamoxifen, and aromatase inhibitors) decrease mortality from breast cancer, but their efficacy is limited by intrinsic and acquired therapeutic resistance. Candidate molecular biomarkers and gene expression signatures of tamoxifen response emphasize the importance of deregulation of proliferation and survival signalling in endocrine resistance. However, definition of the specific genetic lesions and molecular processes that determine clinical endocrine resistance is incomplete. The development of large-scale computational and genetic approaches offers the promise of identifying the mediators of endocrine resistance that may be exploited as potential therapeutic targets and biomarkers of response in the clinic.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.