bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3982: Super-resolution imaging of drug delivery to live cells using real-time structured illumination microscopy
Authors: Lefman Jonathan , Cheuk Tai , Metaferia Belhu , Tsang Patricia , Scott Keana , Stranick Stephan , Khan Javed 
Published: February 2011

Abstract
Imaging the effects of drug delivery in live cells is most often performed by confocal microscopy, which has a resolution limited by the diffraction of light. Here, we report the development of a novel method for imaging drug delivery to live cells using real-time super-resolution microscopy in wide-field mode. Structured illumination microscopy (SIM) is one of several super-resolving microscopy techniques and is capable of imaging beyond the resolution of conventional microscopy to less than 100 nm. In SIM, each super-resolution (SR) image is computationally constructed from a dataset of numerous raw images. Due to the computational time required for SR image construction, datasets are usually post-processed to avoid slowdowns during the acquisition process. Although post-processing is convenient, this approach has limited use since SR images are not available during image acquisition and thus cannot be utilized for real-time evaluation of the sample. Utilizing SR images in real-time is particularly important when objects of interest are smaller than the resolution limit of conventional microscopy. Applications such as determining optimal focus and finding desirable regions of interest are depending on real-time feedback to user. When performing real-time SIM imaging live cells, image acquisition, processing, and the display of SR images must occur in rapid succession thereby reducing the effects of molecular movement. To achieve the data processing speed necessary for real-time imaging of live cells, we utilized a graphics processing unit (GPU) to perform high-speed SR image construction. Each function for processing SIM data was optimized for parallel operation using GPU kernels. Excluding data transfer overhead, the actual GPU processing time for synthesizing the SR image was 45 milliseconds. Compared with parallel processing on a multi-core computer (CPU), using the GPU achieved a 45-fold increase in processing speed. Overall, data throughput using the GPU attained an 8-fold speed increase over CPU processing, thus allowing real-time high resolution imaging. We applied this SIM platform to record the action of nocodazole on microtubule depolymerization in HeLa cells. We are currently developing this real-time imaging method to investigate the delivery and release mechanism of therapeutic cargoes contained within nanoparticles.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3982.
Abstract 4000: Cellular MRI of human breast cancer cells labeled with gadofluorine M
Authors: Lizardo Michael M. , Ronald John A. , Chen Yuanxin , Misselwitz Bernd , Rutt Brian K. , Chambers Ann F. 
Published: February 2011

Abstract
The ability to non-invasively locate and quantify tumor cell number at a metastatic site would be of considerable interest in pre-clinical and clinical metastasis research. To this end, our objective is to develop positive-contrast cellular magnetic resonance imaging (MRI) for use in quantifying tumor cell number at a metastatic site in vivo. The goals of the current study were to characterize the in vitro labeling of MDA-MB-231-luc-D3H2LN human breast cancer cells with a novel positive contrast MR agent Gadofluorine M (GdF), and to demonstrate the detectability of GdF-labeled cells in vitro at clinical strength MRI (1.5 and 3Tesla) scanners. Briefly, cells (1.5 × 107cells) were loaded by simple incubation for 24h with GdF at concentrations ranging from 25μM to 10mM. GdF-loading from 25μM to 1000μM did not result in significant changes in metabolic activity. Higher GdF-loading concentrations, 2500μM and 10mM, resulted in a 16% and 21% reduction in metabolic activity, respectively. The lowest GdF-loading concentration used (25μM) resulted in a significant (9-fold) increase in MR signal enhancement which then plateaued from 100μM to 1000μM. T1-relaxometry of cell pellets demonstrated a similar statistical trend in relaxation rates of cell pellets for all loading conditions, and at both field strengths. Inductively-coupled plasma atomic emission spectroscopy was performed on the cell pellet extracts to assess the average amount of GdF that had accumulated per cell at each incubating concentration. Since the relaxivity of an MR contrast agent can be affected by its intracellular location, we assessed whether internalized GdF-cc (GdF analog where the mannose moiety was replaced with carbocyanine) was cytosolic or compartmentalized into endosomes, via immunostaining for mannose-6-phosphate receptor. Using confocal fluorescence microscopy, we found that GdF is largely cytosolic and did not co-localize to late endosomes, an optimal situation for achieving maximum positive-contrast by T1-shortening since endosomal compartmentalization can lessen the enhancement seen in MR images. From these results, we have determined that the GdF loading concentration of 1000μM permits the highest payload for detection by cellular MRI in clinical field strength scanners. Information from this proof-of-principle study will support future work to develop positive-contrast cellular MRI as a new approach to quantitative imaging of metastatic cells in vivo.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4000.
Abstract 4025: SHIP-1 is involved in resistance to alkyl-lysophospholipid induced apoptosis in S49 T-cell lymphoma cells
Authors: Alderliesten Maaike , Klarenbeek Jeffrey , van der Luit Arnold , van Lummel Menno , van Blitterswijk Wim , Verheij Marcel 
Published: February 2011

Abstract
Edelfosine (ALP, Et-18-OCH3) is a prototype alkyl-lysophospholipid that has effective antitumoral activity. It inserts in the membrane and accumulates in lipid rafts leading to apoptosis in S49 mouse T cell lymphoma cells. A variant cell line, made resistant to ALP (S49AR) shows in impaired uptake of ALP. S49AR cells are not only resistant to a variety of ALP analogues, but also to DNA damage and Fas/CD95 death receptor induced apoptosis, suggesting another cause for resistance in addition to impaired ALP uptake. Here we studied the ALP resistance of S49AR. We observe an upregulation of phosho-PKB/Akt and phospho-ERK1/2 which are key proteins in the canonical survival signaling pathways. However inhibition of ERK and/or PKB/Akt using pharmacological inhibitors has no effect on the resistance of the S49AR cells to apoptotic stimuli. PKB/Akt and ERK1/2 activation is regulated by PI(3,4,5)P3 formation. The levels of phosphoinositides in the various cell lines were measured with HPLC. The cell lines resistant to apoptotic inducing agents show decreased levels of the diverse phosphopoinositides. SHIP-1 is a SH2 domain containing inositol phosphatase that removes the 5′ phosphate of PI(3,4,5)P3 and is mainly expressed in hemotopoietic cells. It decreases the pool of PI(3,4,5)P3 thereby negatively regulating the activation of PKB/Akt. We see down regulation of SHIP-1 both on gene expression and protein level in the S49AR compared to S49 cells. Other components of the phosphoinositide metabolism, like PI3Kinase and SHIP2, did not show any changes. Resensitization of the S49AR cells to ALP leads to restoration of SHIP-1 expression. Knocking down SHIP-1 using siRNA causes resistance to various ALPs, DNA damage and Fas/CD95 death receptor induced apoptosis. Microarray analysis show that the S49AR and S49siSHIP cells show remarkably similar expression profile which are distinct from the expression profiles shown by S49 and S49mock cells.
Concluding, SHIP-1 is downregulated in ALP resistant T cell lymphoma cells concurrent with a general downregulation of phosphoinositide levels in the cells which is associated with the resistance to ALP induced apoptosis. How ALP resistance is caused is yet unknown and is the scope of current research.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4025.
Abstract 4027: The lectin concanavalin-A induces cyclooxygenase-2 expression through an IKKgamma/NFkB-dependent pathway in U87 glioblastoma cells
Authors: Sina Asmaa , Proulx-Bonneau Sébastien , Annabi Borhane 
Published: February 2011

Abstract
The lectin from Canavalia ensiformis (Concanavalin-A, ConA), one of the most abundant lectins known, enables one to mimic biological lectin/carbohydrate interactions that regulate extracellular matrix protein recognition. As such, ConA is known to induce membrane type-1 matrix metalloproteinase (MT1-MMP) and is, therefore, routinely used to assess MT1-MMP-mediated functions. Given that gliomas with increasing histological grade demonstrated MT1-MMP expression that correlated with high expression of cyclooxygenase (COX)-2, we specifically assessed the early proinflammatory cellular signaling processes triggered by ConA, a lectin known to induce MT1-MMP expression, in the regulation of COX-2. We found that treatment with ConA or direct overexpression of a recombinant MT1-MMP resulted in the induction of COX-2 expression. This increase in COX-2 was correlated with a concomitant decrease in phosphorylated AKT suggestive of cell death induction, and was independent of MT1-MMP's catalytic function. ConA and MT1-MMP-mediated intracellular signaling and induction of COX-2 was also validated in both wild-type and Nuclear Factor-kappaB (NF-κB) p65−/− mutant mouse embryonic fibroblasts (MEF), but was abrogated in NF-κB1 (p50)−/− and in I kappaB kinase (IKK) γ−/− mutant MEF cells. Collectively, our results highlight an IKK/NF-κB-dependent pathway linking MT1-MMP-mediated intracellular signaling to the induction of COX-2 by ConA. That signaling pathway could account for the inflammatory balance responsible for the therapy resistance phenotype of glioblastoma cells, and prompts for the design of new therapeutic strategies that target cell surface carbohydrate structures and MT1-MMP-mediated signaling.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4027.
Abstract 4046: Androgen-mediated phenotypic change in prostate carcinoma cells and the microRNA-ome
Authors: Segal Corrinne , Powell Chris J. , Gooderham Nigel J. 
Published: February 2011

Abstract
Activation of the androgen receptor (AR) results in phenotypic change in androgen-responsive cells; for example, in the human prostate carcinoma cell line (LNCaP) androgens mediate cell proliferation. Factors controlling the range of phenotypic responses mediated by androgens are only partially understood, but include both transcriptional and post-transcriptional mechanisms. One such mechanism that appears to offer wide ranging, yet highly selective control, is the expression of the miRNA-ome. In the present study, we assessed the influence of endocrine-active compounds that act via the AR pathway on the microRNA (miRNA) profile. As negative regulators of gene expression, miRNA are short non-coding RNA that are able to suppress translation or induce degradation of their target mRNA transcripts (post-transcriptional) leading to decreased protein expression.
The effect of exposure of LNCaP cells to the AR agonists mibolerone and dihydrotestosterone, and the antagonist bicalutamide, was determined at various time points up to 120 hours. Phenotypic response to exposure was assessed as an alteration of proliferative ability, expression of prostate-specific antigen (PSA) and alteration of the miRNA-ome. As expected, each of the agonists significantly induced proliferation, compared to vehicle control, and the antagonist decreased proliferation. Concurrent with changes in proliferation, were an up-regulation of PSA secretion for mibolerone and DHT. The temporal effects of exposure to androgenic compounds on the expression profile of 850 miRNAs was assessed using Agilent's miRNA microarray version 3. The ability of androgens to alter the miRNA-ome was confirmed and found to be temporally-dependent. Bioinformatic analysis of the phenotypic changes induced by the androgens is reflected in the changes in the miRNA-ome.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4046.
Abstract 4048: Increased expression of PACS-1 in cervical cancer is associated with loss of microRNA449a
Authors: Veena Mysore S. , Raychaudhuri Santanu , You Huihong , Basak Saroj K. , Zainabadi Kayvan , Thomas Gary , Srivatsan Eri 
Published: February 2011

Abstract
Cervical cancer is one of the leading causes of female death world wide with approximately 50,000 deaths per year. We identified a 300 kb deletion of chromosome 11q13 in cervical cancer and mapped eleven genes to this region. Of these, phosphofurin acidic cluster sorting −1 (PACS-1) gene encodes a multi-functional sorting protein involved in secretory pathway membrane traffic. Expression studies showed the presence of an abnormal PACS-1 transcript in tumorigenic cell lines. Protein expression studies in paired normal and cervical tumors showed over-expression of PACS-1 protein in tumor specimens. RT-PCR indicated that protein over-expression was related to over-expression at the RNA level. These findings together with the absence of detectable mutations in PACS-1 exons in HeLa or SiHa cervical carcinoma cell lines raised the possibility that dysregulation of a microRNA (miRNA) may alter PACS-1 expression in cervical cancer. Consistent with this possibility, a UCSC genome database search showed the presence of binding sites for miRNA449a in the 3′ UTR (untranslated region) of the PACS-1 RNA transcript. Co-transfection of PACS-1 3′UTR luciferase reporter with miRNA449a resulted in reduced expression of luciferase. Expression of miR449a in HeLa and SiHa cells led to reduced expression of PACS-1 and increased expression of p53 and p21 proteins. FACS analysis of HeLa cells transfected with miR449a showed a reduction in S phase indicating the growth suppressive effect of miR449a. These results indicate that miR449a regulates PACS-1 expression and loss of miR449a expression leads to over-expression of PACS-1. This in turn seems to result in the destabilization of p53 in cervical cancer. Our findings suggest PACS-1 plays a role in cervical cancer development and its expression is regulated post-transcriptionally by miRNA449a.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4048.
Abstract 4049: MiR-187 is a marker of poor prognosis in estrogen receptor-positive breast cancer
Authors: Mulrane Laoighse , Madden Stephen , Brennan Donal J. , McGee Sharon F. , Jirström Karin , Veer Laura van't , Bernards Rene , Higgins Des , Gallagher William M. , O'Connor Darran P. 
Published: February 2011

Abstract
Resistance to endocrine-directed therapy represents a significant problem in the management of breast cancer. Here we describe an integrated bioinformatics and translational pathology approach to identifying novel microRNAs (miRNA) controlling this phenomenon.
Differential gene expression can, in part, be attributed to the activity of specific miRNAs. Given a database of miRNA binding site motifs and gene expression levels determined by transcriptomic profiling, correspondence analysis, between group analysis and co-inertia analysis can be combined to produce a ranked list of miRNAs associated with a specific gene signature and phenotype. We have applied this approach to examine gene expression data from 69 breast cancer patients treated with tamoxifen (1) and have identified miR-187 as the principle miRNA associated with poor response to anti-estrogen therapy.
Expression of miR-187 was subsequently evaluated in a cohort of breast cancer patients (n=111), by locked nucleic acid in situ hybridisation (LNA-ISH) on tissue microarrays, and quantified by automated image analysis. LNA-ISH signal was validated by miR-187-specific Taqman PCR in a subset of tumours. High miR-187 expression was significantly associated with poor outcome in ER+ breast cancer patients (p = 0.05) and correlated with increased tumour size (p=0.009), higher grade (p=0.005) and PR negativity (p=0.014). Additionally, the prognostic significance of the miR-187 target genes OCA2 and HIPK3 was examined in an independent dataset comprising 155 breast cancer patients treated with adjuvant tamoxifen (2). Low mRNA expression of both OCA2 (p=0.0001) and HIPK3 (p=0.016) was found to be significantly associated with poor outcome. These data support the hypothesis that miR-187 and its targets play an important role in anti-estrogen resistance and may be useful as biomarkers to aid treatment options and as potential drug targets to restore tamoxifen sensitivity in resistant patients.
1.
Kok M et al. Comparison of gene expression profiles predicting progression in breast cancer patients treated with tamoxifen. Breast Cancer Res Treat 2009;113(2):275
2.
Chanrion M et al., A gene expression signature that can predict the recurrence of tamoxifen-treated primary breast cancer. Clin Cancer Res 2008;14(6):1744-52.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4049.
Abstract 4057: Negative regulation of prostate specific membrane antigen by androgen is mediated by TMPRSS2-ERG gene fusion in VCaP prostate cancer cells
Authors: Yin Lihong , Rao Pravin , Wang Jianghua , Ittmann Michael , Heston Warren D.W. 
Published: February 2011

Abstract
Prostate specific membrane antigen (PSMA) is a type II transmembrane glycoprotein over-expressed in prostate carcinoma. Elevated PSMA expression has been correlated with aggressive disease and risk of early recurrence after radical prostatectomy. This molecule is also expressed in the neovasculature of multiple nonprostate solid tumors. Consequently, this unique cell marker has been targeted for diagnosis and therapy of prostate cancer (PCa) and other malignancies. Recently studies have shown that a significant fraction of PCa harbor a signature gene fusion between the androgen-responsive TMPRSS2 gene and transcription factors in the ETS family - most commonly ERG. The TMPRSS2-ERG fusion is likely the cause for over-expression of ERG in PCa. PSMA, unlike ERG, is negatively regulated by androgen. Elucidation of the relationship between TMPRSS2 gene fusions and PSMA expression could reveal mechanisms to alter PSMA expression and disease course. The purpose of this investigation was to determine whether PSMA gene expression could be regulated by the TMPRSS2-ERG fusion in prostate cancer cells.
We employed VCaP cells, which harbor TMPRSS2-ERG fusion, and LNCaP cells, which lack the fusion. Our data showed that after 24h androgen R1881 treatment, ERG and TMPRSS2-ERG mRNA level were increased in VCaP cells and unchanged in LNCaP cells. PSMA and androgen receptor (AR) mRNA level were dramatically decreased in VCaP cells and only modestly decreased in LNCaP cells. Treatment with the androgen antagonist flutamide partially restored PSMA and AR expression in androgen-treated VCaP cells. Knocking down ERG by siRNA in VCaP cells enhances PSMA expression both in the presence and absence of R1881. When LNCaP cells transfected with TMPRSS2-ERG fusion transcripts, PSMA was down-regulated both in the presence or absence of R1881. Using PSMA-based luciferase reporter assays, we found TMPRSS2-ERG fusion can inhibit PSMA activity at the transcriptional level. Our data indicated that negative regulation of PSMA by androgen is mediated by TMPRSS2-ERG gene fusion in VCaP prostate cancer cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4057.
Abstract 4061: Depleting the cellular level of glutathione and subsequently S-glutathionylation of keap1 by electrophilic agents activates keap1-nrf2 pathway
Authors: Zhang Xiaoyu , Ma Zhongjun , Sun Fang , Shen Liming 
Published: February 2011

Abstract
S-glutathionylation is a reversible post-translational modification of protein cysteine with critical roles in oxidative stress and signal transduction. Keap1-Nrf2 pathway has emerged as a master regulator for the endogenous antioxidant response, which is critical in defending cells against carcinogenesis. Herein, we demonstrated that after depleting the cellular level of glutathione (GSH) by electrophilic agent (the GSH level decreased to 23 percent of control after the agent treatment for 4 h), Keap1 was modified by S-glutathionylation and Nrf2 expression increased both in nucleus and total cellular homogenates. The modification could be blocked by the addition of exogenous GSH, suggesting depleting the cellular level of GSH and alteration of intracellular GSH/GSSG ratio might be essential for S-glutathionylation of Keap1 and activating Keap1-Nrf2 pathway. Flexidock program was employed to elucidate the influence of Keap1 S-glutathionylation on Keap1-Nrf2 complex. After enforcing a disulfide bond between GSH and Cys434 residue in Keap1 and energy minimization, the two carboxylate oxygen atoms of GSH participate in hydrogen bond interaction with Arg483 and Arg380 residues in Keap1, which had been previously verified bound to DxETGE motif of Nrf2. The distance between GSH O1 and Arg483 NH1, GSH O2 and Arg380 NH1 were 2.587 Å and 2.569 Å, respectively, which could form potent hydrogen bonds and diminish the interaction between Keap1 and Nrf2, resulting in the accumulation of Nrf2 in the nucleus. We concluded from our findings that the activation of Keap1-Nrf2 pathway was triggered by Keap1 S-glutathionylation and conjugation with intracellular GSH might be a key event involved in the Nrf2 inducing activities of electrophilic agents.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4061.