bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4190: Ezrin plays a key role in the regulation of translation in metastatic osteosarcoma
Authors: Morrow James J. , Briggs Joseph , Ren Ling , Chakrabarti Kristi , Cassavaugh Jessica , Veenstra Timothy D. , Chen Qingrong , Khan Javed , Uren Aykut , Khanna Chand 
Published: August 2012

Abstract
Our previous studies have demonstrated the association between Ezrin and the metastatic biology of pediatric sarcomas including osteosarcoma (OS) and rhabdomyosarcoma. Mechanistic studies exploring this association have shown that Ezrin expression enhances the survival of metastatic cells upon their arrival to the secondary metastatic site. In order to better understand this role in metastasis, we undertook two non-candidate analyses of Ezrin function including a microarray subtraction of high and low Ezrin expressing cells and a proteomic approach to identify proteins that bind the N-terminus of Ezrin in tumor lysates. Functional analyses of these data led to a novel and unifying hypothesis that Ezrin contributes to the efficiency of metastasis through regulation of protein translation. In support of this hypothesis we found Ezrin to be part of a ribonucleoprotein complex and to bind with poly A binding protein 1 (PABA1; PABPC1). Using luciferase reporter-based assays, we have shown that OS cells expressing high levels of Ezrin are able to translate mRNAs containing a stem loop 5′ UTR structure, so called “weakly translated mRNAs,” more efficiently than low Ezrin OS cells. This finding suggests that Ezrin's contribution to the metastatic phenotype may be due in part to enhanced translation of specific mRNAs during metastasis that are normally expressed at low levels outside of the metastatic context. Ongoing studies will now assess the ability of Ezrin to enhance the expression of specific mRNAs in 3-dimensional contexts more relevant to cancer cell growth in vivo. We have developed stable high and low Ezrin osteosarcoma cell lines that express a GFP reporter with or without a complex 5′ UTR stem loop structure in the mRNA transcript and with and without protein destabilizing elements. Initial studies have shown that the addition of the 5′ UTR structure and destabilizing elements progressively limits GFP reporter expression. We plan to confirm that this reduction in expression is due to reduced translation and to assess whether 3-D culture conditions or the in vivo environment enhance expression of these tunable reporters of translation in an Ezrin-dependant manner. We expect these results to provide a novel mechanistic basis to consider how Ezrin may contribute to metastasis.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4190. doi:1538-7445.AM2012-4190
Abstract 4192: LIN28 mRNA targets in breast cancer cells
Authors: Kinyamu Harriet K. , Yang Jun , Archer Trevor K. 
Published: August 2012

Abstract
LIN28 is a RNA binding protein and a pluripotency factor. It represses tumor suppressing microRNA let-7 and activates let-7 oncogene targets such as HMGA2 and c-Myc. Recent reports show that LIN28 overexpression promotes tumor cell migration and cellular transformation through repression of let-7, and that overexpression is associated with advanced stages of disease, including breast cancer. The molecular function and mode of action of LIN28 in breast cancer is not yet elucidated. To further understand the function of LIN28, we explored LIN28 mRNA targets in breast cancer cells using RNA-protein immunoprecipitation (RIP) followed by RNA sequencing (RIP-Seq). Only 418 genes (1.7% of the human total genes) are enriched more than 1.0 RPKM (reads per kilobase of exon model per million mapped reads) in the LIN28 RIP relative to control RIP. LIN28 mRNA targets in breast cancer cells function in processes that drive tumorigenesis, including cell proliferation, inflammation and metastasis. Therapeutic drugs inhibiting LIN28 could be promising in treatment of cancer. Our experiments also demonstrate that MG132, a proteasome inhibitor, inhibits LIN28 expression and modulates expression of LIN28 mRNA targets in breast cancer cells. Studies are ongoing to reveal the mechanisms by which LIN28 regulates bound targets and how proteasome inhibitors impact this regulation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4192. doi:1538-7445.AM2012-4192
Abstract 4195: Protein phosphatase PPM1G regulates protein translation and cell growth by dephosphorylating 4E-BP1
Authors: Liu Jianyu , Gao Tianyan 
Published: August 2012

Abstract
Protein translation initiation is a tightly controlled process responding to nutrient availability and mitogen stimulation. Deregulation of translation initiation leads to tumor development and progression. Serving as one of the most important negative regulators of protein translation, 4E binding protein 1 (4E-BP1) binds to translation initiation factor 4E and inhibits cap-dependent translation in a phosphorylation-dependent manner. Hyperphosphorylation of 4E-BP1, which leads to inactivation of 4E-BP1, has been linked to human cancers with increased malignancy. While it has been demonstrated previously that the phosphosphorylation of 4E-BP1 is controlled by mTOR in the mTOR complex 1 (mTORC1), the mechanism underlying the dephosphorylation of 4E-BP1 remains elusive. Here, we report the identification of PPM1G as the phosphatase of 4E-BP1 through an shRNA library screen of Ser/Thr protein phosphatases. Co-immunoprecipitation experiment reveals that PPM1G binds to 4E-BP1 in cells, and purified PPM1G dephosphorylates 4E-BP1 in vitro. Knockdown of PPM1G in 293E and colon cancer HCT116 and SW480 cells results in an increase in the phosphorylation of 4E-BP1 at both Thr37/46 and Ser65 sites. This PPM1G-mediated dephosphorylation of 4E-BP1 is specific as the phosphorylation of upstream regulators of 4E-BP1 including Akt and mTOR is not altered in PPM1G knockdown cells. Furthermore, the time course of 4E-BP1 dephosphorylation induced by amino acid starvation or mTOR inhibitor treatment is significantly slowed down in PPM1G knockdown cells. Functionally, the amount of 4E-BP1 bound to the cap-dependent translation initiation complex is decreased when expression of PPM1G is depleted. As the result, the rate of cap-dependent translation, cell size, and protein content are increased in PPM1G knockdown cells. Taken together, our study has identified protein phosphatase PPM1G as a novel regulator of protein translation by negatively controlling the phosphorylation of 4E-BP1. Thus, PPM1G may serve as a tumor suppressor by directly counteracting mTOR to inhibit cell growth in cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4195. doi:1538-7445.AM2012-4195
Abstract 4196: Identification and investigation of ethnic specific gene expression differences in non-cancerous breast tissue
Authors: Baumbach-Reardon Lisa L. , Gomez Carmen , Ahearn Mary Ellen , Green Ashley , Ellison Kevin , Yariz Kemal O. , Issac Biju , Clarke Jennifer , Ambs Stefan , Pegram Mark 
Published: August 2012

Abstract
Disparities in breast cancer (BC) stage of presentation and survival are well documented in patients of different ethnicities. These differences are undoubtedly due to a combination of extrinsic and intrinsic factors. Our group is focused on the genetic contributions to these disparities. Recent observations by our group and others suggest not only the involvement of specific genes contributing to BC risk in African-American (AA) women, but that multiple distinct ethnic-specific gene expression patterns exist in both matched cancerous and normal breast tissue samples. We report the first results of a parallel study which is addressing an unanswered question: are there ethnic-specific differences in the transcriptome of normal breast tissue? We are completing gene expression profiling studies in normal breast FFPE samples from 25 AA and 25 Caucasian (Cauc) women with no history of breast cancer. Laser capture micro-dissection (LCM) is used to further identify and extract epithelial vs stromal cells from each FFPE slide for use in RNA expression profiling. RNA isolation and hybridization occurs in collaboration with Almac Diagnostics (Dx) using their proprietary Breast Cancer DSA array. Gene expression data analyses involves multiple statistical packages developed for DNA microarray studies, and is focusing on comparison of gene expression profiles across four study groups- AA vs Cauc samples and epithelial vs stroma cells. For baseline comparison, a subset of this study group (10 AA and 10 Cauc samples non-LCM dissected) has also been analyzed. Results from these non-LCM dissected samples displayed expression differences between AA and Cauc in 333 known genes. Applying the stringency criteria of a fold change of two or greater and a statistical p-value of 0.01, reduced the significant gene list to 61 genes. Initial pathway analyses indicate these genes are involved in cell adhesion, G-protein signaling, apoptosis and survival pathways, and cytoskeleton remodeling - all critical pathways for cell survival. These initial results are being validated in the LCM-dissected samples, and our latest results will be presented. Results from analyses of these normal samples will be compared to our previous results obtained in matched tumor-normal triple negative AA and Cauc breast cancer samples (as well as publicly available data sets). Combined analysis of tumor and normal breast expression (transcriptome) data will help to better understand the possible significance of gene expression differences in breast tissue between ethnic groups.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4196. doi:1538-7445.AM2012-4196
Abstract 4197: Discovering FUS-CHOP targets: A Chip-Seq approach
Authors: Tonin Elena , Sirocco Francesco G. , Rossi Sabrina , Tos Angelo Paolo Dei , Libra Massimo , Hannon Gregory J. , Maestro Roberta 
Published: August 2012

Abstract
Myxoid liposarcoma (M-LS) is one of the most common soft tissue sarcomas in adults. Approximately 90% of cases show the characteristic t(12;16)(q13;p11) translocation, which produces the FUS-CHOP (FC) oncogene. FUS is a RNA-binding protein expressed in several tissues; CHOP a bZIP transcription factor involved in adipocyte differentiation. Although it is known that CHOP bZIP region is essential for FC-induced transformation, little is known about FC transcriptional targets and how FC participates in the development and progression of M-LS. Moreover, it is unclear whether FC controls the transcription of a set of genes different from the set controlled by CHOP. Understanding how the FUS-CHOP fusion protein causes M-LS will aid in the development of novel targeted therapies. To shed light on this issue we sought to exploit the ChIP-Seq technique (Chromatin Immunoprecipitation followed by next generation sequencing). To this end, chromatin immunorecipitation was performed on cell lines expressing FC (endogenous or ectopic). DNA co-precipitated together with the FC protein was analyzed by using an Illumina GAIIX platform. FC-bound DNA was mapped to the genome using the aligner Bowtie and the enriched regions were identified by using the MACS peak caller. ChIP-Seq data were combined with RNA-seq analysis to screen for the potential targets. Our approach was validated by the identification of LONP1, CLCN3 and GADD34, which have been previously reported to be modulated by CHOP. The most interesting candidates will be further investigated for their implication in FC development and progression.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4197. doi:1538-7445.AM2012-4197
Abstract 4199: CDKN2A/p16INK4a 5′UTR variants in melanoma predisposition: Lost in translation, somewhere
Authors: Bisio Alessandra , Andreotti Virginia , Latorre Elisa , Vescovo Valerio Del , Ciribilli Yari , Provenzani Alessandro , Quattrone Alessandro , Bianchi-Scarra' Giovanna , Denti Michela A. , Ghiorzo Paola , Inga Alberto 
Published: August 2012

Abstract
The CDKN2A gene is the most common high penetrance susceptibility gene identified to date in melanoma families. While functional tests for determining the pathogenicity of missense germline mutations in the CDKN2A coding region have been developed, rare polymorphisms or sequence variants at the CDKN2A/ p16INK4a 5′UTR, encountered during routine screening, are usually defined as variants with unknown significance after determining their frequency in control population and the cosegregation analysis in the family, when possible. We recently developed reporter assays to study a panel of p16INK4a 5′UTR variants identified as heterozygous changes in patients from a hospital-based series of melanoma cases (c.-21C&gt;T; c.-25C&gt;T&c.-180G&gt;A; c.-56G&gt;T; c.-67G&gt;C). Monocistronic as well as bicistronic luciferase-based reporter vectors were developed and used to test wild type and variant p16INK4a 5′UTR activity upon transient transfection in melanoma-derived cells (WM266-4, G361 and SK-Mel-5) and in the breast cancer-derived MCF7 cells. Results revealed that the c.-21C&gt;T variant had a strong negative impact on the reporter activity, similar to that of the known melanoma-predisposing mutation c.-34G&gt;T, included as a control. The variants at –56 and at –25&-180 exhibited a milder impact, while results with c.-67G&gt;C were dependent on the type of reporter vector. Quantification of the luciferase mRNA conducted in parallel with the luciferase assay indicated that the impact of the variants was mainly post-transcriptional. We also applied a polysomal profiling technique to measure allelic imbalance starting from heterozygous patient-derived cell lines and found that the c.-21C&gt;T variant but also c.-56T&gt;G and c.-67G&gt;C exhibited lower association with the polysomes suggestive of reduced mRNA translation efficiency. A panel of eleven additional germline variants in the 5′UTR of p16INK4a is being investigated. In particular we are focusing on the functional interactions between wild type and variant p16INK4a 5′- and 3′-UTR sequences and on the impact the variants can have on the targeting of the p16INK4a mRNA by microRNAs (including mir-346, -636, -639, -935) or RNA binding proteins (including YB-1).
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4199. doi:1538-7445.AM2012-4199
Abstract 42: Expression of interleukin-7 and its signalling intermediates in human neuroblastoma tumours.
Authors: Prasad Linda , Gayagay Andrew , Charlton Amanda , Henwood Anthony , Graf Nicole , Arbuckle Susan , Catchpoole Daniel R. 
Published: August 2012

Abstract
Neuroblastoma (NB) is the most common extracranial childhood malignant solid tumour which shows remarkable biological heterogeneity. It has been speculated that schwann cells influence NB tumour growth, by secreting as yet to be identified ‘soluble factors’ that serve as anti-proliferative and differentiation signals for neuronal cells. Several gene expression studies indicate that interleukin 7 (IL7) has increased expression in NB specifically in tumours with a better prognosis, making IL7 a key candidate for this soluble factor. In this study, the expression of IL7, IL7 receptor (IL7R) and its downstream signalling proteins, including the Janus Kinases (JAK1 and JAK3), Signal Transducers and Activators of Transcription (STAT5) and Phosphorylated STAT5 (pSTAT5) were analysed using immunohistochemical stains in a cohort of 100 patients with stroma poor NB and 24 with stroma rich ganglioneuroma (GN). The expression of these proteins were correlated to the expression of the diagnostic markers S100 (stromal marker), NB84 (neuroblast marker) and CD99 (negative marker for NB). The immunohistochemical analysis showed that IL7 expression was strongly positive exclusively in schwannian stroma in both favourable and unfavourable histology whilst staining ganglionic cells as well. The levels of expression, as quantified by specialised digital image analysis algorithms (Aperio, USA), revealed IL7, IL7R, JAK1, STAT5 and pSTAT5 were all increased in GNs compared to NBs. There was no correlated change in expression levels of JAK3 in the tumours. Expression of pStat5 was found to be significantly reduced (t-test, p=0.00013) in stroma poor NB compared to GN. Our findings implicate IL7 within the schwannian stroma of the tumour architecture as having a paracrine signalling effect on neighbouring neuroblasts which may provide the anti-proliferative and differentiation signals postulated. Further investigation of the importance of IL7 in neuroblastoma will define the biological significance of the IL7-Stat5 signalling cascade and whether targeting the specific IL7 signalling pathway proteins will raise novel treatment strategies.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 42. doi:1538-7445.AM2012-42
Abstract 420: Physiological β-catenin signaling regulates pluripotency genes in cancer microcell hybrids
Authors: Cheng Yue , Cheung Arthur Kwok Leung , Ko Josephine Mun Yee , Phoon Yee Peng , Lung Maria L. 
Published: August 2012

Abstract
Both β-catenin signaling and Nanog were previously reported to be involved in cell fusion-mediated somatic cell reprogramming. It remains unclear as to how the β-catenin signaling pathway is initiated and whether this pathway may directly control the expression of core stem cell factors such as Nanog and Oct4. Since β-catenin signaling is a predominating force for the regulation of cellular fate and basic levels of this signaling are needed for somatic cell reprogramming, we speculate that transfer of a single copy of chromosome 3, where β-catenin maps and is controlled by its natural regulators, into somatic cancer cells may appropriately induce this pathway and switch on the expression of endogenous pluripotency genes in recipient cells. We previously generated human nasopharyngeal (HONE1) and esophageal (SLMT1) carcinoma hybrid cells with an intact copy of transferred chromosome 3. At both transcriptional and translational levels, we detected obvious expression of genes related to the Wnt/β-catenin pathway in HONE1/chromosome 3 hybrid cells. In these hybrid cells, β-catenin, c-Myc, Axin2, Tcf1, Sox2, Klf4, Oct4, and Nanog were either strongly expressed or up-regulated. The loss of region that contains B-catenin locus in transferred chromosome 3 abolishes the expression of core stem cell genes. The control of these gene activities by physiological β-catenin signaling was further confirmed in HONE1/chromosome 17 hybrids that contain the downstream components of β-catenin signaling Axin2 and Stat3, but was not detected in hybrids with an irrelevant transferred chromosome and SLMT1 cells that had a relatively high level of endogenous β-catenin expression. We also found that HONE1 hybrid cells have stem cell-like properties, including spheroid formation, up-regulation of CD24+ and CD44+ populations and expression of various embryonic markers. Additionally, chromosome 3 transfer induced epithelial-mesenchymal transformation (EMT) events in HONE1 cells that caused different expression of adhesion molecules and up-regulation of their regulators and other markers such as Twist, Snail, Slug, ZEB1, Sip1, and E-cadherin. As expected, we detected that p53, Rb1, and Smad2 involved pathways were activated in HONE1 hybrid cells, suggesting that physiological β-catenin signaling, via multiple signaling pathways, regulates both pluripotency networks and EMT events.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 420. doi:1538-7445.AM2012-420
Abstract 421: Deciphering the molecular mechanisms behind Oct4(hi) tumor-initiating breast cancer cells with global gene expression
Authors: Bliss Sarah A. , Patel Shyam A. , Rameshwar Pranela 
Published: August 2012

Abstract
Breast cancer continues to have one of the highest rates of incidence despite advances in detection and treatment. One of the most troubling aspects of the disease is its tendency to recur after apparent curative therapy. The ability of a subset of breast cancer cells to remain undetected for years in the patient only to recur years later is of particular interest to our laboratory. Breast cancer is well known to metastasize to the bone marrow where we believe a favorable niche exists for it to remain dormant. Our lab has shown that a subset of breast cancer cells with increased expression of octamer-binding transcription factor 4 isoform A (Oct4A) can form gap junctions with bone marrow stroma cells. Gap junction intercellular communication is important for maintaining dormancy in the breast cancer cells. Further characterization of the Oct4(hi) cells found them to be in mostly the G0/G1 phase of cell cycle, have increased stem cell gene expression, formed tumor spheres, could initiate breast cancer when serially passaged in nude BALB/c mice, and showed increased resistance to carboplatin. To understand the functional differences between the Oct4(hi) cancer cells and the non-tumor-initiating cells, we compared the different breast cancer cell subsets for global gene expression, using Affymetrix gene arrays. The initial analyses confirmed the quality of samples with expression levels grouping together in the principle component analysis. Heat map analyses indicated distinct gene expression in which those that were expressed in the tumor-initiating cells were decreased in the non-cancer stem cells. The tumor-initiating cells showed novel genes that are linked to NFκB, which we have shown to be the master regulator of self-renewal in the cancer stem cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 421. doi:1538-7445.AM2012-421