bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2035: Activating transcription factor 2 (ATF2) controls tolfenamic acid-induced ATF3 expression via MAP kinase pathways
Authors: Lee Seong-Ho , Bahn Jae Hoon , Whitlock Nichelle , Baek Seung J. 
Published: July 2012

Abstract
Tolfenamic acid (TA) is a non-steroidal anti-inflammatory drug associated with anti-tumorigenic and pro-apoptotic properties in animal and in vitro models of cancer. However, the underlying cellular mechanisms by which TA exerts its effects are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/CREB subfamily of the basic region-leucine zipper family and has been known as a tumor suppressor in human colorectal cancer cells. The present study was performed to observe whether ATF3 mediates TA-induced apoptosis and to elucidate the molecular mechanism of ATF3 transcription induced by TA. TA treatment and ectopic expression of ATF3 increased apoptosis whereas knockdown of ATF3 resulted in significant repression of TA-activated apoptosis. The TA treatment also induced ATF3 promoter activity. Internal deletion and point mutation of the predicted ATF/C/EBP binding site in ATF3 promoter abolished luciferase activation by TA. Overexpression of ATF2 resulted in significant increase of ATF3 promoter activity, and electrophoretic mobility shift assay identified this region as a core sequence to which ATF2 binds. TA treatment resulted in an increase of ATF2 phosphorylation, which was followed by a subsequent increase of ATF3 transcription. Knockdown of ATF2 abolished TA-induced ATF3 expression. We further provide evidence that TA leads to increases of phospho-p38 MAPK, JNK, and ERK levels. Inhibition of these pathways using selective inhibitors and dominant negative constructs ameliorated TA-induced ATF3 expression and promoter activities. The current study demonstrates that TA stimulates ATF3 expression and subsequently induces apoptosis. These pathways are mediated through phosphorylation of ATF2, which is mediated by p38 MAPK, JNK, and ERK-dependent pathways.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2035. doi:10.1158/1538-7445.AM2011-2035
Abstract 2040: Gene expression profile of circulating tumor cells in breast cancer by RT-qPCR
Authors: Strati Areti D. , Markou Athina , Parisi Cleio , Politaki Eleni , Mavroudis Dimitris , Georgoulias Vassilis , Lianidou Evi 
Published: July 2012

Abstract
Background: Circulating tumor cells (CTCs) are associated with prognosis and can be used as a liquid biopsy for repeated follow up examinations. Molecular characterization of CTCs is difficult to address since they are very rare and the amount of available sample is very limited.
Patients and methods: We quantified by RT-qPCR CK-19, MAGE-A3, HER-2, TWIST1, hTERT α+β+, and mammaglobin gene transcripts in immunomagnetically positively selected CTCs from 92 breast cancer patients, and 28 healthy individuals. We compared our results with the CellSearch system in 33 patients with early breast cancer.
Results: RT-qPCR is highly sensitive and specific and can detect the expression of each individual gene at the one cell level. None of the genes tested was detected in the group of healthy donors. In 66 operable breast cancer patients, CK-19 was detected in 42.4%, HER-2 in 13.6%, MAGE-A3 in 21.2%, hMAM in 13.6%, TWIST-1 in 42.4%, and hTERT α+β+ in 10.2%. In 26 patients with verified metastasis, CK-19 was detected in 53.8%, HER-2 in 19.2%, MAGE-A3 in 15.4%, hMAM in 30.8%, TWIST-1 in 38.5% and hTERT α+β+in 19.2%. The comparison between RT-qPCR and CellSearch, showed that RT-qPCR was more sensitive than CellSearch.
Discussion: Molecular characterization of CTCs has revealed a remarkable heterogeneity of gene expression between breast cancer patients. In a small percentage of patients, CTCs were positive for all six genes tested, while in some patients only one of these genes was expressed. The clinical significance of these findings in early breast cancer remains to be elucidated when the clinical outcome for these patients is known.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2040. doi:10.1158/1538-7445.AM2011-2040
Abstract 2043: BORIS directly regulates in vivo expression of the cancer testis antigen, testes-specific protease 50 (TSP50)
Authors: Suzuki Teruhiko , Kosaka-Suzuki Natsuki , Morse Herbert C. , Loukinov Dmitri , Lobanenkov Victor 
Published: July 2012

Abstract
BORIS (Brother of the Regulator of Imprinted Sites), also known as CTCFL, is a paralogous gene of that encoding the versatile chromatin factor CTCF. While BORIS was initially described as a testis-specific gene, recent reports showed that it is also expressed in various tumors and cancer cell lines at the transcriptional and protein levels indicating that BORIS encodes a cancer testis antigen (CTA). Interestingly, several studies have shown that BORIS regulates the expression of other CTAs including MAGE-A1 and NY-ESO-1. Gene expression profiling of testes derived from BORIS knockout and wild type mice suggested that BORIS regulates the expression of another gene encoding a CTA, testes-specific protease 50 (TSP50), also known as PRSS50. To examine this suggestion, we first performed electrophoretic mobility shift assays (EMSA) and found that the mouse TSP50 promoter region contains two BORIS binding sites. Occupancy of these sites by BORIS was confirmed by ChIP analyses of testicular chromatin. Computer analyses of the human TSP50 promoter revealed extensive homology with the mouse TSP50 promoter within BORIS binding sites. We confirmed BORIS binding to those sites by EMSA. Moreover, ChIP analyses of human cancer cell lines expressing TSP50 also showed that BORIS was bound to the promoter. Luciferase reporter assays demonstrated the importance of BORIS for the regulation of TSP50 promoter. Finally, we found that BORIS-induced expression of TSP50 is epigenetically regulated. These findings represent the first demonstration that the CTA, BORIS, itself regulates the expression of other CTAs in vivo.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2043. doi:10.1158/1538-7445.AM2011-2043
Abstract 2046: FoxM1 cooperates with Sp1 to transcriptionally activate the COX-2 promoter
Authors: Xu Kaiming , Shu Hui-Kuo G. 
Published: July 2012

Abstract
Cyclooxygenase-2 (COX-2) induction by epidermal growth factor (EGF) is likely to be an important response to this growth factor in gliomas given its prognostic significance in these tumors. Gaining a greater understanding of the signaling pathway(s) involved in this response may permit development of novel approaches for disrupting this induction with potential therapeutic benefit in such patients. Previously, we showed that p38-MAPK and protein kinase C-delta were required signal transducers in this process that ultimately leads to Sp1-dependent transcriptional activation of the COX-2 promoter in glioma cells. In this current work, we find that the FoxM1 transcription factor is also needed for full induction of COX-2 in response to EGF. Src kinase acts upstream of p38-MAPK to induce both FoxM1 and COX-2 expression. Furthermore, siRNA suppression of FoxM1 significantly reduces COX-2 induction in response to both EGF and the downstream signal transducers Src and p38-MAPK. In addition, increased expression of FoxM1 in an inducible system leads to increased COX-2 expression. Evaluation of the COX-2 promoter in a reporter gene system revealed that while FoxM1 overexpression can have a small effect on promoter activity through the FoxM1 consensus site at approximately -2.5k upstream of the promoter start site, its main activity appears to be through the Sp1 consensus site located from -245 to -240 upstream of the start site. Interestingly, FoxM1 associates with Sp1 by coimmunoprecipitation. In fact, FoxM1 can associate with the Sp1 consensus site both in vitro as assessed by electrophoretic mobility shift assay (EMSA) and in vivo as assessed by a chromatin immunoprecipitation (CHIP) assay. This work demonstrates a novel interaction between Sp1 and FoxM1 whereby FoxM1 can activate transcription of COX-2 through the associated Sp1 factor's consensus site.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2046. doi:10.1158/1538-7445.AM2011-2046
Abstract 2062: HIF-1 is required for ErbB2-mediated anoikis resistance
Authors: Whelan Kelly A. 
Published: July 2012

Abstract
We have previously established hypoxia as an inhibitor of anoikis in mammary epithelial cells as exposure to hypoxic conditions results in suppression of anoikis and delays lumen formation in 3D acinar structures. Inhibition of anoikis in this system is dependent upon both maintenance of EGFR-mediated MAPK signaling and the hypoxia-inducible transcription factor HIF-1. In an effort to determine the mechanism through which hypoxic exposure maintains MAPK signaling in MCF-10As, we compared the gene expression profiles of normoxic and hypoxic 3D acinar structures using microarray analysis. Interestingly, of the more than 70 genes found to be significantly upregulated under hypoxic conditions, a subset of genes emerged that have been implicated in oncogenesis as mediated by, a well-established regulator of anoikis resistance in breast cancer cells. Based on this intersection between HIF and ErbB2 in anoikis-associated signaling as well as the fact that oncogenes, including ErbB2, are known to stabilize HIF under normoxic conditions, we sought to determine what role, if any, HIF-1 plays in ErbB2-mediated oncogenesis. MCF-10A cells overexpressing ErbB2 indeed show increased levels of HIF-1α mRNA and protein under normoxic conditions. We show, for the first time, that depletion of HIF-1 from ErbB2-expressing cells using RNAi leads to restoration of anoikis sensitivity which is associated with both decreased Akt and Erk signaling and the induction of the pro-anoikis protein Bim. This effect was specific to anoikis as depletion of HIF-1 had no effect on survival of attached cells. Similar effects of HIF-1 depletion on anoikis resistance were seen in the human breast cancer cell line SK-BR-3 in which ErbB2 is amplified. Further, expression of at least four genes (integrin alpha 5, angiopoeitin-like 4, endothelin 2 and lysyl oxidase) identified in our microarray analysis as being upregulated by hypoxia also show enhanced expression in normoxic ErbB2-overexpressing cells as compared to parental MCF-10A cells. Here, we suggest that HIF-1 stabilization by ErbB2 under normoxic conditions is novel mechanism through which oncogenes protect cells from anoikis and plan to further explore the mechanism through which HIF-1 augments anoikis resistance in ErbB2-overexpressing cells, possibly by regulating metabolic activity. In addition, we predict that genes whose expression is upregulated by both ErbB2 and HIF-1 may serve as potential new therapeutic targets in the treatment of both hypoxic and ErbB2-positive cancers.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2062. doi:10.1158/1538-7445.AM2011-2062
Abstract 2068: A genome-wide siRNA screen reveals various modulators of the IRE1-XBP-1 signaling branch of the unfolded protein response
Authors: Zhang Jing , Banh Alice , Jayachandran Priya , Wollman Roy , Solow-Codero David E. , Meyer Tobias , Le Quynh-Thu , Koong Albert C. 
Published: July 2012

Abstract
The unfolded protein response (UPR) is an essential cellular mechanism orchestrating endoplasmic reticulum (ER) homeostasis under various cytotoxic stresses. Dysregulation of the UPR signaling pathways is linked to multiple human diseases, including cancer. The inositol requiring kinase 1 (IRE1)-X-box binding protein 1 (XBP-1) pathway is the most evolutionarily conserved signaling branch of the UPR. When activated, the endoribonuclease activity of the IRE1 cleaves the XBP-1 mRNA and generates a spliced form of XBP-1 which transcriptionally regulates cell metabolism, proliferation, survival and apoptosis. Here, we employed a genome-wide siRNA screen to systematically identify genes modulating the IRE1-XBP-1 signaling pathway of the UPR. We induced cellular ER stress with bortezomib, a proteasome inhibitor, and monitored the expression of XBP-1-luciferase fusion protein in which luciferase is fused in-frame with the spliced form of XBP-1. We identified over 100 of genes whose downregulation results in inhibition of bortezomib-induced XBP-1 splicing. These genes include diverse subsets of proteins that are involved in mRNA processing, transcription, cell cycle regulation and cell proliferation and differentiation. Furthermore, the screen reveals a connection of several oncogenes and tumor suppressors, such as Myc, Akt and cyclin K, to the UPR, underlining the important role of the IRE1-XBP-1 signaling branch in human cancers. In summary, our data suggest that the UPR is tightly connected with previously unappreciated pathways regulating various cellular processes.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2068. doi:10.1158/1538-7445.AM2011-2068
Abstract 2082: ERK activation mediated by Duox2 expression and reactive oxygen production is responsible for HIF-1α accumulation and VEGF induction in IFN-γ-treated BxPC-3 pancreatic cancer cells
Authors: Wu Yongzhong , Antony Smitha , Lu Jiamo , Juhasz Agnes , Liu Han , Jiang Guojian , Roy Krishnendu , Doroshow James H. 
Published: July 2012

Abstract
Reactive oxygen species (ROS) play an important role in tumor angiogenesis by up-regulating pro-angiogenic effectors such as HIF-1alpha and vascular endothelial growth factor (VEGF). However, the sources of ROS and the pro-angiogenic signaling pathways they target in tumor cells remain incompletely understood. We recently found that several members of the NADPH Oxidase (Nox) gene family are expressed in many human tumors; of these, Duox (Dual oxidase) 2 is highly expressed in tumors of the gastrointestinal tract. Recently, we demonstrated that IFN-gamma treatment of Bx-PC-3 cells upregulates the expression of Duox2 (and its maturation factor DuoxA2; but no other Nox isoform) leading to long-lived production of H2O2. Using this system, we investigated the role of Duox2-mediated ROS in the regulation of HIF-1alpha and VEGF expression. In BxPC-3 cells, IFN-gamma induction of Duox2/A2 expression was accompanied by both intra- and extracellular ROS accumulation, and by the simultaneous upregulation of HIF-1alpha and VEGF. However, in the MIA-PaCa-2 and PANC-1 lines that do not upregulate Duox2 following IFN-gamma exposure, no HIF-1alpha or VEGF induction was observed. In BxPC-3 cells, both the Nox inhibitor diphenylene iodonium and the ROS scavenger N-acetyl-L-cysteine suppressed IFN-gamma-induced HIF-1alpha accumulation and VEGF upregulation, suggesting that Duox2-derived ROS are involved in VEGF induction. Further experiments revealed that IFN-gamma induced a sustained activation of ERK1/2, which subsequently activated p90 ribosomal S6 kinases (RSKs) and the regulator of protein translation, ribosomal protein S6, resulting in enhanced synthesis of HIF-1alpha. ERK activation was required for IFN-gamma-induced HIF-1alpha and VEGF expression, since treatment with the MEK inhibitor U0126 completely abrogated IFN-gamma-induced HIF-1alpha and VEGF expression. Duox2-specific siRNA experiments showed that IFN-gamma-induced ROS, ERK activation, and HIF-1alpha accumulation were significantly attenuated following silencing of Duox2 expression. However, IFN-gamma-induced expression of VEGF was unchanged following Duox2 knockdown. Ongoing studies are evaluating the role of residual Duox2 or Duox2-independent pathways for VEGF activation following IFN-gamma exposure as well as other downstream, pro-angiogenic targets of Duox2-mediated HIF-1alpha expression under normoxic conditions.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2082. doi:10.1158/1538-7445.AM2011-2082
Abstract 2090: Investigating peroxiredoxin expression, activity, and potential downstream signaling in cancerous MCF7 and normal MCF10A breast epithelial cells
Authors: Sullivan Katie , Goncalves Kevin , Sumra Maryam , Phelan Shelley A. 
Published: July 2012

Abstract
Peroxiredoxins are thiol-specific antioxidant proteins that protect cells from oxidative stress. They have been implicated in cell signaling, proliferation and apoptosis, and studies have found elevated levels in many types of cancer, suggesting a protective role for these proteins in cancer cells. We previously showed that Prdx1 is overexpressed in the MCF7 breast cancer line as compared to the normal MCF10A line, and that suppression of Prdx1 and/or Prdx6 increases susceptibility to oxidative stress-induced apoptosis, with a more profound effect in MCF10A cells. In the present study, we sought to investigate other differences in peroxiredoxin expression and activity between these lines, as well as potential downstream targets. We found that mRNA levels of Prdxs1-5 were significantly elevated in MCF7 cells, while comparable levels of Prdx6 mRNA were found. A Prdx6 antibody, however, detects two bands by western blot: an upper 30-32 kDa species expressed at equal levels in both lines, and a 24-26 kDa species significantly overexpressed in MCF7 cells. An antibody specific for oxidized Prdx6 detected both products, demonstrating elevated levels in the cancer cells. Interestingly, the two species were differentially affected by siRNA-mediated Prdx1 and/or Prdx6 suppression. We further examined potential downstream targets of peroxiredoxin-regulated signaling. The two lines showed relatively comparable levels of p38, JNK1, ERK2, and c-Abl1b mRNA. In contrast, ERK1 mRNA levels were higher in MCF7 cells, while c-Abl1a was expressed only in the normal line. Peroxiredoxin suppression by siRNA transfection had no significant effect on p38, ERK1, or ERK2 in either cell type, but did lead to a decrease in c-Abl and JNK1 expression differentially in the two lines. Together, these data suggest different roles for Prdx1 and Prdx6 in normal vs. cancerous breast epithelial cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2090. doi:10.1158/1538-7445.AM2011-2090
Abstract 2091: Nitrooleic acids induce localization of heat shock protein 70 in PAM212 keratinocyte caveolae
Authors: Zheng Ruijin , Black Adrienne T. , Heck Diane E. , Laskin Debra L. , Laskin Jeffrey D. 
Published: July 2012

Abstract
Keratinocytes can be stimulated to express inducible nitric oxide synthase and generate nitric oxide by proinflammatory mediators including γ-interferon and lipopolysaccharide. Once formed, nitric oxide and its oxidation products form signaling molecules via redox mediated nitration reactions. Important targets for nitration in mammalian cells are unsaturated fatty acids. This can result in the production of reactive electrophilic species including 9-nitrooleate (9-NO) and 10-nitrooleate (10-NO). Oxidative stress is known to upregulate expression of heat shock proteins which are important chaperones functioning in protein-protein interactions including folding and trafficking. In the present studies we characterized nitro-fatty acid-induced expression of heat shock protein 70 (hsp70) in PAM212 mouse keratinocytes. Western blot analysis showed low constitutive levels of hsp70. Treatment of keratinocytes with 5-25 μM 9-NO or 10-NO for 6 hr markedly increased hsp70 expression. 10-NO was more active than 9-NO. Constitutive hsp70 was found to be localized in cytosolic fractions of keratinocytes, 9- or 10-NO did not alter constitutive cytosolic hsp70. In contrast, following treatment of keratinocytes with the nitro-fatty acids, hsp70 was selectively upregulated in lipid raft membrane fractions. Both hsp70 and caveolin-1 were co-localized in the lipid raft fractions of the membranes demonstrating that the lipid rafts are caveolae. In mouse keratinocytes, nitro-fatty acids readily stimulate MAP kinase signaling including JNK and p38 MAP kinases. Inhibitors of JNK (SP600125, 20 μM) or p38 (SB203580, 10 μM) had no effect on induction of hsp70 or its localization in caveolae indicating that nitro-fatty acid-induced expression of this protein was MAP kinase-independent. Taken together these data demonstrate that nitro-fatty acids are important in the control of heat shock protein expression. Moreover, selective localization of hsp70 in caveolae suggests that it functions in protecting caveolar proteins from cellular stress. Supported by CA132624, ES004738, ES005022, GM034310 and AR055073.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2091. doi:10.1158/1538-7445.AM2011-2091