bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1234: Erk-dependent phosphorylation of Notch intracellular domain (NIC) correlates with increased NIC-dependent transcription
Authors: Tremblay Isabelle , Boucher Marie-Josee 
Published: February 2011

Abstract
Background. Recent studies have suggested that the ability of Ras to transform cells depends on cooperation with the Notch signaling pathway. However, the molecular and cellular mechanisms involved in this cooperation remain unknown. Aim. To evaluate the impact of the Mek/Erk pathway, downstream of Ras, on Notch signaling. Methods. HEK293T and human pancreatic cancer cells MIA PaCa-2 were used. Mek/Erk activity was down-regulated by treatment with the specific inhibitor U0126 (10 µM). Transfections or retroviral infections of a constitutive active form of KRas or Mek (MekCA) were used to increase Mek/Erk activity. NIC-dependent transcription was measured by luciferase assays using a specific (CSL) luciferase reporter gene. Results. 1- Transient transfection of an activated KRas stimulated by 1.7-fold NIC-dependent transcription. Transfection of MekCA increased by 4.3-fold NIC-dependent transcription while a wild-type form of Mek (MekWT) was without effect. In parallel, treatment with U0126 reduced by 60% the basal NIC-dependent transcription and completely blocked the KRas- and MekCA-induced NIC-dependent transcription. This negative effect of U0126 on NIC-dependent transcription correlated with decreased nuclear staining of the NIC target gene Hes1. 2- Western blot analysis revealed higher molecular weight forms of NIC when cells were transfected/infected with MekCA as compared to control MekWT-transfected/infected cells. U0126 treatment prevented the MekCA-induced decreased in mobility shift of NIC suggesting that NIC is subjected to Mek-dependent post-translational modifications in vivo. 3- Immunoprecipitation followed by in vitro phosphatase assay revealed that these MekCA-induced higher molecular weight forms of NIC were phosphorylated forms of NIC. 4- By in vitro kinase assays, we demonstrated that NIC worked as Erk substrate. 5- Finally, following in vivo phospholabeling, we observed that NIC immunoprecipitated from MekCA-transfected cells was more phosphorylated as compared to NIC immunoprecipitated from MekWT-transfected cells. Conclusion. Our results provide the novel discovery that Mek/Erk signaling promotes NIC phosphorylation which correlates with increased NIC-dependent transcription. Our discovery thus provides a possible cellular mechanism by which Ras and Notch cooperate to promote cellular transformation.
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 1234.
Abstract 1245: Polyribosome association of tyrosine phosphorylated RACK1 with activated Src regulates translation of specific proteins mediating breast cancer growth and metastasis
Authors: Scott Gary K. , Gabriel Bianca , Held Jason , Benz Christopher C. 
Published: February 2011

Abstract
Dysregulation of translational control, characterized by aberrant expression of proteins critical for growth and metastatic potential, is emerging as an essential aspect of tumorigenesis. Receptor for activated protein kinase C-1 (RACK1) is a scaffold protein known to coordinate the cellular localization of numerous signaling proteins including PKC and Src, and has recently been identified as an essential ribosome component binding to the head region of the 40S subunit. RACK1 was identified in a mass spectrometry screen of polyribosome proteins from human breast cancer cells demonstrating altered mobility on 2D gel electrophoresis following growth-arresting doses of a histone deacetylase (HDAC) inhibitor which suggested that post-translational modifications of ribosome associated RACK1 might selectively influence protein synthesis and cancer cell growth. Polyribosome profiling of MDA-231 and SKBR3 breast cancer cells revealed that while the entire complement of lysate soluble RACK1 was ribosome associated in both cell lines, only RACK1 from the MDA-231 cells appeared significantly tyrosine phosphorylated. Furthermore, tyrosine phosphorylated Src (pTyr-416), while 10 fold more abundant in the SKBR3 untranslated fractions relative to those from MDA-231, was associated with the polyribosome factions of MDA-231 but not those of SKBR3, consistent with previous observations linking activated Src with tyrosine phosphorylated RACK1. Lentiviral delivery of shRNA was used to investigate the functional consequences of selective RACK1 knockdown. In MDA-231 cells, efficient RACK1 knockdown produced complete growth arrest and loss of motility without induction of apoptosis or cell senescence; however, this growth arrested phenotype is associated with near complete loss of cyclin D1 and TGFbetaR1 expression without change in the expression of housekeeping proteins beta-actin and GAPDH. Taken together, these results implicate tyrosine phosphorylated RACK1 in association with polysomal pTyr-Src as translational activators of specific proteins mediating breast cancer proliferation and metastasis.
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 1245.
Abstract 1248: 14-3-3 interacts with TC1(C8orf4) to protect the protein from rapid degradation and regulates cancer cell invasiveness
Authors: Lee Inchul 
Published: February 2011

Abstract
14-3-3 interacts with TC1(C8orf4) to protect the protein from rapid degradation and regulates cancer cell invasiveness.
Jungtae Kim, Yusun Jung, Dong Wook Kim, Hyunju Lee, Kyuyoung Song, Inchul Lee. Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Republic of Korea
TC1(C8orf4) is a multifunctional regulator associated with aggressive biological behavior of cancer and poor survival of patients (Clin Cancer Res 2006;12:3541-8). It regulates the Wnt/β-catenin pathway (Cancer Res 2006;66:723-8).and induces endothelial inflammation (J Immunol 2009;183:3996-4002). TC1 is up-regulated by NF-kB (FEBS letters 2006;580:3519-24), and heat shock and other cellular stress (Biochem Biophys Res Commun 2007;360:447-52).
TC1 is a small protein present in vertebrates, which is degraded rapidly. TC1 interacted with 14-3-3β upon yeast two hybrid screening. The interaction of TC1 with 14-3-3β and 14-3-3ε was confirmed in HEK293T cells upon cotransfection. The deletion mutant analysis showed that the N-terminus of TC1 and C-terminus of 14-3-3 interacted with each other. The binding site of TC1 appeared to involve the Ser15 residue. The interaction was inhibited by serum starvation, staurosporine, and GSK3β inhibitor, indicating the requirement of TC1 phosphorylation, probably of Ser15, for the interaction. The half-life of transfected HA-TC1 was 2.49 hours in HEK293T cells, while it was elongated to 5.07 hours upon co-transfection with 14-3-3β. 14-3-3 knock down reduced TC1 expression. Our data together suggested that 14-3-3 protected TC1 in vivo.
14-3-3 proteins have been implicated in the regulation of various biological functions. However, the role in cancer is not clear. TC1 was shown to enhance the Matrigel invasiveness of cancer cells (Clin Cancer Res 2006;12:3541-8). 14-3-3 knock down using si14-3-3β reduced the Matrigel invasiveness of HeLa cells significantly (p&lt;0.0001). Cancer cell proliferation was not affected by 14-3-3 transfection or knock down. Our data suggest the requirement of 14-3-3 in cancer cell invasiveness potentially by regulating TC1.
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 1248.
Abstract 1250: Inhibition of FAK and engagement of migration leads to similar changes in patterns of transcription factor activation in glioma cells
Authors: Berens Michael E. , Tran Nhan L. , Loftus Joseph C. 
Published: February 2011

Abstract
Malignant dispersion of glioma cells is a nemesis to clinical management, provoking the need for a better understanding of the underlying molecular drivers of invasion. The changes in signal transduction and consequent alterations in activation/de-activation of Transcription Factors (TFs) in glioma cells were investigated coincident to migration-engagement or impaired FAK kinase function by small molecule inhibition (PF-562,271). Earlier work showed that FAK and Pyk2 affect proliferation and migration in reciprocal ways in glioma cells (Lipinski CA, et al 2008; Loftus JC, et al 2009). The interaction of FAK and Pyk2 with specific downstream signaling effectors and the resultant activation of disparate signaling pathways is likely to script a signaling “signature” that will reveal to what extent glioma cell malignant behaviors are dependent on these kinases. Inhibition of FAK leads to diminution of signaling by pSrc, pJnk, and pNFkB, and variable activation of pAkt, and pp38. Of the 20 TFs assayed (Marligen, Inc.), the activation state of 7 TFs showed significant and consistent patterns of change across 6 primary GBM cell strains following FAK inhibition. Across a panel of 6 human GBM xenograft lines SP1, p53, E2F1-5, and NFκB evidenced strong activation (heightened nuclear localization), while AR (androgen receptor), Myc-Max, and CREB activation levels dropped by more than 2-fold following PF-562,271 treatment. Separate studies of established glioma cell lines under conditions of sparse plating (migration) and of dense crowded plating (migration-constrained), showed that p53, E2F1-5, and NFκB were standouts for activation accompanying migration, also associated by strong reduced activation of AR, Myc-Max, and CREB. (Because glioma cells following FAK knockdown or FAK inhibition show reduced entry into cell cycle, the signaling linkage between FAK and Myc-Max activation and also between FAK signaling and CREB activation suggest mechanistic ties to phenotype. E2F1 is a transcription factor that regulates genes involved in cell proliferation and cell survival and has even been suggested to fit a paradigm of oncogene addiction in glioma cells. Our findings demonstrate phenotypic responses in glioma cells downstream of FAK signaling linked to the activation or inactivation of specific transcription factors. If these patterns of TF activation state, and the signaling pathways upstream of that activation, associate (or account for) patterns of glioma cell invasion or proliferation in situ, they will suggest points of vulnerability in the underlying pathological processes of this disease. Supported by NIH NS042262 (Berens) and NIH CA103956 (Loftus).
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 1250.
Abstract 1251: Increased expression of the plasminogen activator system due to differential protease-activated receptor signaling in breast cancer cells
Authors: McEachron Troy , Church Frank , Mackman Nigel 
Published: February 2011

Abstract
Activation of protease activated receptor-1 and −2 (PAR-1 and PAR-2) on tumor cells by coagulation proteases, such as factor Xa (FXa) and thrombin, leads to the expression of urokinase plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor type-1 (PAI-1). uPA has been shown to contribute to malignancy by increasing tumor cell migration, survival, extracellular matrix degradation, and angiogenesis. The goal of this study was to determine how activation of PAR-1 and PAR-2 by coagulation proteases regulates uPA and PAI-1 expression. We used the 4T1 mouse mammary adenocarcinoma cell line as a model because it expresses both PAR-1 and PAR-2. Using shRNA technology, we made derivatives of the 4T1 cells with reduced expression of either PAR-1 or PAR-2. 4T1 cells carrying a non-targeting shRNA construct were used as negative controls. We found that FXa and thrombin induced uPA expression in the control and the PAR-2 shRNA cells, but not in the PAR-1 shRNA cells. In contrast, FXa treatment did not increase PAI-1 levels in the control, PAR-1 shRNA, or PAR-2 shRNA cells. Thrombin was able to induce PAI-1 in the control cells, but not in the PAR-1 shRNA or the PAR-2 shRNA cells. Taken together, our data suggests that uPA expression is dependent on PAR-1 activation whereas PAI-1 expression requires a PAR-1/PAR-2 heterodimer.
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 1251.
Abstract 1254: Kaposi's Sarcoma herpesvirus K1's transcellular inhibition of Fas-mediated apoptosis
Authors: Daniluk Urszula , Berkova Zuzana , Wise Jillian Frances , Tao Rong-Hua , Hossein Rezaeian Abdol , Wang Shu , Prakash Om , Samaniego Felipe 
Published: February 2011

Abstract
The long-term expression of human herpesvirus 8 (HHV-8) K1 produces hyperplasia of lymph nodes, splenomegaly, and lymphomas in mice. The mechanism of how K1 causes hyperplasia and lymphomas is not known. K1 is known to activate Akt and nuclear factor kappa B (NF-kB) through immunoreceptor tyrosine-based activation motif (ITAM) and may also bind to Fas receptor through its immunoglobulin (Ig) chain-like domain and interfere with apoptosis.
We thus hypothesized that development of hyperplasia and lymphomas in K1-expressing mice is driven by altered Fas signaling.
Examination of mice expressing K1 via a ubiquitous promoter showed that 90% K1 transgenic mice (n=10) had developed lymphoid hyperplasia (at least 3 lymph nodes &gt;3 mm) and 60% developed lymphomas after 18 months, while all (26) control nontransgenic mice remained free of lymph node hyperplasia, splenomegaly, and lymphoma. Some K1 mice developed liver or mesenteric tumors (4 of 10 mice). The spleens of 78% of K1 mice were enlarged at 18 months and were on average 3.5 times heavier than spleens of non-K1 transgenic control mice. Hematoxylin and eosin staining of spleen sections showed lymphocyte expansion in the periarteriolar lymphocyte sheath with disruption of normal spleen architecture. Anti-kappa and anti-lambda light chain antibodies revealed the presence of monoclonal foci in 3 out of 3 K1 mice (average 6 foci per single section of spleen), but no foci were present in 4 control non-transgenic mice. Moreover, K1 protein was expressed in approximately 10% of splenic cells after staining with anti-K1 antibody 2H5. In vitro overexpression of an Ig domain-containing protein CD79b or treatment cells with K1 peptides revealed competition with K1-Fas binding in a dose-dependent manner and rate enhancement of Fas-mediated apoptosis. We have also shown that K1 suppressed Fas-mediated apoptosis, even in cells that did not express K1. Transfection of K1 into one pool of mouse cells protected against Fas-mediated apoptosis of a second pool of human Fas-transfected mouse cells indicating protection in trans.
This analysis indicates a key role of K1 in suppression of Fas-mediated apoptosis which operates in a cis and trans protective role against apoptosis.
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 1254.
Abstract 1260: Analysis of death receptor 5 and caspase-8 expression in primary and metastatic head and neck squamous cell carcinoma and their prognostic impact
Authors: Elrod Heath A. , Fan Songqing , Muller Susan , Chen Georgia Z. , Pan Lin , Tighiouart Mourad , Shin Dong M. , Khuri Fadlo R. , Sun Shi-Yong 
Published: February 2011

Abstract
Death receptor 5 (DR5) and caspase-8 are major components in the extrinsic apoptotic pathway. The alterations of the expression of these proteins during the metastasis of head and neck squamous cell carcinoma (HNSCC) and their prognostic impact have not been reported. The present study analyzes the expression of DR5 and caspase-8 by immunohistochemistry (IHC) in primary and metastatic HNSCCs and their impact on patient survival. Tumor samples in this study included approximately 90 primary HNSCC with no evidence of metastasis and approximately 90 primary HNSCC and their matching lymph node metastasis. IHC analysis revealed a significant loss or downregulation of DR5 expression in primary tumors with metastasis [weight index (WI) = 221 ± 64.9 (mean ± SD), n = 92] and their matching lymph node metastasis (WI = 224 ± 71.6, n = 85) compared to primary tumors with no evidence of metastasis (WI = 250 ± 43.9, n = 94) (P &lt; 0.01). A similar trend was also observed in caspase-8 expression although it is not statistically significant. Downregulation of caspase-8 and DR5 expression was significantly correlated with poorly differentiated tumors compared to moderately and well differentiated tumors (P &lt; 0.05). Univariate analysis indicates that, in HNSCC with no metastasis, higher expression of caspase-8 significantly correlated with better disease-free survival and overall survival (P &lt; 0.05 or 0.001) if mean value is used as a cutoff. However, in HNSCC with lymph node metastasis, higher caspase-8 expression significantly correlated with poorer disease-free survival and overall survival (&lt; 0.05 or 0.01). Similar results were also generated when we combined both DR5 and caspase-8. Moreover, multivariable analysis indicates that in patients without lymph node metastasis, high caspase-8 is significantly associated with better survival after adjusting age and stage (P &lt; 0.0001). Together, we suggest that both proteins may be involved in regulation of HNSCC metastasis. (G.C., D.M.S., F.R.K. and S-Y.S. are Georgia Cancer Coalition Distinguished Cancer Scholars. This study was supported by funds from the Georgia Cancer Coalition Distinguished Cancer Scholar and NIH Head and Neck SPORE P50 CA128613 awards)
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 1260.
Abstract 1266: TNF-alpha mediated down-regulation of Na+/H+ exchanger 1 (NHE1) in breast cancer MCF7 cells and its relevance to apoptosis
Authors: Chua Sui Huay , Clement Marie V. 
Published: February 2011

Abstract
Intracellular alkalinization is a hallmark of cancer cells shown to confer resistance against caspase mediated apoptosis. Na+/H+ exchanger 1 (NHE1), an ion exchanger important in the maintenance of intracellular pH and cell volume homeostasis had been implicated in this intracellular alkalinization. Increased NHE1 protein level and activity has been found in many cancer cells types where increase in intracellular pH by constitutively active NHE1 confers resistance to apoptosis in these cells. Silencing of NHE1 protein in cancer cells results in reduced cell growth and increased in sensitivity to death triggers. TNF-α can induce H2O2 production in cells to mediate apoptosis with characteristic cell shrinkage. H2O2 had recently been shown to downregulate NHE1 expression and increase cells’ sensitivity to apoptosis. This study was undertaken to study the role of caspases and H2O2 in the regulation of NHE1 protein and gene expression by TNF-α. Results showed that TNF-α had both cytostatic and cytotoxic effects on MCF-7 cells with concurrent decrease in intracellular pH and NHE1 activity. NHE1 was found to be downregulated both at the protein and mRNA level following TNF-α treatment. Gelshift assay showed that transcription factors binding to the promoter of NHE1 could be blocked by pre-incubation with H2O2, suggesting that transcription of NHE1 could be redox-regulated. Indeed, we also show by using a luciferase reporter assay that NHE1 promoter is down-regulated in presence of H2O2. Various caspases were activated in TNF-α treated cells and the inhibition of caspases prevented the downregulation of NHE1. ROS was elevated in MCF-7 within 2 hours of treatment. Incubation of cells with catalase increased their survival in response to TNF-α, thus implicating H2O2 as a mediator of TNF-α induced cell death. Overexpression of catalase in MCF-7 reduced the downregulation of NHE1 by TNF-α. Our results suggest by TNF-α mediate cell death through decreasing NHE1 activity and down-regulating NHE1 expression in a ROS mediated manner.
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 1266.
Abstract 1268: Identification of a novel tumor necrosis factor receptor-associated factor 6-binding partner that is a potential lysine-63 linked ubiquitination substrate
Authors: Huang Chien-Ling , Cheng Ju-Chien , Liu Shau-Yu , Tseng Ching-Ping 
Published: February 2011

Abstract
Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an ubiquitin E3 ligase that catalyzes lysine-63 linked polyubiquitination of various signaling proteins. The recruitment and formation of different protein complexes with TRAF6 leads to activation of TRAF6-associated signaling and regulates cell proliferation and apoptosis. In this study, we search for novel TRAF6-binding partners that may have implication in TRAF6 signaling and cancer progression. Bioinformatic analysis identified a putative TRAF6-binding protein (TRAF6BP) that contains the consensus TRAF6-binding motif X-X-P-X-E-X-X-Ar/Ac-X and thereby TRAF6BP was subjected to further characterization. In accord with the bioinformatics prediction, coimmunoprecipitation analysis demonstrated the binding between TRAF6BP and TRAF6. TRAF6BP also interacts with other TRAF proteins including TRAF-2, −3, −5 but the interaction was much weaker than TRAF6. Domain mapping with TRAF6 deletion mutants identified the TRAF-C domain of TRAF6 is important for its interaction with TRAF6BP. In vivo ubiquitination assay further unveiled that TRAF6BP is a substrate of TRAF6 E3 ligase and underwent ubiquitination in the presence of TRAF6. Only the expression of full-length TRAF6, but not the TRAF-C deletion mutants of TRAF6 resulted in the ubiquitination of TRAF6BP. In addition, TRAF6BP ubiquitiation was abrogated when the lysine-63 ubiquitin mutant (K63R) but not the lysine-48 mutant (K48R) was used as the ubiquitin substrate. Together, we demonstrated for the first time that TRAF6BP is a novel TRAF6-binding protein and is a potential lysine-63 ubiquitination substrate of TRAF6; the TRAF6BP-TRAF6 interaction is essential for TRAF6 to ubiquitinate TRAF6BP. The significances of TRAF6BP-TRAF6 interactions and TRAF6BP ubiquitination in cancer progression and TRAF6 signaling are worthy to further investigation.
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 1268.