bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract LB-11: PTEN modulates EGFRvIII-induced SHP2 phosphorylation and translocation to affect glioblastoma sensitivity to tyrosine kinase inhibitors (TKIs)
Authors: Kapoor Gurpreet Singh , Zhan Yi , Fetting Heather , O'Rourke Donald M. 
Published: June 2012

Abstract
Co-expression of EGFRvIII and PTEN in a small subset of recurrent glioblastoma tumors has been shown to increase sensitivity to tyrosine kinase inhibitors (TKIs). However, the exact mechanism of EGFRvIII and PTEN interaction in response to TKIs is still unresolved. Our recent work has shown that SHP2 PTPase is required for EGFRvIII-mediated transformation. The present work was aimed to study the effect of PTEN on EGFRvIII-induced SHP2 phosphorylation and translocation and modulate glioblastoma sensitivity to tarceva treatment. We show that tarceva treatment (10μM/ml) abolished EGFRvIII, EGFR, Gab1, SHP2 and Erk1/2 phosphorylation in LN229.EGFRvIII cells at all time intervals. On the contrary, phosphorylation of EGFRvIII and Erk1/2 in U87MG.EGFRvIII cells was inhibited at early time points, but was restored in 2 to 6 hours. Interestingly, phosphorylation of Akt, Gab1 and SHP2 (Tyr580) was unaffected in U87MG.EGFRvIII cells, but EGFR and SHP2 (Tyr542) phosphorylation were inhibited in a time-dependent manner. MTT proliferation and soft agar transformation assays demonstrated that U87MG.EGFRvIII cells were resistant to tarceva treatment when compared to LN229.EGFRvIII cells. Immunofluorescent labeling of U87MG.EGFRvIII cells with an anti-phospho-SHP2 (Tyr542) antibody showed membrane, cytoplasmic, perinuclear and nuclear localization of SHP2, whereas LN229.EGFRvIII cells exhibited membrane staining of phosphorylated SHP2. However, both the cell lines exhibited strong nuclear staining of phospho-SHP2 (Tyr580). Interestingly, tarceva treatment inhibited membrane localization of phospho-SHP2 (Tyr542) and nuclear localization of phospho-SHP2 (Tyr580) in LN229.EGFRvIII cells after 1 hr, but did not affect SHP2 phosphorylation and localization in U87MG.EGFRvIII cells at all time intervals. Furthermore, stable expression of PTEN in U87MG.EGFRvIII cells conferred relocalization of phospho-SHP2 (Tyr542) to the membrane. Notably, U87MG.EGFRvIII/PTEN clones showed a partially untransformed phenotype. Furthermore, phosphorylation of SHP2 (Tyr580) and Erk1/2 was totally abolished in U87MG.EGFRvIII/PTEN subclones. Our data indicate that the expression of PTEN in U87MG.EGFRvIII cells conferred a phenotype similar to LN229.EGFRvIII cells. Collectively, these observations infer that SHP2 is a downstream effecter of PTEN and that PTEN deficiency may lead to SHP2 activation and nuclear localization by EGFRvIII, which may result in increased resistance to TKIs.
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 LB-11. doi:10.1158/1538-7445.AM2011-LB-11
Abstract LB-133: Golgin-160 binds to the tumor suppressor Par-4 and attenuates its secretion
Authors: Bhattarai Tripti Shrestha , Singh Jaya , Qiu Guofang , Machamer Carolyn E. , Rangnekar Vivek M. 
Published: June 2012

Abstract
Prostate apoptosis response-4 (Par-4) is a pro-apoptotic protein that selectively induces apoptosis in cancer cells but not in normal cells. Previously thought to function exclusively by intracellular mechanisms, Par-4 is now recognized to also utilize an extrinsic pathway that is coupled to intracellular Par-4 to mediate apoptosis. Par-4 is secreted by almost all cell types, and is detected in the conditioned medium of cultured cells or in the serum of animals. Systemic Par-4 inhibits tumor growth progression, yet the precise mechanism(s) involved in the regulation of Par-4 secretion has not been characterized. Par-4 secretion is induced by an increase in endoplasmic reticulum (ER) stress; this observation is paradoxical as protein secretion is generally inhibited by elevated ER stress. Toward the goal of investigating proteins that may directly bind and regulate Par-4 secretion, we performed a yeast two-hybrid analysis, as well as co-immunoprecipitation studies. These studies consistently identified the golgi peripheral membrane protein, Golgin-160, as a binding partner of Par-4. We further noted that Golgin-160 down-modulates the secretion of Par-4 in response to ER stress caused by tunicamycin. Our data suggest that Par-4 secretion is attenuated by binding to Golgin-160. This regulatory process may have important implications in microenvironments (for example, those involving inflammation) that have increased Golgin-160, as depleted Par-4 secretion may show greater propensity for transformation and malignant progression. Since Par-4 selectively induces apoptosis in transformed cells but not in normal/non-transformed cells, strategies to down-modulate Golgin-160 to promote Par-4 secretion may have broad implications in cancer therapeutics.
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 LB-133. doi:10.1158/1538-7445.AM2011-LB-133
Abstract LB-14: Low connexin-26 predicts the development of metastasis after radical prostatectomy
Authors: Bijnsdorp Irene V. , Rozendaal Laurence , van Moorselaar R. Jeroen A. , Geldof Albert A. 
Published: June 2012

Abstract
Prostate cancer is the second most common cause of death in males. Not all tumors will become metastatic within a patients life time, but when metastasized no curative therapy is available. It is therefore important to identify molecules that predict whether the tumor will become metastatic. Connexin-26 (Cx26) is a gap-junction protein that is involved in cell-cell contacts and in cell adhesion. Cx26 is involved as a tumor suppressor in various tumor types. The aim of the present study was to determine Cx26 expression in localized prostate cancer and relate the expression to the development of metastasis. Cx26 was stained by immunohistochemical staining in radical prostatectomy tissues of 43 patients. The expression levels were scored by a pathologist. Cx26 expression was observed in 95% of the patients. No relation was found to Cx26 expression in the tumor and the development of metastasis (p=0.2). Interestingly, a clear relation was found between low Cx26 expression in benign epithelial cells within the same sections and the development of metastasis (p&lt;0.03). These metastases developed in about 5–40 months after radical prostatectomy. Kaplan Meier analysis showed a relation between a low Cx26 (score &lt;75) expression in benign epithelial cells and time to PSA progression (p=0.01). Time to progression was associated with PSA and Cx26 expression in benign epithelial cells (Multivariate Cox proportional hazards analysis, p=0.05). In conclusion, Cx26 expression in the benign epithelial cells was associated with the development of metastasis. Cx26 expression could therefore be used as a predictor of outcome after radical prostatectomy.
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 LB-14. doi:10.1158/1538-7445.AM2011-LB-14
Abstract LB-141: Expression and localization of Id3 in human prostate cancer
Authors: Sharma Pankaj , Patel Divya , Chinaranagari Swathi , Chaudhary Jaideep 
Published: June 2012

Abstract
Purpose: The inhibitor of differentiation (Id) proteins are dominant negative basic helix-loop-helix family of transcription factors that lack the DNA-binding basic domain but have intact HLH domain. The four members of the Id protein family (Id1-Id4) are known to play a critical role in the coordinated regulation of gene expression during cell growth, differentiation and tumorigenesis. Although in vitro studies have demonstrated the role of Id1 in regulating prostate cancer (PCa) cell proliferation, apoptosis and androgen independence, its clinical significance in PCa remains controversial. On the other hand there is lack of evidence on the expression of Id2 and Id3 in PCa progression. Studies have demonstrated that silencing of Id3 is significantly more effective in blocking proliferation of PCa cells as compared to Id1 whereas Id2 silencing has been primarily shown to be involved in apoptotic pathway. Hence in this study we re-evaluated the role of Id1 in PCa and extended our study to show that Id3 protein expression has better clinical relevance compared to Id1 and Id2 in PCa.
Experimental design: The expression of Id-1, -2 and -3 was determined by real time and Western blotting along with their sub-cellular localization by ICC in PCa cell lines LNCaP, DU145 and PC3. To assess their significance in prostate cancer progression, the protein expression was investigated in clinical prostate tumor samples on high density tissue microarray by IHC.
Results: The expression of Id1 and Id3 mRNA was low in LNCaP and DU145 as compared to PC3 whereas the level of Id2 expression was similar between all the PCa cell lines. The protein expression data was consistent with the mRNA levels in the PCa cell lines. All three Id's were primarily cytoplasmic with some nuclear presence. The IHC data showed a significant increase in the expression of Id1 and Id3 in clinical prostate tumor tissue samples compared to normal prostate tissue whereas Id2 showed elevated levels but was not significant as compared to Id1 and Id3. The expression of Id3 protein correlated with the Gleason grading and stage of PCa.
Conclusions: This is the first study demonstrating a correlation between increased expression of Id3 and prostate cancer progression. It also reconfirms and establishes the association of Id1with PCa. The results warrant further investigation into isoform specific effects of Id1and Id3 on prostate tumorigenesis. (Research Support: NIH/NCI RO1 CA128914 and NIH/NCRR/RCMI G12RR03062. The first two authors contributed equally to this work.
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 LB-141. doi:10.1158/1538-7445.AM2011-LB-141
Abstract LB-144: I-kappa-B kinase (IKK)ε expression in pancreatic ductal adenocarcinoma
Authors: Guo Jianping , Cheng Anna , Henderson-Jackson Evita B. , Kim Donghwa , Malafa Mokenge , Coppola Domenico 
Published: June 2012

Abstract
I-kappa-B-kinase (IKKε) is a serine/threonine protein kinase that belongs to the IKK kinase family. Recent studies have shown that IKKε functions as a breast and ovarian cancer oncogene. Here we demonstrate frequent overexpression of IKKε in pancreatic ductal adenocarcinoma (PDA). We immunohistochemically evaluated 78 PDA using the avidin-biotin-peroxidase method and the anti-IKKε, rabbit polyclonal antibody. Elevated IKKε reactivity (IHC score 4–9) was observed in 64.1 % (50/78) PDAs, but in 0% (0/113) of non neoplastic pancreatic ductal epithelium (NMP) (p &lt; 0.001). Kaplan-Meier analysis of overall survival (OS) revealed that patients with high IKKε-IHC scores (4–9) had a significantly shorter survival than that of patients with low IKKε -IHC scores (0–3) (Log-rang test p = 0.023), independent of either tumor stage or grade. These data indicate that deregulation of IKKε is a common event in PDA and might play an important role in the pathogenesis of this deadly disease. In addition, IKKε could serve as a prognostic marker and potential therapeutic target for PDA intervention.
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 LB-144. doi:10.1158/1538-7445.AM2011-LB-144
Abstract LB-151: Tumor VEGF-C promotes immune suppression and tolerance
Authors: Lund Amanda W. , Raghavan Vidya , Hirosue Sachiko , Duraes Fernanda , Hugues Stephanie , Swartz Melody 
Published: June 2012

Abstract
The expression of the vascular endothelial growth factor, VEGF-C, is correlated with tumor invasion and hypothesized to induce metastasis through enhanced lymphangiogenesis and the creation of an “escape route”. However, new evidence suggests that VEGF-C can induce invasion in the absence of obvious tumor lymphangiogenesis, and furthermore, that lymphatic transport may play a role in modulating immunity. Still however, the role of the lymphatics as players in anti-tumor immunity and tumor invasion remains unexplored. Here we present a new model for VEGF-C induced tumor-invasion in which VEGF-C and lymphatic endothelial cells play a direct role in the suppression of anti-tumor immunity. Using a B16 F10 mouse melanoma that overexpresses VEGF-C, we demonstrated that VEGF-C induces the expression of the lymphoid homing cytokine, CCL21, within the stroma of the tumor and drives lymphocyte trafficking, fluid drainage and metastasis to the sentinel draining lymph node. Within the tumor stroma VEGF-C recruited a more regulatory immune cell infiltrate including increased regulatory T cells (CD25+FoxP3+) and M2 macrophages (CD11b+CD80-CD206+) and decreased antigen specific cytotoxic T cells (CD8+Trp2+). To test the ability of this mediated VEGF-C response to overcome host immunity we engineered a B16 F10 line to express ovalbumin (OVA) as a model tumor antigen. When we preimmunized the mice against OVA we observed that VEGF-C provided protection against vaccine (OVA/LPS) induced anti-tumor immunity. Growth of OVA bearing tumors was inhibited with vaccination and correlated with an increase in CD8+ antigen specific cytotoxic T cells. However, neither the growth nor the infiltration of cytotoxic T cells was affected by vaccination when the tumors also overexpressing VEGF-C. Additionally, to determine the fate of antigen specific CD8+ we adoptively transferred OT-I T cells by tail vein injection and observed their homing to the draining lymph nodes and tumor. In these microenvironments, when exposed to VEGF-C, adoptively transferred cells lost function over time as shown by the detection of Annexin V and decreased IFNγ expression. These results suggest that the expression of VEGF-C by a primary tumor not only promotes metastasis through the expansion of the lymphatic network but also through an immunological switch within the tumor and draining lymph node. We therefore present one of the first studies to identify an active, rather than passive, role for the lymphangiogenic growth factor, VEGF-C, and local lymphatic endothelial cells in the regulation of tumor immunity.
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 LB-151. doi:10.1158/1538-7445.AM2011-LB-151
Abstract LB-155: A new syngeneic MYCN-overexpressing neuroblastoma mouse model and MYCN-DNA vaccine
Authors: Stermann Alexander , Huebener Nicole , Lode Holger N. 
Published: June 2012

Abstract
High-level expression of MycN caused by amplification of the gene characterizes the malignant phenotype of neuroblastoma. Recent studies suggest that MYCN is a suitable target for immunotherapy, but up to now, a syngeneic NB mouse model over expressing MYCN is not available to examine immunotherapeutic strategies in vivo.
Here, we report the development of a tetracycline inducible MYCN expressing murine NB cell line syngeneic to A/J mice and a MYCN-DNA vaccine. For this purpose, the murine NB cell line C1300, syngeneic to A/J mice, was stably transfected with a tetracycline inducible MYCN expression vector. Stable transfection was verified by real-time PCR and Western-Blot, revealing high expression levels of MYCN RNA and protein, respectively. Furthermore, a MYCN-DNA vaccine, based on epitopes encoding for three peptides from the murine MYCN protein sequence with high affinity to the A/J mouse MHC class I allele H2-Kk, was designed and tested in vivo for its ability to induce an antigen-specific immune response. Lymphocytes isolated from A/J mice vaccinated with the MYCN vaccine effectively lysed C1300-MYCN +tet cells in cytotoxicity assays in contrast to wild type C1300 cells and lymphocytes from control mice. Lymphocytes from minigene vaccinated mice produced significantly higher amounts of IFN-γ after stimulation with irradiated C1300 cells than lymphocytes from control mice. Interestingly, vaccine induced cytotoxic T lymphocytes also kill parental C1300 tumor cells which show low MYCN expression. We expect that this effect will be enhanced when MYCN-over expressing C1300 cells are employed in a similar cytotoxicity assay which will be reported at the meeting.
In summary, we report the development of a new MYCN-DNA vaccine and a murine tetracycline inducible MYCN NB cell line providing an useful syngeneic mouse model for in vivo evaluation of MYCN directed immunotherapeutic strategies.
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 LB-155. doi:10.1158/1538-7445.AM2011-LB-155
Abstract LB-214: Rac1 and Cdc42 GTPases as novel targets in ovarian cancer
Authors: Wandinger-Ness Angela , Kenney S. Ray , Agola Jacob , Roxby Joshua , Surviladze Zurab , Silberberg Melina , Zeineldin Reema , Vestling Anna , Bologa Cristian , Ursu Oleg , Oprea Tudor , Muller Carolyn , Lomo Lesley , Sklar Larry , Hudson Laurie G. 
Published: June 2012

Abstract
Epithelial ovarian cancer is the major cause of gynecologic malignancy deaths. Because of their roles in cell adhesion and migration, Rho family GTPases have been suggested as potential therapeutic targets in human cancers. We identify the Rac1 and Cdc42 GTPases as relevant targets in papillary serous and endometriod tumors. Cdc42 is overexpressed in primary human ovarian tumors and cancer cell lines, and a novel splice variant Rac1b is upregulated in tumors of advanced stage and grade. GTPase activities in primary ascites are 3 to 6-fold higher than in cultured cells. R-Naproxen was identified by high throughput screening of a Prestwick compound library as a select non-steroidal anti-inflammatory drug (NSAID) from 23 tested that selectively targets Rac1 and Cdc42 in a bead-based assay using purified proteins. The drug is demonstrated to have positive benefit against cell behaviors required for ovarian cancer dissemination and metastasis using both cell lines and primary human tumor cell isolates. Human ovarian cells show slowed cell proliferation, as well as impaired migration, adhesion and invadopodia formation. Other NSAIDs with structural similarity (S-naproxen and 6-methoxy naphthalene acetic acid) lack these properties, while a specific Rac inhibitor NSC 23766 mimics the effects. Molecular docking shows R-Naproxen can bind the GDP-bound, but not GTP-bound Rac1, suggesting it may act by stabilizing Rac and Cdc42 in the inactive state. R-Naproxen has potential for rapid translation and efficacy in the treatment of metastatic ovarian cancer on account of FDA approval and novel activities against Rho-family GTPases.
Funding for this study was generously provided by NIH grants U54MH074425, U54MH084690, R03MH081231, P30CA118100 and UNM Cancer Center FIG.0990MD.
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 LB-214. doi:10.1158/1538-7445.AM2011-LB-214
Abstract LB-243: Functional oncogene identification in hematologic malignancies
Authors: Weigert Oliver , Lane Andrew , Kopp Nadja , Rodig Scott , Yoda Akinori , Weinstock David M. 
Published: June 2012

Abstract
Next generation sequencing of hematologic malignancies has identified tens to hundreds of mutations in coding sequence per sample. However, the functional significance of nearly all of these mutations remains unclear. Importantly, systematic analyses to determine the phenotypic effects of somatic mutations from cancer samples have proven cumbersome and low-yield. We developed an alternate approach to efficiently identify functionally-important, cryptic alterations directly from hematologic malignancy specimens. In this system, retroviral cDNA libraries are constructed from patient samples and then used to infect the IL3-dependent B-cell line, BaF3. Expression of oncogenic kinases, transcription factors and other oncogenes results in IL3-independent survival, allowing for the isolation of individual transformed clones and sequencing of integrated cDNA. Streamlined methods for cDNA cloning and retroviral transduction have made it both feasible and cost-efficient to construct patient-specific libraries for oncogene identification. With this approach, cryptic mutations, translocations and other rearrangements with functional significance can be identified. We previously performed functional oncogene screening in a panel of precursor B-cell acute lymphoblastic leukemia (B-ALL) specimens with normal karyotypes. From our initial screen, we recovered an IL3-independent BaF3 clone that harbored a full-length mutant version of the cytokine receptor subunit CRLF2. We subsequently demonstrated that 5–10% of adult and pediatric B-ALL harbor CRLF2 alterations that frequently coincide with activating mutations in Janus kinase 2. With support from Stand Up To Cancer, we applied functional screening to 6 additional hematologic malignancy subtypes. We supplemented screening with limited exome sequencing of angioimmunoblastic T-cell lymphomas, biphenotypic acute leukemia and BALL to confirm the presence of functional alleles and recover possible cooperating mutations. With this approach, we identified a panel of alterations in these diseases and confirmed several to be somatic and functionally relevant, including novel mutations in JAK2, TYK2, IDH2 and FLT3. In addition, targeted sequencing identified the same nonsense mutation in an alpha kinase in multiple cases of angioimmunoblastic T-cell lymphoma. In conclusion, large-scale sequencing efforts are underway at many centers to identify somatic mutations in hematologic malignancy samples. Screening of retroviral cDNA libraries offers an efficient alternative, focused on phenotypically meaningful, and therefore potentially drugabble, alterations.
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 LB-243. doi:10.1158/1538-7445.AM2011-LB-243