bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4680: DNA dependent protein kinase as a new molecular target for treatment of non-small cell lung cancer
Authors: Aragane Naoko , Sato Akemi , Iwanaga Kentaro , Kobayash Naomi , Kimura Shinya , Sueoka Eisaburo 
Published: August 2012

Abstract
Prognosis with non-small cell lung cancer (NSCLC) has improved with the recent introduction of molecular targeted therapy. However, it is limited to patients with epidermal growth factor receptor (EGFR) mutations, who benefit from EGFR tyrosine kinase inhibitors (EGFR-TKI). A new molecular target is needed with other NSCLC patients. In general, chemotherapeutic agents cause DNA double-strand breaks (DNA DSB), leading to apoptosis of cancer cells; DNA repair reverses their effect, resulting in resistance to chemotherapy. DNA DSB repair can be mediated via two major pathways: homologous recombination (HR) and non-homologous end-joining (NHEJ). More than 90% of DSBs in mammalian cells are repaired by NHEJ, which is accomplished by core protein components including Ku70/Ku86, DNA-dependent protein kinase (DNA-PK), XRCC4, DNA ligase IV, Artemis, and Cernunnos-XLF. We recently reported that NK314, a dual inhibitor of topoisomerase IIα (Top2β) and DNA-PK, evidences a potent anti-tumor effect in adult T-cell leukemia-lymphoma (ATL). NK314 induced DNA DSBs and inhibited DNA repair mediated through degradation of the DNA-PK catalytic subunit (DNA-PKcs). In the present study, we examined the effect of NK314 in NSCLC cell lines and assessed DNA-PK as a possible molecular target for NSCLC. Twenty separate NSCLC cell lines were used, with IC50 varying from 46-193 nM. Levels of DNA-PKcs protein varied among the cell lines, whereas those of Ku70 and Ku86 did not. The inhibitory effect of cell growth was closely related to level of DNA-PKcs protein, but not to levels of other DNA-damage-activated protein kinases such as ATM or ATR. Establishment of predictive markers concomitantly with the development of a novel molecular target is indispensable for clinical application. Because detection of DNA-PKcs in peripheral blood is difficult, we investigated an alternative marker for predicting DNA-PKcs inhibitor. We previously found that heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1), an RNA binding protein, interacts with DNA-PK, and we established a system for detecting hnRNP B1 mRNA in peripheral blood. We therefore examined the suitability of hnRNP B1 as an alternative biomarker for DNA-PK inhibitors. Close correlation between levels of DNA-PKcs and hnRNP B1 proteins was established using Western blot analysis with NSCLC cell lines (p=0.995). These results suggest that DNA-PK is a novel molecular target for NSCLC, and detection of hnRNP B1 might serve as an alternative molecular marker for the amount of DNA-PK inhibitors.
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 4680. doi:1538-7445.AM2012-4680
Abstract 469: CD151 and cell motility in prostate cancer
Authors: Detchokul Sujitra , Parker Michael W. , Williams Elizabeth D. , Herdiman Olivia M. , Davis Melissa , Kee Kelvin , Bolton Damien M. , Frauman Albert G. 
Published: August 2012

Abstract
Prostate cancer (PCa) is one of the leading causes of cancer death in men. CD151 is a member of the tetraspanin family and is associated with regulation of migration of normal and tumour cells via cell surface microdomain formation. Previous studies from our laboratory revealed that expression of CD151 differs across histological grades of PCa and high levels of expression are linked to shorter survival, independent of Gleason score1. In vitro motility assays of human PCa cell lines suggest CD151 is a motility promoter2. We have sought to develop a number of CD151 inhibitors and examine their ability to modulate prostate cancer motility and metastasis. The human PCa cell line, LNCaP (low endogenous level of CD151), transfected with CD151 shows increased motility and invasion compared to control LNCaP, whilst CD151 siRNA knock-down (KD) of PC-3 cells (high endogenous level of CD151), reduces motility compared to control PC-3. We have conducted in silico screening with compounds predicted to bind a model of the large extracellular domain (EC2) of CD151 and found that a number of these small molecules possess bioactivity in vitro and in vivo in inhibiting prostate cancer motility and progression. LNCaP growth and migration was confirmed by stimulating with 1 and 10 nM DHT at 24 hrs in charcoal stripped FBS. It was found that cell proliferation and motility of LNCaP cells was significantly increased after stimulation by 10 nM DHT at 24 hrs (p&lt;0.01) and 48hrs (p&lt;0.01), whilst DHT had minimal effect on control PC-3 and DU-145 cells. We have also analyzed a set of whole genome microarray expression data from PCa cell lines PC-3 and CD151 KD PC-3, and identified differentially expressed genes linked to CD151. Significant changes were seen in 172 genes after CD151 KD in PC-3 cells. We examined the protein interaction networks of our differentially expressed genes using Cytoscape3. Functional network analysis revealed high level of connectivity surrounding genes involved in transcriptional regulation, microtubule-based movement and protein folding and complex formation. CD151 is an important promoter of cell migration and metastatic disease in PCa and may serve as a target for a novel class of anti-metastatic therapeutic agents. A systems biology approach allows for improved mechanistic interpretation of biological data and may facilitate identification of other therapeutic targets. 1 Ang J et al. Cancer Epidemiol Biomarkers & Prevention (2004) 13: 1717-21 2 Ang J et al. Oncology Reports (2010) 24(6): 1593-1597 3 Shannon P et al. Genome research (2003) 13: 2498-2504
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 469. doi:1538-7445.AM2012-469
Abstract 4699: A siRNA high-throughput screening identified Wee1 as determinant of Chk1 inhibitor sensitivity
Authors: Carrassa Laura , Chilà Rosaria , Lupi Monica , Ricci Francesca , Mazzoletti Marco , Celenza Cinzia , Broggini Massimo , Damia Giovanna 
Published: August 2012

Abstract
Targeting Chk1 protein kinase is a valid anti cancer strategy to enhance the cytotoxic effects of radio and chemotherapy. Recent evidence disclosed a role of Chk1 in unperturbed cell proliferation and survival, implying that Chk1 inhibitors could also be effective as single agents in tumors with a specific genetic background. The effect of Chk1 inhibition on a wide panel of cancer cell lines has been herein conducted by using a specific and selective Chk1 inhibitor PF-00477736. The results showed that 2 cancer cell lines out of 16 analyzed (the ovarian cancer cell line OVCA-432 and the breast cancer cell line SK-BR3) were very sensitive to PF-00477736 treatment. To identify genes in synthetic lethality with Chk1, which may justify the sensitivity to Chk1 inhibitor of some cancer cell lines, a high-throughput screening using a siRNA library directed against 719 human protein kinases, in combination with either scramble or Chk1 siRNA, was undertaken. The ovarian cancer cell line OVCAR-5, resistant to Chk1 inhibition, was used to perform the screening. After 2 independent screenings and the validation procedure using specific esiRNAs, and the three siRNAs of each target (used in the screening as a pool), the Wee1 tyrosine kinase was identified as the most significant gene in synthetic lethality with Chk1. Treatment with both PF-00477736 and a Wee1 inhibitor (MK-1775) confirmed the remarkable synergistic effect in various human cancer cell lines (breast, ovarian, colon, prostate). Same results have been obtained with AZD-7762 Chk1 inhibitor. Isogenic cellular systems differing only for the status of p53 (the colon carcinoma cancer cell lines HCT-116 p53 +/+ and p53 -/- and the ovarian cancer cell lines A2780 and A2780/E6) showed a comparable and strong synergistic effect of the combined treatment. Interestingly, in the normal fetal human lung cell line MRC-5 the effect of the combined treatment was additive. Time lapse experiments and an evaluation of the ability of cells to form colonies, suggested that cells treated with the two inhibitors almost completely lost the ability to proliferate and failed to perform a proper cell division. A detailed molecular analysis showed that the combined treatment causes cells to undergo premature mitosis before the end of DNA replication and with damaged DNA, leading to a massive cell death by apoptosis. Taken together these preclinical data address a new promising combined targeted anticancer strategy that deserves clinical investigation.
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 4699. doi:1538-7445.AM2012-4699
Abstract 4711: Epigenetic modulation restores expression of functional progesterone receptor in endometrial cancer cells
Authors: Yang Shujie , Xiao Xue , Zhang Yuping , Meng Xiangbing , Leslie Kimberly K. 
Published: August 2012

Abstract
Endometrial cancer, the most common gynecologic malignancy, is a hormonally regulated tumor. Given progesterone is a tumor suppressor in the endometrium, response to progestin-based therapy correlates positively with progesterone receptor (PR) expression. Many endometrial tumors have lost of PR, which limits the clinical application of progestin-based therapy. PRB promoter methylation was reported in 74% of endometrial cancer patients, which correlate with loss of PR expression. These clinical data suggest that restoring PR expression by epigenetic modulation might sensitize tumors to progestin-based therapy. Therefore, we hypothesized that restoring PR expression in endometrial cancer cells will inhibit proliferation and induce cell death. Epigenetic modulators, such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi) were evaluated as effective agents to restore PR expression in a panel of endometrial cancer cells. Treatment with the DNMTi 5-aza-2′deoxycytidine (5-aza-dC) or the HDACi LBH589 alone or in combination upregulated PGR mRNA levels. At the protein level, LBH589 treatment upregulated PR by 24 hours and sustained expression for at least 72 hours, even in the presence of progestrone. The upregulated PR expression by LBH589 treatment was dose dependent; an obvious increase in PR was detected with 10 nM LBH589 when compared with control, and the expression reached the highest level at 50 nM to 100 nM. To investigate if the restored PR is functional, we examined PR nuclear localization and expression of target genes. First, after treatment with LBH589 in the absence or presence of progesterone, PR nuclear localization was confirmed by immunostaining and nuclear fractionation followed by Western blotting. Next, a progesterone response element (PRE)-luciferase reporter assay was used to directly examine PR transcriptional activity. LBH589 treatment increased PRE-luciferase activity by 8- to 10-fold in Ishikawa and ECC1 cells. Furthermore, expression of endogeneous PR target genes containing PRE (FoxO1 and cyclin D) or Sp1 element (p21 and p27) was studied in response to LBH589 treatment. Restored PR upregulated FoxO1, p21, p27 and downregulated cyclin D1, demonstrating that PR is functional as a transcription factor. Our findings reveal that epigenetic modulators can restore endogenous PR expression in endometrial cancer cell lines. This preclinical study provides strong support that strategy to re-establish PR expression will result in resensitization of endometrial tumors to progestin therapy.
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 4711. doi:1538-7445.AM2012-4711
Abstract 473: Elevated cAMP decreases migratory potential in pancreatic cancer cells
Authors: Zimmerman Noah , Roy Ishan , Wilson Jessica , Dwinell Michael 
Published: August 2012

Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers, primarily resulting from inherent, aggressive dissemination. As elevated concentrations of cAMP are known to inhibit cell movement in multiple tissues, we investigated the role of cAMP in regulating migration of model pancreatic cancer cells. Increased cAMP concentrations were induced either through forskolin, an activator of adenylyl cyclase, the cAMP analog 6-bnz-cAMP, or by two phosphodiesterase cyclic nucleotide inhibitors, cilostamide or IBMX. Transwell migration assays demonstrated cAMP elevating agents significantly decreased migration of Panc1, MiaPaCa2, and HPAFII pancreatic cancer cell lines. In Panc1 cells, inhibition was dose-dependent and not significantly different between forskolin, cilostamide, or IBMX treatment. Importantly, a significant decrease in cell migration was also observed in cells treated with 6-bnz-cAMP, a specific activator of protein kinase A. The decrease in migration did not reflect alterations in cell proliferation as cell cycle analysis demonstrated little to no change in proliferation in treated compared to control cells. Similarly, the decrease in cell migration was not a function of programmed cell death as apoptosis was not elevated in cells treated with cAMP elevating agents. Consistent with its known role in F-actin rearrangement, elevated levels of cAMP increased phosphorylated RhoA and the resultant decrease in active RhoA-GTP. As expected, fluorescence microscopy indicated a significant increase in cortical actin formation along the perimeter of forskolin or cilostamide-treated cells. Taken together these data suggest that the novel use of existing anti-inflammatory drugs that target the cAMP signaling networks have the potential to block pancreatic cancer dissemination.
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 473. doi:1538-7445.AM2012-473
Abstract 4732: Repression of transcriptional activity by the retinoid target gene G0S2
Authors: Ma Tian , Dong Jessica P. , Blumen Steven , Fei Dennis L. , Henderson Michael , Sekula David J. , Freemantle Sarah J. , Dmitrovsky Ethan 
Published: August 2012

Abstract
Acute promyelocytic leukemia (APL) cases that express the PML/RARα fusion protein block maturation of myeloid precursors. All-trans retinoic acid (RA)-based differentiation therapy of these APL cases causes clinical remissions. Yet, clinical use of RA is associated with toxicities and drug resistance. In the search for RA target genes that can serve as alternative therapeutic targets in APL, G0S2 was found as one of the most rapidly and prominently RA-induced species. G0S2 is a 103 amino acid protein without apparent homology domains to other species. It was recently shown to inhibit adipose triglyceride lipase (ATGL) activity, leading to repression of lipolysis. G0S2 is abundantly expressed in adipose tissues, which is consistent with its role in regulating lipolysis. It is also induced in response to inflammatory stimuli in other cell types, indicating it has additional roles beyond fat storage. Here, we report a new G0S2 function uncovered after its transient transfection that led to substantial repression of reporter activities of multiple constructs (including RA-regulated species RARα, UBE1L and G0S2 itself). This repression was antagonized by siRNA-mediated G0S2 knockdown. Notably, an engineered form of G0S2 that lacked the internal hydrophobic domain did not exhibit these repressive effects. Inhibitors of either the proteasomal or lysosomal pathways did not overcome this suppression by G0S2. Thus, these repressive activities were unlikely due to enhanced proteasome or lysosome activities. The reported inhibition of ATGL activity by G0S2 causes an increase in lipid droplet size, which can also be achieved by treating cells with the neutral lipid oleic acid. Yet, this treatment did not impact reporter activity, indicating that changes in lipid droplet size did not affect this transcriptional repression. Intriguingly, G0S2 expression did not reduce endogenous expression of RARα, UBE1L or G0S2 (each RA-regulated species), indicating that only exogenous genes were affected by G0S2 transient transfection. Subcellular localization of endogenous G0S2 was examined in RA-treated NB4 APL cells and G0S2 was markedly expressed in the cytosol and membranes of these cells. Transiently transfected G0S2 protein was also detected in the cytoplasm. In summary, we report a previously unrecognized function for the RA target gene G0S2: it repressed exogenous reporter activity, but not endogenous gene expression. Both endogenous and exogenous G0S2 proteins were detected in the cytoplasm. Mechanistic studies that engage this G0S2 repressive effect are now underway.
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 4732. doi:1538-7445.AM2012-4732
Abstract 4737: Resveratrol targeting of carcinogen-induced brain endothelial cell inflammation biomarkers MMP-9 and COX-2 is Sirt1-independent
Authors: Annabi Borhane , Lord-Dufour Simon , Vezina Amelie , Lamy Sylvie , Beliveau Richard 
Published: August 2012

Abstract
Background: The occurrence of a functional relationship between the release of metalloproteinases (MMPs) and the expression of cyclooxygenase (COX)-2, two inducible pro-inflammatory biomarkers with important pro-angiogenic effects, has recently been inferred. While brain endothelial cells play an essential role as structural and functional components of the blood-brain barrier (BBB), increased BBB breakdown is thought to be linked to neuroinflammation. Chemopreventive mechanisms targeting both MMPs and COX-2 however remain poorly investigated. In this study, we evaluated the pharmacological targeting of Sirt1 by the diet-derived and antiinflammatory polyphenol resveratrol. Methods: Total RNA, cell lysates, and conditioned culture media from human brain microvascular endothelial cells (HBMEC) were analyzed using qRT-PCR, immunoblotting, and zymography respectively. Results: Tissue scan microarray analysis of grade I-IV brain tumours cDNA revealed increased gene expression of Sirt-1 from grade I-III but surprisingly not in grade IV brain tumours. HBMEC were treated with a combination of resveratrol and phorbol 12-myristate 13-acetate (PMA), a carcinogen known to increase MMP-9 and COX-2 through NF-κB. We found that resveratrol efficiently reversed the PMA-induced MMP-9 secretion and COX-2 expression. Gene silencing of Sirt1, a critical modulator of angiogenesis and putative target of resveratrol, did not lead to significant reversal of MMP-9 and COX-2 inhibition. Decreased resveratrol inhibitory potential of carcinogen-induced IαB phosphorylation in siSirt1-transfected HBMEC was however observed. Conclusion: Our results suggest that resveratrol may prevent BBB disruption during neuroinflammation by inhibiting MMP-9 and COX-2 and act as a pharmacological NF-κB signal transduction inhibitor independent of Sirt1.
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 4737. doi:1538-7445.AM2012-4737
Abstract 4742: Comprehensive epitope mapping of antibodies against CXCR4 and Claudin-4 by Shotgun Mutagenesis
Authors: Paes Cheryl , Rucker Joseph , Thaker Yana , Cameron Alex , Maksimchuk Ken , Payne Riley , Doranz Benjamin J. 
Published: August 2012

Abstract
Identifying antibody epitopes on membrane proteins can help differentiate antibody binding mechanisms, identify immunodominant structures, distinguish and classify antibodies, and identify cancer state-specific antigens, providing valuable information for therapeutic and diagnostic applications. However, membrane proteins represent challenging targets for epitope mapping studies using conventional methodologies such as X-ray crystallography or peptide scanning. We have developed a technology, ‘Shotgun Mutagenesis Epitope Mapping’ for rapidly mapping antibody epitopes on structurally-intact proteins expressed in mammalian cells. Here, we applied Shotgun Mutagenesis to create a comprehensive mutation library for CXCR4, a GPCR associated with tumor metastasis. The CXCR4 mutation library, which comprised &gt;700 clones with 2.7x coverage of each of the 352 residues, was screened in triplicate with 5 different anti-CXCR4 MAbs to identify their epitopes. Our analysis revealed that all CXCR4 MAb epitopes were conformational and showed a requirement for charged residues located on the second extracellular loop. CXCR4 MAb epitopes were mapped onto the crystal structure to visualize and identify common structural features. Using epitope information, we generated point mutations in CXCR4 at positions of critical contact residues, incorporated them into virus-like particles (‘Lipoparticles’) and measured their binding kinetics. These approaches helped define the electrostatic contribution of individual amino acid residues on CXCR4 to the association rate, dissociation rate, and overall binding interaction with CXCR4 MAbs. Taking the same approach, we generated a comprehensive mutation library for the biomarker Claudin-4, a tight junction protein upregulated in epithelial cancers. The Claudin-4 mutation library, which comprised &gt;400 clones with complete coverage of each of the 209 residues, was screened with a panel of 7 different anti-Claudin-4 antibodies to map their epitopes. We identified several distinct conformational epitopes that all map exclusively to the large first extracellular loop, identifying this domain as an immunodominant region of claudin-4.
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 4742. doi:1538-7445.AM2012-4742