bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Ruthenium-Containing Organometallic Compound Reduces Tumor Growth through Induction of the Endoplasmic Reticulum Stress GeneCHOP
Authors: Meng Xiangjun , Leyva Mili L. , Jenny Marjorie , Gross Isabelle , Benosman Samir , Fricker Bastien , Harlepp Sébastien , Hébraud Pascal , Boos Anne , Wlosik Pauline , Bischoff Pierre , Sirlin Claude , Pfeffer Michel , Loeffler Jean-Philippe , Gaiddon Christian 
Published: July 2009

AbstractCisplatin-derived anticancer therapy has been used for three decades despite its side effects. Other types of organometallic complexes, namely, some ruthenium-derived compounds (RDC), which would display cytotoxicity through different modes of action, might represent alternative therapeutic agents. We have studied both in vitro and in vivo the biological properties of RDC11, one of the most active compounds of a new class of RDCs that contain a covalent bond between the ruthenium atom and a carbon. We showed that RDC11 inhibited the growth of various tumors implanted in mice more efficiently than cisplatin. Importantly, in striking contrast with cisplatin, RDC11 did not cause severe side effects on the liver, kidneys, or the neuronal sensory system. We analyzed the mode of action of RDC11 and showed that RDC11 interacted poorly with DNA and induced only limited DNA damages compared with cisplatin, suggesting alternative transduction pathways. Indeed, we found that target genes of the endoplasmic reticulum stress pathway, such as Bip, XBP1, PDI, and CHOP, were activated in RDC11-treated cells. Induction of the transcription factor CHOP, a crucial mediator of endoplasmic reticulum stress apoptosis, was also confirmed in tumors treated with RDC11. Activation of CHOP led to the expression of several of its target genes, including proapoptotic genes. In addition, the silencing of CHOP by RNA interference significantly reduced the cytotoxicity of RDC11. Altogether, our results led us to conclude that RDC11 acts by an atypical pathway involving CHOP and endoplasmic reticulum stress, and thus might provide an interesting alternative for anticancer therapy. [Cancer Res 2009;69(13):5458–66]
Lessons from an Aggressive Cancer: Evolutionary Dynamics in Esophageal Carcinoma
Authors: Klein Christoph A. , Stoecklein Nikolas H. 
Published: July 2009

AbstractRapid progression to metastatic disease and an intrinsic resistance to any type of systemic therapy are hallmarks of aggressive solid cancers. The molecular basis for this phenotype is not clear. A detailed study of the somatic progression from local to early systemic esophageal cancer revealed rapid diversification of cancer cells isolated from various sites, but also evidence for early clonal expansion. These findings have implications for diagnostic pathology and therapeutic decision making. [Cancer Res 2009;69(13):5285–8]
Breast Cancer Lung Metastasis Requires Expression of Chemokine Receptor CCR4 and Regulatory T Cells
Authors: Olkhanud Purevdorj B. , Baatar Dolgor , Bodogai Monica , Hakim Fran , Gress Ronald , Anderson Robin L. , Deng Jie , Xu Mai , Briest Susanne , Biragyn Arya 
Published: July 2009

AbstractCancer metastasis is a leading cause of cancer morbidity and mortality. More needs to be learned about mechanisms that control this process. In particular, the role of chemokine receptors in metastasis remains controversial. Here, using a highly metastatic breast cancer (4T1) model, we show that lung metastasis is a feature of only a proportion of the tumor cells that express CCR4. Moreover, the primary tumor growing in mammary pads activates remotely the expression of TARC/CCL17 and MDC/CCL22 in the lungs. These chemokines acting through CCR4 attract both tumor and immune cells. However, CCR4-mediated chemotaxis was not sufficient to produce metastasis, as tumor cells in the lung were efficiently eliminated by natural killer (NK) cells. Lung metastasis required CCR4+ regulatory T cells (Treg), which directly killed NK cells using β-galactoside–binding protein. Thus, strategies that abrogate any part of this process should improve the outcome through activation of effector cells and prevention of tumor cell migration. We confirm this prediction by killing CCR4+ cells through delivery of TARC-fused toxins or depleting Tregs and preventing lung metastasis. [Cancer Res 2009;69(14):5996–6004]
The Liver Is a Site for Tumor-Induced Myeloid-Derived Suppressor Cell Accumulation and Immunosuppression
Authors: Ilkovitch Dan , Lopez Diana M. 
Published: July 2009

AbstractTumor-induced immunosuppression plays a key role in tumor evasion of the immune system. A key cell population recognized as myeloid-derived suppressor cells (MDSC) contributes and helps orchestrate this immunosuppression. MDSC can interact with T cells, macrophages, and natural killer cells to create an environment favorable for tumor progression. In various tumor models, their presence at high levels has been reported in the bone marrow, blood, spleen, and tumor. We report for the first time that MDSC accumulate and home to the liver in addition to the other organs. Liver MDSC suppress T cells and accumulate to levels comparable with splenic MDSC. Additionally, hematopoiesis in the liver contributes to the dramatic expansion of MDSC in this organ. Furthermore, MDSC in the liver interact with macrophages, also known as Kupffer cells, and cause their up-regulation of PD-L1, a negative T-cell costimulatory molecule. The liver is thus an organ in which MDSC accumulate and can contribute to immunosuppression directly and indirectly. MDSC play a role in various pathologic states in addition to cancer, and these results contribute to our understanding of their biology and interactions with immune-related cells. [Cancer Res 2009;69(13):5514–21]
Identification of Inhibitors of ABCG2 by a Bioluminescence Imaging–Based High-Throughput Assay
Authors: Zhang Yimao , Byun Youngjoo , Ren Yunzhao R. , Liu Jun O. , Laterra John , Pomper Martin G. 
Published: July 2009

Abstract
ABCG2 is a member of the ATP-binding cassette (ABC) family of transporters, the overexpression of which is associated with tumor resistance to a variety of chemotherapeutic agents. Accordingly, combining ABCG2 inhibitor(s) with chemotherapy has the potential to improve treatment outcome. To search for clinically useful ABCG2 inhibitors, a bioluminescence imaging (BLI)–based assay was developed to allow high-throughput compound screening. This assay exploits our finding that d-luciferin, the substrate of firefly luciferase (fLuc), is a specific substrate of ABCG2, and ABCG2 inhibitors block the export of d-luciferin and enhance bioluminescence signal by increasing intracellular d-luciferin concentrations. HEK293 cells, engineered to express ABCG2 and fLuc, were used to screen the Hopkins Drug Library that includes drugs approved by the Food and Drug Administration (FDA) as well as drug candidates that have entered phase II clinical trials. Forty-seven compounds showed BLI enhancement, a measure of anti-ABCG2 activity, of ≥5-fold, the majority of which were not previously known as ABCG2 inhibitors. The assay was validated by its identification of known ABCG2 inhibitors and by confirming previously unknown ABCG2 inhibitors using established in vitro assays (e.g., mitoxantrone resensitization and BODIPY-prazosin assays). Glafenine, a potent new inhibitor, also inhibited ABCG2 activity in vivo. The BLI-based assay is an efficient method to identify new inhibitors of ABCG2. As they were derived from a FDA-approved compound library, many of the inhibitors uncovered in this study are ready for clinical testing. [Cancer Res 2009;69(14):5867–75]
Depletion of Embryonic Stem Cell Signature by Histone Deacetylase Inhibitor in NCCIT Cells: Involvement of Nanog Suppression
Authors: You Jueng Soo , Kang Jae Ku , Seo Dong-Wan , Park Jae Hyun , Park Jong Woo , Lee Jae Cheol , Jeon Yae Jee , Cho Eun Jung , Han Jeung-Whan 
Published: July 2009

Abstract
The embryonic stem cell-like gene expression signature has been shown to be associated with poorly differentiated aggressive human tumors and has attracted great attention as a potential target for future cancer therapies. Here, we investigate the potential of the embryonic stem cell signature as molecular target for the therapy and the strategy to suppress the embryonic stem cell signature. The core stemness gene Nanog is abnormally overexpressed in human embryonic carcinoma NCCIT cells showing gene expression profiles similar to embryonic stem cells. Down-regulation of the gene by either small interfering RNAs targeting Nanog or histone deacetylase inhibitor apicidin causes reversion of expression pattern of embryonic stem cell signature including Oct4, Sox2, and their target genes, leading to cell cycle arrest, inhibition of colony formation in soft agar, and induction of differentiation into all three germ layers. These effects are antagonized by reintroduction of Nanog. Interestingly, embryonic carcinoma cells (NCCIT, NTERA2, and P19) exhibit a higher sensitivity to apicidin in down-regulation of Nanog compared with embryonic stem cells. Furthermore, the down-regulation of Nanog expression by apicidin is mediated by a coordinated change in recruitment of epigenetic modulators and transcription factors to the promoter region. These findings indicate that overexpression of stemness gene Nanog in NCCIT cells is associated with maintaining stem cell-like phenotype and suggest that targeting Nanog might be an approach for improved therapy of poorly differentiated tumors. [Cancer Res 2009;69(14):5716–25]
Cell Survival under Stress Is Enhanced by a Mitochondrial ATP-Binding Cassette Transporter That Regulates Hemoproteins
Authors: Lynch John , Fukuda Yu , Krishnamurthy Partha , Du Guoqing , Schuetz John D. 
Published: July 2009

AbstractThe ATP-binding cassette (ABC) transporter ABCB6 localizes to the mitochondria, where it imports porphyrins and up-regulates de novo porphyrin synthesis. If ABCB6 also increases the intracellular heme concentration, it may broadly affect the regulation and physiology of cellular hemoproteins. We tested whether the ability of ABCB6 to accelerate de novo porphyrin biosynthesis alters mitochondrial and extramitochondrial heme levels. ABCB6 overexpression increased the quantity of cytosolic heme but did not affect mitochondrial heme levels. We then tested whether the increased extramitochondrial heme would increase the concentration and/or activity of cellular hemoproteins (hemoglobin, catalase, and cytochrome c oxidase). ABCB6 overexpression increased the activity and quantity of hemoproteins found in several subcellular compartments, and reduction of ABCB6 function (by small interfering RNA or knockout) reversed these findings. In complementary studies, suppression of ABCB6 expression sensitized cells to stress induced by peroxide and cyanide, whereas overexpression of ABCB6 protected against both stressors. Our findings show that the ability of ABCB6 to increase cytosolic heme levels produces phenotypic changes in hemoproteins that protect cells from certain stresses. Collectively, these findings have implications for the health and survival of both normal and abnormal cells, which rely on heme for multiple cellular processes. [Cancer Res 2009;69(13):5560–7]
Negative Regulation of β4 Integrin Transcription by Homeodomain-Interacting Protein Kinase 2 and p53 Impairs Tumor Progression
Authors: Bon Giulia , Di Carlo Selene E. , Folgiero Valentina , Avetrani Paolo , Lazzari Chiara , D'Orazi Gabriella , Brizzi Maria Felice , Sacchi Ada , Soddu Silvia , Blandino Giovanni , Mottolese Marcella , Falcioni Rita 
Published: July 2009

Abstract
Increased expression of α6β4 integrin in several epithelial cancers promotes tumor progression; however, the mechanism underlying its transcriptional regulation remains unclear. Here, we show that depletion of homeodomain-interacting protein kinase 2 (HIPK2) activates β4 transcription that results in a strong increase of β4-dependent mitogen-activated protein kinase and Akt phosphorylation, anchorage-independent growth, and invasion. In contrast, stabilization of HIPK2 represses β4 expression in wild-type p53 (wtp53)-expressing cells but not in p53-null cells or cells expressing mutant p53, indicating that HIPK2 requires a wtp53 to inhibit β4 transcription. Consistent with our in vitro findings, a strong correlation between β4 overexpression and HIPK2 inactivation by cytoplasmic relocalization was observed in wtp53-expressing human breast carcinomas. Under loss of function of HIPK2 or p53, the p53 family members TAp63 and TAp73 strongly activate β4 transcription. These data, by revealing that β4 expression is transcriptionally repressed in tumors by HIPK2 and p53 to impair β4-dependent tumor progression, suggest that loss of p53 function favors the formation of coactivator complex with the TA members of the p53 family to allow β4 transcription. [Cancer Res 2009;69(14):5978–86]
The Inhibitor of Apoptosis Protein Livin (ML-IAP) Plays a Dual Role in Tumorigenicity
Authors: Abd-Elrahman Ihab , Hershko Klilah , Neuman Tzahi , Nachmias Boaz , Perlman Riki , Ben-Yehuda Dina 
Published: July 2009

AbstractThe inhibitor of apoptosis protein (IAP) family can inhibit apoptosis induced by a variety of stimuli. We and others previously described the IAP Livin (ML-IAP). We found that Livin is unique among the IAP members as, on a strong apoptotic stimulus, it is specifically cleaved by caspases to produce a truncated protein with paradoxical proapoptotic activity (tLivin). We also showed that Livin encodes two splicing variants, termed Livin α and β, with diverse antiapoptotic effects in vitro. In this study, we compared the Livin isoforms in vivo. An animal model was established and the effects of Livin α and β on the initiation and development of tumors were compared. In the animal model, Livin α promotes tumor initiation in comparison with control. Interestingly, the growth of tumors originating from cells expressing Livin β was inhibited. In these tumors, Livin β was cleaved and produced a high level of the proapoptotic tLivin β that repressed tumor development. When we eliminated the proapoptotic effect of Livin β by point mutations, the resulting antiapoptotic Livin β mutants contributed to tumor progression. In terms of mechanism, we show that Livin β tumors develop only in mice lacking natural killer (NK) cell activity. Thus, from the animal model, we can conclude that Livin plays a major role in tumorigenicity and that NK cells induce cleavage of Livin to its proapoptotic truncated protein that in turn inhibits tumor growth. Therefore, Livin and tLivin may serve as potential targets for cancer therapy. [Cancer Res 2009;69(13):5475–80]
Protein Kinase D Regulates Cell Migration by Direct Phosphorylation of the Cofilin Phosphatase Slingshot 1 Like
Authors: Peterburs Philipp , Heering Johanna , Link Gisela , Pfizenmaier Klaus , Olayioye Monilola A. , Hausser Angelika 
Published: July 2009

Abstract
Protein kinase D (PKD) has been identified as a negative regulator of epithelial cell migration; however, its molecular substrates and downstream signaling pathways that mediate this activity have remained elusive. In this study, we provide evidence that the cofilin phosphatase slingshot 1 like (SSH1L), an important regulator of the complex actin remodeling machinery, is a novel in vivo PKD substrate. PKD-mediated phosphorylation of serines 937 and 978 regulates SSH1L subcellular localization by binding of 14-3-3 proteins and thus impacts the control of local cofilin activation and actin remodeling during cell migration. In line with this, we show that the loss of PKD decreases cofilin phosphorylation, induces a more spread cell morphology, and stimulates chemotactic migration of breast cancer cells in an SSHL1-dependent fashion. Our data thus identify PKD as a central regulator of the cofilin signaling network via direct phosphorylation and regulation of SSH1L. [Cancer Res 2009;69(14):5634–8]
Development of Tumor-Reactive T Cells After Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplant for Chronic Lymphocytic Leukemia
Authors: Nishida Tetsuya , Hudecek Michael , Kostic Ana , Bleakley Marie , Warren Edus H. , Maloney David , Storb Rainer , Riddell Stanley R. 
Published: July 2009

Abstract
Purpose: Allogeneic nonmyeloablative hematopoietic stem cell transplant (NM-HSCT) can result in durable remission of chronic lymphocytic leukemia (CLL). It is thought that the efficacy of NM-HSCT is mediated by recognition of tumor cells by T cells in the donor stem cell graft. We evaluated the development of CTLs specific for CLL after NM-HSCT to determine if their presence correlated with antitumor efficacy.
Experimental Design: Peripheral blood mononuclear cells obtained from 12 transplant recipients at intervals after NM-HSCT were stimulated in vitro with CLL cells. Polyclonal T-cell lines and CD8+ T-cell clones were derived from these cultures and evaluated for lysis of donor and recipient target cells including CLL. The presence and specificity of responses was correlated with clinical outcomes.
Results: Eight of the 12 patients achieved remission or a major antitumor response and all 8 developed CD8+ and CD4+ T cells specific for antigens expressed by CLL. A clonal analysis of the CD8+ T-cell response identified T cells specific for multiple minor histocompatibility (H) antigens expressed on CLL in six of the responding patients. A significant fraction of the CD8+ T-cell response in some patients was also directed against nonshared tumor-specific antigens. By contrast, CLL-reactive T cells were not detected in the four patients who had persistent CLL after NM-HSCT, despite the development of graft-versus-host disease.
Conclusions: The development of a diverse T-cell response specific for minor H and tumor-associated antigens expressed by CLL predicts an effective graft-versus-leukemia response after NM-HSCT.
Id1 Is Down-Regulated by Hepatocyte Growth Factor via ERK-Dependent and ERK-Independent Signaling Pathways, Leading to Increased Expression of p16INK4a in Hepatoma Cells
Authors: Ushio Kazutaka , Hashimoto Tomio , Kitamura Naomi , Tanaka Toshiaki 
Published: July 2009

Abstract
Hepatocyte growth factor (HGF) inhibits the proliferation of several tumor cell lines and tumor growth in vivo. We showed previously that HGF induces cell cycle arrest at G1 in a human hepatoma cell line, HepG2, by up-regulating the expression of p16INK4a through strong activation of extracellular signal-regulated kinase (ERK). However, although essential, the activation was not sufficient for the up-regulation of p16. In this study, we examined regulatory mechanisms of p16 expression through a transcription factor, Ets, which has been shown previously to bind to the promoter. The treatment of HepG2 cells with HGF induced ERK-dependent phosphorylation of Ets, which leads to its activation, before the up-regulation of p16, suggesting that another factor suppresses Ets activity. We found that HGF reduces the amount of Id1, which is a dominant-negative inhibitor of Ets, leading to a decrease in Ets associated with Id1. Id1 was down-regulated via transcriptional regulation not via the ubiquitin-proteasome-mediated pathway. Inhibition of the HGF-induced high-intensity ERK activity had a modest effect on the Id1 down-regulation, and inhibition of the phosphatidylinositol 3-kinase pathway had no effect, showing that Id1 is regulated by ERK-dependent and -independent pathways other than the phosphatidylinositol 3-kinase pathway. Exogenously expressed Id1 suppressed the up-regulation of p16 by HGF and the antiproliferative effect of HGF. Knockdown of Id1 significantly enhanced the activity of the p16 promoter coordinately with the activation of ERK. Our results indicated that down-regulation of Id1 plays a key role in the inhibitory effect of HGF on cell proliferation and provides a molecular basis for cancer therapy with HGF. (Mol Cancer Res 2009;7(7):1179–88)
Adducin forms a bridge between the erythrocyte membrane and its cytoskeleton and regulates membrane cohesion
Authors: Anong William A. , Franco Taina , Chu Haiyan , Weis Tahlia L. , Devlin Emily E. , Bodine David M. , An Xiuli , Mohandas Narla , Low Philip S. 
Published: July 2009

AbstractThe erythrocyte membrane skeleton is the best understood cytoskeleton. Because its protein components have homologs in virtually all other cells, the membrane serves as a fundamental model of biologic membranes. Modern textbooks portray the membrane as a 2-dimensional spectrin-based membrane skeleton attached to a lipid bilayer through 2 linkages: band 3–ankyrin–β-spectrin and glycophorin C–protein 4.1–β-spectrin.1–7 Although evidence supports an essential role for the first bridge in regulating membrane cohesion, rupture of the glycophorin C–protein 4.1 interaction has little effect on membrane stability.8 We demonstrate the existence of a novel band 3–adducin–spectrin bridge that connects the spectrin/actin/protein 4.1 junctional complex to the bilayer. As rupture of this bridge leads to spontaneous membrane fragmentation, we conclude that the band 3–adducin–spectrin bridge is important to membrane stability. The required relocation of part of the band 3 population to the spectrin/actin junctional complex and its formation of a new bridge with adducin necessitates a significant revision of accepted models of the erythrocyte membrane.
Mitogen-activated protein kinases and NFκB are involved in SP-A-enhanced responses of macrophages to mycobacteria
Authors: Lopez Joseph P , Vigerust David J , Shepherd Virginia L 
Published: July 2009

AbstractBackgroundSurfactant protein A (SP-A) is a C-type lectin involved in surfactant homeostasis as well as host defense in the lung. We have recently demonstrated that SP-A enhances the killing of bacillus Calmette-Guerin (BCG) by rat macrophages through a nitric oxide-dependent pathway. In the current study we have investigated the role of tyrosine kinases and the downstream mitogen-activated protein kinase (MAPK) family, and the transcription factor NFκB in mediating the enhanced signaling in response to BCG in the presence of SP-A.MethodsHuman SP-A was prepared from alveolar proteinosis fluid, and primary macrophages were obtained by maturation of cells from whole rat bone marrow. BCG-SP-A complexes were routinely prepared by incubation of a ratio of 20 μg of SP-A to 5 × 105BCG for 30 min at 37°C. Cells were incubated with PBS, SP-A, BCG, or SP-A-BCG complexes for the times indicated. BCG killing was assessed using a 3H-uracil incorporation assay. Phosphorylated protein levels, enzyme assays, and secreted mediator assays were conducted using standard immunoblot and biochemical methods as outlined.ResultsInvolvement of tyrosine kinases was demonstrated by herbimycin A-mediated inhibition of the SP-A-enhanced nitric oxide production and BCG killing. Following infection of macrophages with BCG, the MAPK family members ERK1 and ERK2 were activated as evidence by increased tyrosine phosphorylation and enzymatic activity, and this activation was enhanced when the BCG were opsonized with SP-A. An inhibitor of upstream kinases required for ERK activation inhibited BCG- and SP-A-BCG-enhanced production of nitric oxide by approximately 35%. Macrophages isolated from transgenic mice expressing a NFκB-responsive luciferase gene showed increased luciferase activity following infection with BCG, and this activity was enhanced two-fold in the presence of SP-A. Finally, lactacystin, an inhibitor of IκB degradation, reduced BCG- and SP-A-BCG-induced nitric oxide production by 60% and 80% respectively.ConclusionThese results demonstrate that BCG and SP-A-BCG ingestion by macrophages is accompanied by activation of signaling pathways involving the MAP kinase pathway and NFκB.