bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis ofN-glycan in serum glycoproteins fromdb/dbmice and humans with type 2 diabetes
Authors: Itoh Naofumi , Sakaue Shinji , Nakagawa Hiroaki , Kurogochi Masaki , Ohira Hiroshi , Deguchi Kisaburo , Nishimura Shin-Ichiro , Nishimura Masaharu
Published: August 2007

Glycosylation has an important role in regulating properties of proteins and is associated with many diseases. To examine the alteration of serum N-glycans in type 2 diabetes, we used the db/db mouse model. Serum N-glycans were fluorescence labeled and applied to HPLC. There were reproducible differences in N-glycan profiles between the db/db mouse model and the db/+ control. The structures of the oligosaccharides, which had changed in their amounts, were analyzed by a two-dimensional mapping method, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, and exoglycosidase digestion. Those analyses revealed an increase in the N-glycans possessing α1,6-fucose in the serum of db/db mice. The level of α1,6-fucosyltransferase mRNA was increased in the liver of the db/db mice. The ratio of a biantennary N-glycan with α1,6-fucose to that without α1,6-fucose in the liver tissue of the db/db mouse was increased relative to the db/+ control. Next, we analyzed the serum N-glycan profile in human subjects with type 2 diabetes and found an increased amount of a biantennary N-glycan that had an α1,6-fucose with a bisecting N-acetylglucosamine. In conclusion, the increase in α1,6-fucosylation is a striking change in the serum N-glycans of the db/db mice, whereas the change in the fucosylation in humans with type 2 diabetes was small, albeit statistically significant. It is likely that the change is caused, at least partially, by the increase in the α1,6-fucosyltransferase mRNA level in the liver. The increased α1,6-fucosylation may affect protein properties associated with the pathophysiology of type 2 diabetes.
Hypoxia is a potential risk factor for chronic inflammation and adiponectin reduction in adipose tissue ofob/oband dietary obese mice
Authors: Ye Jianping , Gao Zhanguo , Yin Jun , He Qing
Published: August 2007

Chronic inflammation and reduced adiponectin are widely observed in the white adipose tissue in obesity. However, the cause of the changes remains to be identified. In this study, we provide experimental evidence that hypoxia occurs in adipose tissue in obese mice and that adipose hypoxia may contribute to the endocrine alterations. The adipose hypoxia was demonstrated by a reduction in the interstitial partial oxygen pressure (Po2), an increase in the hypoxia probe signal, and an elevation in expression of the hypoxia response genes in ob/ ob mice. The adipose hypoxia was confirmed in dietary obese mice by expression of hypoxia response genes. In the adipose tissue, hypoxia was associated with an increased expression of inflammatory genes and decreased expression of adiponectin. In dietary obese mice, reduction in body weight by calorie restriction was associated with an improvement of oxygenation and a reduction in inflammation. In cell culture, inflammatory cytokines were induced by hypoxia in primary adipocytes and primary macrophages of lean mice. The transcription factor NF-κB and the TNF-α gene promoter were activated by hypoxia in 3T3-L1 adipocytes and NIH3T3 fibroblasts. In addition, adiponectin expression was reduced by hypoxia, and the reduction was observed in the gene promoter in adipocytes. These data suggest a potential role of hypoxia in the induction of chronic inflammation and inhibition of adiponectin in the adipose tissue in obesity.
Mechanisms of Feature- and Space-Based Attention: Response Modulation and Baseline Increases
Authors: McMains Stephanie A. , Fehd Hilda M. , Emmanouil Tatiana-Aloi , Kastner Sabine
Published: August 2007

Selective attention modulates neural activity in the visual system both in the presence and in the absence of visual stimuli. When subjects direct attention to a particular location in a visual scene in anticipation of the stimulus onset, there is an increase in baseline activity. How do such baseline increases relate to the attentional modulation of stimulus-driven activity? Using functional magnetic resonance imaging, we demonstrate that baseline increases related to the expectation of motion or color stimuli at a peripheral target location do not predict the modulation of neural responses evoked by these stimuli when attended. In areas such as MT and TEO that were more effectively activated by one stimulus type than the other, attentional modulation of visually evoked activity depended on the stimulus preference of a visual area and was stronger for the effective than for the noneffective stimulus. In contrast, baseline increases did not reflect the stimulus preference of a visual area. Rather, these signals were shown to be spatially specific and appeared to be dominated by the location information and not by the feature information of the cue with the experimental paradigms under study. These findings provide evidence that baseline increases in visual cortex during cue periods do not reflect the activation of a memory template that includes particular stimulus properties of the expected target, but rather carry information about the location of an expected target stimulus. In addition, when the stimulus contained both color and motion, an object-based attention effect was observed, with significant attentional modulation in the area that responded preferentially to the unattended feature.
Effects of Stimulus Spectral Contrast on Receptive Fields of Dorsal Cochlear Nucleus Neurons
Authors: Reiss Lina A. J. , Bandyopadhyay Sharba , Young Eric D.
Published: August 2007

Neurons in the dorsal cochlear nucleus (DCN) exhibit strong nonlinearities in spectral processing. Low-order models that transform the stimulus spectrum into discharge rate using a combination of first- and second-order weighting of the spectrum (quadratic models) usually fail to predict responses to novel stimuli for principal neurons in the DCN, even though they work well in ventral cochlear nucleus. Here we investigate the effects of spectral contrast on the performance of such models. Typically, the models fail for stimuli with natural-sound–like spectral contrasts (∼12 dB), but have good prediction performance at small (3-dB) contrasts. The weights also typically increase substantially in amplitude at smaller spectral contrast. These changes in weight size with contrast are partly inherited from similar effects seen in auditory nerve fibers, but there must be additional effects from inhibitory circuits in the DCN. These results provide insight into the reasons for the poor performance of spectrotemporal receptive field (STRF) models in predicting responses of auditory neurons. Because the general shapes of the weights do not change between low and high contrast, they also suggest that STRFs may capture meaningful properties of neural receptive fields, even though they do not do well at predicting responses.
CXC Chemokine Receptor-4 Antagonist Blocks Both Growth of Primary Tumor and Metastasis of Head and Neck Cancer in Xenograft Mouse Models
Authors: Yoon Younghyoun , Liang Zhongxing , Zhang Xin , Choe Mison , Zhu Aizhi , Cho Heidi T. , Shin Dong M. , Goodman Mark M. , Chen Zhuo (Georgia) , Shim Hyunsuk
Published: August 2007

Squamous cell carcinoma of the head and neck (SCCHN) metastasizes to the lymph nodes and lungs. We have generated previously an orthotopic mouse model for head and neck metastasis and did in vivo selection of SCCHN cells through four rounds of serial metastases. A subpopulation of 686LN cells with high metastatic potential (686LN-Ms) was isolated. When the highly metastatic cells were compared with their low metastatic parental cells (686LN-Ps), we found that CXC chemokine receptor-4 (CXCR4) mRNA levels were significantly higher in the 686LN-Ms cells than the 686LN-Ps cells. Interestingly, the metastatic subclones had lost epithelial morphology and acquired mesenchymal features, which were maintained during cell expansion in vitro. This was featured by decreased E-cadherin and involucrin and increased vimentin and integrin β1. These results imply that CXCR4 and epithelial-mesenchymal transition markers can be potential biomarkers to identify the subpopulation of cells with high metastatic potential. Using the orthotopic SCCHN animal model, we showed that anti-CXCR4 treatment suppressed primary tumor growth by inhibiting tumor angiogenesis and prevented lung metastasis. Because the reduction of metastasis seen in the treated group could have resulted from 2-fold reduction in primary tumor size compared with that in the control group, we examined the effects of the CXCR4 antagonist in an experimental metastatic animal model in which 686LN-Ms cells were i.v. injected. 686LN-Ms cells failed to metastasize in the CXCR4 antagonist-treated group, whereas they metastasized to the lungs in the control group. Our data indicate that CXCR4 is an important target to inhibit tumor progression in SCCHN. [Cancer Res 2007;67(15):7518–23]
Protection of Zinc against Tumor Necrosis Factor–Induced Lethal Inflammation Depends on Heat Shock Protein 70 and Allows Safe Antitumor Therapy
Authors: Van Molle Wim , Van Roy Maarten , Van Bogaert Tom , Dejager Lien , Van Lint Philippe , Vanlaere Ineke , Sekikawa Kenji , Kollias George , Libert Claude
Published: August 2007

Tumor necrosis factor (TNF)–induced inflammation prevents its broad application as an antitumor agent. We here report that addition of ZnSO4 to the drinking water of mice induces expression of heat shock protein 70 (HSP70) in several organs, notably the gastrointestinal track. Zinc conferred dose-responsive protection against TNF-induced hypothermia, systemic induction of interleukin-6 and NOx, as well as against TNF-induced bowel cell death and death of the organism. The protective effect of zinc was completely absent in mice deficient in the major HSP70-inducible gene, hsp70.1, whereas transgenic mice constitutively expressing the human HSP70.A gene, under control of a β-actin promoter, was also protected against TNF, indicating that an increase in HSP70 is necessary and sufficient to confer protection. The therapeutic potential of the protection induced by ZnSO4 was clearly shown in a TNF/IFNγ–based antitumor therapy using three different tumor models. In hsp70.1 wild-type mice, but not in hsp70.1-deficient mice, zinc very significantly protected against lethality but left the antitumor effect intact. We conclude that zinc protects against TNF in a HSP70-dependent way and that protection by zinc could be helpful in developing a safer anticancer therapy with TNF/IFNγ. [Cancer Res 2007;67(15):7301–7]
Exposure to the Tobacco Smoke Constituent 4-Aminobiphenyl Induces Chromosomal Instability in Human Cancer Cells
Authors: Saletta Federica , Matullo Giuseppe , Manuguerra Maurizio , Arena Sabrina , Bardelli Alberto , Vineis Paolo
Published: August 2007

The relationships between environmental factors and the genetic abnormalities that drive carcinogenesis are supported by experimental and epidemiologic evidence but their molecular basis has not been fully elucidated. At the genomic level, most human cancers display either chromosomal (CIN) or microsatellite (MIN) instability. The molecular mechanisms through which normal cells acquire these forms of instability are largely unknown. The arylamine 4-aminobiphenyl (4-ABP) is a tobacco smoke constituent, an environmental contaminant, and a well-established carcinogen in humans. Among others, bladder, lung, colon, and breast cancers have been associated with 4-ABP. We have investigated the effects of 4-ABP and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on genetically stable colorectal (HCT116) and bladder (RT112) cancer cells. Cells were treated with carcinogens to generate resistant clones that were then subjected to genetic analysis to assess whether they displayed either CIN or MIN. We found that 50% to 60% of cells treated with 4-ABP developed CIN but none developed MIN as confirmed by their ability to gain and lose chromosomes. In contrast, all MNNG-treated clones (12/12) developed MIN but none developed CIN as shown by the microsatellite assay. The mismatch repair protein expression analysis suggests that the acquired mechanism of MIN resistance in the HCT116 MNNG-treated cells is associated with the reduction or the complete loss of MLH1 expression. By providing a mechanistic link between exposure to a tobacco constituent and the development of CIN, our results contribute to a better understanding of the origins of genetic instability, one of the remaining unsolved problems in cancer research. [Cancer Res 2007;67(15):7088–94]
Promoter Hypermethylation Contributes to Frequent Inactivation of a Putative Conditional Tumor Suppressor Gene Connective Tissue Growth Factor in Ovarian Cancer
Authors: Kikuchi Ryoko , Tsuda Hitoshi , Kanai Yae , Kasamatsu Takahiro , Sengoku Kazuo , Hirohashi Setsuo , Inazawa Johji , Imoto Issei
Published: August 2007

Connective tissue growth factor (CTGF) is a secreted protein belonging to the CCN family, members of which are implicated in various biological processes. We identified a homozygous loss of CTGF (6q23.2) in the course of screening a panel of ovarian cancer cell lines for genomic copy number aberrations using in-house array-based comparative genomic hybridization. CTGF mRNA expression was observed in normal ovarian tissue and immortalized ovarian epithelial cells but was reduced in many ovarian cancer cell lines without its homozygous deletion (12 of 23 lines) and restored after treatment with 5-aza 2′-deoxycytidine. The methylation status around the CTGF CpG island correlated inversely with the expression, and a putative target region for methylation showed promoter activity. CTGF methylation was frequently observed in primary ovarian cancer tissues (39 of 66, 59%) and inversely correlated with CTGF mRNA expression. In an immunohistochemical analysis of primary ovarian cancers, CTGF protein expression was frequently reduced (84 of 103 cases, 82%). Ovarian cancer tended to lack CTGF expression more frequently in the earlier stages (stages I and II) than the advanced stages (stages III and IV). CTGF protein was also differentially expressed among histologic subtypes. Exogenous restoration of CTGF expression or treatment with recombinant CTGF inhibited the growth of ovarian cancer cells lacking its expression, whereas knockdown of endogenous CTGF accelerated growth of ovarian cancer cells with expression of this gene. These results suggest that epigenetic silencing by hypermethylation of the CTGF promoter leads to a loss of CTGF function, which may be a factor in the carcinogenesis of ovarian cancer in a stage-dependent and/or histologic subtype-dependent manner. [Cancer Res 2007;67(15):7095–105]
Oncogenic Activity of Epidermal Growth Factor Receptor Kinase Mutant Alleles Is Enhanced by the T790M Drug Resistance Mutation
Authors: Godin-Heymann Nadia , Bryant Ianthe , Rivera Miguel N. , Ulkus Lindsey , Bell Daphne W. , Riese David J. , Settleman Jeffrey , Haber Daniel A.
Published: August 2007

Activating mutations in the epidermal growth factor receptor (EGFR) characterize a subset of non–small cell lung cancers (NSCLC) with extraordinary sensitivity to targeted tyrosine kinase inhibitors (TKI). A single secondary EGFR mutation, T790M, arising in cis with the primary activating mutation, confers acquired resistance to these drugs. However, the T790M mutation is also detected in the absence of drug selection, suggesting that it may provide a growth advantage. We show here that although T790M alone has only a modest effect on EGFR function, when combined with the characteristic activating mutations L858R or del746–750, it results in a dramatic enhancement of EGFR activity. The double mutants show potent ligand-independent receptor autophosphorylation associated with altered cellular phenotypes, soft agar colony formation, and tumorigenesis in nude mice. The significant gain-of-function properties of these double mutants may explain their initial presence before drug selection and their rapid selection as the single drug resistance mutation during therapy with gefitinib/erlotinib, and suggests that they may contribute to the adverse clinical course of TKI-resistant NSCLC. [Cancer Res 2007;67(15):7319–26]
A Combination of Chemoimmunotherapies Can Efficiently Break Self-Tolerance and Induce Antitumor Immunity in a Tolerogenic Murine Tumor Model
Authors: Ko Hyun-Jeong , Kim Yeon-Jeong , Kim Yun-Sun , Chang Woo-Sung , Ko Sung-Youl , Chang Sun-Young , Sakaguchi Shimon , Kang Chang-Yuil
Published: August 2007

Her-2/neu is a well-characterized tumor-associated antigen overexpressed in human carcinomas such as breast cancer. Because Her-2/neu is a self-antigen with poor immunogenicity due to immunologic tolerance, active immunotherapy targeting Her-2/neu should incorporate methods to overcome immunologic tolerance to self-proteins. In this study, we developed a tolerogenic tumor model in mice using mouse Her-2/neu as self-antigen and investigated whether genetic vaccination with DNA plasmid and/or adenoviral vector expressing the extracellular and transmembrane domain of syngeneic mouse Her-2/neu or xenogenic human Her-2/neu could induce mouse Her-2/neu–specific CTL responses. Interestingly, adenoviral vectors expressing xenogenic human Her-2/neu (AdhHM) proved capable of breaking immune tolerance and of thereby inducing self-reactive CTL and antibodies, but not to the degree required to induce therapeutic antitumor immunity. In attempting to generate therapeutic antitumor immunity against established tumors, we adopted several approaches. Treatment with agonistic anti-glucocorticoid-induced TNFR family-related receptor (GITR) antibody plus AdhHM immunization significantly increased self-reactive CTL responses, and α-galactosylceramide (αGalCer)–loaded dendritic cells (DC) transduced with AdhHM were shown to break self-tolerance in a tolerogenic murine tumor model. Furthermore, gemcitabine treatment together with either AdhHM plus agonistic anti-GITR antibody administration or αGalCer-loaded DC transduced with AdhHM showed potent therapeutic antitumor immunity and perfect protection against preexisting tumors. Gemcitabine treatment attenuated the tumor-suppressive environment by eliminating CD11b+/Gr-1+ myeloid-derived suppressor cells. When combined with immunotherapies, gemcitabine offers a promising strategy for the Ag-specific treatment of human cancer. [Cancer Res 2007;67(15):7477–86]
Targeting Human γδ T Cells with Zoledronate and Interleukin-2 for Immunotherapy of Hormone-Refractory Prostate Cancer
Authors: Dieli Francesco , Vermijlen David , Fulfaro Fabio , Caccamo Nadia , Meraviglia Serena , Cicero Giuseppe , Roberts Andrew , Buccheri Simona , D'Asaro Matilde , Gebbia Nicola , Salerno Alfredo , Eberl Matthias , Hayday Adrian C.
Published: August 2007

The increasing evidence that γδ T cells have potent antitumor activity suggests their value in immunotherapy, particularly in areas of unmet need such as metastatic carcinoma. To this end, we initiated a phase I clinical trial in metastatic hormone-refractory prostate cancer to examine the feasibility and consequences of using the γδ T-cell agonist zoledronate, either alone or in combination with low-dose interleukin 2 (IL-2), to activate peripheral blood γδ cells. Nine patients were enlisted to each arm. Neither treatment showed appreciable toxicity. Most patients were treated with zoledronate + IL-2, but conversely only two treated with zoledronate displayed a significant long-term shift of peripheral γδ cells toward an activated effector-memory–like state (TEM), producing IFN-γ and perforin. These patients also maintained serum levels of tumor necrosis factor–related apoptosis inducing ligand (TRAIL), consistent with a parallel microarray analysis showing that TRAIL is produced by γδ cells activated via the T-cell receptor and IL-2. Moreover, the numbers of TEM γδ cells showed a statistically significant correlation with declining prostate-specific antigen levels and objective clinical outcomes that comprised three instances of partial remission and five of stable disease. By contrast, most patients treated only with zoledronate failed to sustain either γδ cell numbers or serum TRAIL, and showed progressive clinical deterioration. Thus, zoledronate + IL-2 represents a novel, safe, and feasible approach to induce immunologic and clinical responses in patients with metastatic carcinomas, potentially providing a substantially increased window for specific approaches to be administered. Moreover, γδ cell phenotypes and possibly serum TRAIL may constitute novel biomarkers of prognosis upon therapy with zoledronate + IL-2 in metastatic carcinoma. [Cancer Res 2007;67(15):7450–7]
BRCA1- and BRCA2-Deficient Cells Are Sensitive to Etoposide-Induced DNA Double-Strand Breaks via Topoisomerase II
Authors: Treszezamsky Alejandro D. , Kachnic Lisa A. , Feng Zhihui , Zhang Junran , Tokadjian Chake , Powell Simon N.
Published: August 2007

The function of BRCA1 and BRCA2 in DNA repair could affect the sensitivity of cells to cytotoxic agents, and would therefore be an important component of planning therapy for breast and ovarian cancers. Previously, both BRCA1- and BRCA2-deficient tumors were shown to be sensitive to mitomycin C, and the mechanism was presumed to be a defect in the repair of interstrand crosslinks by homologous recombination. Here, we show that both BRCA1 and BRCA2 determine the sensitivity to the cytotoxic drug, etoposide, using genetic complementation of BRCA-deficient cells. Etoposide is known to bind to topoisomerase II and prevent the resolution of the “cleavable complex,” in which one DNA duplex is passed through a second duplex. The specificity of this BRCA-dependent sensitivity was confirmed by the use of aclarubicin, which is a catalytic inhibitor of topoisomerase II and prevents the formation of the cleavable complex. In the presence of aclarubicin, the differential sensitivity of BRCA-proficient and BRCA-deficient cells was lost. Thus, etoposide requires the presence of topoisomerase II to show specific sensitization in the absence of the function of BRCA1 or BRCA2. We conclude that homologous recombination is used in the repair of DNA damage caused by topoisomerase II poisons. Overall, these results suggest that etoposide is a potentially useful drug in the treatment of BRCA-deficient human cancers. [Cancer Res 2007;67(15):7078–81]
IFN-β Signaling Positively Regulates Tumorigenesis in Aggressive Fibromatosis, Potentially by Modulating Mesenchymal Progenitors
Authors: Tjandra Sean S. , Hsu Claire , Goh Ingrid , Gurung Ananta , Poon Raymond , Nadesan Puviindran , Alman Benjamin A.
Published: August 2007

Aggressive fibromatosis (also called desmoid tumor) is a benign, locally invasive, soft tissue tumor composed of cells with mesenchymal characteristics. These tumors are characterized by increased levels of β-catenin–mediated T-cell factor (TCF)–dependent transcriptional activation. We found that type 1 IFN signaling is activated in human and murine aggressive fibromatosis tumors and that the expression of associated response genes is regulated by β-catenin. When mice deficient for the type 1 IFN receptor (Ifnar1−/−) were crossed with mice predisposed to developing aggressive fibromatosis tumors (Apc/Apc1638N), a significant decrease in aggressive fibromatosis tumor formation was observed compared with littermate controls, showing a novel role for type 1 IFN signaling in promoting tumor formation. Type 1 IFN activation inhibits cell proliferation but does not alter cell apoptosis or the level of β-catenin–mediated TCF-dependent transcriptional activation in aggressive fibromatosis cell cultures. Thus, these changes cannot explain our in vivo results. Intriguingly, Ifnar1−/− mice have smaller numbers of mesenchymal progenitor cells compared with littermate controls, and treatment of aggressive fibromatosis cell cultures with IFN increases the proportion of cells that exclude Hoechst dye and sort to the side population, raising the possibility that type 1 IFN signaling regulates the number of precursor cells present that drive aggressive fibromatosis tumor formation and maintenance. This study identified a novel role for IFN type 1 signaling as a positive regulator of neoplasia and suggests that IFN treatment is a less than optimal therapy for this tumor type. [Cancer Res 2007;67(15):7124–31]
Silencing of FLRG, an Antagonist of Activin, Inhibits Human Breast Tumor Cell Growth
Authors: Razanajaona Diane , Joguet Stéphanie , Ay Anne-Sophie , Treilleux Isabelle , Goddard-Léon Sophie , Bartholin Laurent , Rimokh Ruth
Published: August 2007

Activin, a member of the transforming growth factor β (TGFβ) superfamily, regulates diverse processes, such as cellular growth and differentiation. There is increasing evidence that TGFβ and its signaling effectors are key determinants of tumor cell behavior. Loss of sensitivity to TGFβ-induced growth arrest is an important step toward malignancy. We previously characterized FLRG as an extracellular antagonist of activin. Here, we show that activin-induced growth inhibition is altered in FLRG-expressing breast cancer lines. Silencing FLRG induced growth inhibition, which is reversible upon addition of exogenous FLRG. We showed that FLRG silencing effects resulted from restoration of endogenous activin functions as shown by increased levels of phosphorylated smad2 and up-regulation of activin target gene transcripts. Furthermore, the growth inhibition induced by FLRG silencing was reversible by treatment with a soluble form of type II activin receptor. Finally, a strong expression of FLRG was observed in invasive breast carcinomas in contrast with the normal luminal epithelial cells in which FLRG was not detected. Our data provide strong evidence that endogenous FLRG contributes to tumor cell proliferation through antagonizing endogenous activin effects. [Cancer Res 2007;67(15):7223–9]
Antiangiogenic Strategies on Defense: On the Possibility of Blocking Rebounds by the Tumor Vasculature after Chemotherapy
Authors: Shaked Yuval , Kerbel Robert S.
Published: August 2007

Rapid or accelerated tumor cell repopulation after significant tumor cell killing induced by various cytotoxic agents often compromises the expected therapeutic benefit of such tumor responses. Here, we discuss the concept that tumor cell repopulation after certain cytotoxic therapies, using vascular disrupting agents as an example, may be aided by a reactive, systemic host response involving the mobilization of bone marrow–derived circulating cells, including endothelial progenitor cells, which subsequently home to the vasculature of treated tumors and promote tumor neovascularization. These vasculogenic “rebounds” can be blocked, at least in some cases, by treatment with an antiangiogenic drug. There is limited preliminary evidence that maximum tolerated dose chemotherapy causes a similar effect. This could constitute one way by which antiangiogenic therapy could increase the efficacy of conventional cytotoxic chemotherapy regimens; it also raises the specter of new molecular targets for systemic cancer therapies which are involved in therapy-induced bone marrow–derived cell mobilization, homing to tumors, and tumor retention. [Cancer Res 2007;67(15):7055–8]
Nm23-H1 Suppresses Tumor Cell Motility by Down-regulating the Lysophosphatidic Acid Receptor EDG2
Authors: Horak Christine E. , Lee Jong Heun , Elkahloun Abdel G. , Boissan Mathieu , Dumont Sylvie , Maga Tara K. , Arnaud-Dabernat Sandrine , Palmieri Diane , Stetler-Stevenson William G. , Lacombe Marie-Lise , Meltzer Paul S. , Steeg Patricia S.
Published: August 2007

Exogenous overexpression of the metastasis suppressor gene Nm23-H1 reduces the metastatic potential of multiple types of cancer cells and suppresses in vitro tumor cell motility and invasion. Mutational analysis of Nm23-H1 revealed that substitution mutants P96S and S120G did not inhibit motility and invasion. To elucidate the molecular mechanism of Nm23-H1 motility suppression, expression microarray analysis of an MDA-MB-435 cancer cell line overexpressing wild-type Nm23-H1 was done and cross-compared with expression profiles from lines expressing the P96S and S120G mutants. Nine genes, MET, PTN, SMO, FZD1, L1CAM, MMP2, NETO2, CTGF, and EDG2, were down-regulated by wild-type but not by mutant Nm23-H1 expression. Reduced expression of these genes coincident with elevated Nm23-H1 expression was observed in human breast tumor cohorts, a panel of breast carcinoma cell lines, and hepatocellular carcinomas from control versus Nm23-M1 knockout mice. The functional significance of the down-regulated genes was assessed by transfection and in vitro motility assays. Only EDG2 overexpression significantly restored motility to Nm23-H1–suppressed cancer cells, enhancing motility by 60-fold in these cells. In addition, silencing EDG2 expression with small interfering RNA reduced the motile phenotype of metastatic breast cancer cells. These data suggest that Nm23-H1 suppresses metastasis, at least in part, through down-regulation of EDG2 expression. [Cancer Res 2007;67(15):7238–46]
Statin-Induced Breast Cancer Cell Death: Role of Inducible Nitric Oxide and Arginase-Dependent Pathways
Authors: Kotamraju Srigiridhar , Willams Carol L. , Kalyanaraman Balaraman
Published: August 2007

Statins are widely used cholesterol-lowering drugs that selectively inhibit the enzyme 3-hydroxy-3-methylglutaryl CoA reductase, leading to decreased cholesterol biosynthesis. Emerging data indicate that statins stimulate apoptotic cell death in several types of proliferating tumor cells, including breast cancer cells, which is independent of its cholesterol-lowering property. The objective here was to elucidate the molecular mechanism(s) by which statins induce breast cancer cell death. Fluvastatin and simvastatin (5–10 μmol/L) treatment enhanced the caspase-3–like activity and DNA fragmentation in MCF-7 cells, and significantly inhibited the proliferation of MCF-7 cells but not MCF-10 cells (noncancerous epithelial cells). Statin-induced cytotoxic effects were reversed by mevalonate, an immediate metabolic product of the acetyl CoA/3-hydroxy-3-methylglutaryl CoA reductase reaction. Both simvastatin and fluvastatin enhanced nitric oxide (·NO) levels which were inhibited by mevalonate. Statin-induced ·NO and tumor cell cytotoxicity were inhibited by 1400W, a more specific inhibitor of inducible nitric oxide synthase (iNOS or NOS II). Both fluvastatin and simvastatin increased iNOS mRNA and protein expression. Stimulation of iNOS by statins via inhibition of geranylgeranylation by GGTI-298, but not via inhibition of farnesylation by FTI-277, enhanced the proapoptotic effects of statins in MCF-7 cells. Statin-mediated antiproliferative and proapoptotic effects were exacerbated by sepiapterin, a precursor of tetrahydrobiopterin, an essential cofactor of ·NO biosynthesis by NOS. We conclude that iNOS-mediated ·NO is responsible in part for the proapoptotic, tumoricidal, and antiproliferative effects of statins in MCF-7 cells. [Cancer Res 2007;67(15):7386–94]
Novel Tryptophan Catabolic Enzyme IDO2 Is the Preferred Biochemical Target of the Antitumor Indoleamine 2,3-Dioxygenase Inhibitory Compound d-1-Methyl-Tryptophan
Authors: Metz Richard , DuHadaway James B. , Kamasani Uma , Laury-Kleintop Lisa , Muller Alexander J. , Prendergast George C.
Published: August 2007

Small-molecule inhibitors of indoleamine 2,3-dioxygenase (IDO) are currently being translated to clinic for evaluation as cancer therapeutics. One issue related to trials of the clinical lead inhibitor, d-1-methyl-tryptophan (D-1MT), concerns the extent of its biochemical specificity for IDO. Here, we report the discovery of a novel IDO-related tryptophan catabolic enzyme termed IDO2 that is preferentially inhibited by D-1MT. IDO2 is not as widely expressed as IDO but like its relative is also expressed in antigen-presenting dendritic cells where tryptophan catabolism drives immune tolerance. We identified two common genetic polymorphisms in the human gene encoding IDO2 that ablate its enzymatic activity. Like IDO, IDO2 catabolizes tryptophan, triggers phosphorylation of the translation initiation factor eIF2α, and (reported here for the first time) mobilizes translation of LIP, an inhibitory isoform of the immune regulatory transcription factor NF-IL6. Tryptophan restoration switches off this signaling pathway when activated by IDO, but not IDO2, arguing that IDO2 has a distinct signaling role. Our findings have implications for understanding the evolution of tumoral immune tolerance and for interpreting preclinical and clinical responses to D-1MT or other IDO inhibitors being developed to treat cancer, chronic infection, and other diseases. [Cancer Res 2007;67(15):7082–7]
Phase 1 Study of Lumiliximab with Detailed Pharmacokinetic and Pharmacodynamic Measurements in Patients with Relapsed or Refractory Chronic Lymphocytic Leukemia
Authors: Byrd John C. , O'Brien Susan , Flinn Ian W. , Kipps Thomas J. , Weiss Mark , Rai Kanti , Lin Thomas S. , Woodworth James , Wynne Dee , Reid Jennifer , Molina Arturo , Leigh Bryan , Harris Sarah
Published: August 2007

Purpose: Therapeutic antibodies have improved the outcome for patients with chronic lymphocytic leukemia (CLL). We conducted a phase 1, dose escalation and schedule optimization study of the primatized anti-CD23 antibody, lumiliximab, in patients with previously treated and refractory CLL.

Experimental Design: Forty-six patients were assigned sequentially to cohorts 1 through 6 and received lumiliximab at 125, 250, or 375 mg/m2 weekly for 4 weeks; 500 mg/m2 weekly for 4 weeks [500(A)]; 500 mg/m2 thrice during week 1 then 500 mg/m2 weekly for the next 3 weeks [500(B)]; or 500 mg/m2 thrice a week for 4 weeks [500(C)], respectively.

Results: The median age was 62 years (range, 47-80), and the median number of prior regimens was four (range, 1-13). No partial or complete responses were observed. Toxicity was limited and unrelated to dose. The pharmacokinetics of lumiliximab was similar to other IgG1 monoclonal antibodies with accumulation at doses ≥250 mg/m2 and a median terminal half-life of 7 days. Pharmacodynamic studies showed dose-dependent increases in soluble CD23, but no down-regulation of CD23 antigen. Saturation of CD23 receptors occurred at 250 mg/m2 and was maintained for ≥1 week following completion of therapy at ≥375 mg/m2.

Conclusions: Treatment with lumiliximab seemed to be well tolerated and to have clinical activity in patients with relapsed or refractory CLL.
The Tyrosine Kinase Inhibitor, AZD2171, Inhibits Vascular Endothelial Growth Factor Receptor Signaling and Growth of Anaplastic Thyroid Cancer in an Orthotopic Nude Mouse Model
Authors: Gomez-Rivera Fernando , Santillan-Gomez Alfredo A. , Younes Maher N. , Kim Seungwon , Fooshee David , Zhao Mei , Jasser Samar A. , Myers Jeffrey N.
Published: August 2007

Purpose: Anaplastic thyroid cancer (ATC) is a locally aggressive type of thyroid tumor with high rate of distant metastases. With conventional treatment, the median survival ranges from 4 to 12 months; therefore, new treatment options are needed. AZD2171 is a tyrosine kinase inhibitor of the vascular endothelial growth factor receptors (VEGFR) VEGFR-1, VEGFR-2, and VEGFR-3. The objective of the study is to determine whether AZD2171 can inhibit VEGFR-2 signaling and decrease tumor growth and prolong survival of ATC in an orthotopic nude mouse model.

Experimental Design: We examined the effects of AZD2171 on phosphorylation of VEGFR-2, mitogen-activated protein kinase, and AKT in human umbilical vascular endothelial cells. To determine the antiproliferative and antiapoptotic effects of AZD2171, we did 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays, respectively. We assessed the antitumor effects of AZD2171 in a xenograft model of ATC using control, AZD2171, paclitaxel, and combination groups by measuring tumor size and survival.

Results: Treatment with AZD2171 led to dose-dependent inhibition of VEGFR-2 phosphorylation and its downstream signaling in human umbilical vascular endothelial cells (IC50 for cell proliferation, 500 nmol/L). In the ATC cell lines DRO and ARO, IC50 was 7.5 μmol/L. AZD2171 induced apoptosis in 50% of endothelial and ATC cells at 3 and 10 μmol/L concentrations, respectively. In vivo, AZD2171 led to a significant reduction in tumor size between control and AZD2171 (P = 0.002) or AZD2171 + paclitaxel group (P = 0.002) but not the paclitaxel alone group (P = 0.11). Survival was significantly higher among AZD2171 (P < 0.001) and combination groups (P < 0.001) compared with control.

Conclusions: AZD2171 effectively inhibits tumor growth and prolongs survival of ATC-bearing mice. The main effect of AZD2171 is mediated through angiogenesis inhibition.
Frequent Inactivation of RAMP2, EFEMP1 and Dutt1 in Lung Cancer by Promoter Hypermethylation
Authors: Yue Wen , Dacic Sanja , Sun Quanhong , Landreneau Rodney , Guo Mingzhou , Zhou Wei , Siegfried Jill M. , Yu Jian , Zhang Lin
Published: August 2007

Purpose: The goal of this study is to identify novel genes frequently silenced by promoter hypermethylation in lung cancer.

Experimental Designs: Bioinformatic analysis was done to identify candidate genes significantly down-regulated in lung cancer. The effects of DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine on the expression of the candidate genes were determined. Methylated CpG sites in the promoters of the candidate genes were identified using bisulfite DNA sequencing. Methylation-specific PCR was developed and used to analyze DNA methylation in cell lines and clinical specimen. Pathologic and functional analyses were done to study the role of one candidate gene, receptor activity-modifying protein 2 (RAMP2), in suppressing lung cancer cell growth.

Results: Among 54 candidate genes down-regulated in lung cancer, 31 were found to contain CpG islands in their promoters. Six of these 31 genes could be reactivated by 5-aza-2′-deoxycytidine in at least four of six lung cancer cell lines analyzed. Promoter hypermethylation of RAMP2, epidermal growth factor–containing fibulin-like extracellular matrix protein 1, and deleted in U Twenty Twenty cells was detected in 36% to 77% of 22 lung cancer cell lines and in 38% to 50% of 32 primary lung tumors, whereas hypermethylathion of these genes was rarely found in the matched normal samples. The methylation frequencies of these genes in lung cancer were similar to those of commonly used methylation markers, such as RAS association domain family protein 1A, p16, and methylguanine-DNA methyltransferase. Immunohistochemistry showed that RAMP2 was down-regulated in a majority of lung tumors, and RAMP2 down-regulation was correlated with high tumor grade. Ectopic expression of RAMP2 inhibited lung cancer cell growth and caused apoptotic cell death. Knockdown of RAMP2 by RNA interference stimulated cell proliferation.

Conclusions: Studying the newly identified genes may provide new insight into lung tumorigenesis. These genes might be useful as molecular markers of lung cancer.
FOXA1 Expression in Breast Cancer—Correlation with Luminal Subtype A and Survival
Authors: Badve Sunil , Turbin Dmitry , Thorat Mangesh A. , Morimiya Akira , Nielsen Torsten O. , Perou Charles M. , Dunn Sandi , Huntsman David G. , Nakshatri Harikrishna
Published: August 2007

Purpose: FOXA1, a forkhead family transcription factor, is essential for optimum expression of ∼50% of estrogen receptor α (ERα):estrogen responsive genes. FOXA1 is expressed in breast cancer cells. It segregates with genes that characterize the luminal subtypes in DNA microarray analyses. The utility of FOXA1 as a possible independent prognostic factor has not been determined in breast cancers.

Materials and Methods: A tissue microarray comprising tumors from 438 patients with 15.4 years median follow-up was analyzed for FOXA1 expression by immunohistochemistry. Interpretable FOXA1 expression obtained in 404 patients was analyzed along with other prognostic factors like tumor grade, size, nodal status, ER, progesterone receptor (PR), and HER2/neu.

Results: FOXA1 expression (score >3) was seen in 300 of 404 breast cancers and it correlated with ER (P = 0.000001), PR (P = 0.00001), and luminal A subtype (P = 0.000001). Loss of expression was noted with worsening tumor grade (P = 0.001). Univariate analysis showed nodal status (P = 0.0000012), tumor size (P = 0.00001), FOXA1 (P = 0.0004), and ER (P = 0.012) to be predictors of breast cancer–specific survival. Multivariate analysis showed only nodal status (P = 0.001) and tumor size (P = 0.039) to be significant prognostic factors, whereas FOXA1 (P = 0.060) and ER (P = 0.131) were not significant. In luminal subtype A patient subgroup, FOXA1 expression was associated with better cancer-specific survival (P = 0.024) and in ER-positive subgroup, it was better predictor of cancer-specific survival (P = 0.009) than PR (P = 0.213).

Conclusion: FOXA1 expression correlates with luminal subtype A breast cancer and it is significant predictor of cancer-specific survival in patients with ER-positive tumors. Prognostic ability of FOXA1 in these low-risk breast cancers may prove to be useful in clinical treatment decisions.
L-BLP25: A Peptide Vaccine Strategy in Non–Small Cell Lung Cancer
Authors: Sangha Randeep , Butts Charles
Published: August 2007

MUC1 is a mucinous glycoprotein which is overexpressed and under or aberrantly glycosylated in many human malignancies. MUC1 is associated with cellular transformation and can confer resistance to genotoxic agents. L-BLP25 is a peptide vaccine strategy that targets the exposed core peptide of MUC1. In preclinical studies, L-BLP25 induced a cellular immune response characterized by T-cell proliferation in response to MUC1 and production of IFN-γ. Phase I and II trials have established the dose and schedule of the vaccine as well as its excellent safety profile. A randomized phase II trial of maintenance L-BLP25 versus best supportive care in patients with stage IIIB/IV non–small cell lung cancer who experienced clinical benefit from initial therapy has been reported. Updated survival analysis of this trial continues to show a strong survival trend in favor of L-BLP25 (median survival, 30.6 versus 13.3 months) in a subgroup of patients with locoregional stage IIIB disease. These promising results will be tested in a phase III trial of L-BLP25 versus placebo in patients with stage III non–small cell lung cancer after response to primary chemoradiotherapy.
Corruption of the Fas Pathway Delays the Pulmonary Clearance of Murine Osteosarcoma Cells, Enhances Their Metastatic Potential, and Reduces the Effect of Aerosol Gemcitabine
Authors: Gordon Nancy , Koshkina Nadezhda V. , Jia Shu-Fang , Khanna Chand , Mendoza Arnulfo , Worth Laura L. , Kleinerman Eugenie S.
Published: August 2007

Purpose: Pulmonary metastases continue to be a significant problem in osteosarcoma. Apoptosis dysfunction is known to influence tumor development. Fas (CD95, APO-1)/FasL is one of the most extensively studied apoptotic pathways. Because FasL is constitutively expressed in the lung, cells that express Fas should be eliminated by lung endothelium. Cells with low or no cell surface Fas expression may be able to evade this innate defense mechanism. The purpose of these studies was to evaluate Fas expression in osteosarcoma lung metastases and the effect of gemcitabine on Fas expression and tumor growth.

Experimental Design and Results: Using the K7M2 murine osteosarcoma model, Fas expression was quantified using immunohistochemistry. High levels of Fas were present in primary tumors, but no Fas expression was present in actively growing lung metastases. Blocking the Fas pathway using Fas-associated death domain dominant-negative delayed tumor cell clearance from the lung and increased metastatic potential. Treatment of mice with aerosol gemcitabine resulted in increased Fas expression and subsequent tumor regression.

Conclusions: We conclude that corruption of the Fas pathway is critical to the ability of osteosarcoma cells to grow in the lung. Agents such as gemcitabine that up-regulate cell surface Fas expression may therefore be effective in treating osteosarcoma lung metastases. These data also suggest that an additional mechanism by which gemcitabine induces regression of osteosarcoma lung metastases is mediated by enhancing the sensitivity of the tumor cells to the constitutive FasL in the lung.
Sequential Flavopiridol, Cytosine Arabinoside, and Mitoxantrone: A Phase II Trial in Adults with Poor-Risk Acute Myelogenous Leukemia
Authors: Karp Judith E. , Smith B. Douglas , Levis Mark J. , Gore Steven D. , Greer Jacqueline , Hattenburg Catherine , Briel Janet , Jones Richard J. , Wright John J. , Colevas A. Dimitri
Published: August 2007

Purpose: Flavopiridol is a cyclin-dependent kinase inhibitor that is cytotoxic to leukemic blasts. In a phase I study of flavopiridol followed by 1-β-d-arabinofuranosylcytosine (ara-C) and mitoxantrone, overall response rate for adults with relapsed and refractory acute myelogenous leukemias (AML) was 31%. We have now completed a phase II study of sequential flavopiridol, ara-C, and mitoxantrone in 62 adults with poor-risk AML.

Experimental Design: Flavopiridol (50 mg/m2) was given by 1-h infusion daily × 3 beginning day 1 followed by 2 gm/m2/72 h ara-C beginning day 6 and 40 mg/m2 mitoxantrone on day 9.

Results: Flavopiridol caused a ≥50% decrease in peripheral blood blasts in 44% by median day 2 and ≥80% decrease in 26% by day 3. Self-limited tumor lysis occurred in 53%. Three (5%) died during therapy (2 multiorgan failure and 1 fungal pneumonia). Complete remissions (CR) were achieved in 12 of 15 (75%) newly diagnosed secondary AML, 18 of 24 (75%) first relapse after short CR (median CR, 9 months, including prior allotransplant), and 2 of 13 (15%) primary refractory but 0 of 10 multiply refractory AML. Disease-free survival for all CR patients is 40% at 2 years, with newly diagnosed patients having a 2-year disease-free survival of 50%.

Conclusions: Flavopiridol has anti-AML activity directly and in combination with ara-C and mitoxantrone. This timed sequential regimen induces durable CRs in a significant proportion of adults with newly diagnosed secondary AML (including complex cytogenetics) and adults with AML in first relapse after short first CR.
Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors Vandetanib (ZD6474) and AZD2171 in Lung Cancer
Authors: Hanrahan Emer O. , Heymach John V.
Published: August 2007

Vascular endothelial growth factor (VEGF) is a rational target for advanced non–small cell lung cancer (NSCLC), a hypothesis validated by the recent Eastern Cooperative Oncology Group E4599 trial showing that the addition of the VEGF monoclonal antibody bevacizumab to chemotherapy prolongs overall survival. Several new tyrosine kinase inhibitors targeting the VEGF pathway are currently in advanced clinical development for NSCLC and offer several possible advantages compared with monoclonal antibodies, including oral administration, more flexible dosing, a broader spectrum of target inhibition, and different toxicity profiles. Among these agents, vandetanib (ZD6474), an inhibitor of the VEGF receptor (VEGFR)-2 and epidermal growth factor receptor tyrosine kinase, has been the most extensively studied. In a randomized phase II study of patients with platinum-refractory NSCLC, including squamous histology, vandetanib prolonged progression-free survival compared with gefitinib. In another phase II trial, an improvement in progression-free survival was observed for vandetanib in combination with docetaxel compared with docetaxel alone. AZD2171 is an inhibitor of VEGFR-1, VEGFR-2, and VEGFR-3 and other tyrosine kinases that has shown clinical activity in NSCLC in combination with carboplatin and paclitaxel. Several phase III trials are under way testing these agents either as monotherapy or in combination with chemotherapy in patients with lung cancer. Early results with these agents, and others being tested, raise the possibility that there will eventually be multiple VEGF-targeted therapies available in the clinic that can potentially benefit a broader range of patients with advanced-stage NSCLC.