bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of Platelet-Activating Factor Receptor and Pleiotropic Effects on Tyrosine Phospho-EGFR/Src/FAK/Paxillin in Ovarian Cancer
Authors: Aponte Margarita , Jiang Wei , Lakkis Montaha , Li Ming-Jiang , Edwards Dale , Albitar Lina , Vitonis Allison , Mok Samuel C. , Cramer Daniel W. , Ye Bin
Published: July 2008

Among the proinflammatory mediators, platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) is a major primary and secondary messenger involved in intracellular and extracellular communication. Evidence suggests that PAF plays a significant role in oncogenic transformation, tumor growth, angiogenesis, and metastasis. However, PAF, with its receptor (PAFR) and their downstream signaling targets, has not been thoroughly studied in cancer. Here, we characterized the PAFR expression pattern in 4 normal human ovarian surface epithelial (HOSE) cell lines, 13 ovarian cancer cell lines, paraffin blocks (n = 84), and tissue microarrays (n = 230) from patients with ovarian cancer. Overexpression of PAFR was found in most nonmucinous types of ovarian cancer but not in HOSE and mucinous cancer cells. Correspondingly, PAF significantly induced cell proliferation and invasion only in PAFR-positive cells (i.e., OVCA429 and OVCA432), but not in PAFR-negative ovarian cells (HOSE and mucinous RMUG-L). The dependency of cell proliferation and invasion on PAFR was further confirmed using PAFR-specific small interfering RNA gene silencing probes, antibodies against PAFR and PAFR antagonist, ginkgolide B. Using quantitative multiplex phospho-antibody array technology, we found that tyrosine phosphorylation of EGFR/Src/FAK/paxilin was coordinately activated by PAF treatment, which was correlated with the activation of phosphatidylinositol 3-kinase and cyclin D1 as markers for cell proliferation, as well as matrix metalloproteinase 2 and 9 for invasion. Specific tyrosine Src inhibitor (PP2) reversibly blocked PAF-activated cancer cell proliferation and invasion. We suggest that PAFR is an essential upstream target of Src and other signal pathways to control the PAF-mediated cancer progression. [Cancer Res 2008;68(14):5839–48]
GSTP1 Promoter Haplotypes Affect DNA Methylation Levels and Promoter Activity in Breast Carcinomas
Authors: Rønneberg Jo Anders , Tost Jörg , Solvang Hiroko K. , Alnaes Grethe I.G. , Johansen Fredrik E. , Brendeford Elen M. , Yakhini Zohar , Gut Ivo G. , Lønning Per Eystein , Børresen-Dale Anne-Lise , Gabrielsen Odd S. , Kristensen Vessela N.
Published: July 2008

The CpG island spanning the transcription start of the glutathione S-transferase P1 becomes methylated in a variety of human cancers including breast cancer. To study the effect of sequence variation on hypermethylation of the GSTP1 promoter, we analyzed the genetic and epigenetic variability in 90 tumors from patients with locally advanced breast cancer. High-resolution quantitative analysis revealed large variability in the DNA methylation levels. Lack of methylation was more often observed in the basal and normal-like estrogen receptor (ER)-negative tumors, and methylated GSTP1 was associated with better overall survival (P = 0.00063). Studies of the genetic variation identified 14 different haplotypes. The distribution of methylation levels of tumors homozygous for the most frequent haplotype was significantly different from other haplotype combinations (P = 0.011), the difference being more pronounced in ER-positive (P = 0.005) and progesterone receptor–positive (P = 0.008) tumors. Regression modeling identified the ER status and haplotype as the main determinants of DNA methylation variability. We identified a putative c-Myb response element (MRE) that was present in one of two minimal promoter haplotypes. In vitro analysis showed that c-Myb binds to the MRE, but binding was weakened by the two polymorphisms. Transient cotransfections in luminal-type and basal-like breast cancer cell lines confirmed cell-specific differential binding of c-Myb to the polymorphic sites, leading to a change in the expression from the GSTP1 promoter in vivo. GSTP1 expression was moderately but significantly (P = 0.01) reduced after siRNA-mediated knockdown of c-Myb. Our results indicate that haplotype structure of a promoter is important for the extent of DNA methylation. [Cancer Res 2008;68(14):5562–71]
Cathepsin G Enhances Mammary Tumor–Induced Osteolysis by Generating Soluble Receptor Activator of Nuclear Factor-κB Ligand
Authors: Wilson Thomas J. , Nannuru Kalyan C. , Futakuchi Mitsuru , Sadanandam Anguraj , Singh Rakesh K.
Published: July 2008

Breast cancer commonly causes osteolytic metastases in bone, a process that is dependent on tumor-stromal interaction. Proteases play an important role in modulating tumor-stromal interactions in a manner that favors tumor establishment and progression. Whereas several studies have examined the role of proteases in modulating the bone microenvironment, little is currently known about their role in tumor-bone interaction during osteolytic metastasis. In cancer-induced osteolytic lesions, cleavage of receptor activator of nuclear factor-κB ligand (RANKL) to a soluble version (sRANKL) is critical for widespread osteoclast activation. Using a mouse model that mimics osteolytic changes associated with breast cancer–induced bone metastases, we identified cathepsin G, cathepsin K, matrix metalloproteinase (MMP)-9, and MMP13 to be proteases that are up-regulated at the tumor-bone interface using comparative cDNA microarray analysis and quantitative reverse transcription-PCR. Moreover, we showed that cathepsin G is capable of shedding the extracellular domain of RANKL, generating active sRANKL that is capable of inducing differentiation and activation of osteoclast precursors. The major source of cathepsin G at the tumor-bone interface seems to be osteoclasts that up-regulate production of cathepsin G via interaction with tumor cells. Furthermore, we showed that in vitro osteoclastogenesis is reduced by inhibition of cathepsin G in a coculture model and that in vivo inhibition of cathepsin G reduces mammary tumor–induced osteolysis. Together, our data indicate that cathepsin G activity at the tumor-bone interface plays an important role in mammary tumor–induced osteolysis and suggest that cathepsin G is a potentially novel therapeutic target in the treatment of breast cancer bone metastasis. [Cancer Res 2008;68(14):5803–11]
Vaccination Elicits Correlated Immune and Clinical Responses in Glioblastoma Multiforme Patients
Authors: Wheeler Christopher J. , Black Keith L. , Liu Gentao , Mazer Mia , Zhang Xiao-xue , Pepkowitz Samuel , Goldfinger Dennis , Ng Hiushan , Irvin Dwain , Yu John S.
Published: July 2008

Cancer vaccine trials have failed to yield robust immune-correlated clinical improvements as observed in animal models, fueling controversy over the utility of human cancer vaccines. Therapeutic vaccination represents an intriguing additional therapy for glioblastoma multiforme (GBM; grade 4 glioma), which has a dismal prognosis and treatment response, but only early phase I vaccine trial results have been reported. Immune and clinical responses from a phase II GBM vaccine trial are reported here. IFN-γ responsiveness was quantified in peripheral blood of 32 GBM patients given therapeutic dendritic cell vaccines. Posttreatment times to tumor progression (TTP) and survival (TTS) were compared in vaccine responders and nonresponders and were correlated with immune response magnitudes. GBM patients (53%) exhibited ≥1.5-fold vaccine-enhanced cytokine responses. Endogenous antitumor responses of similar magnitude occurred in 22% of GBM patients before vaccination. Vaccine responders exhibited significantly longer TTS and TTP relative to nonresponders. Immune enhancement in vaccine responders correlated logarithmically with TTS and TTP spanning postvaccine chemotherapy, but not with initial TTP spanning vaccination alone. This is the first report of a progressive correlation between cancer clinical outcome and T-cell responsiveness after therapeutic vaccination in humans and the first tracing of such correlation to therapeutically exploitable tumor alteration. As such, our findings offer unique opportunities to identify cellular and molecular components of clinically meaningful antitumor immunity in humans. [Cancer Res 2008;68(14):5955–64]
The Novel Angiogenic Inhibitor, Angiocidin, Induces Differentiation of Monocytes to Macrophages
Authors: Gaurnier-Hausser Anita , Rothman Vicki L. , Dimitrov Svetoslav , Tuszynski George P.
Published: July 2008

We previously showed that angiocidin, a tumor and vascular associated protein, is a potent inhibitor of angiogenesis and tumor growth. Angiocidin is a multidomain protein that exerts its antiangiogenic activity through multiple mechanisms, including effects on cell matrix interaction. Here, we describe another activity of angiocidin that may contribute to its antitumor activity. We show that angiocidin activates monocytes to secrete a mixture of proinflammatory cytokines and induces them to differentiate into macrophage-like cells. Using the monocytic cell line THP-1, we show that angiocidin induces the cells to become adherent and phagocytic, express macrophage markers, and secrete matrix metalloproteinase-9. Microarray analysis of control and angiocidin-treated THP-1 cells revealed that angiocidin up-regulated p105/p50, p100/p52, and rel B, components of the nuclear factor-κB (NF-κB) pathway. We confirmed the microarray data and showed that angiocidin induced phosphorylation of Iκβ, p50, and p65 and translocation of p50 and p65 to the nucleus. We also showed that angiocidin activated up-stream mediators of NF-κB, such as the mitogen-activated protein kinase (MAPK) pathway and phosphoinositide-3 kinase (PI3K). Blockage of NF-κB and MAPK activation with small molecule inhibitors completely prevented angiocidin-mediated secretion of cytokines from THP-1 cells, but did not inhibit their adhesive phenotype. Blocking PI3K inhibited both secretion of cytokines, as well as the adhesive phenotype. These data suggest that angiocidin activates monocytes to secrete cytokines and differentiates them to a macrophage-like phenotype through at least two pathways mediated by MAPK and NF-κB, as well as PI3K. [Cancer Res 2008;68(14):5905–14]
Cell Lineage Analysis of a Mouse Tumor
Authors: Frumkin Dan , Wasserstrom Adam , Itzkovitz Shalev , Stern Tomer , Harmelin Alon , Eilam Raya , Rechavi Gideon , Shapiro Ehud
Published: July 2008

Revealing the lineage relations among cancer cells can shed light on tumor growth patterns and metastasis formation, yet cell lineages have been difficult to come by in the absence of a suitable method. We previously developed a method for reconstructing cell lineage trees from genomic variability caused by somatic mutations. Here, we apply the method to cancer and reconstruct, for the first time, a lineage tree of neoplastic and adjacent normal cells obtained by laser microdissection from tissue sections of a mouse lymphoma. Analysis of the reconstructed tree reveals that the tumor initiated from a single founder cell, ∼5 months before diagnosis, that the tumor grew in a physically coherent manner, and that the average number of cell divisions accumulated in cancerous cells was almost twice than in adjacent normal lung epithelial cells but slightly less than the expected figure for normal B lymphocytes. The cells were also genotyped at the TP53 locus, and neoplastic cells were found to share a common mutation, which was most likely present in a heterozygous state. Our work shows that the ability to obtain data regarding the physical appearance, precise anatomic position, genotypic profile, and lineage position of single cells may be useful for investigating cancer development, progression, and interaction with the microenvironment. [Cancer Res 2008;68(14):5924–31]
Inhibition of Glycogen Synthase Kinase 3β Attenuates Neurocognitive Dysfunction Resulting from Cranial Irradiation
Authors: Thotala Dinesh K. , Hallahan Dennis E. , Yazlovitskaya Eugenia M.
Published: July 2008

There are now more than 10 million cancer survivors in the United States. With these numbers, chronic sequelae that result from cancer therapy have become a major health care problem. Although radiation therapy of the brain has improved cancer cure rates, learning disorders and memory deficits are a common consequence of this therapy. Here we show that glycogen synthase kinase 3β (GSK-3β) is required for radiation-induced hippocampal neuronal apoptosis and subsequent neurocognitive decline. Inhibition of GSK-3β either by small molecules (SB216763 or SB415286) or by ectopic expression of kinase-inactive GSK-3β before irradiation significantly attenuated radiation-induced apoptosis in hippocampal neurons. GSK-3β inhibition with SB216763 or SB415286 also decreased apoptosis in the subgranular zone of the hippocampus in irradiated mice, leading to improved cognitive function in irradiated animals. Studies of the molecular mechanisms of the cytoprotective effect showed that GSK-3β activity in hippocampal neurons was not significantly altered by radiation, pointing to the indirect involvement of this enzyme in radiation-induced apoptosis. At the same time, radiation led to increased accumulation of p53, whereas inhibition of the basal level of GSK-3β activity before radiation prevented p53 accumulation, suggesting a possible mechanism of cytoprotection by GSK-3β inhibitors. These findings identify GSK-3β signaling as a key regulator of radiation-induced damage in hippocampal neurons and suggest that GSK-3β inhibitors may have a therapeutic role in protecting both pediatric and adult cancer patients and may help to improve quality of life in cancer survivors. [Cancer Res 2008;68(14):5859–68]
A Role for the Cyclin Box in the Ubiquitin-Mediated Degradation of Cyclin G1
Authors: Piscopo Denise M. , Hinds Philip W.
Published: July 2008

Cyclin G1 was identified as a transcriptional target of p53 that encodes a protein with strong homology to the cyclin family of cell cycle regulators. We show that either ectopically expressed or endogenous cyclin G1 protein is very unstable, undergoes modification with ubiquitin, and is likely degraded by the proteasome. Ectopic cyclin G1 protein stability is increased by cyclin box mutation or by association with inactive cyclin-dependent kinase (CDK) subunits, suggesting that a function of cyclin G1 as a CDK regulator may be required for its rapid turnover. Furthermore, cyclin G1 and the cyclin box mutant interact with and are ubiquitinated by MDM2, another transcriptional target of p53 that acts as a negative regulator of p53 stability. These data suggest that the cyclin box has a role in the proteasome-mediated degradation of cyclin G1 and thus suggest a putative role for a CDK in cyclin G1 metabolism and function. [Cancer Res 2008;68(14):5581–90]
Noninvasive Assessment of E2F-1–Mediated Transcriptional Regulation In vivo
Authors: Monfared Parisa , Winkeler Alexandra , Klein Markus , Li Hongfeng , Klose Anke , Hoesel Marianna , Waerzeggers Yannic , Korsching Sigrun , Jacobs Andreas H.
Published: July 2008

Targeted therapies directed against individual cancer-specific molecular alterations offer the development of disease-specific and individualized treatment strategies. Activation of the transcription factor E2F-1 via alteration of the p16-cyclinD-Rb pathway is one of the key molecular events in the development of gliomas. E2F-1 binds to and activates the E2F-1 promoter in an autoregulatory manner. The human E2F-1 promoter has been shown to be selectively activated in tumor cells with a defect in the pRb pathway. Paradoxically, E2F-1 also carries tumor suppressor function. Our investigations focused on analyzing the dynamics of the activity of the E2F-1 responsive element under basal conditions and certain stimuli such as chemotherapy using molecular imaging technology. We constructed a retrovirus bearing the Cis-E2F-TA-LITG reporter system to noninvasively assess E2F-1–dependent transcriptional regulation in culture and in vivo. We show that our reporter system is sensitive to monitor various changes in cellular E2F-1 levels and its transcriptional control of our reporter system to follow the state of the Rb/E2F pathway and the DNA damage–induced up-regulation of E2F-1 activity in vivo. Exposure to 1,3-bis(2-chloroethyl)-1-nitrosourea leads to increased E2F-1 expression levels in a dose- and time-dependent manner, which can be quantified by imaging in vivo, leading to an alteration of cell cycle progression and caspase 3/7 activity. In summary, noninvasive imaging of E2F-1 as a common downstream regulator of cell cycle progression using the Cis-E2F-TA-LUC-IRES-TKGFP reporter system is highly attractive for evaluating the kinetics of cell cycle regulation and the effects of novel cell cycle targeting anticancer agents in vivo. [Cancer Res 2008;68(14):5932–40]
The Pervasive Presence of Fluctuating Oxygenation in Tumors
Authors: Cárdenas-Navia Laura I. , Mace Daniel , Richardson Rachel A. , Wilson David F. , Shan Siqing , Dewhirst Mark W.
Published: July 2008

Tumor hypoxia is a persistent obstacle for traditional therapies in solid tumors. Strategies for mitigating the effects of hypoxic tumor cells have been developed under the assumption that chronically hypoxic tumor cells were the central cause of treatment resistance. In this study, we show that instabilities in tumor oxygenation are a prevalent characteristic of three tumor lines and previous characterization of tumor hypoxia as being primarily diffusion-limited does not accurately portray the tumor microenvironment. Phosphorescence lifetime imaging was used to measure fluctuations in vascular pO2 in rat fibrosarcomas, 9L gliomas, and R3230 mammary adenocarcinomas grown in dorsal skin-fold window chambers (n = 6 for each tumor type) and imaged every 2.5 minutes for a duration of 60 to 90 minutes. O2 delivery to tumors is constantly changing in all tumors, resulting in continuous reoxygenation events throughout the tumor. Vascular pO2 maps show significant spatial heterogeneity at each time point, as well as between time points. The fluctuations in oxygenation occur with a common periodicity within and between tumors, suggesting a common mechanism, but have tumor type–dependent spatial patterns. The widespread presence of fluctuations in tumor oxygenation has broad ranging implications for tumor progression, stress response, and signal transduction, which are altered by oxygenation/reoxygenation events. [Cancer Res 2008;68(14):5812–9]
Low-Dose Radiation Enhances Survivin-Mediated Virotherapy against Malignant Glioma Stem Cells
Authors: Nandi Suvobroto , Ulasov Ilya V. , Tyler Matthew A. , Sugihara Adam Quasar , Molinero Luciana , Han Yu , Zhu Zeng B. , Lesniak Maciej S.
Published: July 2008

To improve the efficacy and selectivity of virotherapy for malignant glioma, we designed a strategy to amplify adenoviral replication in conjunction with radiotherapy using a radioinducible promoter. First, we compared the radiation-inducible activity of FLT-1, vascular endothelial growth factor, DR5, Cox2, and survivin. We then examined the capacity of the optimal promoter to modulate transgene expression followed by E1A activity in vitro and in vivo in a glioma stem cell model. In the presence of radiation, survivin mRNA activity increased 10-fold. Luciferase transgene expression was dose dependent and optimal at 2 Gy. A novel oncolytic adenovirus, CRAd-Survivin-pk7, showed significant toxicity and replication against a panel of passaged and primary CD133+ glioma stem cells. On delivery of radiation, the toxicity associated with CRAd-Survivin-pk7 increased by 20% to 50% (P < 0.05). At the same time, the level of E1A activity increased 3- to 10-fold. In vivo, treatment of U373MG CD133+ stem cells with CRAd-Survivin-pk7 and radiation significantly inhibited tumor growth (P < 0.05). At the same time, the level of E1A activity was 100-fold increased versus CRAd-Survivin-pk7 alone. Selected genes linked to radioinducible promoters whose expression can be regulated by ionizing radiation may improve the therapeutic ratio of virotherapy. In this study, we have identified a new radioinducible promoter, survivin, which greatly enhances the activity of an oncolytic adenovirus in the presence of low-dose radiotherapy. [Cancer Res 2008;68(14):5778–84]
Prostate Cancer Induces Bone Metastasis through Wnt-Induced Bone Morphogenetic Protein-Dependent and Independent Mechanisms
Authors: Dai Jinlu , Hall Christopher L. , Escara-Wilke June , Mizokami Atsushi , Keller Jill M. , Keller Evan T.
Published: July 2008

Prostate cancer (PCa) is frequently accompanied by osteosclerotic (i.e., excessive bone production) bone metastases. Although bone morphogenetic proteins (BMP) and Wnts are mediators of PCa-induced osteoblastic activity, the relation between them in PCa bone metastases is unknown. The goal of this study was to define this relationship. Wnt3a and Wnt5a administration or knockdown of DKK-1, a Wnt inhibitor, induced BMP-4 and 6 expression and promoter activation in PCa cells. DKK-1 blocked Wnt activation of the BMP promoters. Transfection of C4-2B cells with axin, an inhibitor of canonical Wnt signaling, blocked Wnt3a but not Wnt5a induction of the BMP promoters. In contrast, Jnk inhibitor I blocked Wnt5a but not Wnt3a induction of the BMP promoters. Wnt3a, Wnt5a, and conditioned medium (CM) from C4-2B or LuCaP23.1 cells induced osteoblast differentiation in vitro. The addition of DKK-1 and Noggin, a BMP inhibitor, to CM diminished PCa CM–induced osteoblast differentiation in a synergistic fashion. However, pretreatment of PCa cells with DKK-1 before collecting CM blocked osteoblast differentiation, whereas pretreatment with Noggin only partially reduced osteoblast differentiation, and pretreatment with both DKK-1 and Noggin had no greater effect than pretreatment with DKK-1 alone. Additionally, knockdown of BMP expression in C4-2B cells inhibited Wnt-induced osteoblastic activity. These results show that PCa promotes osteoblast differentiation through canonical and noncanonical Wnt signaling pathways that stimulate both BMP-dependent and BMP-independent osteoblast differentiation. These results show a clear link between Wnts and BMPs in PCa-induced osteoblast differentiation and provide novel targets, including the noncanonical Wnt pathway, for therapy of PCa. [Cancer Res 2008;68(14):5785–94]
Vimentin Filaments Support Extension of Tubulin-Based Microtentacles in Detached Breast Tumor Cells
Authors: Whipple Rebecca A. , Balzer Eric M. , Cho Edward H. , Matrone Michael A. , Yoon Jennifer R. , Martin Stuart S.
Published: July 2008

Solid tumor metastasis often involves detachment of epithelial carcinoma cells into the vasculature or lymphatics. However, most studies of cytoskeletal rearrangement in solid tumors focus on attached cells. In this study, we report for the first time that human breast tumor cells produce unique tubulin-based protrusions when detached from extracellular matrix. Tumor cell lines of high metastatic potential show significantly increased extension and frequency of microtubule protrusions, which we have termed tubulin microtentacles. Our previous studies in nontumorigenic mammary epithelial cells showed that such detachment-induced microtentacles are enriched in detyrosinated α-tubulin. However, amounts of detyrosinated tubulin were similar in breast tumor cell lines despite varying microtentacle levels. Because detyrosinated α-tubulin associates strongly with intermediate filament proteins, we examined the contribution of cytokeratin and vimentin filaments to tumor cell microtentacles. Increased microtentacle frequency and extension correlated strongly with loss of cytokeratin expression and up-regulation of vimentin, as is often observed during tumor progression. Moreover, vimentin filaments coaligned with microtentacles, whereas cytokeratin did not. Disruption of vimentin with PP1/PP2A-specific inhibitors significantly reduced microtentacles and inhibited cell reattachment to extracellular matrix. Furthermore, expression of a dominant-negative vimentin mutant disrupted endogenous vimentin filaments and significantly reduced microtentacles, providing specific genetic evidence that vimentin supports microtentacles. Our results define a novel model in which coordination of vimentin and detyrosinated microtubules provides structural support for the extensive microtentacles observed in detached tumor cells and a possible mechanism to promote successful metastatic spread. [Cancer Res 2008;68(14):5678–88]
Ability of Mature Dendritic Cells to Interact with Regulatory T Cells Is Imprinted during Maturation
Authors: Muthuswamy Ravikumar , Urban Julie , Lee Je-Jung , Reinhart Todd A. , Bartlett David , Kalinski Pawel
Published: July 2008

Preferential activation of regulatory T (Treg) cells limits autoimmune tissue damage during chronic immune responses but can also facilitate tumor growth. Here, we show that tissue-produced inflammatory mediators prime maturing dendritic cells (DC) for the differential ability of attracting anti-inflammatory Treg cells. Our data show that prostaglandin E2 (PGE2), a factor overproduced in chronic inflammation and cancer, induces stable Treg-attracting properties in maturing DC, mediated by CCL22. The elevated production of CCL22 by PGE2-matured DC persists after the removal of PGE2 and is further elevated after secondary stimulation of DC in a neutral environment. This PGE2-induced overproduction of CCL22 and the resulting attraction of FOXP3+ Tregs are counteracted by IFNα, a mediator of acute inflammation, which also restores the ability of the PGE2-exposed DC to secrete the Th1-attracting chemokines: CXCL9, CXCL10, CXCL11, and CCL5. In accordance with these observations, different DCs clinically used as cancer vaccines show different Treg-recruiting abilities, with PGE2-matured DC, but not type 1–polarized DC, generated in the presence of type I and type II IFNs, showing high Treg-attracting activity. The current data, showing that the ability of mature DC to interact with Treg cells is predetermined at the stage of DC maturation, pave the way to preferentially target the regulatory versus proinflammatory T cells in autoimmunity and transplantation, as opposed to intracellular infections and cancer. [Cancer Res 2008;68(14):5972–8]
Human Endogenous Retrovirus K Triggers an Antigen-Specific Immune Response in Breast Cancer Patients
Authors: Wang-Johanning Feng , Radvanyi Laszlo , Rycaj Kiera , Plummer Joshua B. , Yan Peisha , Sastry K. Jagannadha , Piyathilake Chandrika J. , Hunt Kelly K. , Johanning Gary L.
Published: July 2008

Recent evidence indicates that human cancer cells reactivate the expression of latent human endogenous retroviral (HERV) proteins. However, the extent to which cancer patients mount de novo immune responses against expressed HERV elements is unclear. In this study, we determined the extent of HERV-K env expression in human breast cancer (BC) and whether both humoral and cell-mediated immunity against HERV-K can be found in BC patients. We found HERV-K env protein expression in 88% of BC (n = 119) but not in normal breast (n = 76) tissues. ELISA screening assays detected significant titers of anti–HERV-K env IgG in a large proportion of BC patients. T-cell responses against HERV-K were also detected in peripheral blood mononuclear cells (PBMC) from BC patients stimulated with autologous dendritic cells pulsed with HERV-K env SU antigens. These responses included induction of T-cell proliferation (P = 0.0043), IFN-γ production measured by enzyme-linked immunospot (P < 0.0001), and multiplex cytokine secretion (P = 0.0033). Multiplex cytokine analysis found a T-helper 1 cytokine response, including interleukin (IL)-2 (P = 0.0109), IL-6 (P = 0.0396), IL-8 (P = 0.0169), and IP-10 (P = 0.0045) secretion during in vitro stimulation of BC PBMC with HERV-K antigen. We also found HERV-K–specific CTLs that were capable of lysing target cells expressing HERV-K env protein in BC patients but not in normal female controls without cancer. These findings suggest that retroviral gene products are capable of acting as tumor-associated antigens activating both T-cell and B-cell responses in BC patients. [Cancer Res 2008;68(14):5869–77]
Breast Cancer Risk Reduction and Membrane-Bound CatecholO-Methyltransferase Genetic Polymorphisms
Authors: Ji Yuan , Olson Janet , Zhang Jianping , Hildebrandt Michelle , Wang Liewei , Ingle James , Fredericksen Zachary , Sellers Thomas , Miller William , Dixon J. Michael , Brauch Hiltrud , Eichelbaum Michel , Justenhoven Christina , Hamann Ute , Ko Yon , Brüning Thomas , Chang-Claude Jenny , Wang-Gohrke Shan , Schaid Daniel , Weinshilboum Richard
Published: July 2008

Catechol O-methyltransferase (COMT)-catalyzed methylation of catecholestrogens has been proposed to play a protective role in estrogen-induced genotoxic carcinogenesis. We have taken a comprehensive approach to test the hypothesis that genetic variation in COMT might influence breast cancer risk. Fifteen COMT single nucleotide polymorphisms (SNPs) selected on the basis of in-depth resequencing of the COMT gene were genotyped in 1,482 DNA samples from a Mayo Clinic breast cancer case control study. Two common SNPs in the distal promoter for membrane-bound (MB) COMT, rs2020917 and rs737865, were associated with breast cancer risk reduction in premenopausal women in the Mayo Clinic study, with allele-specific odds ratios (OR) of 0.70 [95% confidence interval (CI), 0.52–0.95] and 0.68 (95% CI, 0.51–0.92), respectively. These two SNPs were then subjected to functional genomic analysis and were genotyped in an additional 3,683 DNA samples from two independent case control studies (GENICA and GESBC). Functional genomic experiments showed that these SNPs could up-regulate transcription and that they altered DNA-protein binding patterns. Furthermore, substrate kinetic and exon array analyses suggested a role for MB-COMT in catecholestrogen inactivation. The GENICA results were similar to the Mayo case control observations, with ORs of 0.85 (95% CI, 0.72–1.00) and 0.85 (95% CI, 0.72–1.01) for the two SNPs. No significant effect was observed in the GESBC study. These studies showed that two SNPs in the COMT distal promoter were associated with breast cancer risk reduction in two of three case control studies, compatible with the results of functional genomic experiments, suggesting a role for MB-COMT in breast cancer risk. [Cancer Res 2008;68(14):5997–6005]
Extracellular Redox State Regulates Features Associated with Prostate Cancer Cell Invasion
Authors: Chaiswing Luksana , Zhong Weixiong , Cullen Joseph J. , Oberley Larry W. , Oberley Terry D.
Published: July 2008

We have examined the possible role of extracellular reduction-oxidation (redox) state in regulation of biological/biochemical features associated with prostate cancer cell invasion. DU145, PC-3, and RWPE1-derived human prostate cancer (WPE1-NB26) cell lines were used for the present in vitro analysis. Increasing levels of nitric oxide using S-nitroso-N-acetylpenicillamine resulted in a decrease in cell invasion ability, whereas increasing levels of extracellular superoxide radical (O2•−) using xanthine/xanthine oxidase resulted in an increase in cell invasion ability in these three cell lines. WPE1-NB26 cells exhibited an increased glutathione/glutathione disulfide ratio in the medium in comparison with RWPE1 cells (immortalized but nonmalignant prostate epithelial cells), suggesting an alteration of extracellular redox state of WPE1-NB26 cells. We hypothesized that O2•− production at or near the plasma membrane or in the adjacent extracellular matrix at least partially regulated prostate cancer cell invasion. Using adenovirus-mediated extracellular superoxide dismutase (EC-SOD) gene transduction to enzymatically decrease O2•− levels, we showed that in the presence of heparin, adenovirus EC-SOD gene transduction resulted in an increase in the expression of EC-SOD outside the cells with resultant inhibition of cell invasion ability. This inhibition correlated with reduced metalloproteinase [matrix metalloproteinase (MMP) 2/membrane type 1-MMP] activities and increased levels of extracellular nitrite. Our results suggest a prominent role of extracellular redox status in regulation of cell invasion, which may provide opportunities for therapeutic interventions. [Cancer Res 2008;68(14):5820–6]
Merlin Is a Potent Inhibitor of Glioma Growth
Authors: Lau Ying-Ka Ingar , Murray Lucas B. , Houshmandi Sean S. , Xu Yin , Gutmann David H. , Yu Qin
Published: July 2008

Neurofibromatosis 2 (NF2) is an inherited cancer syndrome in which affected individuals develop nervous system tumors, including schwannomas, meningiomas, and ependymomas. The NF2 protein merlin (or schwannomin) is a member of the Band 4.1 superfamily of proteins, which serve as linkers between transmembrane proteins and the actin cytoskeleton. In addition to mutational inactivation of the NF2 gene in NF2-associated tumors, mutations and loss of merlin expression have also been reported in other types of cancers. In the present study, we show that merlin expression is dramatically reduced in human malignant gliomas and that reexpression of functional merlin dramatically inhibits both subcutaneous and intracranial growth of human glioma cells in mice. We further show that merlin reexpression inhibits glioma cell proliferation and promotes apoptosis in vivo. Using microarray analysis, we identify altered expression of specific molecules that play key roles in cell proliferation, survival, and motility. These merlin-induced changes of gene expression were confirmed by real-time quantitative PCR, Western blotting, and functional assays. These results indicate that reexpression of merlin correlates with activation of mammalian sterile 20-like 1/2–large tumor suppressor 2 signaling pathway and inhibition of canonical and noncanonical Wnt signals. Collectively, our results show that merlin is a potent inhibitor of high-grade human glioma. [Cancer Res 2008;68(14):5733–42]
A Central Role for HER3 in HER2-Amplified Breast Cancer: Implications for Targeted Therapy
Authors: Lee-Hoeflich Si Tuen , Crocker Lisa , Yao Evelyn , Pham Thinh , Munroe Xander , Hoeflich Klaus P. , Sliwkowski Mark X. , Stern Howard M.
Published: July 2008

Epidermal growth factor receptor (EGFR) and HER3 each form heterodimers with HER2 and have independently been implicated as key coreceptors that drive HER2-amplified breast cancer. Some studies suggest a dominant role for EGFR, a notion of renewed interest given the development of dual HER2/EGFR small-molecule inhibitors. Other studies point to HER3 as the primary coreceptor. To clarify the relative contributions of EGFR and HER3 to HER2 signaling, we studied receptor knockdown via small interfering RNA technology across a panel of six HER2-overexpressing cell lines. Interestingly, HER3 was as critical as HER2 for maintaining cell proliferation in most cell lines, whereas EGFR was dispensable. Induction of HER3 knockdown in the HER2-overexpressing BT474M1 cell line was found to inhibit growth in three-dimensional culture and induce rapid tumor regression of in vivo xenografts. Furthermore, preferential phosphorylation of HER3, but not EGFR, was observed in HER2-amplified breast cancer tissues. Given these data suggesting HER3 as an important therapeutic target, we examined the activity of pertuzumab, a HER2 antibody that inhibits HER3 signaling by blocking ligand-induced HER2/HER3 heterodimerization. Pertuzumab inhibited ligand-dependent morphogenesis in three-dimensional culture and induced tumor regression in the heregulin-dependent MDA-MB-175 xenograft model. Importantly, these activities of pertuzumab were distinct from those of trastuzumab, a monoclonal antibody currently used for treatment of HER2-amplified breast cancer patients. Our data suggest that inhibition of HER3 may be more clinically relevant than inhibition of EGFR in HER2-amplified breast cancer and also suggest that adding pertuzumab to trastuzumab may augment therapeutic benefit by blocking HER2/HER3 signaling. [Cancer Res 2008;68(14):5878–87]
Thymoquinone Triggers Inactivation of the Stress Response Pathway SensorCHEK1and Contributes to Apoptosis in Colorectal Cancer Cells
Authors: Gali-Muhtasib Hala , Kuester Doerthe , Mawrin Christian , Bajbouj Khuloud , Diestel Antje , Ocker Matthias , Habold Caroline , Foltzer-Jourdainne Charlotte , Schoenfeld Peter , Peters Brigitte , Diab-Assaf Mona , Pommrich Ulf , Itani Wafica , Lippert Hans , Roessner Albert , Schneider-Stock Regine
Published: July 2008

There are few reports describing the role of p53-dependent gene repression in apoptotic cell death. To identify such apoptosis-associated p53 target genes, we used the pro-oxidant plant-derived drug thymoquinone and compared p53+/+ and p53−/− colon cancer cells HCT116. The p53 wild-type (wt) status correlated with more pronounced DNA damage and higher apoptosis after thymoquinone treatment. A significant up-regulation of the survival gene CHEK1 was observed in p53−/− cells in response to thymoquinone due to the lack of transcriptional repression of p53. In p53−/− cells, transfection with p53-wt vector and CHEK1 small interfering RNA treatment decreased CHEK1 mRNA and protein levels and restored apoptosis to the levels of the p53+/+ cells. p53−/− cells transplanted to nude mice treated with thymoquinone up-regulated CHEK1 expression and did not undergo apoptosis unlike p53+/+ cells. Immunofluorescence analysis revealed that the apoptosis resistance in p53−/− cells after thymoquinone treatment might be conveyed by shuttling of CHEK1 into the nucleus. We confirmed the in vivo existence of this CHEK1/p53 link in human colorectal cancer, showing that tumors lacking p53 had higher levels of CHEK1, which was accompanied by poorer apoptosis. CHEK1 overexpression was correlated with advanced tumor stages (P = 0.03), proximal tumor localization (P = 0.02), and worse prognosis (1.9-fold risk, univariate Cox regression; Kaplan-Meier, P = 0.04). We suggest that the inhibition of the stress response sensor CHEK1 might contribute to the antineoplastic activity of specific DNA-damaging drugs. [Cancer Res 2008;68(14):5609–18]
Pten Deficiency in Melanocytes Results in Resistance to Hair Graying and Susceptibility to Carcinogen-Induced Melanomagenesis
Authors: Inoue-Narita Tae , Hamada Koichi , Sasaki Takehiko , Hatakeyama Sachiko , Fujita Sachiko , Kawahara Kohichi , Sasaki Masato , Kishimoto Hiroyuki , Eguchi Satoshi , Kojima Itaru , Beermann Friedrich , Kimura Tetsunori , Osawa Masatake , Itami Satoshi , Mak Tak Wah , Nakano Toru , Manabe Motomu , Suzuki Akira
Published: July 2008

Phosphate and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor gene inactivated in numerous sporadic cancers, including melanomas. To analyze Pten functions in melanocytes, we used the Cre-loxP system to delete Pten specifically in murine pigment-producing cells and generated DctCrePtenflox/flox mice. Half of DctCrePtenflox/flox mice died shortly after birth with enlargements of the cerebral cortex and hippocampus. Melanocytes were increased in the dermis of perinatal DctCrePtenflox/flox mice. When the mutants were subjected to repeated depilations, melanocyte stem cells in the bulge of the hair follicle resisted exhaustion and the mice were protected against hair graying. Although spontaneous melanomas did not form in DctCrePtenflox/flox mice, large nevi and melanomas developed after carcinogen exposure. DctCrePtenflox/flox melanocytes were increased in size and exhibited heightened activation of Akt and extracellular signal–regulated kinases, increased expression of Bcl-2, and decreased expression of p27Kip1. Our results show that Pten is important for the maintenance of melanocyte stem cells and the suppression of melanomagenesis. [Cancer Res 2008;68(14):5760–8]
Statistical Approaches to Computer-Assisted Translation
Authors: Barrachina Sergio , Bender Oliver , Casacuberta Francisco , Civera Jorge , Cubel Elsa , Khadivi Shahram , Lagarda Antonio , Ney Hermann , Tomás Jesús , Vidal Enrique , Vilar Juan-Miguel
Published: July 2008

Current machine translation (MT) systems are still not perfect. In practice, the output from these systems needs to be edited to correct errors. A way of increasing the productivity of the whole translation process (MT plus human work) is to incorporate the human correction activities within the translation process itself, thereby shifting the MT paradigm to that of computer-assisted translation. This model entails an iterative process in which the human translator activity is included in the loop: In each iteration, a prefix of the translation is validated (accepted or amended) by the human and the system computes its best (or n-best) translation suffix hypothesis to complete this prefix. A successful framework for MT is the so-called statistical (or pattern recognition) framework. Interestingly, within this framework, the adaptation of MT systems to the interactive scenario affects mainly the search process, allowing a great reuse of successful techniques and models. In this article, alignment templates, phrase-based models, and stochastic finite-state transducers are used to develop computer-assisted translation systems. These systems were assessed in a European project (TransType2) in two real tasks: The translation of printer manuals; manuals and the translation of the Bulletin of the European Union. In each task, the following three pairs of languages were involved (in both translation directions): English-Spanish, English-German, and English-French.
Experimental Identification and Analysis of the Dynamics of a PHANToM Premium 1.5A Haptic Device
Authors: Taati Babak , Tahmasebi Amir M. , Hashtrudi-Zaad Keyvan
Published: July 2008

The dynamics of a PHANToM Premium 1.5A haptic device from SensAble Technologies, Inc. is experimentally identified and analyzed for different installations of the device and its accessories, such as the typical upright, upside down, with gimbal and counterbalance weight, and with force sensor.1 An earlier formulation of the robot dynamic model is augmented with a friction model, linearly parameterized, and experimentally identified using least squares. The identified dynamics are experimentally evaluated with an inverse dynamics controller and verified by comparing user hand force estimates with the measured values. The contribution of different dynamic terms such as inertial, Coriolis and centrifugal, gravitational, and Coulomb and viscous friction are demonstrated and discussed. The identified model can be used for a variety of haptic applications, such as hand force estimation, accurate active gravity compensation and counterbalance weight determination for various installation conditions, and model-based control for haptic simulation and teleoperation.
Haptic Manipulation of Microspheres Using Optical Tweezers Under the Guidance of Artificial Force Fields
Authors: Bukusoglu Ibrahim , Basdogan Cagatay , Kiraz Alper , Kurt Adnan
Published: July 2008

Using optical tweezers (OT) and a haptic device, microspheres having diameters ranging from 3 to 4 μm (floating in a fluid solution) are manipulated in order to form patterns of coupled optical microresonators by assembling the spheres via chemical binding. For this purpose, biotin-coated microspheres trapped by a laser beam are steered and chemically attached to an immobilized streptavidin-coated sphere (i.e., the anchor sphere) one by one using an xyz piezo scanner controlled by a haptic device. The positions of all spheres in the scene are detected using a CCD camera and a collision-free path for each manipulated sphere is generated using the potential field approach. The forces acting on the manipulated particle due to the viscosity of the fluid and the artificial potential field are scaled and displayed to the user through the haptic device for better guidance and control during steering. In addition, a virtual fixture is implemented such that the desired angle of approach and strength are achieved during the binding phase. Our experimental studies in virtual and real environments with eight human subjects show that haptic feedback significantly improves the user performance by reducing the task completion time, the number of undesired collisions during steering, and the positional errors during binding. To our knowledge, this is the first time that a haptic device is coupled with OTs to guide the user during an optical manipulation task involving steering and assembly of microspheres to construct a coupled microresonator.
Sound Localization Using an Acoustical Telepresence Robot: TeleHead II
Authors: Toshima Iwaki , Aoki Shigeaki , Hirahara Tatsuya
Published: July 2008

TeleHead I is an acoustical telepresence robot that we built on the basis of the concept that remote sound localization could be best achieved by using a user-like dummy head whose movement synchronizes with the user's head movement in real time. We clarified the characteristics of the latest version of TeleHead I, TeleHead II, and verified the validity of this concept by sound localization experiments. TeleHead II can synchronize stably with the user's head movement with a 120-ms delay. The driving noise level measured through headphones is below 24 dB SPL from 1 to 4 kHz. The shape difference between the dummy head and the user is about 3% in head width and 5% in head length. An overall measurement metric indicated that the difference between the head-related transfer functions (HRTFs) of the dummy head and the modeled listener is about 5 dB. The results of the sound localization experiments using TeleHead II clarified that head movement improves horizontal-plane sound localization performance even when the dummy head shape differs from the user's head shape. In contrast, the results for head movement when the dummy head shape and user head shape are different were inconsistent in the median plane. The accuracy of sound localization when using the same-shape dummy head with movement tethered to the user's head movement was always good. These results show that the TeleHead concept is acceptable for building an acoustical telepresence robot. They also show that the physical characteristics of TeleHead II are sufficient for conducting sound localization experiments.
Improving Presence Theory Through Experiential Design
Authors: Chertoff Dustin B. , Schatz Sae Lynne , McDaniel Rudy , Bowers Clint A.
Published: July 2008

Despite ongoing research over the last 15 years, the presence construct remains somewhat limited in its ability to be applied beyond the sensory domain. In order to increase its usefulness for applied challenges (e.g., using presence theory to enhance simulators' effectiveness), a discussion about a new conceptualization of presence is introduced. This novel perspective on presence is rooted in the notion of “experiential design,” an approach businesses use to create strategically compelling and memorable experiences. The paper begins with a brief review of presence and then a description of the concepts of experimental design. Following this, a theoretical model of presence, based upon experimental design, is offered. Using this model, an exploration on the mitigation of breaks in presence is offered (a break in presence occurs when presence fails to be maintained). These ideas are presented in order to improve the likelihood of presence emerging for simulation participants and to enhance interdisciplinary researchers' shared conceptualizations of presence.
The Latin Infinitivus Historicus Revisited
Authors: Rosén Hannah
Published: July 2008

Embarking upon yet another examination of the so-called Infinitivus Historicus [IH] (or 'descriptivus', 'adumbrativus', et sim ) appears not uncalled for this rather bizarre feature of Latin has been studied most extensively1), yet not altogether satisfactorily, and certainly not exhaustively We have to do here with a usage deeply rooted in the Latin literary language from Plautus onwards, until eventually becoming a literary convention, at the same time the Historic Infinitive is an almost unique phenomenon in Latin, as it is comparable, amongst the other infinitival constructions, only to the rare infinitivus 'imperativus' and 'prohibitivus', in that they all constitute non-embedded constructions which involve non-accusatival subjects2)