bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of a catalytically inactive transmembrane protein tyrosine phosphatase ϵ (tm‐PTPϵ) delays optic nerve myelination
Authors: Muja Naser , Lovas Gabor , Romm Elena , Machleder Dietrich , Ranjan Mukul , Gallo Vittorio , Hudson Lynn D.
Published: June 2004

Reversible tyrosine phosphorylation is integral to the process of oligodendrocyte differentiation. To interfere with the subset of the phosphorylation cycle overseen by protein tyrosine phosphatase ϵ (PTPϵ) in oligodendrocytes, we applied a substrate‐trapping approach in the development of transgenic mice overexpressing a catalytically inactive, transmembrane PTPϵ‐hemaglutinin (tm‐PTPϵ‐HA) from the dual promoter element of the gene encoding the myelin protein 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP). Transgene expression peaked during the active myelinating period, at 2–3 weeks postnatal. Two tyrosine phosphoproteins, α‐enolase and β‐actin, were phosphorylated to a greater degree in transgenic mice. Despite a high degree of tm‐PTPϵ‐HA expression, myelin was grossly normal in nearly all axonal tracts. Phenotypic abnormalities were limited to optic nerve, where a decrease in the degree of myelination was reflected by reduced levels of myelin proteins on postnatal day 21 (PND21), as well as a decrease in the density of differentiated oligodendrocytes. The optic chiasm was reduced in thickness in transgenic mice; optic nerves similarly exhibited a reduction in transverse width. Further analyses of the optic pathway demonstrated that transgenic protein was unexpectedly present in retinal ganglion cells, whose axons are the targets of myelination by optic nerve oligodendrocytes. On PND28, transgenic protein declined dramatically in both oligodendrocytes and retinal ganglion cells contributing to the recovery of optic nerve myelination. Thus, delayed myelination arises only when tm‐PTPϵ‐HA is simultaneously expressed in myelin‐forming glia and their neuronal targets. While tm‐PTPϵ related signaling pathways may figure in axon‐glial interactions, interfering with tm‐PTPϵ activity does not perceptibly affect the development or myelinating capacity of most oligodendrocytes. © 2004 Wiley‐Liss, Inc.
Interleukin‐1β upregulates functional expression of neurokinin‐1 receptor (NK‐1R) via NF‐κB in astrocytes
Authors: Guo Chang‐Jiang , Douglas Steven D. , Gao Zhiyong , Wolf Bryan A. , Grinspan Judith , Lai Jian‐Ping , Riedel Eric , Ho Wen‐Zhe
Published: June 2004

Cytokines and neuropeptides are modulators of neuroimmunoregulation in the central nervous system (CNS). The interaction of these modulators may have important implications in CNS diseases. We investigated whether interleukin‐1β (IL‐1β) modulates the expression of neurokinin‐1 receptor (NK‐1R), the primary receptor for substance P (SP), a potent neuropeptide in the CNS. IL‐1β upregulated NK‐1R expression in human astroglioma cells (U87 MG) and primary rat astrocytes at both mRNA and protein levels. IL‐1β treatment of U87 MG cells and primary rat astrocytes led to an increase in cytosolic Ca2+ in response to SP stimulation, indicating that IL‐1β‐induced NK‐1R is functional. CP‐96,345, a specific non‐peptide NK‐1R antagonist, inhibited SP‐induced rise of [Ca2+]i in the astroglioma cells. Investigation of the mechanism responsible for IL‐1β action revealed that IL‐1β has the ability of activating nuclear factor‐κb (NF‐κB). Caffeic acid phenethyl ester (CAPE), a specific inhibitor of NF‐κB activation, not only abrogated IL‐1β‐induced NF‐κB promoter activation, but also blocked IL‐1β‐mediated induction of NK‐1R gene expression. These findings provide additional evidence that there is a biological interaction between IL‐1β and the neuropeptide SP in the CNS, which may have important implications in the inflammatory diseases in the CNS. © 2004 Wiley‐Liss, Inc.
Astroglial glutamine transport by system N is upregulated by glutamate
Authors: Bröer Angelika , Deitmer Joachim W. , Bröer Stefan
Published: June 2004

Release of glutamine from astrocytes is an essential step of the glutamate‐glutamine cycle, and hence for the maintenance of neuronal glutamate and γ‐aminobutyric acid (GABA) pools. The glutamine transporter SNAT3 (SN1) has recently been identified as one of the major mediators of glutamine efflux from astrocytes. We investigated the regulation of SNAT3 mediated glutamine transport in cultured astrocytes. Incubation of primary astrocyte cultures with physiological concentrations of glutamate resulted in a rapid, about twofold, upregulation of SNAT3‐mediated transport activity. The effect was not mediated by glutamate receptors but required uptake of glutamate into astrocytes. Both net uptake and net efflux increased after treatment of cells with glutamate, excluding an acceleration of the transport by way of an exchange mechanism. Elevated intracellular glutamate most likely reduces the Kmof SNAT3 for its substrate glutamine. The results suggest that astrocytes respond actively to the release of glutamate by increasing glutamine release and thereby may modulate glutamatergic neurotransmission. © 2004 Wiley‐Liss, Inc.
Spatiotemporal wavelet resampling for functional neuroimaging data
Authors: Breakspear Michael , Brammer Michael J. , Bullmore Ed T. , Das Pritha , Williams Leanne M.
Published: June 2004

The study of dynamic interdependences between brain regions is currently a very active research field. For any connectivity study, it is important to determine whether correlations between two selected brain regions are statistically significant or only chance effects due to non‐specific correlations present throughout the data. In this report, we present a wavelet‐based non‐parametric technique for testing the null hypothesis that the correlations are typical of the data set and not unique to the regions of interest. This is achieved through spatiotemporal resampling of the data in the wavelet domain. Two functional MRI data sets were analysed: (1) Data from 8 healthy human subjects viewing a checkerboard image, and (2) “Null” data obtained from 3 healthy human subjects, resting with eyes closed. It was demonstrated that constrained resampling of the data in the wavelet domain allows construction of bootstrapped data with four essential properties: (1) Spatial and temporal correlations within and between slices are preserved, (2) The irregular geometry of the intracranial images is maintained, (3) There is adequate type I error control, and (4) Expected experiment‐induced correlations are identified. The limitations and possible extensions of the proposed technique are discussed. Hum. Brain Mapp. 23:1–25, 2004. © 2004 Wiley‐Liss, Inc.
A novel DNA methyltransferase I–derived peptide eluted from soluble HLA‐A*0201 induces peptide‐specific, tumor‐directed cytotoxic T cells
Authors: Berg Martina , Barnea Eilon , Admon Arie , Zavazava Nicholas
Published: June 2004

MHC peptides derived from tumor‐associated antigens (TAAs) can serve as the basis for the development of immunotherapeutics to treat human malignancies. Previously, we identified novel HLA‐A*0201 (HLA‐A2)–restricted peptides recovered from soluble HLA molecules secreted by human tumor cell lines, transfected with truncated genes of HLA‐A2 and HLA‐B7. Here, 4 candidate peptides eluted from soluble HLA‐A2 were selected on the basis of their precursor proteins being TAAs. Peptide p1028 (GLIEKNIEL), derived from DNA methyltransferase I (DNMT‐1), which is overexpressed in various human tumors, showed the highest affinity to HLA‐A2 and was relatively abundant in the sMHC/peptide complexes of all transfected breast, ovarian and prostate cancer cell lines. Peptide p1028‐specific CTLs were generated in vitro and shown to efficiently lyse not only target cells pulsed with the peptide but also HLA‐A2‐positive breast cancer cell lines MDA‐231 and MCF‐7. The peptide induced IFN‐γ production in CTLs, which were selectively stained by a p1028 tetramer. Since DNMT‐1 is a widely expressed tumor‐associated enzyme, the novel DNMT‐1‐derived, HLA‐A2‐restricted peptide GLIEKNIEL identified here may provide a suitable candidate for a therapeutic cancer vaccine. © 2004 Wiley‐Liss, Inc.
Accuracy of human papillomavirus testing in primary screening of cervical neoplasia: Results from a multicenter study in India
Authors: Sankaranarayanan Rengaswamy , Chatterji Ramdas , Shastri Surendra S. , Wesley Ramani S. , Basu Partha , Mahe Cédric , Muwonge Richard , Seigneurin Daniel , Somanathan Thara , Roy Chinmoy , Kelkar Rohini , Chinoy Roshini , Dinshaw Ketayun , Mandal Ranajit , Amin Geethanjali , Goswami Smriti , Pal Smarajit , Patil Sharmila , Dhakad Namrata , Frappart Lucien , Fontaniere Bernard ,   IARC Multicenter Study Group on Cervical Cancer Prevention in India
Published: June 2004

The knowledge that cervical neoplasia are caused by human papillomavirus (HPV) infection has led to the evaluation of its role in screening. We evaluated the accuracy of HPV testing by Hybrid capture II (HC II) method in detecting cervical intraepithelial neoplasia grade 2 and 3 (CIN 2 and 3) lesions in 4 cross‐sectional studies with common protocol and questionnaire in 3 different locations (Kolkata, Mumbai and Trivandrum) in India. These studies involved 18,085 women aged 25–65 years. The reference standard for final diagnosis was a combination of colposcopy/biopsy. All women were investigated with colposcopy and 3,116 received directed biopsy. The sensitivity of HPV testing for detecting CIN 2–3 lesions varied from 45.7% to 80.9% across the study sites; the specificity varied from 91.7% to 94.6% and the positive predictive value from 6.7% to 13.7%. Retesting of 298 randomly chosen denatured samples in France revealed an agreement rate of 85.9% and a κ‐value of 0.72. Although HPV testing seems to be a promising approach for cervical cancer prevention, a large range in sensitivity was observed in our study, possibly due to variations in the quality of specimen collection and reference standards. A higher sensitivity was associated with the center performing the test well. Further developments in terms of more reproducible, less expensive and less sophisticated testing are essential to make the test feasible and effective in low‐resource settings. © 2004 Wiley‐Liss, Inc.
Immunohistochemical investigation of SV40 large T antigen in Hodgkin and non‐Hodgkin's lymphoma
Authors: Brousset Pierre , de Araujo Valquiria , Gascoyne Randy D.
Published: June 2004

DNA sequences from simian virus 40 (SV40) have been detected in various human tumors, including non‐Hodgkin's lymphomas (NHLs), by highly sensitive PCR techniques. However, there is a strong debate as to whether SV40 is present in lymphoma cells. Using immunohistochemistry and tissue microarrays, we investigated a series of French and Canadian cases of Hodgkin's lymphomas (HLs) and NHLs and tried to detect the SV40 large T antigen using routine paraffin sections with standard and highly sensitive catalyzed system amplification methods. None of the cases of HLs (n = 250) or NHLs (n = 232) were found to contain a single large T antigen‐positive cell, whereas 2 positive controls were repeatedly stained. Therefore, our results do not support the hypothesis that SV40 is implicated in the etiology of human lymphomas. © 2004 Wiley‐Liss, Inc.
Global gene expression profiles of human head and neck squamous carcinoma cell lines
Authors: Jeon Geoung A. , Lee Ju‐Seog , Patel Vyomesh , Gutkind J. Silvio , Thorgeirsson Snorri S. , Kim Eun Cheol , Chu In‐Sun , Amornphimoltham Panomwat , Park Myung Hee
Published: June 2004

For genomewide monitoring and identification of biomarkers of head and neck squamous cell carcinoma (HNSCC), we have conducted a systematic characterization of gene expression profiles, using human cDNA microarrays containing 9K clones, in 25 HNSCC cell lines and 1 immortalized human oral keratinocyte cell line. We used normal human oral keratinocytes (NHOKs) as a reference. Our study showed that genes primarily involved in cell cycle regulation, oncogenesis, cell proliferation, differentiation, apoptosis and cell adhesion were widely altered in the 26 cell lines. Upregulated genes included known oncogenes, protein kinases, DNA‐binding proteins and cell cycle regulators, while those commonly downregulated included differentiation markers, cell adhesion proteins, extracellular matrix proteins, structural proteins (keratins) and protease inhibitor proteins. Compared to NHOK, we observed a striking reduction in the expression of genes involved in terminal differentiation, suggesting that a loss in this process is an important signature of HNSCC. In addition, hierarchical clustering analysis as well as principal component analysis revealed 2 distinctive subtypes of gene expression patterns among the 26 cell lines, reflecting a degree of heterogeneity in HNSCC. By applying significance analysis of microarrays, 128 genes were selected for being distinctively expressed between the 2 groups. Genes differentially expressed in the 2 subgroups include cell proliferation‐related genes, IGFBP6, EGFR and VEGFC; tumor suppression and apoptosis‐related genes such as Tp53, Tp63; as well as cell cycle regulators such as CCND1 and CCND2 (cyclins D1 and D2), suggesting that the 2 subgroups might have undergone different pathways of carcinogenesis. Published 2004 Wiley‐Liss, Inc.
Anti‐tumor activity of a combination of plasminogen activator and captopril in a human melanoma xenograft model
Authors: de Groot‐Besseling Renate R.J. , Ruers Theo J.M. , van Kraats Annemieke A. , Poelen Geert J.M. , Ruiter Dirk J. , de Waal Robert M.W. , Westphal Johan R.
Published: June 2004

Angiostatin, a proteolytic fragment of plasminogen consisting of the first 3 or 4 kringle domains, reduces tumor growth by specifically inhibiting tumor angiogenesis. Angiostatin is generated in vitro in a 2‐step process. First, plasminogen is converted to plasmin by plasminogen activators. Next, plasmin excises the angiostatin fragment from plasminogen, a process requiring molecules that are able to donate a free sulfhydryl group. In this study, we investigated whether stimulation of in vivo angiostatin generation by administration of plasminogen activator and a free sulfhydryl group donor (FSD) has anti‐tumor activity. First, we determined the optimal conditions for in vitro angiostatin generation by incubating murine plasma with different concentrations of plasminogen activator and/or the FSD captopril. Angiostatin generation was monitored by western blot analysis. Our results were extrapolated to the in vivo situation by administering the optimal dose of tissue‐type plasminogen activator (tPA, i.v. injection 3 times/week) and captopril (in drinking water) to mice and analyzing the presence of angiostatin in the circulation. Angiostatin was readily detectable in mice receiving both tPA and captopril, but not in mice receiving either one of the agents. Finally, the anti‐tumor activity of the tPA/captopril treatment was tested in a human melanoma xenograft model. Administration of tPA alone had only a marginal effect on tumor growth. Captopril alone reduced tumor growth by about 60%, whereas treatment with both captopril and tPA resulted in 83% inhibition of tumor growth. © 2004 Wiley‐Liss, Inc.
Vegetable, fruit and meat consumption and potential risk modifying genes in relation to colorectal cancer
Authors: Turner Faye , Smith Gillian , Sachse Christoph , Lightfoot Tracy , Garner R. Colin , Wolf C. Roland , Forman David , Bishop D. Timothy , Barrett Jennifer H. ,   on behalf of the Colorectal Cancer Study Group
Published: June 2004

Epidemiological evidence shows high red meat consumption to increase the risk of colorectal cancer, while the consumption of fruit and vegetables has been shown to be protective. Many genes have been identified that encode for enzymes involved in the metabolism of dietary carcinogens or anti‐carcinogens. A study of 500 incident colorectal cancer cases and population controls, matched for age, sex and general practitioner, was conducted in the United Kingdom to investigate whether 6 such genes (CYP1A1, GSTT1, GSTM1, GSTP1, EPHX1 and NQO1) modify the relationship between diet and disease risk. Usual diet was estimated using a detailed questionnaire administered by interview. Fruit and vegetable consumption were both found to protect against colorectal cancer, while overall meat and red meat consumption were found to increase risk. There was some evidence of interaction between GSTT1 and vegetable consumption (p=0.006, not adjusted for multiple tests) but no evidence of interaction with GSTM1. The protective effect of vegetables was only seen in those with deficient or intermediate GSTT1 predicted phenotype [OR 0.3, 95% confidence interval (0.1, 0.6), and OR 0.6 (0.4, 0.96), OR 1.4 (0.3, 2.4) for those with fast phenotype], and a similar result was observed for cruciferous vegetables. There was also weak evidence of interaction between red meat intake and GSTT1 (p=0.06), GSTP1 (p=0.16, with p=0.02 after adjustment for potential confounders) and NQO1 predicted phenotype (p=0.01). Because of the multiple hypotheses tested in our study, these findings require independent confirmation. © 2004 Wiley‐Liss, Inc.
Efficacy of transferrin‐conjugated paclitaxel‐loaded nanoparticles in a murine model of prostate cancer
Authors: Sahoo Sanjeeb K. , Ma Wenxue , Labhasetwar Vinod
Published: June 2004

Chemotherapy remains the preferred choice of treatment for prostate cancer but modest drug response and significant toxicity by conventional methods of administration limit their efficacy. In our study, we determined the efficacy of paclitaxel (Tx)‐loaded biodegradable nanoparticles (NPs) on tumor inhibition. We hypothesized that NPs following conjugation to transferrin (Tf) ligand (NPs‐Tf) would enhance the therapeutic efficacy of the encapsulated drug. The antiproliferative activity of NPs was determined in human prostate cancer cell line (PC3) and their effect on tumor inhibition in a murine model of prostate cancer. NPs (∼ 220 nm in diameter, 5.4% w/w drug loading) under in vitro conditions exhibited sustained release of the encapsulated drug (60% release in 60 days). The IC50 (concentration of drug for 50% inhibition of cell growth) of the drug with Tf‐conjugated NPs (Tx‐NPs‐Tf) was about 5‐fold lower than that with unconjugated NPs (Tx‐NPs) or drug in solution. Animals that received a single‐dose intratumoral injection of Tx‐NPs‐Tf (Tx dose = 24 mg/kg) demonstrated complete tumor regression and greater survival rate than those that received either Tx‐NPs or Tx‐Cremophor® EL formulation. In conclusion, sustained release NPs demonstrated greater antitumor activity following their conjugation to Tf ligand. © 2004 Wiley‐Liss, Inc.
Effect of tetravalent bispecific CD19×CD3 recombinant antibody construct and CD28 costimulation on lysis of malignant B cells from patients with chronic lymphocytic leukemia by autologous T cells
Authors: Reusch Uwe , Le Gall Fabrice , Hensel Manfred , Moldenhauer Gerhard , Ho Anthony D. , Little Melvyn , Kipriyanov Sergey M.
Published: June 2004

To develop an effective antitumor immunotherapy for B‐lineage non‐Hodgkin's lymphoma, we constructed a tetravalent tandem diabody (tanDb) specific for both human CD19 (B‐cell marker) and CD3 (T‐cell antigen). Here, we report the effective killing of malignant primary B cells from patients with B‐cell chronic lymphocytic leukemia (B‐CLL) by autologous T cells induced by tanDb at very low E:T ratios. Mononuclear cells from patients with B‐CLL were cultured with bispecific antibody fragments in either the presence or absence of monospecific anti‐CD28 antibody. Use of tetravalent tanDbs caused almost quantitative elimination of malignant B cells from the blood samples of 19 patients and some cytotoxic activity in 3 of 23 analyzed cases. In contrast, the structurally similar but bivalent diabody and single‐chain diabody demonstrated nearly no antitumor activity in an autologous system. tanDb‐induced activation and proliferation of T cells occurred only in the presence of CD19+ target cells. Expression of the B7‐1 (CD80) and B7‐2 (CD86) molecules on the surface of leukemia cells made unnecessary the additional CD28‐costimulation of T cells. When only a few tanDb molecules were present, the effect of CD28 costimulation on T‐cell activation was more pronounced. Depending on the patient sample, we observed a 10‐ to 1,000‐fold decrease of the half‐maximal concentrations of tanDb for cell lysis. Upon CD28 crosslinking by agonistic MAb, specific tumor cell lysis was found at tanDb concentrations as low as 0.5 pM. These data demonstrate that the tetravalent CD19×CD3 tanDb might be a promising tool for the immunotherapy of human B‐cell leukemias and lymphomas. © 2004 Wiley‐Liss, Inc.
Unconjugated bilirubin induces apoptosis in colon cancer cells by triggering mitochondrial depolarization
Authors: Keshavan Pavitra , Schwemberger Sandy J. , Smith Darcey L.H. , Babcock George F. , Zucker Stephen D.
Published: June 2004

Bilirubin is the principal end product of heme degradation. Prompted by epidemiologic analyses demonstrating an inverse correlation between serum bilirubin levels and cancer mortality, we examined the effect(s) of bilirubin on the growth and survival of colon adenocarcinoma cells. Adenocarcinoma cell monolayers were treated with bilirubin over a range of bilirubin:BSA molar ratios (0–0.6), and viability was assessed colorimetrically. Apoptosis was characterized by TUNEL assay, annexin V staining and caspase‐3 activation. The mechanism(s) by which bilirubin induces apoptosis was investigated by Western blotting for cytochrome c release, assaying for caspase‐8 and caspase‐9 activation and for mitochondrial depolarization by JC‐1 staining. The direct effect of bilirubin on the membrane potential of isolated mitochondria was evaluated using light‐scattering and fluorescence techniques. Bilirubin decreased the viability of all colon cancer cell lines tested in a dose‐dependent manner. Cells exhibited substantial apoptosis when exposed to bilirubin concentrations ranging 0–50 μM, as demonstrated by an 8‐ to 10‐fold increase in TUNEL and annexin V staining and in caspase‐3 activity. Bilirubin treatment evokes specific activation of caspase‐9, enhances cytochrome c release into the cytoplasm and triggers the mitochondrial permeability transition in colon cancer monolayers. Additionally, bilirubin directly induces the depolarization of isolated rat liver mitochondria, an effect that is not inhibited by cyclosporin A. Bilirubin stimulates apoptosis of colon adenocarcinoma cells in vitro through activation of the mitochondrial pathway, apparently by directly dissipating mitochondrial membrane potential. As this effect is triggered at concentrations normally present in the intestinal lumen, we postulate a physiologic role for bilirubin in modulating colon tumorigenesis. © 2004 Wiley‐Liss, Inc.
An intronic variant of the TGFBR1 gene is associated with carcinomas of the kidney and bladder
Authors: Chen Taiping , Jackson Chad , Costello Ben , Singer Natalie , Colligan Bruce , Douglass Larry , Pemberton Jackson , Deddens James , Graff Jeremy R. , Carter Julia H.
Published: June 2004

TGF‐β signaling is frequently perturbed in many human cancers, including renal cell carcinomas (RCCs) and transitional cell carcinomas (TCCs) of the bladder. Genetic alterations of the TGF‐β type 1 receptor (TGFBR1) may contribute to these perturbations. We therefore examined variations in the TGFBR1 gene by PCR, SSCP and RFLP in carcinomas of the urinary system and in tissues from noncancer, age‐matched controls. A G→A variant 24 bp downstream of the exon/intron 7 boundary of the TGFBR1 gene (Int7G24A) was evident in patients with RCC (46.5%, n = 86) and bladder and upper urinary tract TCC (49.2%, n = 65) significantly more frequently than in age‐matched controls (28.3%, n = 113, p < 0.002 by χ2 test). Moreover, 8 homozygous variant carriers were found in the cancer groups, whereas not a single homozygous variant carrier was found in the control group. The Int7G24A allele (both heterozygous G/A and homozygous A/A carriers) was associated with increased RCC incidence (OR = 2.20, 95% CI 1.22–3.96) and TCC incidence (OR = 2.45, 95% CI 1.89–3.16). One somatic mutation of serine to phenylalanine at codon 57 of the TGFBR1 gene was confirmed in an upper urinary tract TCC. In conclusion, the Int7G24A variant in the TGFBR1 gene is significantly more frequent in patients with RCC and TCC than normal age‐matched controls, suggesting that it may represent a risk factor for the development of kidney and bladder carcinomas. © 2004 Wiley‐Liss, Inc.
High‐density methylation of p14ARF and p16INK4A in Epstein‐Barr virus–associated gastric carcinoma
Authors: Sakuma Kazuya , Chong Ja‐Mun , Sudo Makoto , Ushiku Tetsuo , Inoue Yoko , Shibahara Junji , Uozaki Hiroshi , Nagai Hideo , Fukayama Masashi
Published: June 2004

Promoter hypermethylation of various tumor‐related genes is extremely frequent in gastric carcinoma (GC) associated with Epstein‐Barr virus (EBV). To investigate the significance of the promoter methylation in this type of GC, we examined the methylation densities of the promoter regions of p14ARF and p16INK4A in EBV‐associated (n = 7) and EBV‐negative (n = 14) GC. Bisulfite sequencing demonstrated a high frequency of concurrent methylation of p14ARF and p16INK4A promoter regions in EBVaGC. Methylation was observed in all 29 CpG sites of p14ARF and all 16 sites of p16INK4A with equally high densities. In EBV‐negative GC, the methylation profiles differed between the 2 genes. Promoter methylation was sporadic and variable in p14ARF, and only the last position of CpG in p14ARF was methylated at high frequency. High‐density methylation in p16INK4A was observed in a subset of GC, but the first position of CpG was never methylated in EBV‐negative GC. These findings suggest the presence of mechanisms of de novo and maintenance methylation specific to EBVaGC that might be associated with EBV infection. © 2004 Wiley‐Liss, Inc.
Treatment of aggressive thyroid cancer with an oncolytic herpes virus
Authors: Yu Zhenkun , Eisenberg David P. , Singh Bhuvanesh , Shah Jatin P. , Fong Yuman , Wong Richard J.
Published: June 2004

Although many thyroid cancers carry a favorable prognosis, there is a subgroup of patients with more aggressive histologies. Current therapies offer no significant survival benefit to patients with anaplastic thyroid carcinomas, which are considered fatal. Oncolytic herpes simplex viruses (HSVs) have potent antitumor effects against a variety of human malignancies. We assessed the activity of a replication‐competent, attenuated, oncolytic HSV (NV1023) against 7 different thyroid cancers, including one papillary (NPA‐187), one follicular (WRO82‐1), one medullary (DRO81‐1) and 4 anaplastic (DRO90‐1, ARO, KAT‐4C and KAT‐18) cell lines. Only the follicular WRO82‐1 line was resistant to NV1023 infection and cell lysis at a concentration of 5 viral pfu per cell (MOI 5). All other cell lines at MOI 5 demonstrated >95% infection in vitro at day 2 by X‐gal staining and >88% cell death at day 4 by cytotoxicity assays. Even at MOI 0.1, 4 of these lines displayed complete cell death by day 7. Viral proliferation assays revealed that all of the nonfollicular cell lines supported logarithmic viral replication. Flank tumors of NPA‐187, DRO81‐1, DRO90‐1 and ARO in athymic nude mice were treated with NV1023 (2 × 107 pfu). All NPA‐187 tumors completely regressed following a single dose. DRO81‐1 tumors demonstrated partial response with a single dose and significant improvement with 3 serial doses. ARO and DRO90‐1 tumors showed a significant response following either single injection (54 ± 22 and 292 ± 138 mm3, respectively) or 3 serial injections (33 ± 14 and 241 ± 68 mm3, respectively) compared to saline injections (472 ± 193 and 1,257 ± 204 mm3, respectively) at day 20. These data suggest that herpes oncolytic therapy may be effective for the treatment of aggressive thyroid carcinomas and merits further investigation. © 2004 Wiley‐Liss, Inc.
Transgenic overexpression of a dominant negative mutant of FADD that, although counterselected during tumor progression, cooperates in L‐myc‐induced tumorigenesis
Authors: Hueber Anne‐Odile , Bösser Susanne , Zörnig Martin
Published: June 2004

Activation of the so‐called death receptors, e.g., CD95/Fas/Apo‐1, is a potent stimulus to trigger apoptosis. Overexpression of the C‐terminal FADD deletion mutant FADD‐DN blocks death receptor–induced apoptosis, but despite this antiapoptotic activity, lck FADD‐DN transgenic mice do not develop lymphomas. To analyze whether functional inactivation of FADD cooperates with Myc overexpression in tumorigenesis, lck FADD‐DN transgenic mice were crossed with Eμ L‐myc transoncogenic animals. While no tumors were detected in single transgenic FADD‐DN or L‐myc mice within 15 months, 5 of 17 (29%) FADD‐DN/L‐myc double transgenic animals developed lymphomas with an average latency period of 47 weeks. Protein analysis of FADD‐DN/L‐myc tumors showed, however, undetectable levels of FADD‐DN protein. FADD‐DN protein expression was again lost in 16 of 17 FADD‐DN/p53 k.o. T‐cell lymphomas, though no significant acceleration of tumorigenesis in P53‐deficient lck FADD‐DN mice compared to p53 k.o. animals was observed. These data suggest a strong counterselection against the FADD‐DN protein during tumor progression, which could be explained by the cell cycle inhibitory activity of FADD‐DN. Such counterselection would have to be compensated for by other antiapoptotic mutations, and indeed, strong upregulation of the antiapoptotic Bcl‐2 family member Bcl‐xL was found in one of the tumors. This in vivo mouse model demonstrates that an antiapoptotic protein involved in the onset of tumorigenesis is selected against and consequently lost during tumor progression because of its additional antiproliferative activity. © 2004 Wiley‐Liss, Inc.
Role of reactive oxygen species in the induction of apoptosis by α‐tocopheryl succinate
Authors: Kang Young‐Hwa , Lee Eunmyong , Choi Moon‐Kyung , Ku Ja‐Lok , Kim So Hee , Park Yong‐Geun , Lim Soo‐Jeong
Published: June 2004

α‐Tocopheryl succinate (TOS), a vitamin E analog, is a promising anticancer agent due to its abilities to inhibit proliferation and to induce apoptosis in a variety of human malignant cell lines, while being relatively less active toward normal cells. However, the molecular mechanisms underlying the apoptotic effects of TOS are not precisely understood. Reports that TOS can generate reactive oxygen species (ROS) prompted us to investigate the role of ROS in TOS‐induced apoptosis in cancer cells. We found that the human lung cancer A549 and H460 cell lines were much more sensitive to TOS‐induced apoptosis than the human glioblastoma T98G and U87MG cell lines. Our data suggested that the differential TOS sensitivity was not caused by differences in the uptake and retention of TOS between TOS‐sensitive and –resistant cancer cells. The differential ability of cancer cells to generate ROS in response to TOS appears to be an important factor in determining the susceptibility of cells to TOS‐induced apoptosis. Our results further suggest that TOS‐induced generation of ROS is involved in caspase‐independent apoptosis. Taken together, our findings suggest an important role of ROS generation in TOS‐induced, caspase‐independent apoptosis of cancer cells. © 2004 Wiley‐Liss, Inc.
Genetic background markedly influences vulnerability of the hippocampal neuronal organization in the “twitcher” mouse model of globoid cell leukodystrophy
Authors: Tominaga Kumiko , Matsuda Junko , Kido Makiko , Naito Etsuo , Yokota Ichiro , Toida Kazunori , Ishimura Kazunori , Suzuki Kunihiko , Kuroda Yasuhiro
Published: June 2004

The twitcher mouse is well known as a naturally occurring authentic mouse model of human globoid cell leukodystrophy (GLD; Krabbe disease) due to genetic deficiency of lysosomal galactosylceramidase. The twitcher mice used most commonly are on the C57BL/6J background. We generated twitcher mice that were on the mixed background of C57BL/6J and 129SvEv, the standard strain for production of targeted mutations. Twitcher mice on the mixed background were smaller and had a shorter lifespan than were those on the C57BL/6J background. Many twitcher mice on the mixed background developed generalized seizures around 30 days that were never seen in twitcher mice on the C57BL/6J background. Neuropathologically, although the degree of the typical demyelination with infiltration of macrophages was similar in the central and peripheral nervous systems, in both strains, marked neuronal cell death was observed only in twitcher mice on the mixed background. In the hippocampus, the neuronal cell death occurred prominently in the CA3 region in contrast to the relatively well‐preserved CA1 and CA2 areas. This neuropathology has never been seen in twitcher mice on the C57BL/6J background. Biochemically, the brain of twitcher mice on the mixed background showed much greater accumulation of lactosylceramide. Genetic background must be carefully taken into consideration when phenotype of mutant mice is evaluated, particularly because most targeted mutants are initially on a mixed genetic background and gradually moved to a pure background. These findings also suggest an intriguing possibility of important function of some sphingolipids in the hippocampal neuronal organization and maintenance. © 2004 Wiley‐Liss, Inc.
Antisense peptide nucleic acid targeting GluR3 delays disease onset and progression in the SOD1 G93A mouse model of familial ALS
Authors: Rembach Alan , Turner Bradley J. , Bruce Stephen , Cheah Irwin K. , Scott Rachel L. , Lopes Elizabeth C. , Zagami Chrissandra J. , Beart Philip M. , Cheung Nam S. , Langford Steven J. , Cheema Surindar S.
Published: June 2004

Glutamate excitotoxicity is strongly implicated as a major contributing factor in motor neuron degeneration in amyotrophic lateral sclerosis (ALS). Excitotoxicity results from elevated intracellular calcium ion (Ca2+) levels, which in turn recruit cell death signaling pathways. Recent evidence suggests that α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) receptor subunit (GluR) stoichiometry is a dominant factor leading to excess Ca2+ loading in neurodegeneration. In particular, the Ca2+ permeable glutamate receptor subunit 3 (GluR3) has been implicated in several neurologic conditions such as bipolar disorder and epilepsy. Recent proteomic analysis within our group on the copper zinc superoxide dismutase (SOD1)G93A transgenic mouse model of familial ALS (FALS) reveals a potentially deleterious upregulation of GluR3 in spinal cord compared to that in wild‐type littermates. Based on this finding we designed a 12mer antisense peptide nucleic acid (PNA) directed against GluR3. This sequence significantly reduced levels of GluR3 protein and protected neuroblastoma × spinal cord (NSC‐34) cells against death induced by the AMPA receptor‐specific agonist (S)‐5‐fluorowillardiine. We subsequently treated SOD1G93A mice thrice weekly with intraperitoneal injections of the antisense PNA (2.5 mg/kg) commencing at postnatal day 50. Mice treated with the antisense sequence had significantly extended survival compared to mice injected with a nonsense sequence. Western blot analysis, however, did not reveal a significant reduction in GluR3 protein levels in whole extracts of the lumbar spinal cord. These results suggest that interference with the GluR3 component of the AMPA receptor assembly may be a novel strategy for controlling excitotoxic destruction of motor neurons and may lead to new therapeutic opportunities for the treatment of human ALS. © 2004 Wiley‐Liss, Inc.
Food deprivation decreases responsiveness of ventromedial hypothalamic neurons to melanocortins
Authors: Li Y.Z. , Davidowa H.
Published: June 2004

The melanocortin system is involved in regulation of food intake and energy balance. Melanocyte‐stimulating hormone (α‐MSH) is an endogenous melanocortin receptor (MC‐R) agonist. It acts on MC3/4 receptors to reduce appetite and to increase energy expenditure. The production of α‐MSH is reduced during food deprivation, but MC4‐R density is increased. The net effect of reduced α‐MSH production and increased receptor level is not clear. To address this question, responses of ventromedial hypothalamic (VMH) neurons to melanotan II (MTII; a synthetic analogue of α‐MSH) were recorded in brain slices from fed and food‐deprived rats. Responses to the highest dose MTII were observed in 61% of VMH neurons from fed rats but only 33% of VMH neurons from food‐deprived rats. To assess a possible mechanism by which responsiveness to melanocortins is diminished even though receptor number is augmented during fasting, we examined the effect of agouti gene‐related peptide (AGRP), an endogenous MC‐R antagonist that stimulates food intake. The synthesis of AGRP increases during fasting. AGRP significantly reduced VMH responsiveness to MTII. Additionally, AGRP by itself evoked neuronal responses, in contrast to synthetic MC‐R antagonists. AGRP (1 nM) induced a predominant inhibitory effect on VMH neurons in food‐deprived rats but not in fed rats. In the presence of AGRP, MTII induced a significant inhibition of neuronal activity in deprived rats, but not in fed rats. Inhibition of VMH neurons reduces energy expenditure and the satiety signal. These findings suggest that although food deprivation increases MC4‐R density, it nevertheless reduces the effectiveness of melanocortins on VMH neurons, possibly by the involvement of AGRP. © 2004 Wiley‐Liss, Inc.
Remote Raman spectroscopy as a prospective tool for planetary surfaces
Authors: Klein V. , Popp J. , Tarcea N. , Schmitt M. , Kiefer W. , Hofer S. , Stuffler T. , Hilchenbach M. , Doyle D. , Dieckmann M.
Published: June 2004

This paper summarizes the content of four Technical Notes that were established within a study contracted by the European Space Agency concerning the possibility of applying Raman spectroscopy in the field of remote imaging. An overview of the scientific demands and Raman spectroscopy from the user's point of view is provided together with a few key aspects in the field of planetary research. Laboratory Raman experiments were used for establishing a basis for the subsequent extrapolation to remote Raman spectroscopy. A detailed numerical simulator was used to derive numbers concerning link budgets and overall remote Raman spectroscopy instrument performance for a number of different scenarios. A summary of subsystem technologies and criticalities is also presented together with the necessary R&D efforts. Copyright © 2004 John Wiley & Sons, Ltd.
Raman spectroscopy of ion‐irradiated interplanetary carbon dust analogues
Authors: Baratta G. A. , Mennella V. , Brucato J. R. , Colangeli L. , Leto G. , Palumbo M. E. , Strazzulla G.
Published: June 2004

Interplanetary dust particles (IDPs) and meteorites provide a unique opportunity to study extraterrestrial materials in the laboratory. Different Raman studies have shown that most of IDPs exhibit the characteristic amorphous carbon Raman feature. Different degrees of order have been recognized in the amorphous carbon phase of IDPs, testifying either to different origins or to different processing under different physical conditions (temperature, pressure, etc.). This paper presents a comparison between the amorphous carbon Raman features of IDPs and those of carbon dust analogues obtained in the laboratory by ion irradiation of carbon‐containing frozen gases and by arc discharge. We propose a possible mechanism able to induce an ‘evolution’ of IDPs. In particular, amorphous carbon with different degrees of order could be indicative of different irradiation doses by solar wind particles and fast solar protons suffered by IDPs in the interplanetary medium before collection in the Earth's atmosphere. Copyright © 2004 John Wiley & Sons, Ltd.
Raman spectroscopy of desert varnishes and their rock substrata
Authors: Edwards Howell G. M. , Moody Caroline A. , Jorge Villar Susana E. , Mancinelli Rocco
Published: June 2004

The Fourier—transform Raman spectra of desert varnish specimens and their rock substrata from locations in Colorado and Nevada, USA, are reported. The Colorado specimen exhibits molecular signatures for β‐carotene and scytonemin; the latter is a characteristic biomarker of cyanobacterial colonies and is produced by these organisms in response to high UV‐radiation stress. The Nevada specimen, on the other hand, exhibited characteristic Raman bands arising from whewellite and lichen metabolites such as atranorin and paretin, indicative of an epilithic lichen colonization. The application of Raman microscopy for the identification of extinct or extant biological colonization of rocks in exposed hot desert environments could form a useful adjunct for database construction relevant to exobiological studies and key spectral bioindicators for the robotic exploration of planetary surfaces. Copyright © 2004 John Wiley & Sons, Ltd.
Biological modification of haematite in Antarctic cryptoendolithic communities
Authors: Edwards Howell G. M. , Wynn‐Williams David D. , Villar Susana E. Jorge
Published: June 2004

Detailed FT‐Raman spectra of Antarctic cryptoendolithic colonies in Beacon sandstone have revealed some novel information about the biogeological modification process involving iron(III) mobilization by the organism. The previously unreported but characteristic orange–yellow surface colour of endolithic rock specimens is attributed to the presence of goethite, α‐FeOOH, iron(III) oxide hydroxide, which has been converted from haematite, α‐Fe2O3, by cyanobacterial modification. Although goethite is also identified in the biological layers, haematite is found unchanged elsewhere in the specimens. No spectroscopic evidence is found for iron(III) complexes of metabolic byproducts such as oxalate or pyruvate. The results are of relevance to remote spectroscopic sensing experiments for Martian planetary surface exploration, where the presence of iron(III) oxide is evident, below which it seems likely that a significant quantity of hydroxyl groups in the form of water could exist. Copyright © 2004 John Wiley & Sons, Ltd.
Protective pigmentation in UVB‐screened Antarctic lichens studied by Fourier transform Raman spectroscopy: an extremophile bioresponse to radiation stress
Authors: Edwards Howell G. M. , Cockell Charles S. , Newton Emma M. , Wynn‐Williams David D.
Published: June 2004

FT‐Raman spectra were obtained for two Antarctic extremophiles, the epilithic lichens Xanthoria elegans and Caloplaca sublobulata from the maritime ecological long‐term research site on Leonie Island. Twelve specimens from cloches designed for the filtering out and transmission of UVB radiation over a 2 year period and two specimens from the natural habitat outside the cloches were analysed in terms of their characteristic Raman bands from the two photoprotective pigments parietin and β‐carotene. Following chemometric analysis, the specimens inside the UVB‐protective cloches exhibited a lower parietin:β‐carotene ratio than specimens from the same habitat that did not have UVB protection. The relative roles of parietin, a passive UVB photoprotectant, and β‐carotene are discussed and a possible duality of biological function is suggested for these pigments. Copyright © 2004 John Wiley & Sons, Ltd.
Raman spectroscopy of sediments from the Antarctic Dry Valleys; an analogue study for exploration of potential paleolakes on Mars
Authors: Edwards Howell G. M. , Jorge Villar Susana E. , Bishop Janice L. , Bloomfield Matthew
Published: June 2004

A Raman spectroscopic study was performed on igneous sediments dominated by plagioclase, K‐feldspar, quartz and pyroxene from the Dry Valleys region of Antarctica. Lakes from this region of Antarctica have been investigated as possible analogues for paleolake environments on early Mars. Gaining Raman spectra of such sediments provides compositional information for missions to Mars, and also the necessary ground truthing for use of Raman spectroscopy for exploration of geology, and perhaps biology, on Mars. Sediments measured in this study were collected from the perennially ice‐covered Lake Hoare in the Taylor Valley and include surface sediments, and lakebottom sediments from oxic and anoxic zones of the lake. Micro‐Raman spectroscopy provides a unique opportunity for in situ exploration of biogeochemical processes on the micron scale at field sites. For example, in these potential paleolake analogue sediments, ∼5 µm sized sulfide deposits were observed on the surface of quartz grains in one of the anoxic sediments. Small amounts of calcite, organics, clays and iron oxides/hydroxides were also identified. Copyright © 2004 John Wiley & Sons, Ltd.
Mineralogy of a Martian meteorite as determined by Raman spectroscopy
Authors: Wang Alian , Kuebler Karla , Jolliff Bradley , Haskin Larry A.
Published: June 2004

Using the Raman point‐count procedure that we anticipate using in planetary surface exploration, we have identified and characterized the major, minor and trace mineral phases in rock chips of a Martian meteorite, EETA 79001. Raman spectra are shown for pyroxene, olivine, maskelynite (shocked, isotropized feldspar), chromite, magnetite, ilmenite, ulvöspinel, pyroxferroite, merrillite, apatite, anatase, an Fe sulfide, calcite and hematite. Raman spectra provide information on compositional variations of pyroxene, olivine and FeTiCr oxides and modal proportions of the rock. The maskelynite‐free mineral mode obtained on rough rock surfaces is consistent with modes obtained by optical microscopy on a thin section of lithology A of this meteorite. Compositions and variations in compositions of major silicate minerals (pyroxene and olivine) on the basis of Raman peak positions are consistent with those obtained in previous studies by electron probe microanalysis. The variations in composition of the silicate minerals represent different stages of crystallization during the formation of this rock near the Martian surface. Copyright © 2004 John Wiley & Sons, Ltd.
Comparative micro‐Raman study of the Nakhla and Vaca Muerta meteorites
Authors: Rull F. , Martinez‐Frias J. , Sansano A. , Medina J. , Edwards H. G. M.
Published: June 2004

A comprehensive micro‐Raman spectroscopic analysis of the Nakhla and Vaca Muerta meteorites is reported. The major and minor mineral components were identified from comparison with mineralogical standards and literature databases. The compositions of pyroxenes and olivines were obtained using only this technique and correlation data between band parameters and the chemical composition of reference materials existing in the literature. The presence of calcite in both meteorite specimens was noted; its identification inside eucrite grains in the Vaca Muerta meteorite is particularly noteworthy. Their spectral parameters show strong similarities. Aragonite associated with calcite is reported for the first time in Vaca Muerta meteorite. Spectra of siderite, which appears associated with clinopyroxenes, are also reported in Nakhla meteorite. Iron oxides were analysed in detail in both meteorites. Magnetite is the main oxide phase observed in Nakhla and goethite, lepidocrocite and magnetite in Vaca Muerta. In both cases haematite was not observed. A comparison of the spectral parameters of these mineral phases observed in both meteorites was made and their possible origin as secondary minerals is discussed. This study stresses the potential of Raman spectroscopy in the mineralogical characterization of meteorites on a very small scale and also the potential applications of Raman spectroscopy for use on landers or rovers on the surface of Mars or other planetary bodies. Copyright © 2004 John Wiley & Sons, Ltd.