bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibodies to Conserved Pneumococcal Antigens Correlate with, but Are Not Required for, Protection against Pneumococcal Colonization Induced by Prior Exposure in a Mouse Model
Authors: Trzciński Krzysztof , Thompson Claudette , Malley Richard , Lipsitch Marc
Published: September 2005

In mice following intranasal exposure to
Streptococcus pneumoniae
, protection against pneumococcal colonization was independent of antibody but dependent on CD4
+
T cells. Nonetheless, concentrations of antibodies to three conserved pneumococcal antigens correlated with protection against colonization. Concentrations of antibodies to conserved pneumococcal antigens may be correlates of protection without being effectors of protection.
Streptomycin-Dependent Exhibition of Cytokine-Inducing Activity in Streptomycin-DependentMycobacterium tuberculosisStrain 18b
Authors: Fukasawa Yutaka , Kawamura Ikuo , Uchiyama Ryosuke , Yamamoto Kazuhiro , Kaku Taijin , Tominaga Takanari , Nomura Takamasa , Ichiyama Satoshi , Ezaki Takayuki , Mitsuyama Masao
Published: September 2005

Peritoneal exudate cells of mice were stimulated with a streptomycin-dependentMycobacterium tuberculosisstrain, 18b. Gamma interferon production by natural killer cells depending on interleukin-12 and interleukin-18 was induced only in the presence of a high dose of streptomycin. This study suggested the requirement of active bacterial metabolism for this host response.
Mycobacterial Lipomannan Induces Matrix Metalloproteinase-9 Expression in Human Macrophagic Cells through a Toll-Like Receptor 1 (TLR1)/TLR2- and CD14-Dependent Mechanism
Authors: Elass Elisabeth , Aubry Laëtitia , Masson Maryse , Denys Agnès , Guérardel Yann , Maes Emmanuel , Legrand Dominique , Mazurier Joël , Kremer Laurent
Published: September 2005

Lipomannans (LM) from various mycobacterial species were found to induce expression and secretion of the matrix metalloproteinase 9 (MMP-9) both in human macrophage-like differentiated THP-1 cells and in primary human macrophages. Inhibition studies using antireceptor-neutralizing antibodies are indicative of a Toll-like receptor 1 (TLR1)/TLR2- and CD14-dependent signaling mechanism. Moreover, LM was shown to down-regulate transcription of the metalloproteinase inhibitor TIMP-1, a major endogenous MMP-9 regulator.
CONSTRAINTS ON OSCILLATING QUINTOM FROM SUPERNOVA, MICROWAVE BACKGROUND AND GALAXY CLUSTERING
Authors: XIA JUN-QING , FENG BO , ZHANG XINMIN
Published: September 2005

We consider in this paper a simple oscillating Quintom model of dark energy which has two free parameters and an equation of state oscillating and crossing -1. For low redshifts the equation of state of this model resembles itself similar to the linearly parametrized dark energy, however differs substantially at large redshifts. We fit our model to the observational data separately from the new high redshifts supernova observations from the HST/GOODS program and previous supernova, CMB and galaxy clustering. Our results show that because of the oscillating feature of our model the constraints from observations at large redshifts such as CMB become less stringent.
(1+1)-DIMENSIONAL DIRAC EQUATION WITH NON-HERMITIAN INTERACTION
Authors: SINHA A. , ROY P.
Published: September 2005

We study (1+1)-dimensional Dirac equation with non-Hermitian interactions, but real energies. In particular, we analyze the pseudoscalar and scalar interactions in detail, illustrating our observations with some examples. We also show that the relevant hidden symmetry of the Dirac equation with such an interaction is pseudo-supersymmetry.
NEUTRON STAR MATTER EQUATION OF STATE AND GRAVITATIONAL WAVE EMISSION
Authors: BENHAR OMAR
Published: September 2005

The EOS of strongly interacting matter at densities ten to fifteen orders of magnitude larger than the typical density of terrestrial macroscopic objects determines a number of neutron star properties, including the pattern of gravitational waves emitted following the excitation of nonradial oscillation modes. This paper reviews some of the approaches employed to model neutron star matter, as well as the prospects for obtaining new insights from the experimental study of gravitational waves emitted by neutron stars.
ABELIAN GAUGE THEORY IN DE SITTER SPACE
Authors: ROUHANI S. , TAKOOK M. V.
Published: September 2005

Quantization of spinor and vector free fields in four-dimensional de Sitter spacetime, in the ambient space notation, has been studied in the previous works. Various two-point functions for the above fields are presented in this paper. The interaction between the spinor field and the vector field is then studied by the Abelian gauge theory. The U (1) gauge invariant spinor field equation is obtained in a coordinate independent way notation and their corresponding conserved currents are computed. The solution of the field equation is obtained by the use of the perturbation method in terms of the Green's function. The null curvature limit is discussed in the final stage.
THE ECOLOGICAL SIGNIFICANCE OF TALLGRASS PRAIRIE ARTHROPODS
Authors: Whiles Matt R. , Charlton Ralph E.
Published: September 2005

▪ Abstract  Tallgrass prairie (TGP) arthropods are diverse and abundant, yet they remain poorly documented and there is still much to be learned regarding their ecological roles. Fire and grazing interact in complex ways in TGP, resulting in a shifting mosaic of resource quantity and quality for primary consumers. Accordingly, the impacts of arthropod herbivores and detritivores are expected to vary spatially and temporally. Herbivores generally do not control primary production. Rather, groups such as grasshoppers have subtle effects on plant communities, and their most significant impacts are often on forbs, which represent the bulk of plant diversity in TGP. Belowground herbivores and detritivores influence root dynamics and rhizosphere nutrient cycling, and above- and belowground groups interact through plant responses and detrital pathways. Large-bodied taxa, such as cicadas, can also redistribute significant quantities of materials during adult emergences. Predatory arthropods are the least studied in terms of ecological significance, but there is evidence that top-down processes are important in TGP.
Effective Cancer Therapy Through Immunomodulation
Authors: Waldmann Thomas A.
Published: September 2005

MAbs directed toward tumor cells, tumor neovasculature, and host negative immunoregulatory elements (checkpoints) have emerged as useful immunotherapeutic agents against cancer. However, effective active modulation of the immune response with anticancer vaccines will require identifying appropriate tumor-rejection antigens; optimizing the interactions of peptides, antigen-presenting cells, and T cells; and blockading negative immunological checkpoints that impede an effective immune response. Checkpoints being targeted include CTLA-4 and PD1 that are negative signaling receptors expressed on activated T cells, CD4+CD25+Foxp3-expressing Tregs (suppressor T cells), IL-2-mediated activation-induced cell death (AICD), and the cytokine TGFβ.
CLAUDINS AND EPITHELIAL PARACELLULAR TRANSPORT
Authors: Van Itallie Christina M. , Anderson James M.
Published: September 2005

▪ Abstract  Tight junctions form continuous intercellular contacts controlling solute movement through the paracellular pathway across epithelia. Paracellular barriers vary among epithelia in electrical resistance and behave as if they are lined with pores that have charge and size selectivity. Recent evidence shows that claudins, a large family (at least 24 members) of intercellular adhesion molecules, form the seal and its variable pore-like properties. This evidence comes from the study of claudins expressed in cultured epithelial cell models, genetically altered mice, and human mutants. We review information on the structure, function, and transcriptional and posttranslational regulation of the claudin family as well as of their evolutionarily distant relatives called the PMP22/EMP/MP20/claudin, or pfam00822, superfamily.
Targeted histone H4 acetylation via phosphoinositide 3-kinase- and p70s6-kinase-dependent pathways inhibits iNOS induction in mesangial cells
Authors: Yu Zhiyuan , Kone Bruce C.
Published: September 2005

The inducible nitric oxide synthase (iNOS) gene plays an important role in the response to and propagation of injury in glomerular mesangial cells. Although several cis and trans regulatory factors have been characterized, epigenetic regulation of the iNOS gene has not been considered extensively. In this report, we explored the role of histone acetylation in interleukin (IL)-1β-mediated iNOS induction in cultured murine mesangial cells. Treatment of cells with the histone deacetylase inhibitor trichostatin A (TSA, 200 nM) resulted in a time-dependent, selective increase in histone H4 acetylation. TSA treatment of cells stably transfected with an iNOS promoter-luciferase construct inhibited IL-1β induction of endogenous nitric oxide and iNOS protein production and iNOS promoter-luciferase activity. Chromatin immunoprecipitation assays revealed that, under basal conditions, acetylated histone H4 associated with the region −978 to −710 of the iNOS promoter, a region rich in gene control elements and that IL-1β significantly increased this binding, which was further accentuated by cotreatment with TSA. Blockade of the phosphoinositide 3-kinase pathway with LY-294002 or the p70s6-kinase pathway with rapamycin in the presence of TSA and IL-1β inhibited389Thr phosphorylation of p70s6 kinase, promoted binding of acetylated histone H4 to the iNOS promoter, and further suppressed iNOS protein expression and iNOS promoter activity. Thus TSA diminishes IL-1β-induced iNOS transcription through phosphoinositide 3-kinase- and p70s6 kinase-dependent pathways that increase site-specific histone H4 acetylation at the −978 to −710 region of the iNOS promoter. This novel epigenetic control mechanism extends the network of regulatory controls governing NO production in mesangial cells.
A cross-species analysis of the rodent uterotrophic program: elucidation of conserved responses and targets of estrogen signaling
Authors: Kwekel Joshua C. , Burgoon Lyle D. , Burt Jeremy W. , Harkema Jack R. , Zacharewski Timothy R.
Published: September 2005

Physiological, morphological, and transcriptional alterations elicited by ethynyl estradiol in the uteri of Sprague-Dawley rats and C57BL/6 mice were assessed using comparable study designs, microarray platforms, and analysis methods to identify conserved estrogen signaling networks. Comparative analysis identified 153 orthologous gene pairs that were positively correlated, suggesting conserved transcriptional targets important in uterine proliferation. Functional annotation for these responses were associated with angiogenesis, water and solute transport, cell cycle control, redox control, DNA replication, protein synthesis and transport, xenobiotic metabolism, cell-cell communication, energetics, and cholesterol and fatty acid regulation. The identification of conserved temporal expression patterns of these orthologs provides experimental support for the transfer of functional annotation from mouse orthologs to 44 previously unannotated rat expressed sequence tags based on their homology and co-expression patterns. The identification of comparable temporal phenotypic responses linked to related gene expression profiles demonstrates the ability of systematic comparative genomic assessments to elucidate important conserved mechanisms in rodent estrogen signaling during uterine proliferation.
An Angiogenesis Inhibitor E7820 Shows Broad-Spectrum Tumor Growth Inhibition in a Xenograft Model
Authors: Semba Taro , Funahashi Yasuhiro , Ono Naoto , Yamamoto Yuji , Sugi Naoko Hata , Asada Makoto , Yoshimatsu Kentaro , Wakabayashi Toshiaki
Published: September 2005

We reported previously that an angiogenesis inhibitor, E7820, inhibits in vitro tube formation of human umbilical vein endothelial cell through the suppression of integrin α2 expression. Here we describe the antiangiogenic and antitumor effects of E7820 in mice and discuss the feasibility of using platelet integrin α2 expression on platelets as a biological marker of the efficacy of E7820. Oral administration of E7820 significantly inhibited basic fibroblast growth factor-induced angiogenesis in Matrigel implants and human colon WiDr tumor-induced angiogenesis in a dorsal air sac model. Twice-daily treatment with E7820 clearly inhibited the s.c. tumor growth of seven tumor cell lines derived from human colon, breast, pancreas, and kidney, and completely suppressed the growth of human pancreatic KP-1 and human colon LoVo cell lines. Moreover, E7820 significantly inhibited the growth of KP-1 and human colon tumor Colo320DM cells orthotopically implanted in the pancreas and cecum, respectively. The efficacy of E7820 was comparable in the s.c. and orthotopic transplantation models. Immunohistochemical analyses using anti-CD31 antibody showed that E7820 significantly reduced microvessel density in orthotopically implanted KP-1 tumor. E7820 reduced integrin α2 expression on a megakaryocytic cell line, Dami cells, induced by phorbol 12-myristate 13-acetate treatment. It also decreased the expression level of integrin α2 on platelets withdrawn from mice bearing s.c. KP-1 tumor at a dosage close to that affording antitumor activity. These data demonstrate that E7820 showed a broad-spectrum antitumor effect in mice through inhibition of angiogenesis and indicate that the decrease of integrin α2 on platelets might serve as a biological marker for the antitumor efficacy of E7820.
Prognostic Significance of Activated Akt Expression in Pancreatic Ductal Adenocarcinoma
Authors: Yamamoto Shinji , Tomita Yasuhiko , Hoshida Yoshihiko , Morooka Takaya , Nagano Hiroaki , Dono Keizo , Umeshita Koji , Sakon Masato , Ishikawa Osamu , Ohigashi Hiroaki , Nakamori Shoji , Monden Morito , Aozasa Katsuyuki
Published: September 2005

Purpose: Akt is a serine/threonine kinase that plays a central role in tumorigenesis. Among the members of Akt family, Akt2 is associated with the development of human cancers. The present study was designed to clarify the prognostic significance of Akt2 and activated Akt expression in pancreatic ductal adenocarcinoma (PDAC). In addition, activated extracellular signal-regulated kinase 1 and 2 (ERK1/2) and the proliferation activity of tumor cells detected by Ki-67 immunohistochemistry were examined.

Experimental Design: Immunohistochemical analysis was performed on paraffin-embedded specimens from 65 patients with PDAC; 36 males and 29 females with ages ranging from 48 to 79 years (median, 66 years) of age. Expression levels of Akt2, phosphorylated Akt (p-Akt), and phosphorylated ERK 1/2 (p-ERK 1/2) were categorized as either weaker (low intensity) or equal to stronger (high intensity) compared with those in the endothelial cells of the same specimens. For Ki-67 immunohistochemistry, cases were divided into two groups: level 1, Ki-67 labeling index (LI), <20%; level 2, Ki-67 LI, ≥20%.

Results: Twenty-six (42.6%), 28 (45.9%), 39 (63.9%), and 46 (75.4%) of the tumors showed high intensity of Akt2, p-Akt, and p-ERK 1/2 expression, and Ki-67 LI level 2, respectively. A significant positive correlation was observed between Akt2 and p-Akt expression (P < 0.01). Multivariate analysis revealed that p-Akt expression, Ki-67 LI, and histological differentiation are independent prognosticators for PDAC.

Conclusions: p-Akt expression is a significant prognostic indicator for PDAC. Inhibition of Akt is a possible molecular approach for treatment of PDAC.
Loss of Heterozygosity at the Thymidylate Synthase (TS) Locus on Chromosome 18 Affects Tumor Response and Survival in Individuals Heterozygous for a 28-bp Polymorphism in theTSGene
Authors: Uchida Kazumi , Hayashi Kazuhiko , Kawakami Kazuyuki , Schneider Sylke , Yochim Ji Min , Kuramochi Hidekazu , Takasaki Ken , Danenberg Kathleen D. , Danenberg Peter V.
Published: September 2005

Thymidylate synthase (TS), the target enzyme of the fluoropyrimidine class of drugs, has a 28-bp repeat polymorphism in the promoter region that has been associated with response of tumors to 5-fluorouracil-based therapy. Patients homozygous for the double repeat (2R/2R) in the TS gene have an overall better outcome from treatment than patients homozygous for the triple repeat (3R/3R). However, due to loss of heterozygosity at the TS locus on chromosome 18 in cancer cells, heterozygous 2R/3R individuals can acquire the 2R/loss or the 3R/loss genotype in their tumors. The purpose of this study was to determine whether the response of colorectal cancer to fluoropyrimidine therapy is associated with the resulting tumor TS genotype when loss of heterozygosity occurs in tumor DNA. A total of 30 colorectal cancer patients treated with the fluoropyrimidine-based combination S-1, all of whom had stage IV disease, were studied. The response rate to S-1 in this group of patients was 13 of 30 (43%). The heterozygous 2R/3R genotype was found in 22 of 30 normal tissues, whereas 10 (45%) of the matched cancer tissues showed only the 2R-sequence band (2R/loss), and 7 cancer tissues (32%) showed only the 3R-sequence band (3R/loss). The response rate of the 2R/loss tumor genotype patients was 80% (8 of 10) compared with 14% (1 of 7) in the 3R/loss genotype group (P = 0.029). Patients with tumor 3R/loss genotypes had significantly lower survival than 2R/loss genotypes. Heterozygous patients with a 2R/loss tumor genotype had the same survival as 2R/2R patients, whereas patients with a 2R/3R tumor genotype had a short survival similar to homozygous 3R/3R genotypes. These results show that: (a) response to 5-fluorouracil-based therapy is determined by tumor genotype; and (b) the 3R repeat is a direct negative determinant of outcome.
Novel Temperature-Sensitive Liposomes with Prolonged Circulation Time
Authors: Lindner Lars H. , Eichhorn Martin E. , Eibl Hansjoerg , Teichert Nicole , Schmitt-Sody Marcus , Issels Rolf D. , Dellian Marc
Published: September 2005

Hyperthermia increases the efficiency of various chemotherapeutic drugs and is administered as an adjunct to chemotherapy for the treatment of cancer patients. The temperature-dependent effect can be strongly increased by the use of temperature-sensitive liposomes in combination with regional hyperthermia, which specifically releases the entrapped drug in the heated tumor tissue. The novel lipid 1.2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPPGOG), which is closely related to the naturally occurring 1.2-dipalmitoyl-sn-glycero-3-phosphoglycerol, in combination with 1.2-dipalmitoyl-sn-glycero-3-phosphocholine and 1.2-distearoyl-sn-glycero-3-phosphocholine provides long-circulating temperature-sensitive liposomes with favorable properties under mildly hyperthermic conditions (41–42°C). DPPGOG facilitates temperature-triggered drug release from these liposomes (diameter, 175 nm) and leads to a substantially prolonged plasma half-life for the encapsulated drug with t1/2 = 9.6 h in hamsters and t1/2 = 5.0 h in rats. Quantitative fluorescence microscopy of amelanotic melanoma grown in the transparent dorsal skin fold chamber of hamsters demonstrated a favorable drug accumulation in heated tissue after i.v. application of these liposomes (42°C for 1 h). The mean area under the curve for tissue drug concentration was increased by more than sixfold by application of the new liposomes compared with nonliposomal drug delivery. In summary, we present a new DPPGOG-based liposomal formulation enabling long circulation time combined with fast and efficient drug release under mild hyperthermia. This adds positively to the results with lipid-grafted polyethylenglycol used thus far in temperaturesensitive liposomes and widens the possibilities for clinical applications.
Determinants of Rapamycin Sensitivity in Breast Cancer Cells
Authors: Noh Woo-Chul , Mondesire Wallace H. , Peng Junying , Jian Weiguo , Zhang Haixia , Dong JinJiang , Mills Gordon B. , Hung Mien-Chie , Meric-Bernstam Funda
Published: September 2005

Purpose: Rapamycin inhibits the serine-threonine kinase mammalian target of rapamycin (mTOR), blocking phosphorylation of p70 S6 kinase (S6K1) and 4E-binding protein 1 (4E-BP1) and inhibiting protein translation and cell cycle progression. Rapamycin and its analogues are currently being tested in clinical trials as novel-targeted anticancer agents. Although rapamycin analogues show activity in clinical trials, only some of the treated patients respond. The purpose of this study is to identify determinants of rapamycin sensitivity that may assist the selection of appropriate patients for therapy.

Experimental Design: Breast cancer cell lines representing a spectrum of aberrations in the mTOR signaling pathway were tested for rapamycin sensitivity. The expression and phosphorylation state of multiple components of the pathway were tested by Western blot analysis, in the presence and absence of rapamycin.

Results: Cell proliferation was significantly inhibited in response to rapamycin in 12 of 15 breast cancer cell lines. The ratio of total protein levels of 4E-BP1 to its binding partner eukaryotic initiation factor 4E did not predict rapamycin sensitivity. In contrast, overexpression of S6K1, and phosphorylated Akt independent of phosphatase and tensin homologue deleted from chromosome 10 status, were associated with rapamycin sensitivity. Targeting S6K1 and Akt with small interfering RNA and dominant-negative constructs, respectively, decreased rapamycin sensitivity. Rapamycin inhibited the phosphorylation of S6K1, ribosomal S6 protein, and 4E-BP1 in rapamycin-resistant as well as -sensitive cells, indicating that its ability to inhibit the mTOR pathway is not sufficient to confer sensitivity to rapamycin. In contrast, rapamycin treatment was associated with decreased cyclin D1 levels in the rapamycin-sensitive cells but not in rapamycin-resistant cells.

Conclusions: Overexpression of S6K1 and expression of phosphorylated Akt should be evaluated as predictors of rapamycin sensitivity in breast cancer patients. Furthermore, changes in cyclin D1 levels provide a potential pharmacodynamic marker of response to rapamycin.
Phase II Randomized Trial of Autologous Formalin-Fixed Tumor Vaccine for Postsurgical Recurrence of Hepatocellular Carcinoma
Authors: Kuang Ming , Peng Bao G. , Lu Ming D. , Liang Li J. , Huang Jie F. , He Qiang , Hua Yun P. , Totsuka Saeri , Liu Shu Q. , Leong Kam W. , Ohno Tadao
Published: September 2005

Purpose: We conducted a Phase II clinical trial with randomized patients to determine whether autologous formalin-fixed tumor vaccine (AFTV) protects against postsurgical recurrence of hepatocellular carcinoma (HCC).

Experimental Design: Forty-one patients with HCC who had undergone curative resection were randomly allocated to the vaccine treatment (n = 19) or no adjuvant control group (n = 22). Three intradermal vaccinations were administered at 2-week intervals beginning 4–6 weeks after hepatic resection. A delayed-type hypersensitivity test was performed before and after vaccination. Primary and secondary end points are recurrence-free survival and overall survival, respectively. Observation continued until the majority of surviving patients had lived >12 months after the curative resection.

Results: In a median follow-up of 15 months, the risk of recurrence in vaccinated patients was reduced by 81% (95% confidence interval, 33–95%; P = 0.003). Vaccination significantly prolonged the time to first recurrence (P = 0.003) and improved recurrence-free survival (P = 0.003) and overall survival rates (P = 0.01). AFTV played a significant role in preventing recurrence in patients with small tumors. Adverse effects were limited to grade 1 or 2 skin toxicities such as erythema, dry desquamation, and pruritus.

Conclusions: AFTV therapy is a safe, feasible, and effective treatment for preventing postoperational recurrence of HCC. Patients with low tumor burdens benefit from the treatment. This treatment should be advanced to a large-scale randomized trial.
Resveratrol Suppresses the Angiogenesis and Tumor Growth of Gliomas in Rats
Authors: Tseng Sheng-Hong , Lin Swei-Ming , Chen Jin-Cherng , Su Yen-Hao , Huang Hsin-Yi , Chen Chia-Kang , Lin Po-Yin , Chen Yun
Published: September 2005

Purpose: We wanted to investigate the antitumor effects and effect on angiogenesis of resveratrol in rat RT-2 gliomas.

Experimental Design: RT-2 glioma cells were treated with resveratrol, and then cytotoxicity was assayed, apoptosis was measured by flow-activated cell sorter flow cytometry, and expression of vascular endothelial growth factor was measured by reverse transcription-PCR. Tumor size, animal survival time, and survival rate were followed in resveratrol-treated rats with s.c. or intracerebral gliomas. Furthermore, in vitro proliferation was assayed to explore the effect of resveratrol on the proliferation of ECV304 human umbilical vein endothelial cells. Expression of CD31 in resveratrol-treated gliomas was followed immunohistochemically to study the effect of resveratrol on the glioma-induced angiogenesis.

Results: Resveratrol was demonstrated to exert cytotoxic effects and induce glioma cell apoptosis in a concentration- and time-dependent manner (P < 0.05). Resveratrol (40 mg/kg/day) exerted significant antitumor effects on s.c. tumors, including slower tumor growth rate, longer animal survival time, and higher animal survival rate (P < 0.05). In contrast, resveratrol affected intracerebral tumors at only an increased dose (100 mg/kg/day), prolonging animal survival (P < 0.05) without affecting survival rate. The expression of vascular endothelial growth factor in the glioma cells and the proliferation of ECV304 cells were inhibited by resveratrol in a concentration-dependent manner. Immunohistochemical analyses showed that the s.c. gliomas from resveratrol-treated rats had fewer microvessel densities than did control rats (P < 0.01).

Conclusions: Resveratrol caused significant glioma cell cytotoxicity and apoptosis, exerted antitumor effects on the s.c. and intracerebral gliomas, and inhibited angiogenesis in s.c. gliomas. Thus, resveratrol might be considered a possible treatment strategy for gliomas.
Demethylation of the
Synuclein
γ Gene CpG Island in Primary Gastric Cancers and Gastric Cancer Cell Lines
Authors: Yanagawa Naoki , Tamura Gen , Honda Teiichiro , Endoh Makoto , Nishizuka Satoshi , Motoyama Teiichi
Published: September 2005

Purpose: Whereas synuclein γ (SNCG) gene expression is usually highly tissue-specific and restricted to the nervous system, SNCG is expressed in advanced-stage breast and ovarian cancers. When overexpressed, SNCG stimulates cancer cell proliferation and metastasis. It is thought that the molecular mechanism of CpG island demethylation may underlie aberrant SNCG expression. To determine whether aberrant SNCG expression and demethylation play a role in gastric carcinogenesis, we examined the expression and methylation status of SNCG in primary gastric cancers, gastric cancer cell lines, and non-neoplastic gastric mucosal tissues.

Experimental Design: Ten gastric cancer cell lines, 105 primary gastric cancers, and 10 non-neoplastic gastric mucosal tissues were examined. SNCG expression and methylation status were examined by reverse transcription-PCR and bisulfite-single-strand conformational polymorphism followed by direct sequencing, respectively. The relationship between SNCG methylation status and various clinicopathological factors of the primary gastric cancers was then analyzed.

Results: SNCG mRNA expression was observed in 5 of 10 cell lines. Analysis of cell lines positive for SNCG expression revealed that most of the SNCG CpGs were demethylated. SNCG mRNA was not expressed in the 10 non-neoplastic gastric mucosal tissues, although several CpGs were demethylated. Of the 105 primary gastric cancers, 40 (38.1%) showed apparent SNCG demethylation, similar to the result obtained using cell lines. SNCG demethylation was more frequent in primary gastric cancers positive for lymph node metastasis (51%; 26 of 51) than in cancers without lymph node involvement (26%; 14 of 54; P < 0.05), and also more common in stage II-IV (48%; 27 of 56) than in stage I (27%; 13 of 49) cancers (P < 0.05).

Conclusions: Aberrant SNCG gene expression can occur via CpG island demethylation, and tends to occur during the more progressive stages of gastric carcinogenesis.
Down-Regulated Expression of Cytokeratin 18 Promotes Progression of Human Breast Cancer
Authors: Woelfle Ute , Sauter Guido , Santjer Sonja , Brakenhoff Ruud , Pantel Klaus
Published: September 2005

Purpose: Cytokeratins (CKs) have been recognized for >20 years as structural marker proteins specific for epithelial cells. Recent expression profiling analyses indicate, however, that CK down-regulation may occur in breast cancer.

Experimental Design: Here we evaluated the expression pattern of CK18 by immunohistochemical analysis of primary breast carcinomas (n = 1458) spotted on a high-density tissue microarray. The findings were correlated to histopathological risk factors and clinical outcome.

Results: Down-regulation of CK18 (as compared to normal breast tissue) was observed in 25.4% of the tumors with a lower rate in lobular carcinomas (17.0%) than in ductal carcinomas (25.4%) or other histological entities (32.5%). CK down-regulation was significantly correlated to advanced tumor stage and high grade but not to axillary lymph node status. Kaplan-Meier survival analysis revealed CK18 as a prognostic indicator of overall survival (P = 0.015) and cancer-specific survival (P = 0.005).

Conclusions: Down-regulation of the luminal CK18 is not rare and a clinically relevant event in breast cancer. This finding has important implications for the use of CK18 as epithelial tumor marker. The correlations with clinical follow-up suggest that CK18 might suppress tumor pro-gression.
Biologically Different Subgroups of Invasive Ductal Carcinoma of the Pancreas
Authors: Takahashi Hidenori , Oda Tatsuya , Hasebe Takahiro , Aoyagi Yasuyuki , Kinoshita Taira , Konishi Masaru , Nakagohri Toshio , Inoue Kazuto , Takahashi Shinichiro , Kawahira Hiroshi , Monden Morito , Ochiai Atsushi
Published: September 2005

Purpose: Among invasive ductal carcinomas of the pancreas (IDCP), there is a morphologically characteristic subgroup accompanied by abundant intraductal carcinoma components (ICCs). With the aim of determining whether ICC-rich IDCP are biologically different from ICC-poor IDCP, the expression status of Dpc4 protein was analyzed.

Experimental Design: A total of 43 IDCP was subdivided into two groups: (a) ICC-rich IDCP (ICCs area occupies ≥10% of the entire tumorous area); and (b) ICC-poor IDCP (with <10% of ICCs area). A total of 10 invasive carcinomas derived from intraductal papillary-mucinous neoplasms (ICs from IPMNs) were also analyzed. Each invasive and intraductal carcinoma area was then evaluated for Dpc4 protein status by immunohistochemistry.

Results: In a total of 43 IDCP, there were 23 ICC-rich IDCP and 20 ICC-poor IDCP. Dpc4-positive immunostaining was observed in the invasive carcinoma component of ICC-rich IDCP, ICC-poor IDCP, and ICs from IPMN in 18 of 23 (78%), 4 of 20 (20%), and 7 of 10 (70%) cases, respectively. In the intraductal component, positive staining for Dpc4 was found in 20 of 23 (87%), 3 of 7 (41%), and 8 of 10 (80%) cases, respectively. Dpc4 expression was found in both the invasive and ICC components of ICC-rich IDCP, similar to that found in IC derived from IPMN, whereas the expression of Dpc4 was largely diminished in ICC-poor IDCP.

Conclusions: Morphologically distinct subgroups of invasive ductal carcinomas of the pancreas, namely ICC-rich IDCP and ICC-poor IDCP, are also biologically distinguishable as revealed by the differential expression of Dpc4.
Ribonucleotide Reductase Messenger RNA Expression and Survival in Gemcitabine/Cisplatin-Treated Advanced Non-Small Cell Lung Cancer Patients
Authors: Rosell Rafael , Danenberg Kathleen D. , Alberola Vincente , Bepler Gerold , Sanchez Jose Javier , Camps Carlos , Provencio Mariano , Isla Dolores , Taron Miquel , Diz Pilar , Artal Angel ,   on behalf of the Spanish Lung Cancer Group
Published: September 2005

Purpose: No chemotherapy regimen, including the widely used combination of gemcitabine/cisplatin, confers significantly improved survival over any other in metastatic non-small cell lung cancer (NSCLC); however, the selection of patients according to key genetic characteristics can help to tailor chemotherapy. Ribonucleotide reductase subunit M1 (RRM1) is involved in DNA synthesis and repair and in gemcitabine metabolism, and the excision repair cross-complementing group 1 (ERCC1) gene has been related to cisplatin activity.

Experimental Design: Patients were part of a large randomized trial carried out from September 1998 to July 2000, comparing gemcitabine/cisplatin versus gemcitabine/cisplatin/vinorelbine versus gemcitabine/vinorelbine followed by vinorelbine/ifosfamide. We analyzed RRM1 and ERCC1 mRNA expression in paraffin-embedded samples obtained from bronchoscopy by real-time quantitative reverse transcription-PCR. Results were correlated with survival using the Kaplan-Meier method.

Results: A total of 100 patients were assessed. There was a strong correlation between RRM1 and ERCC1 mRNA expression levels (Spearman r = 0.410; P < 0.001). In the gemcitabine/cisplatin arm, patients with low RRM1 mRNA expression levels had significantly longer median survival than those with high levels [13.7 versus 3.6 months; 95% confidence interval (CI), 9.6–17.8 months; P = 0.009]. Median survival was also significantly longer among patients with low mRNA expression levels of both RRM1 and ERCC1 (not reached), than among those with high levels of both genes (6.8 months; 95% CI, 2.6–11.1 months; P = 0.016).

Conclusions: RRM1 mRNA expression is a crucial predictive marker of survival in gemcitabine/cisplatin-treated patients. Genetic testing of RRM1 mRNA expression levels can and should be used to personalize chemotherapy.
Phase I Trial of Temozolomide and Protracted Irinotecan in Pediatric Patients with Refractory Solid Tumors
Authors: Wagner Lars M. , Crews Kristine R. , Iacono Lisa C. , Houghton Peter J. , Fuller Christine E. , McCarville M. Beth , Goldsby Robert E. , Albritton Karen , Stewart Clinton F. , Santana Victor M.
Published: September 2005

Purpose: The purpose is to estimate the maximum-tolerated dose (MTD) of temozolomide and irinotecan given on a protracted schedule in 28-day courses to pediatric patients with refractory solid tumors.

Experimental Design: Twelve heavily pretreated patients received 56 courses of oral temozolomide at 100 mg/m2/day for 5 days combined with i.v. irinotecan given daily for 5 days for 2 consecutive weeks at either 10 mg/m2/day (n = 6) or 15 mg/m2/day (n = 6). We assessed toxicity, the pharmacokinetics of temozolomide and irinotecan, and the DNA repair phenotype in tumor samples.

Results: Two patients experienced dose-limiting toxicity (DLT) at the higher dose level; one had grade 4 diarrhea, whereas the other had bacteremia with grade 2 neutropenia. In contrast, no patient receiving temozolomide and 10 mg/m2/day irinotecan experienced DLT. Myelosuppression was minimal and noncumulative. No pharmacokinetic interaction was observed. Drug metabolite exposures at the MTD were similar to exposures previously associated with single-agent antitumor activity. One complete response, two partial responses, and one minor response were observed in Ewing’s sarcoma and neuroblastoma patients previously treated with stem cell transplant. Responding patients had low or absent O6-methylguanine-DNA methyltransferase expression in tumor tissue.

Conclusions: The MTD using this schedule was temozolomide (100 mg/m2/day) and irinotecan (10 mg/m2/day), with DLT being diarrhea and infection. Drug clearance was similar to single-agent values, and clinically relevant SN-38 lactone and MTIC exposures were achieved at the MTD. As predicted by xenograft models, this combination and schedule appears to be tolerable and active in pediatric solid tumors. Evaluation of a 21-day schedule is planned.
Elevated Expression of Valosin-Containing Protein (p97) Is Associated with Poor Prognosis of Prostate Cancer
Authors: Tsujimoto Yuichi , Tomita Yasuhiko , Hoshida Yoshihiko , Kono Takuro , Oka Toshitsugu , Yamamoto Shinji , Nonomura Norio , Okuyama Akihiko , Aozasa Katsuyuki
Published: September 2005

Purpose: Valosin-containing protein (VCP) has been shown to be associated with metastasis and prognosis in human cancers. In the present study, the correlation of VCP with recurrence and prognosis in patients with prostate cancer (PCA) receiving conservative therapy was examined.

Experimental Design: VCP expression was analyzed immunohistochemically in 136 patients ranging from 46 to 92 years (median, 72 years), who received conservative therapy, including androgen deprivation, radiotherapy, or watchful waiting. Staining intensity of tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. The correlation of VCP expression between the mRNA and protein levels was examined in 10 patients.

Results: Thirty-two cases (23.5%) showed level 1 and 100 (76.5%) level 2 VCP expression. Quantitative reverse transcription-PCR analysis revealed greater VCPmRNA expression in level 2 (n = 5) than level 1 cases (n = 5; P < 0.05). A significant difference was observed between VCP level 1 and 2 patients in the positive rate for the digital rectal examination (P < 0.01), serum prostate-specific antigen level (P < 0.0001), cancer volume (P < 0.0001), Gleason score (P < 0.0001), stage (P < 0.0001), and progression-free and overall survival (P < 0.0001 for both). Multivariate analysis revealed VCP expression level, serum prostate-specific antigen level, and Gleason score to be independent prognosticators for progression-free and overall survival. Progression of PCA was found in 9.4% of level 1 but in 64% of level 2 patients.

Conclusions: PCA with level 1 VCP expression could be treated conservatively.
Noninvasive Measurements of Capecitabine Metabolism in Bladder Tumors Overexpressing Thymidine Phosphorylase by Fluorine-19 Magnetic Resonance Spectroscopy
Authors: Chung Yuen-Li , Troy Helen , Judson Ian R. , Leek Russell , Leach Martin O. , Stubbs Marion , Harris Adrian L. , Griffiths John R.
Published: September 2005

Purpose: Previous studies have shown that tumor response to capecitabine strongly correlates with tumor thymidine phosphorylase (TP). The aims of our study were to (a) investigate the pharmacological role of TP by measuring the pharmacokinetics (PK) of capecitabine in a human bladder tumor model that was characterized by the overexpression of TP and (b) develop the use of PK measurements for capecitabine by fluorine-19 magnetic resonance spectroscopy as a noninvasive surrogate marker for determining TP levels in tumors and for predicting tumor response to capecitabine in patients.

Experimental Design: TP overexpressing (2T10) and control tumors were grown s.c. in nude mice. Mice were given a dose of capecitabine or 5′-deoxy-5-fluorouridine (5′DFUR). 19F tumor spectra were acquired for determination of rate constants of capecitabine breakdown and buildup and subsequent breakdown of intermediates, 5′-deoxy-5-fluorocytidine (5′DFCR) and 5′DFUR. The rate constant of 5′DFUR breakdown was also evaluated.

Results: The rate constant of breakdown of intermediates was significantly faster in 2T10 tumors than controls (P < 0.003). No significant differences in the rate of capecitabine breakdown or intermediate buildup were observed. The rate constant of 5′DFUR breakdown in the 2T10 tumors was doubled compared with controls (P < 0.001).

Conclusions: This study confirmed the expected pathway of capecitabine metabolism and showed that the level of TP was related to the rate of 5′DFUR conversion. Using in vivo fluorine-19 magnetic resonance spectroscopy to mea-sure the PK of capecitabine and its intermediate metabolites in tumors may provide a noninvasive surrogate method for determining TP levels in tumors and for predicting tumor response to capecitabine in patients.
Evaluating Antiangiogenesis Agents in the Clinic
Authors: Sparano Joseph A. , Gray Robert , Giantonio Bruce , O’Dwyer Peter , Comis Robert L.
Published: September 2005

Recent evidence indicates that treatment with a humanized monoclonal antibody (bevacizumab) directed at vascular endothelial growth factor improves response and survival in metastatic colorectal cancer when added to standard chemotherapy, validating angiogenesis as a therapeutic target. Investigators from the Eastern Cooperative Oncology Group (ECOG) have initiated a number of Phase III studies that will help further define the role of antiangiogenic agents for the treatment of breast, colon, lung, renal, and head and neck cancer, as well as melanoma and myeloma. The agents being evaluated target various biological functions involved in angiogenesis, including vascular endothelial growth factor (bevacizumab), endothelial cell proliferation (thalidomide, IFN-α), and matrix metalloproteinases (marimastat). These clinical trials include correlative laboratory studies aimed at elucidating how these agents may exert their clinical effects. The portfolio of Eastern Cooperative Oncology Group studies will serve to further define the role of this therapeutic strategy for patients with advanced cancer.
Predictive Significance of the Alterations of p16INK4A, p14ARF, p53, and Proliferating Cell Nuclear Antigen Expression in the Progression of Cervical Cancer
Authors: Wang Jian-Liu , Zheng Bi-Ying , Li Xi-Dan , Ångström Tord , Lindström Mikael S. , Wallin Keng-Ling
Published: September 2005

Purpose: The purpose of this research was to evaluate the clinical significance of p16INK4A, p14ARF, p53, and proliferating cell nuclear antigen (PCNA) expression in tumor progression of cervical cancer.

Design: Seventeen patients (40 samples) with consecutive cervical lesions from normal squamous epithelium, inflammation of the cervix to cervical intraepithelial neoplasm (CIN) and invasive cervical squamous cell cancer (SCC), or from CIN to SCC were collected for this study. Expression of p16INK4A, p14ARF, p53, and PCNA were detected by immunohistochemistry on paraffin-embedded sections. Human papillomavirus DNA was detected simultaneously with PCR and typed according to its DNA sequence.

Results: p16INK4A overexpression was significantly higher in CIN (75%) and in SCC (75%) than in normal or inflammation of the cervix (12.5%; P < 0.01, P < 0.05, respectively). The positive rate of p14ARF expression was higher in SCC (83%) than in normal/inflammation of the cervix (25%; P < 0.05). PCNA expression was negative in normal or inflammation of the cervix, but an increased in expression was seen in 63.2% in CIN and 100% in SCC (P < 0.01, P < 0.05). When the time interval for disease progression from initial biopsy to CIN 3 or invasive cancer was compared with states of p16INK4A expression, cases stained positive for p16INK4A progressed within 64.2 months as compared with 122.3 months among those stained negatively (P < 0.01). Cases with increased p14ARF expression also had a short time interval for disease progression of 78.8 months as compared with 108.3 months in cases that were p14ARF negative. Cases with stable or decreased p53 expression had the shortest time interval for progression of 32.3 months in contrast to cases with no p53 expression (113.9 months). However, cases with increasing p53 expression progressed within 60.8 months.

Conclusions: Our results suggested that altered states of p16INK4A, p14ARF, p53, and PCNA may be valuable markers to predict the progression of cervical neoplasia.
Specific Chemopreventive Agents Trigger Proteasomal Degradation of G1 Cyclins: Implications for Combination Therapy
Authors: Dragnev Konstantin H. , Pitha-Rowe Ian , Ma Yan , Petty W. Jeffrey , Sekula David , Murphy Bryan , Rendi Mara , Suh Nanjoo , Desai Neil B. , Sporn Michael B. , Freemantle Sarah J. , Dmitrovsky Ethan
Published: September 2005

Purpose: There is a need to identify cancer chemoprevention mechanisms. We reported previously that all-trans-retinoic acid (RA) prevented carcinogenic transformation of BEAS-2B immortalized human bronchial epithelial cells by causing G1 arrest, permitting repair of genomic DNA damage. G1 arrest was triggered by cyclin D1 proteolysis via ubiquitin-dependent degradation. This study investigated which chemopreventive agents activated this degradation program and whether cyclin E was also degraded.

Experimental Design: This study examined whether: (a) cyclin E protein was affected by RA treatment; (b) cyclin degradation occurred in derived BEAS-2B-R1 cells that were partially resistant to RA; and (c) other candidate chemopreventive agents caused cyclin degradation.

Results: RA treatment triggered degradation of cyclin E protein, and ALLN, a proteasomal inhibitor, inhibited this degradation. Induction of the retinoic acid receptor β, growth suppression, and cyclin degradation were each inhibited in BEAS-2B-R1 cells. Transfection experiments in BEAS-2B cells indicated that RA treatment repressed expression of wild-type cyclin D1 and cyclin E, but ALLN inhibited this degradation. Mutation of threonine 286 stabilized transfected cyclin D1, and mutations of threonines 62 and 380 stabilized transfected cyclin E, despite RA treatment. Specific chemopreventive agents triggered cyclin degradation. Nonclassical retinoids (fenretinide and retinoid X receptor agonists) and a synthetic triterpenoid (2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid) each suppressed BEAS-2B growth and activated this degradation program. However, a vitamin D3 analog (RO-24–5531), a cyclooxygenase inhibitor (indomethacin), and a peroxisome proliferator-activated receptor γ agonist (rosiglitazone) each suppressed BEAS-2B growth, but did not cause cyclin degradation. BEAS-2B-R1 cells remained responsive to nonclassical retinoids and to 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid.

Conclusions: Specific chemopreventive agents activate cyclin proteolysis. Yet, broad resistance did not occur after acquired resistance to a single agent. This provides a therapeutic rationale for combination chemoprevention with agents activating non-cross-resistant pathways.