bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification and functional analysis of chemotaxis by laser scanning cytometry
Authors: Butt Omar I. , Krishnan Padmavathy , Kulkarni Sumant S. , Moldovan Leni , Moldovan Nicanor I.
Published: February 2005

Background

Evaluation of chemotaxis assays traditionally relies on cumbersome and at times inaccurate visual counting. Moreover, many physiologic parameters that could be evaluated in conjunction with chemotactic migration, aside from morphologic changes, usually are not assessed due to the lack of a simultaneous method of analysis. We tested the suitability of laser scanning cytometry (LSC) as a convenient platform for counting migrated cells and for concurrent analysis of some features associated with their physiologic status.

Methods

We induced migration of THP‐1 monocytes across Nuclepore filters with monocyte chemotactic protein‐1 or vascular endothelial growth factor, alone or in combination. Filters were collected, and cells were fixed on filters and stained with the nuclear stain propidium iodide. Chemotactic indices were obtained by counting representative microscopic fields and by scanning the filters in LSC mode.

Results

We found an excellent correlation between direct counting and LSC. In addition, the software tools embodied in the LSC instrument allowed the observation of changes in nuclear compactness (increase in propidium iodide brightness) and morphology (increase in nuclear area and perimeter) that occurred in transmigrated cells. Monocyte chemotactic protein‐1 and vascular endothelial growth factor acted as additive stimuli on these parameters.

Conclusions

LSC analysis of cells undergoing chemotaxis provides a reliable and comprehensive assessment of the numbers and distribution of migrated cells and some of their nuclear parameters. The method can be easily extended to include the assessment of coincident molecular changes in cells due to chemotactic stimulation. © 2005 Wiley‐Liss, Inc.
Genetically encoded sensors for metabolites
Authors: Deuschle Karen , Fehr Marcus , Hilpert Melanie , Lager Ida , Lalonde Sylvie , Looger Loren L. , Okumoto Sakiko , Persson Jörgen , Schmidt Anja , Frommer Wolf B.
Published: February 2005

Background

Metabolomics, i.e., the multiparallel analysis of metabolite changes occurring in a cell or an organism, has become feasible with the development of highly efficient mass spectroscopic technologies. Functional genomics as a standard tool helped to identify the function of many of the genes that encode important transporters and metabolic enzymes over the past few years. Advanced expression systems and analysis technologies made it possible to study the biochemical properties of the corresponding proteins in great detail. We begin to understand the biological functions of the gene products by systematic analysis of mutants using systematic PTGS/RNAi, knockout and TILLING approaches. However, one crucial set of data especially relevant in the case of multicellular organisms is lacking: the knowledge of the spatial and temporal profiles of metabolite levels at cellular and subcellular levels.

Methods

We therefore developed genetically encoded nanosensors for several metabolites to provide a basic set of tools for the determination of cytosolic and subcellular metabolite levels in real time by using fluorescence microscopy.

Results

Prototypes of these sensors were successfully used in vitro and also in vivo, i.e., to measure sugar levels in fungal and animal cells.

Conclusions

One of the future goals will be to expand the set of sensors to a wider spectrum of substrates by using the natural spectrum of periplasmic binding proteins from bacteria and by computational design of proteins with altered binding pockets in conjunction with mutagenesis. This toolbox can then be applied for four‐dimensional imaging of cells and tissues to elucidate the spatial and temporal distribution of metabolites as a discovery tool in functional genomics, as a tool for high‐throughput, high‐content screening for drugs, to test metabolic models, and to analyze the interplay of cells in a tissue or organ. © 2005 Wiley‐Liss, Inc.
MHC class I‐restricted exogenous presentation of a synthetic 102‐mer malaria vaccine polypeptide
Authors: Prato Sandro , Maxwell Tammy , Pinzón‐Charry Alberto , Schmidt Christopher William , Corradin Giampietro , López José Alejandro
Published: February 2005

The circumsporozoite (CS) is the most abundant surface protein of the Plasmodium sporozoite, and is also present early in the liver stage of the infection. Following successful protective experiments in mice and monkeys, the synthetic 102‐mer malaria vaccine polypeptide representing the C‐terminal region of the CS of Plasmodium falciparum was tested in a clinical trial with healthy human volunteers. This vaccine induced strong CD8+, CD4+ T lymphocyte and antibody responses specific for the immunizing peptide. CD8+ T lymphocyte responses elicited in HLA‐A*0201 volunteers recognized two well‐defined cytotoxic T lymphocyte epitopes within the CS. Here, we show that both monocyte‐derived dendritic cells (Mo‐DC) and Epstein‐Barr virus‐transformed B‐lymphoblastoid cells (LCL) can present a cytotoxic T lymphocyte epitope contained within the 102‐mer synthetic peptide. Paraformaldehyde and low temperature inhibited presentation, indicating that cellular processing was required. Using specific inhibitors, we show that, in both cell types, processing requires the proteasome and the MHC class I pathway, while the endosomal compartment appears to be critical only for the presentation by Mo‐DC. Antigen uptake is associated with actin polymerization in both cell types. These in vitro results demonstrate the likely pathway of antigen presentation achieved via vaccination with this synthetic peptide.
Carcinogenic polycyclic aromatic hydrocarbon‐DNA adducts and mechanism of action
Authors: Baird William M. , Hooven Louisa A. , Mahadevan Brinda
Published: February 2005

Polycyclic aromatic hydrocarbons (PAHs) are a class of widespread environmental carcinogens. Most of our knowledge of their mechanisms of metabolic activation to DNA‐binding “ultimate carcinogenic” metabolites has come from analysis of the DNA interaction products formed by these highly reactive intermediates. Studies of their role in forming DNA‐binding intermediates identical to those formed in vivo from the PAH itself have also allowed identification of the particular cytochrome P450 enzymes involved in activating various structural classes of carcinogenic PAHs. It has been established that PAHs, after metabolic activation in vivo, are capable of inducing mutations in oncogenes and, by inducing multiple mutations, may result in tumors. PAHs also cause changes in cellular gap‐junction communication similar to those caused by the tumor promoter 12‐O‐tetradecanoylphorbol‐13‐acetate. Thus, PAHs may also act through a promotional mechanism in addition to serving as tumor initiators. Previous studies on these mechanisms are described and summarized. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Generation of loss of heterozygosity and its dependency on p53 status in human lymphoblastoid cells
Authors: Honma Masamitsu
Published: February 2005

Loss of heterozygosity (LOH) is a critical event in the development of human cancers. LOH is thought to result from either a large deletion or recombination between homologous alleles during repair of DNA double‐strand breaks (DSBs). These types of genetic alterations produce mutations in the TK gene mutation assay, which detects a wide mutational spectrum, ranging from point mutations to LOH‐type mutations. TK6, a human lymphoblastoid cell line, is heterozygous for the thymidine kinase (TK) gene and has a wild‐type p53 gene. The related cell lines, TK6‐E6 and WTK‐1, which are p53‐deficient and p53‐mutant (Ile237), respectively, are also heterozygous for the TK gene and LOH‐type mutation can be detected in these cells. Therefore, comparative studies of TK mutation frequency and spectrum with these cell lines are useful for elucidating the role of p53 in generating LOH and maintaining genomic stability in human cells. We demonstrate here that LOH and its associated genomic instability strongly depend on the p53 status in these cells. TK6‐E6 and WTK‐1 are defective in the G1/S checkpoint and in apoptosis. Unrepaired DSBs that escape from the checkpoint can potentially initiate genomic instability after DNA replication, resulting in LOH and a variety of chromosome changes. Moreover, genomic instability is enhanced in WTK‐1 cells. It is likely that the mutant p53 protein in WTK‐1 cells increases LOH in a dominant‐negative manner due to its abnormal recombination capacity. We discuss the mutator phenotype and genomic instability associated with p53 inactivation with the goal of elucidating the mechanisms of mutation and DNA repair in untargeted mutagenesis. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Use of biomarkers to elucidate genetic susceptibility to cancer
Authors: Au William W. , Salama Salama A.
Published: February 2005

Genetic variations have generally been accepted to be the major mechanism for the differences observed in susceptibility to cancer. However, extensive investigations on genotype‐disease associations have not produced consistent results. The inconsistency may be caused by many factors, such as improper study design, insufficient sample size, complexity of the traits under investigation, heterogeneity of the study subjects, incorrect assumptions about the underlying genetic architecture, misclassification of the disease, improper selection of potential alleles, and overinterpretation of the data. Besides these “traditional” factors, a recent problem is that the function of many variant genotypes is unknown, especially with regard to polymorphic DNA repair genes. Therefore, in addition to the genotype‐disease relationship, it may be prudent to step back and investigate the fundamental role of genetic variation in the development of cancer. The latter studies may focus on understanding the genotype‐exposure interactions and evaluating genotype‐health risk associations. This review will emphasize the use of relevant biomarkers and polymorphic DNA repair genes for investigations. These data will be useful for a better understanding of the complexity of disease causation and development, developing new models for human disease, and identifying pathways for prevention of cancer. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Human population studies with cytogenetic biomarkers: Review of the literature and future prospectives
Authors: Bonassi Stefano , Ugolini Donatella , Kirsch‐Volders Micheline , Strömberg Ulf , Vermeulen Roel , Tucker James D.
Published: February 2005

Cytogenetic biomarkers are by far the most frequently used endpoints in human population studies. Their sensitivity for measuring exposure to genotoxic agents and their role as early predictors of cancer risk have contributed to this success. In this article, we present an overview of the last 25 years of population studies with cytogenetic biomarkers, describing the evolution of this research and addressing the most promising innovations for the future. The evaluation has been restricted to the most popular assays, i.e., chromosomal aberrations (CAs) and micronucleus (MN), which are considered to be causally related to early stages of chronic diseases, especially cancer, and may therefore play a major role in prevention. An extensive literature search covering the period 1 January 1980 to 31 December 2003 was performed using the Medline/PubMed database. A total of 833 population studies using CAs and 434 using matched MN inclusion criteria were included in the analysis. We report the distribution of selected papers by year of publication, country, language, agents investigated, and methods employed. The state of the art and future prospects regarding cytogenetic techniques and epidemiologic and statistical methods are discussed. The role of susceptibility and its potential impact on genotoxic damage are discussed with special attention to the effect of major genetic polymorphisms on the baseline frequency of CAs and micronuclei. Environ. Mol. Mutagen., 2005. © 2005 Wiley‐Liss, Inc.
Serial in vivo loss and in vitro gain of Fas expression and function in human cancerous pancreatic duct cells
Authors: Radfar Soroosh , Davrinche Christian , Hollande Etienne
Published: February 2005

Recent studies have shown the involvement of the Fas system (Fas receptor and its ligand FasL) in cancerous processes. The absence or downregulation of Fas, reported in the majority of human tumors, conflicts with its presence in cancerous cells from the same tumors but maintained in vitro. Recently, the eventual role of environmental factors in the loss of Fas expression, or in the in vivo selection of a Fas‐negative cell population has been suggested. We determined the Fas expression and function in the Capan‐1 human cancerous pancreatic duct cells over 2 successive passages in vivo separated by a period of 10–20 passages in vitro. We showed that Capan‐1 cells express Fas and are sensitive to Fas‐mediated apoptosis when maintained in vitro. When these cells were xenografted into nude mice the expression of Fas was lost in the majority of the tumors. Culture of tumor‐derived cells exhibited that they became Fas‐positive and sensitive to Fas‐mediated apoptosis after a short period in vitro. The loss/gain of Fas was reproduced after re‐explantation and re‐culture of these Fas‐expressing cells. Furthermore, RT‐PCR evidenced a strong inhibition of Fas, FLICE and FADD mRNAs expression in the xenografts. Our observations indicate that the expression of Fas and its function could depend to factors in the tumoral environment. The in vivo loss of Fas may thus play an important role in the tumor formation and in the evasion of tumor cells from immune surveillance. © 2005 Wiley‐Liss, Inc.
Simultaneous targeting of IL2 and IL12 to Hodgkin's lymphoma cells enhances activation of resting NK cells and tumor cell lysis
Authors: Hombach Andreas , Heuser Claudia , Abken Hinrich
Published: February 2005

Hodgkin's disease (HD) is characterized by the accumulation of functionally anergic T cells in the vicinity of the malignant Hodgkin/Reed‐Sternberg (H/RS) cells. To revert cellular anergy against H/RS cells, we generated an anti‐CD30‐antibody‐interleukin‐(IL)‐2 and an anti‐CD30‐antibody‐IL12 fusion protein that target IL2 and IL12, respectively, specifically to CD30+ H/RS cells. Both antibody‐cytokine fusion proteins act cooperatively in the activation of resting NK cells, the induction of IFN‐gγ secretion and enhanced target cell lysis. The cooperative activity of the targeted cytokines suggests that the application of both antibody‐cytokine fusion proteins may be particularly suitable for the specific immunotherapy of Hodgkin's lymphoma. © 2005 Wiley‐Liss, Inc.
Tissue inhibitor of metalloproteinase‐3 (TIMP‐3) gene is methylated in the development of esophageal adenocarcinoma: Loss of expression correlates with poor prognosis
Authors: Darnton S. Jane , Hardie Laura J. , Muc Ronald S. , Wild Christopher P. , Casson Alan G.
Published: February 2005

Amongst involvement in diverse physiological and pathological processes, TIMP‐3 may have an important role in tumour development, growth and metastasis by interaction with metalloproteases in the extracellular matrix. We studied the role and prognostic effect of TIMP‐3 in esophageal adenocarcinoma (EADC). TIMP‐3 gene methylation and TIMP‐3 mRNA expression were analysed in 5 esophageal cell lines and 24 resected EADCs. TIMP‐3 protein expression was examined in the 5 cell lines and 79 resected EADCs with known clinicopathological features. TIMP‐3 methylation signal was only detected in the OE33 EADC cell line. In tissues, 0% of case‐matched normal, 72% of BE and 90% of EADC were positive for methylation. TIMP‐3 mRNA was detected in all the cell lines and normal, metaplastic and tumour tissues. TIMP‐3 protein was localised to the cytoplasm in cell lines and tissues. Demethylating treatment of OE33 increased protein expression. At the invading edge of tumours, protein staining was equal to, or reduced, compared to normal tissues. Reduction of protein expression was associated with disease stage (p = 0.046) and poor patient survival (OR 2.1, 95% CI 1.2–3.5, p = 0.007). Mean survival time was halved in patients with reduced tumour TIMP‐3 expression, from 49 to 24 months. These studies have demonstrated association between methylation of the TIMP‐3 gene and BE and EADC. Reduced expression of TIMP‐3 protein in EADC is associated with increased tumour invasiveness and reduced patient survival. © 2005 Wiley‐Liss, Inc.
Characterization of a rat model with site‐specific bone metastasis induced by MDA‐MB‐231 breast cancer cells and its application to the effects of an antibody against bone sialoprotein
Authors: Bäuerle Tobias , Adwan Hassan , Kiessling Fabian , Hilbig Heidegard , Armbruster Franz P. , Berger Martin R.
Published: February 2005

Metastasis into the skeleton is a serious complication of certain neoplastic diseases such as breast, prostate and lung cancer, but the reasons for this osteotropism are poorly understood. Our aim was to establish a physiologically relevant animal model that is characterized by osteolytic lesions confined to the hind leg of nude rats. For this purpose, we injected 1×105 MDA‐MB‐231 human breast cancer cells transfected with GFP into the superficial epigastric artery, which is an anastomosing vessel between the femoral and iliac arteries. As assessed with the aid of X‐rays, computed tomography and immunohistochemisty, osteolytic lesions occurred exclusively in the femur, tibia and fibula of the animals. The tumor take rate was 93% in a series of 96 rats and the increase in lesion size was observed up to 110 days after tumor cell inoculation. When applying this animal model to the effects of an antibody against bone sialoprotein (BSP), a significantly reduced osteolytic lesion size was observed after preincubation of cells (2 hr, 600 μg/ml anti‐BSP) prior to intra‐arterial tumor cell injection resulting in 19 T/C% at day 60 after tumor implantation (p < 0.05). In addition, the osteolytic lesion size was also significantly reduced after s.c. treatment of the animals with the antibody (20 mg/kg anti‐BSPx3 within 5 days after tumor implantation), resulting in 30 T/C% at day 60 after tumor cell implantation (p < 0.05). In conclusion, the novel rat model for site‐specific osteolytic lesions provides in vivo evidence that preincubation of MDA‐MB‐231GFP cells and treatment of rats after tumor implantation with an antibody against BSP significantly reduces the size of lytic lesions in bone. © 2005 Wiley‐Liss, Inc.
Effect of α‐naphthyl isothiocyanate on 2‐amino‐3‐methylimidazo[4,5‐b]pyridine (PhIP)‐induced mammary carcinogenesis in rats
Authors: Sugie Shigeyuki , Ohnishi Masami , Ushida Jun , Yamamoto Tomohiro , Hara Akira , Koide Akihiro , Mori Yukio , Kohno Hiroyuki , Suzuki Rikako , Tanaka Takuji , Wakabayashi Keiji , Mori Hideki
Published: February 2005

The modifying effects of α‐naphthyl isothiocyanate (ANIT) on 2‐amino‐3‐methylimidazo[4,5‐b]pyridine (PhIP)‐induced mammary carcinogenesis were investigated in female Sprague‐Dawley (SD) rats, and the hepatic activities of the phase II detoxifying enzymes glutathione S‐transferase (GST) and quinone reductase (QR) were also assayed. Ninety‐eight rats were divided into 4 groups. Starting at 6 weeks of age, rats were fed the high‐fat diet without ANIT (Groups 1 and 4) or the experimental diet (high‐fat diet mixed with 400 ppm ANIT, Groups 2 and 3). At 7 weeks of age, Groups 1 and 2 were given PhIP in corn oil (85 mg/kg body weight, 8 times for 11 days) by intragastric intubation. One week after the last PhIP injection, 5 rats in each group were sacrificed to assay GST and QR activities, and the experimental diets for Groups 2 and 3 were switched to the high‐fat diet without ANIT until termination of the experiment. Group 4 served as the vehicle control. All rats were sacrificed at 24 weeks after the start of the experiment. At termination of the experiment, mammary tumours were detected in Groups 1 (PhIP alone) and 2 (PhIP + ANIT) and were shown histologically to be adenocarcinomas; their incidences (multiplicities) were 56.3% (1.66 ± 2.31/rat) in Group 1 and 6.7% (0.07 ± 0.25/rat) in Group 2 (p < 0.001). Mean sizes of the tumours were 10.6 ± 5.3 mm in Group 1 and 6.5 mm in Group 2. No mammary tumours were observed in rats of Groups 3 and 4. In addition, ANIT treatment significantly increased the activities of GST and QR in the livers of rats in Groups 2 and 3 as compared to Groups 1 and 4. These results imply that the isothiocyanate compound ANIT shows potent inhibitory effects on mammary carcinogenesis induced by PhIP in female SD rats when administered during the initiation stage. © 2005 Wiley‐Liss, Inc.
Fas‐associated factor‐1 mediates chemotherapeutic‐induced apoptosis via death effector filament formation
Authors: Park Min‐Young , Ryu Seung‐Wook , Kim Kwang Dong , Lim Jong‐Seok , Lee Zee‐Won , Kim Eunhee
Published: February 2005

Fas‐associated factor‐1 (FAF1) is a newly introduced member of the Fas death‐inducing signaling complex and potentiates Fas‐mediated apoptosis. Clinical study has revealed that FAF1 is significantly reduced in gastric carcinomas. The present study demonstrates that FAF1 mediates chemotherapeutic‐induced apoptosis via participation in the formation of death effector filament (DEF), a cytoskeleton‐like structure found in receptor‐independent apoptosis. Overexpression of FAF1 enhanced DEF assembly and cell death induced by chemotherapeutics such as staurosporine (STS), cisplatin (CDDP) and etoposide (VP16). FAF1 sensitized cells to STS, CDDP and VP16 in dose‐ and time‐dependent manner. Introduction of antisense FAF1 construct inhibited DEF assembly and chemotherapeutic‐induced apoptosis. Analysis using FAF1 truncates showed that the FAF1 domain interacting with DEDs of FADD and caspase‐8 was sufficient to enhance DEF assembly. Confocal microscopy revealed that FAF1 was present in DEFs together with FADD and caspase‐8. Collectively, our data provide a molecular mechanism for the chemosensitization by FAF1 (i.e., mediating DEF assembly). © 2005 Wiley‐Liss, Inc.
Tumor HLA‐DR expression linked to early intrahepatic recurrence of hepatocellular carcinoma
Authors: Matoba Katsuhiro , Iizuka Norio , Gondo Toshikazu , Ishihara Tokuhiro , Yamada‐Okabe Hisafumi , Tamesa Takao , Takemoto Norikazu , Hashimoto Kiichiro , Sakamoto Kazuhiko , Miyamoto Takanobu , Uchimura Shunji , Hamamoto Yoshihiko , Oka Masaaki
Published: February 2005

The outcome of patients with hepatocellular carcinoma (HCC) remains poor because of the high frequency of intrahepatic recurrence (IHR), particularly early IHR within 1 year of hepatectomy. To search for genes involved in early IHR, we performed DNA microarray analysis in a training set of 33 HCCs and selected 46 genes linked to early IHR from approximately 6,000 genes by means of a supervised learning method. Gene selection was validated by a false discovery rate of 0.37%. The 46 genes included many immune response‐related genes, which were all downregulated in HCCs with early IHR. Four of these genes (HLA‐DRA, HLA‐DRB1, HLA‐DG and HLA‐DQA), encoding MHC class II antigens, were coordinately downregulated in HCCs with early IHR compared to levels in HCCs with nonrecurrence. A cluster analysis reproduced expression patterns of the 4 MHC class II genes in 27 blinded HCC samples. To localize the major site of production of HLA‐DR protein in the tumor, we used 50 frozen specimens from 50 HCCs. Immunofluorescence staining showed that HLA‐DR protein levels in tumor cells, but not in stromal cells, were associated with the transcription levels of HLA‐DRA determined by both DNA microarray analysis and real‐time quantitative reverse transcription‐PCR. Univariate analysis showed that tumor HLA‐DR protein expression, pTNM stage and venous invasion were associated with early IHR. Multivariate analysis showed that tumor HLA‐DR protein expression was one of the independent risk factors for early IHR, suggesting HLA‐DR protein potential as a biomarker and a molecular target for therapeutic intervention. © 2005 Wiley‐Liss, Inc.
HPV16 semiquantitative viral load and serologic biomarkers in oral and oropharyngeal squamous cell carcinomas
Authors: Kreimer Aimée R. , Clifford Gary M. , Snijders Peter J.F. , Castellsagué Xavier , Meijer Chris J.L.M. , Pawlita Michael , Viscidi Raphael , Herrero Rolando , Franceschi Silvia
Published: February 2005

A considerable subset of oropharyngeal squamous cell carcinomas (SCCs) are positive for human papillomavirus (HPV); however, delineating etiologically‐associated HPV infections from SCCs with concurrent HPV infection unrelated to tumorigenesis is challenging. Viral load assessment in biopsy specimens may help facilitate such differentiation. HPV16 viral load and serologic markers were assessed among oral and oropharyngeal cases from a multinational study conducted by the International Agency for Research on Cancer (IARC). HPV16 viral load, measured semiquantitatively by PCR‐enzyme immunoassay, was dichotomized as high or low based on the median optical density value. Serologic antibodies to HPV16 virus‐like particles (VLPs) and to HPV16 E6 and E7 proteins were measured by ELISA. Compared to HPV DNA‐negative cases (n = 852), HPV16 DNA‐positive cases with high viral load (n = 26) were significantly more likely to originate in the oropharynx (odds ratio [OR], 12.0; 95% confidence interval [CI], 5.2–27.5) and, after adjustment for tumor site (AdjOR), have antibodies against HPV16 VLPs (AdjOR, 14.6; 95% CI, 6.0–35.6), E6 (AdjOR, 57.6; 95% CI, 21.4–155.3) and E7 (AdjOR, 25.6; 95% CI, 9.3–70.8). HPV16 DNA‐positive cases with low viral load (n = 27) were more commonly oropharyngeal (OR, 2.7; 95% CI, 1.1–6.2) and seropositive for HPV16 VLPs (AdjOR, 2.7; 95% CI, 1.1–6.9), E6 (AdjOR, 3.0; 95% CI, 0.7–14.0) and E7 (AdjOR, 3.5; 95% CI, 0.7–16.3), compared to HPV DNA‐negative cases; the associations, however, were neither as strong nor as significant as the associations for high viral load. As there appears to be a strong association between HPV16 serologic markers and viral load, in the absence of data on serologic markers, HPV16 viral load may be used to help delineate the subset of HPV16 DNA‐positive oral and oropharyngeal cancers that may be the consequence of HPV infection. © 2005 Wiley‐Liss, Inc.
Cyclooxygenase‐2 inhibitor celecoxib augments chemotherapeutic drug‐induced apoptosis by enhancing activation of caspase‐3 and ‐9 in prostate cancer cells
Authors: Dandekar Devendra S. , Lopez Monica , Carey Robert I. , Lokeshwar Bal L.
Published: February 2005

Many tumors constitutively express high levels of the inducible form of proinflammatory enzyme, cyclooxygenase‐2 (COX‐2). Increased COX‐2 expression is associated with tumor cell resistance to many cytotoxic chemotherapy drugs. Furthermore, increased resistance to cytotoxic antitumor drugs is also known to be dependent on associated stromal cells in many tumors. We investigated whether prostate tumor‐associated stromal cells, marrow‐derived osteoblasts, affect cytotoxicity of 2 antitumor drugs, COL‐3 and docetaxel (TXTR), and whether it is dependent on COX‐2 activity. We further examined whether inhibiting the activity of COX‐2 negate the stroma‐induced decrease in drug sensitivity in tumor cells. COX‐2‐specific inhibitor celecoxib (CXB) was used to inhibit COX‐2 activity and associated alteration in cell death signaling was investigated. Coculturing PC‐3ML cells with osteoblasts decreased the cytotoxicity of the tested antitumor drugs and was associated with increased COX‐2 activity in PC‐3ML cells. A significant decrease in drug‐induced PGE2 increase and an increase in cytotoxicity were observed when cells were treated with COL‐3 or TXTR combined with CXB. Cytotoxicity of single or combination treatment increased apoptosis, which was associated with caspase‐3 and ‐9 activation, PARP cleavage, increased BAD protein, but decreased protein levels of XIAP and BCL‐xL. Oral administration of CXB (40 mg/kg) to mice with PC‐3ML tumors for 42 days increased tumor latency, decreased tumor growth and enhanced tumor control with COL‐3 or TXTR. Overall, a synergistic enhancement of antitumor activity in combination treatment was observed in vitro and an additive effect in vivo. These observations suggest a potential clinical use of combined dosing of COX‐2 inhibitors and cytotoxic drugs at lower, nontoxic dose than currently used to treat advanced prostate cancer. © 2005 Wiley‐Liss, Inc.
Metastatic transcriptional pattern revealed by gene expression profiling in primary colorectal carcinoma
Authors: D'Arrigo Antonello , Belluco Claudio , Ambrosi Alessandro , Digito Maura , Esposito Giovanni , Bertola Antonella , Fabris Michele , Nofrate Valentina , Mammano Enzo , Leon Alberta , Nitti Donato , Lise Mario
Published: February 2005

Metastatic spread to the liver is the major contributor to mortality in patients with colorectal carcinoma (CRC). In order to seek for gene expression patterns associated with metastatic potential in primary CRC, we compared the transcriptional profiles of 10 radically resected primary CRCs from patients who did not develop distant metastases within a 5‐year follow‐up period with those of 10 primary/metastatic tumor pairs from patients with synchronous liver metastases. To focus selectively on neoplastic cells, the study was conducted on laser‐microdissected bioptic tissues. Arrays of 7,864 human cDNAs were utilized. While a striking transcriptional similarity was observed between the primary tumors and their distant metastases, the nonmetastasizing primary tumors were clearly distinct from the primary/metastatic tumor pairs. Of 37 gene expression differences found between the 2 groups of primary tumors, 29 also distinguished nonmetastasizing tumors from metastases. The gene encoding for mannosyl (α‐1,3‐)‐glycoprotein β‐1,4‐N‐acetyl‐glucosaminyl‐transferase (GnT‐IV) became significantly upregulated in primary/metastatic tumor pairs (p < 0.001). GnT‐IV upregulation was confirmed by RT‐PCR. These data support the existence of a specific transcriptional signature distinguishing primary colon adenocarcinomas with different metastatic potential, the further pursuit of which may lead to relevant clinical and therapeutic applications. © 2005 Wiley‐Liss, Inc.
Comparison of the effects of the chemopreventive agent resveratrol and its synthetic analog trans 3,4,5,4′‐tetramethoxystilbene (DMU‐212) on adenoma development in the ApcMin+ mouse and cyclooxygenase‐2 in human‐derived colon cancer cells
Authors: Sale Stewart , Tunstall Richard G. , Ruparelia Ketan C. , Potter Gerry A. , Steward William P. , Gescher Andreas J.
Published: February 2005

Naturally occurring molecules with putative cancer chemopreventive properties such as the phytoalexin resveratrol (3,5,4′‐trihydroxystilbene) are lead molecules that guide the design of novel agents with improved pharmacologic properties. The synthetic resveratrol analog 3,4,5,4′‐tetramethoxystilbene (DMU‐212) has been shown to possess stronger antiproliferative properties in human colon cancer cells than resveratrol. We tested the hypothesis that DMU‐212 is also a more potent inhibitor of adenoma development in the ApcMin+ mouse, a model of human intestinal carcinogenesis. ApcMin+ mice received either stilbene derivative with the diet (0.2%), and adenomas were counted after experiments were terminated. Resveratrol and DMU‐212 decreased adenoma load by 27% and 24%, respectively, compared to untreated controls. Cyclooxygenase (COX) enzymes are important mechanistic targets of resveratrol, and we investigated whether DMU‐212 interferes with the expression and activity of COX in human colon cells. Incubation of HCA‐7 cancer cells for 24–96 hr with either stilbene derivative (1–50 μM) decreased prostaglandin E‐2 (PGE‐2) production, but only resveratrol decreased COX‐2 protein expression. In mice, which received either stilbene derivative (0.2%) for 3 weeks with their diet, PGE‐2 levels in the intestinal mucosa were reduced by between 45% and 62% compared to mice on control diet. While resveratrol inhibited enzyme activity in purified COX preparations, DMU‐212 failed to do so. The PGE‐2 decrease seen with DMU‐212 in cells and in vivo is probably mediated via its metabolites. The results suggest that alteration of the resveratrol molecule to generate DMU‐212 does not abrogate its ability to decrease adenoma number in ApcMin+ mice or to interfere with PGE‐2 generation in cells. © 2005 Wiley‐Liss, Inc.
DHCR24 gene expression is upregulated in melanoma metastases and associated to resistance to oxidative stress‐induced apoptosis
Authors: Di Stasi Delia , Vallacchi Viviana , Campi Valentina , Ranzani Tiziana , Daniotti Maria , Chiodini Elena , Fiorentini Silvia , Greeve Isabell , Prinetti Alessandro , Rivoltini Licia , Pierotti Marco A. , Rodolfo Monica
Published: February 2005

The DHCR24 gene encoding for the 3β‐hydroxysterol Δ24‐reductase, an oxidoreductase involved in cholesterol biosynthesis, was isolated by subtractive hybridization as highly expressed in a short‐term melanoma cell line derived from a cutaneous metastases (S/M2) compared to that obtained from the autologous primary tumor (S/P). DHCR24 (alias seladin‐1, diminuto/dwarf1 homolog) has been reported to act as an antiapoptotic factor in neurons. Gene expression analysis by Northern blot confirmed that DHCR24 was 5‐fold upregulated in S/M2 compared to S/P cells. High levels of DHCR24 gene expression were detected in 13/25 melanoma metastases and in 1/7 primary melanomas by real‐time PCR, indicating that upregulation of this gene may occur in melanoma progression. In S/M2 cells, high DHCR24 gene expression associated with resistance to apoptosis triggered by oxidative stress induced by exposure to hydrogen peroxide. DHCR24 gene transfer was shown to protect melanoma cells from H2O2‐induced cytotoxicity. Although higher cholesterol levels were shown in S/M2 cells compared to S/P cells, DHCR24 gene transfer did not increase cholesterol content. To evaluate whether DHCR24 acts as an antiapoptotic factor in melanoma metastases, the cytotoxic effect of chemotherapeutic agents was tested in DHCR24 transfectants and in the presence of a DHCR24 inhibitor, U18666A. High DHCR24 gene expression in transfectants did not result in a higher resistance to cytotoxic agents; treatment with U18666A was cytotoxic in S/P cells with a lower DHCR24 content and showed additive cytotoxic effect only when associated with H2O2 and not with cysplatin or etoposide, indicating that the DHCR24 protective effect is exerted through an oxidative stress‐specific mechanism. © 2005 Wiley‐Liss, Inc.
Risk factors for Kaposi's sarcoma among HHV‐8 seropositive homosexual men with AIDS
Authors: Nawar Eric , Mbulaiteye Sam M. , Gallant Joel E. , Wohl David A. , Ardini Marianne , Hendershot Tabitha , Goedert James J. , Rabkin Charles S.
Published: February 2005

Kaposi's sarcoma (KS) is a frequent complication of the acquired immunodeficiency syndrome (AIDS) in homosexual men. Risk factors for developing this malignancy are uncertain, other than immunosuppression and coinfection with human herpesvirus 8 (HHV‐8). We therefore examined factors associated with KS in a cross‐sectional analysis of 99 cases among 503 HHV‐8 seropositive homosexual men with AIDS. Data were collected by computer‐assisted personal interviews and medical chart reviews. HHV‐8 seroreactivity was determined by enzyme‐linked immunosorbent assay for antibodies against HHV‐8 K8.1 glycoprotein. KS was significantly less common in blacks compared to whites [risk ratio (RR) = 0.4; 95% CI = 0.2 =0.8] and more common in subjects who had completed college (RR = 1.7; 95% CI = 1.1–2.7) or had annual income greater than $30,000 (RR = 1.5; 95% CI = 1.1–2.2). KS was less common in cigarette smokers (RR = 0.6; 95% CI = 0.5–0.9) and users of crack cocaine (RR = 0.4; 95% CI = 0.1–0.8). KS was less common in bisexual men compared to men who were exclusively homosexual (estimated RR = 0.6; 95% CI = 0.4–0.9) and inversely associated with number of female partners. KS was also less common in men who had received pay for sex (RR = 0.6; 95% CI = 0.4–1.0). These cross‐sectional associations could be biased by potential differences in relative timing of HHV‐8 and HIV infection, a postulated determinant of KS risk. Alternatively, our findings may reflect factors protective against KS in individuals infected with HHV‐8. Future research should focus on identifying practical measures for countering KS that do not increase the risk of other diseases. Published 2005 Wiley‐Liss, Inc.
Suppression of hepatocellular carcinoma by transplantation of ex‐vivo immune‐modulated NKT lymphocytes
Authors: Margalit Maya , Shibolet Oren , Klein Athalia , Elinav Eran , Alper Ruslana , Thalenfeld Barbara , Engelhardt Dean , Rabbani Elazar , Ilan Yaron
Published: February 2005

NKT cells are a regulatory subset of T lymphocytes with immune modulatory effects and an important role in anti‐tumor immunity. The feasibility of “ex‐vivo education” of NKT cells has recently been demonstrated. To evaluate the anti‐tumor effect of ex‐vivo immune‐modulated NKT lymphocytes in a murine model of hepatocellular carcinoma. Athymic Balb/C mice were sublethally irradiated and transplanted with human Hep3B HCC. NKT cells prepared from immunocompetent Balb/C mice were pulsed ex vivo with HCC‐derived antigens (Group A), Hep3B cells (group B) or BSA (group C), and adoptively transferred into HCC harboring mice (1 × 06 NKT cells per mouse). Group D mice did not undergo NKT cell transplantation. Group E mice were transplanted with 1 × 106 NKT cells from HBV‐immunized donors. Mice were followed for tumor size and weight. To determine the mechanism of the anti‐tumor effect, intrasplenic lymphocyte populations were analyzed by FACS for NKT, CD4+ and CD8+ lymphocyte subpopulations; STAT 1, 4 and 6 expression in splenocytes was assessed by Western blot, and serum cytokine levels were measured by ELISA. Adoptive transfer of NKT cells pulsed with HCC‐derived antigens (group A) and NKT cells from immunized donors (group E) resulted in complete disappearance of tumors within 4 weeks and attenuated weight loss (6.5% and 7% in groups A and E, respectively). In contrast, mice in groups B, C, and D developed large, necrotic tumors and severe weight loss (21%, 17% and 23% weight loss in groups B, C, and D, respectively). NKT/CD4 and CD8/CD4 ratios were significantly increased in groups A and E (12.3 and 17.6 in groups A and D, respectively, compared to 6.4, 4.8 and 5.6 in groups B, C and D, respectively, for the NKT/CD4 ratio; 41 and 19.8 in groups A and E, respectively, compared to 6.5, 11.8 and 3.2 in groups B, C, and D, respectively, for the CD8/CD4 ratio). Expression of the transcription factor STAT4 was evident in group A, but not in groups B‐D. Serum IFNγ, IL12 and IL4 levels were increased in groups A and E. Adoptive transfer of NKT lymphocytes exposed ex vivo by HCC‐derived antigens loaded on dendritic cells and NKT cells from immunized donors led to suppression of HCC in mice. NKT‐mediated anti‐tumor activity was associated increased NKT and CD8+ T lymphocyte numbers, increased expression of STAT4, a marker for IL‐12 activity and elevated serum levels of the proinflammatory cytokines IFNγ and IL12, and of IL4. Ex‐vivo modulation of NKT lymphocytes holds promise as a novel mode of immune therapy for HCC. © 2005 Wiley‐Liss, Inc.
N‐Acetyltransferase‐2, glutathione S‐transferase M1 and T1 genetic polymorphisms, cigarette smoking and hepatocellular carcinoma: A case‐control study
Authors: Gelatti Umberto , Covolo Loredana , Talamini Renato , Tagger Alessandro , Barbone Fabio , Martelli Claudia , Cremaschini Francesca , Franceschi Silvia , Ribero Maria Lisa , Garte Seymour , Nardi Giuseppe , Donadon Valter , Donato Francesco
Published: February 2005

Our aim was to evaluate the role of N‐acetyltransferase (NAT2) and glutathione S‐transferase M1 and T1 (GSTM1 and GSTT1) polymorphisms in hepatocellular carcinoma (HCC) according to cigarette smoking, taking into account hepatitis B (HBV) and C (HCV) viral infection as well as alcohol consumption. A hospital‐based case‐control study was conducted in 2 areas of north Italy. Cases (n = 200) were patients hospitalized for HCC, and controls (n = 400) were patients admitted for reasons other than liver disease, neoplasms and tobacco‐ and alcohol‐related diseases. Genotypes were determined using PCR and the PCR/restriction fragment length polymorphism–based method. The putative risk genotypes NAT2 slow acetylator, GSTM1 null and GSTT1 null were not associated with HCC (OR = 1.3, 95% CI 0.8–2.0; OR = 1.0, 95% CI 0.6–1.5; OR = 0.8, 95% CI 0.4–1.4, respectively). Although not statistically significant, an increase in HCC risk was observed among light smokers (1–20 pack‐years) carrying GSTT1 null (OR = 1.7, 95% CI 0.6–4.7) and NAT2 slow acetylator (OR = 1.3, 95% CI 0.6–3.0) genotypes. In conclusion, there was no evidence for a gene–environment interaction in HCC risk for GSTM1, GSTT1 and NAT2 genotypes. © 2005 Wiley‐Liss, Inc.
Retracted: The evolution of predictive oncology and molecular‐based therapy for oral cancer prevention
Authors: Sudbø Jon , Reith Albrecht
Published: February 2005

Retraction: The following article from International Journal of Cancer, “The evolution of predictive oncology and molecular‐based therapy for oral cancer prevention”, by Jon Sudbø and Albrecht Reith, published online in Wiley InterScience (http://www3.interscience.wiley.com) on 1 February 2005 and in Volume 115, Number 3, pages 339‐345, has been retracted by agreement among the author Albrecht Reith, the journal Editor in Chief, Peter Lichter, and Wiley Periodicals, Inc. The retraction has been agreed following an investigation conducted by the Rikshospitalet‐Radiumhospitalet MC and the University of Oslo into the work carried out by Jon Sudbø.
Cooperative induction of rat mammary cancer by radiation and 1‐methyl‐1‐nitrosourea via the oncogenic pathways involving c‐Myc activation and H‐ras mutation
Authors: Imaoka Tatsuhiko , Nishimura Mayumi , Teramoto Ayako , Nishimura Yukiko , Ootawara Masami , Osada Harumi , Kakinuma Shizuko , Maekawa Akihiko , Shimada Yoshiya
Published: February 2005

Humans are continually exposed to various environmental carcinogens. Cancers may arise as a result of exposure to carcinogenic chemicals, ionizing radiation or a combination thereof. However, the mechanism of combined carcinogenesis has been only deduced from oncogenic actions of individual agents. Here, we analyzed experimental mammary carcinogenesis caused by a combination of radiation and a chemical carcinogen, 1‐methyl‐1‐nitrosourea (MNU). Seven‐week‐old female Sprague‐Dawley rats were divided into 4 groups: control, gγ‐irradiated (2 Gy), MNU‐treated (40 mg/kg, i.p.) and combined treatment of radiation with subsequent MNU after 3 days. Rats with palpable tumors were sacrificed at 50 weeks of age to collect tumors for histologic typing and mutational analysis of the H‐ras gene codon 12. The combined treatment induced adenocarcinomas, but not fibroadenomas, more efficiently than radiation or MNU alone. The H‐ras mutation was not seen in radiation‐induced carcinomas and was specific to MNU‐induced carcinomas in individually treated groups. In the combined treatment group, H‐ras‐mutated, but not nonmutated, tumors were more frequent and developed significantly earlier than in the MNU‐treated group. Significantly higher numbers of cells were stained for activated c‐Myc protein in gγ‐ray‐ and combined treatment‐induced cancers than in MNU‐induced cancers. These results indicate that combined exposure to the 2 carcinogens elicits an unexpected cooperativity in which pre‐irradiation enhances mammary carcinogenesis predominantly through the oncogenic pathway involving H‐ras, possibly by synergism with c‐Myc activation. © 2005 Wiley‐Liss, Inc.
Heuristic molecular lipophilicity potential (HMLP): A 2D‐QSAR study to LADH of molecular family pyrazole and derivatives
Authors: Du Qishi , Mezey P. G. , Chou Kuo‐Chen
Published: February 2005

The quantum chemical and structure‐based technique heuristic molecular lipophilicity potential (HMLP) is used in the liver alcohol dehydrogenase (LADH) study of molecular family pyrazole and derivatives. The molecular lipophilic index LM, molecular hydrophilic index HM, lipophilic indices lss, and hydrophilic indices hss of the substitutes (fragments), and atomic lipophilicity indices las are constructed and used in QSAR study. The HMLP indices are correlated with bioactivities of 18 pyrazole derivatives according to the 2D QSAR procedure. The multiple linear regression equation between the bioactivities of pyrazole derivatives and HMLP indices are built using partial least square (PLS) with the optimal statistical quantity (r = 0.987, s = 0.479, F = 47.19). The inhibition mechanism of LADH of the pyrazole derivatives is explained according to the physical meaning of HMLP indices. During the HMLP calculations for the 2D QSAR, the only input parameters are the atomic van der Waals radius without the need to resort to any empirical parameters. Accordingly, HMLP can provide a rigorous theoretical approach with a crystal clear physical meaning for the 2D QSAR. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 461–470, 2005
Maximal probability domains in linear molecules
Authors: Gallegos A. , Carbó‐Dorca R. , Lodier F. , Cancès E. , Savin A.
Published: February 2005

Regions of space are defined to maximize the probability to find a given number of electrons within. Their chemical significance and their relationship to the electron localization function (ELF) are explored by analyzing the results for a few linear molecules: LiH, BH, N2, CO, CS, C2H2, and C4H2. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 455–460, 2005
Myotubularin phosphoinositide phosphatases, protein phosphatases, and kinases: Their roles in junction dynamics and spermatogenesis
Authors: Zhang Jiayi , Mruk Dolores D. , Cheng C. Yan
Published: February 2005

Spermatogenesis in the seminiferous epithelium of the mammalian testis is a dynamic cellular event. It involves extensive restructuring at the Sertoli–germ cell interface, permitting germ cells to traverse the epithelium from basal to adluminal compartment. As such, Sertoli–germ cell actin‐based adherens junctions (AJ), such as ectoplasmic specializations (ES), must disassemble and reassemble to facilitate this event. Recent studies have shown that AJ dynamics are regulated by intricate interactions between AJ integral membrane proteins (e.g., cadherins, α6β1 integrins and nectins), phosphatases, kinases, adaptors, and the underlying cytoskeleton network. For instance, the myotubularin (MTM) phosphoinositide (PI) phosphatases, such as MTM related protein 2 (MTMR2), can form a functional complex with c‐Src (a non‐receptor protein tyrosine kinase). In turn, this phosphatase/kinase complex associates with β‐catenin, a constituent of the N‐cadherin/β‐catenin functional unit at the AJ site. This MTMR2‐c‐Src‐β‐catenin complex apparently regulates the phosphorylation status of β‐catenin, which determines cell adhesive function conferred by the cadherin–catenin protein complex in the seminiferous epithelium. In this review, we discuss the current status of research on selected phosphatases and kinases, and how these proteins potentially interact with adaptors at AJ in the seminiferous epithelium to regulate cell adhesion in the testis. Specific research areas that are open for further investigation are also highlighted. © 2005 Wiley‐Liss, Inc.