bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Circulating Tumor Cells with Serum Tumor-Related Methylated DNA in Peripheral Blood of Melanoma Patients
Authors: Koyanagi Kazuo , Mori Takuji , O'Day Steven J. , Martinez Steve R. , Wang He-Jing , Hoon Dave S.B.
Published: June 2006

Although previous studies have separately shown the utility of circulating tumor cells (CTC) or cell-free tumor-related DNA in blood of cancer patients, there has been no investigation of their association and/or the prognostic value of combining these assessments. To date, the true source of tumor-related DNA in serum remains unknown. We hypothesized that CTC is a possible origin of serum tumor-related methylated DNA and their combination can predict disease outcome. To test this hypothesis, we obtained matched pairs of peripheral blood lymphocytes and serum specimens simultaneously from 50 American Joint Committee on Cancer stage IV melanoma patients before administration of biochemotherapy. Peripheral blood leukocytes were analyzed for three mRNA markers of CTC: MART-1, GalNAc-T, and MAGE-A3. Sera were analyzed for two methylated DNA markers: RASSF1A and RAR-β2. CTC were detected in 13 of 15 (86%) patients with serum tumor-related methylated DNA and only in 13 of 35 (37%) patients without methylated DNA (P = 0.001). The number of CTC markers detected significantly correlated with methylated DNA (P = 0.008). CTC and methylated DNA were significantly correlated with biochemotherapy-treated patients' outcome. Patients with both CTC and methylated DNA showed significantly poorer response to biochemotherapy (P = 0.02) and worse time to progression and overall survival (P = 0.009 and 0.02, respectively). The correlation between CTC and serum tumor-related methylated DNA and the significant effect of this correlation on disease outcome indicate that a composite molecular assessment in blood may be a useful determinant of disease status and efficacy of systemic therapy for melanoma. (Cancer Res 2006; 66(12): 6111-7)
Hypermethylation of ASC/TMS1 Is a Sputum Marker for Late-Stage Lung Cancer
Authors: Machida Emi Ota , Brock Malcolm V. , Hooker Craig M. , Nakayama Jun , Ishida Akiko , Amano Jun , Picchi Maria A. , Belinsky Steven A. , Herman James G. , Taniguchi Shun'ichiro , Baylin Stephen B.
Published: June 2006

DNA hypermethylated gene promoter sequences are extremely promising cancer markers. Their use for risk assessment, early diagnosis, or prognosis depends on the timing of this gene change during tumor progression. We studied this for the proapoptotic gene ASC/TMS1 in lung cancer and used the findings to develop a sputum marker. ASC/TMS1 protein levels are reduced in all lung cancer types (30 of 40; 75%) but not in 10 preinvasive lesions. Hypermethylation of ASC/TMS1 is also associated with invasive cancers (41 of 152 or 27.0% of all lung cancer types) with variation in incidence between histopathologic types including 32.1% (26 of 81) of adenocarcinomas, 13.2% (7 of 53) of squamous cell carcinomas, 38.5% (5 of 13) of large-cell carcinomas, and 60% (3 of 5) of small-cell lung cancers. The hypermethylation is particularly correlated with late tumor stages being present in only 14% of stage I but 60% of later-stage tumors. The incidence of ASC/TMS1 hypermethylation in sputum DNA fully mimics the tissue findings being present in only 2% (2 of 85) of high-risk, cancer-free smokers, 15% (3 of 18) of patients with stage I non–small-cell lung cancer (NSCLC), but 41% of patients with stage III NSCLC (18 of 44), including 56% (10 of 18) of those with adenocarcinoma. Importantly, sputum is positive for this marker in 24% (10 of 42) of very high risk, clinically cancer-free individuals previously resected for stage I NSCLC. Thus, hypermethylation of ASC/TMS1 is a marker for late-stage lung cancer and, in sputum, could predict prognosis in patients resected for early-stage disease. (Cancer Res 2006; 66(12): 6210-8)
Aptamer:Toxin Conjugates that Specifically Target Prostate Tumor Cells
Authors: Chu Ted C. , Marks John W. , Lavery Laura A. , Faulkner Sarah , Rosenblum Michael G. , Ellington Andrew D. , Levy Matthew
Published: June 2006

We have used RNA aptamer:gelonin conjugates to target and specifically destroy cells overexpressing the known cancer biomarker prostate-specific membrane antigen (PSMA). Aptamer:toxin conjugates have an IC50 of 27 nmol/L and display an increased potency of at least 600-fold relative to cells that do not express PSMA. The aptamer not only promotes uptake into target cells but also decreases the toxicity of gelonin in non-target cells. These results validate the notion that “escort aptamers” may be useful for the treatment of specific tumors expressing unique antigen targets.(Cancer Res 2006; 66(12): 5989-92)
Integrative Genomics Identifies Distinct Molecular Classes of Neuroblastoma and Shows That Multiple Genes Are Targeted by Regional Alterations in DNA Copy Number
Authors: Wang Qun , Diskin Sharon , Rappaport Eric , Attiyeh Edward , Mosse Yael , Shue Daniel , Seiser Eric , Jagannathan Jayanti , Shusterman Suzanne , Bansal Manisha , Khazi Deepa , Winter Cynthia , Okawa Erin , Grant Gregory , Cnaan Avital , Zhao Huaqing , Cheung Nai-Kong , Gerald William , London Wendy , Matthay Katherine K. , Brodeur Garrett M. , Maris John M.
Published: June 2006

Neuroblastoma is remarkable for its clinical heterogeneity and is characterized by genomic alterations that are strongly correlated with tumor behavior. The specific genes that influence neuroblastoma biology and are targeted by genomic alterations remain largely unknown. We quantified mRNA expression in a highly annotated series of 101 prospectively collected diagnostic neuroblastoma primary tumors using an oligonucleotide-based microarray. Genomic copy number status at the prognostically relevant loci 1p36, 2p24 (MYCN), 11q23, and 17q23 was determined by PCR and was aberrant in 26, 20, 40, and 38 cases, respectively. In addition, 72 diagnostic neuroblastoma primary tumors assayed in a different laboratory were used as an independent validation set. Unsupervised hierarchical clustering showed that gene expression was highly correlated with genomic alterations and clinical markers of tumor behavior. The vast majority of samples with MYCN amplification and 1p36 loss of heterozygosity (LOH) clustered together on a terminal node of the sample dendrogram, whereas the majority of samples with 11q deletion clustered separately and both of these were largely distinct from the copy number neutral group of tumors. Genes involved in neurodevelopment were broadly overrepresented in the more benign tumors, whereas genes involved in RNA processing and cellular proliferation were highly represented in the most malignant cases. By combining transcriptomic and genomic data, we showed that LOH at 1p and 11q was associated with significantly decreased expression of 122 (61%) and 88 (27%) of the genes mapping to 1p35-36 and all of 11q, respectively, suggesting that multiple genes may be targeted by LOH events. A total of 71 of the 1p35-36 genes were also differentially expressed in the independent validation data set, providing a prioritized list of candidate neuroblastoma suppressor genes. Taken together, these data are consistent with the hypotheses that the neuroblastoma transcriptome is a sensitive marker of underlying tumor biology and that chromosomal deletion events in this cancer likely target multiple genes through alteration in mRNA dosage. Lead positional candidates for neuroblastoma suppressor genes can be inferred from these data, but the potential multiplicity of transcripts involved has significant implications for ongoing gene discovery strategies. (Cancer Res 2006; 66(12): 6050-62)
Hedgehog Signaling and Bmi-1 Regulate Self-renewal of Normal and Malignant Human Mammary Stem Cells
Authors: Liu Suling , Dontu Gabriela , Mantle Ilia D. , Patel Shivani , Ahn Nam-shik , Jackson Kyle W. , Suri Prerna , Wicha Max S.
Published: June 2006

The epithelial components of the mammary gland are thought to arise from stem cells with a capacity for self-renewal and multilineage differentiation. Furthermore, these cells and/or their immediate progeny may be targets for transformation. We have used both in vitro cultivation and a xenograft mouse model to examine the role of hedgehog signaling and Bmi-1 in regulating self-renewal of normal and malignant human mammary stem cells. We show that hedgehog signaling components PTCH1, Gli1, and Gli2 are highly expressed in normal human mammary stem/progenitor cells cultured as mammospheres and that these genes are down-regulated when cells are induced to differentiate. Activation of hedgehog signaling increases mammosphere-initiating cell number and mammosphere size, whereas inhibition of the pathway results in a reduction of these effects. These effects are mediated by the polycomb gene Bmi-1. Overexpression of Gli2 in mammosphere-initiating cells results in the production of ductal hyperplasia, and modulation of Bmi-1 expression in mammosphere-initiating cells alters mammary development in a humanized nonobese diabetic-severe combined immunodeficient mouse model. Furthermore, we show that the hedgehog signaling pathway is activated in human breast “cancer stem cells” characterized as CD44+CD24−/lowLin−. These studies support a cancer stem cell model in which the hedgehog pathway and Bmi-1 play important roles in regulating self-renewal of normal and tumorigenic human mammary stem cells. (Cancer Res 2006; 66(12): 6063-71)
Restoration of Tamoxifen Sensitivity in Estrogen Receptor–Negative Breast Cancer Cells: Tamoxifen-Bound Reactivated ER Recruits Distinctive Corepressor Complexes
Authors: Sharma Dipali , Saxena Neeraj K. , Davidson Nancy E. , Vertino Paula M.
Published: June 2006

Breast tumors expressing estrogen receptor-α (ER) respond well to therapeutic strategies using selective ER modulators, such as tamoxifen. However, ∼30% of invasive breast cancers are hormone independent because they lack ER expression due to hypermethylation of ER promoter. Treatment of ER-negative breast cancer cells with demethylating agents [5-aza-2′-deoxycytidine (5-aza-dC)] and histone deacetylase (HDAC) inhibitors (trichostatin A) leads to expression of ER mRNA and functional protein. Here, we examined whether epigenetically reactivated ER is a target for tamoxifen therapy. Following treatment with trichostatin A and 5-aza-dC, the formerly unresponsive ER-negative MDA-MB-231 breast cancer cells became responsive to tamoxifen. Tamoxifen-mediated inhibition of cell growth in these cells is mediated at least in part by the tamoxifen-bound ER. Tamoxifen-bound reactivated ER induces transcriptional repression at estrogen-responsive genes by ordered recruitment of multiple distinct chromatin-modifying complexes. Using chromatin immunoprecipitation, we show recruitment of two different corepressor complexes to ER-responsive promoters in a mutually exclusive and sequential manner: the nuclear receptor corepressor-HDAC3 complex followed by nucleosome remodeling and histone deacetylation complex. The mechanistic insight provided by this study might help in designing therapeutic strategies directed toward epigenetic mechanisms in the prevention or treatment of breast cancer. (Cancer Res 2006; 66(12): 6370-8)
Sequence Variations of MicroRNAs in Human Cancer: Alterations in Predicted Secondary Structure Do Not Affect Processing
Authors: Diederichs Sven , Haber Daniel A.
Published: June 2006

Expression levels of microRNAs (miRNAs) are globally reduced in cancer compared with matched normal tissues, and miRNA function has recently been implicated in tumorigenesis. To test whether epigenetic silencing contributes to miRNA suppression in tumors, lung cancer cells were treated with inhibitors of DNA methylation or histone deacetylation. No significant alteration in miRNA expression was detected using microarray profiling. To search for tumor-associated mutations that could affect processing and expression of mature miRNAs, a panel of 91 cancer-derived cell lines was analyzed for sequence variations in 15 miRNAs implicated in tumorigenesis by virtue of their known target transcripts (let-7 family targeting oncogenic Ras) or their localization to sites of frequent chromosomal instability (miR-143, miR-145, miR-26a-1, and miR-21). No mutations were detected within any of the short mature miRNA sequences. In addition to previously reported polymorphisms, 1 sequence variant in a precursor miRNA and 15 variants in primary miRNA (pri-miRNA) transcripts were identified. Despite pri-miRNAs having dramatic changes in the predicted secondary folding structure flanking putative cleavage sites, processing and miRNA maturation were not affected in vivo. Thus, genetic variants in miRNA precursors are common in cancer cells but are unlikely to have physiologic significance. (Cancer Res 2006; 66(12): 6097-104)
Interference with the Complement System by Tumor Cell Membrane Type-1 Matrix Metalloproteinase Plays a Significant Role in Promoting Metastasis in Mice
Authors: Rozanov Dmitri V. , Savinov Alexei Y. , Golubkov Vladislav S. , Tomlinson Stephen , Strongin Alex Y.
Published: June 2006

Neoplasms have developed strategies to protect themselves against the complement-mediated host immunity. Invasion- and metastasis-promoting membrane type-1 (MT1) matrix metalloproteinase (MMP) is strongly associated with many metastatic cancer types. The relative importance of the individual functions of MT1-MMP in metastasis was, however, unknown. We have now determined that the expression of murine MT1-MMP in murine melanoma B16F1 cells strongly increased the number of metastatic loci in the lungs of syngeneic C57BL/6 mice. In contrast, MT1-MMP did not affect the number of metastatic loci in complement-deficient C57BL/6-C3−/− mice. Our results indicated, for the first time, that the anticomplement activity of MT1-MMP played a significant role in promoting metastasis in vivo and determined the relative importance of the anticomplement activity in the total metastatic effect of this multifunctional proteolytic enzyme. We believe that our results shed additional light on the functions of MT1-MMP in cancer and clearly make this protease a promising drug target in metastatic malignancies. (Cancer Res 2006; 66(12): 6258-63)
p53 Down-Regulates Phosphatase and Tensin Homologue Deleted on Chromosome 10 Protein Stability Partially through Caspase-Mediated Degradation in Cells with Proteasome Dysfunction
Authors: Tang Yufang , Eng Charis
Published: June 2006

There has been intense investigation regarding the interaction between the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and p53 tumor suppressors. p53 has been shown to up-regulate PTEN expression as a transcriptional activator. However, clinical observations by immunohistochemistry studies indicate that significant increases in p53 protein levels coexist with reduced or absent expression of PTEN protein in a variety of neoplasias. In this study, we propose a mechanism that begins to explain how p53 can both up-regulate and down-regulate PTEN. We have found that PTEN protein is down-regulated under proteasome dysfunction induced by proteasome inhibitor MG132 in both human lymphoblast cells and MCF7 cells. The reduction of PTEN is coincident with elevated p53 protein levels and the association between PTEN and p53 but independent of its phosphatase activities. Quantitative reverse transcription-PCR indicates that proteasome inhibition does not reduce PTEN message levels but affects PTEN protein stability. The p53 inhibitor, pifithrin-α, is able to attenuate the effect of proteasome inhibition. Using ectopic expression studies in p53-null mouse embryonic fibroblasts and p53/PTEN-null PC3 cells, we show that PTEN is more stable in p53-null cells compared with p53-expressing cells. Inhibition of caspases, the downstream targets of p53, particularly caspase-3, can partially restore the stability of PTEN. This study provides the first evidence that p53 is able to down-regulate PTEN protein stability in stressed cells. Our study sheds some light on the mechanisms that regulate PTEN protein stability, which is important to fully elucidate to comprehend the broad neoplastic manifestations of Cowden syndrome/Bannayan-Riley-Ruvalcaba and sporadic cancers. (Cancer Res 2006; 66(12): 6139-48)
Association of Antigen-Processing Machinery and HLA Antigen Phenotype of Melanoma Cells with Survival in American Joint Committee on Cancer Stage III and IV Melanoma Patients
Authors: Anichini Andrea , Mortarini Roberta , Nonaka Daisuke , Molla Alessandra , Vegetti Claudia , Montaldi Elisabetta , Wang Xinhui , Ferrone Soldano
Published: June 2006

Because changes in the expression level of antigen-processing machinery (APM) components and HLA class I and II antigens in melanoma cells are expected to affect their interactions with the immune system of the host, we assessed the clinical relevance of quantitative variations in the expression of these molecules in melanoma lesions. Short-term (<10 in vitro passages) melanoma cell lines isolated from 85 American Joint Committee on Cancer (AJCC) stage III and IV patients were stained with APM component and HLA class I antigen-specific and HLA class II antigen-specific monoclonal antibodies and analyzed by flow cytometry. The phenotype of all tumors was characterized by intertumor and intratumor heterogeneity in the expression of all the markers and by significant correlations in the level of expression of markers belonging to the HLA class I antigen-processing and presentation pathway. Hierarchical clustering of the mean fluorescence intensity data defined two main clusters of tumors. The corresponding groups of patients differed significantly in the overall survival but not in other relevant clinical variables, including AJCC stage and therapy received after surgery. Cox regression analysis showed that β2-microglobulin and HLA class II antigen expression were significantly associated with patients' survival. This evidence was corroborated by the immunohistochemical analysis for HLA class II antigen expression of melanoma lesions from an unrelated group of 52 AJCC stage III and IV patients. These results suggest that quantitative variations in APM component and HLA expression in melanoma lesions from AJCC stage III and IV patients may have an effect on the clinical course of the disease. (Cancer Res 2006; 66(12): 6405-11)
Nuclear p21-Activated Kinase 1 in Breast Cancer Packs Off Tamoxifen Sensitivity
Authors: Rayala Suresh K. , Molli Poonam R. , Kumar Rakesh
Published: June 2006

There is significant clinical interest in the factors that influence the development of tamoxifen resistance in estrogen receptor-α (ER-α)–positive breast cancers. Recent studies suggest that in ER-positive breast tumor cells, elevated protein levels, and in particular, nuclear localization of p21-activated kinase 1 (PAK1), is associated with the progressive limitation of tamoxifen sensitivity. These phenotypic effects of PAK1 in model systems are mechanistically linked with the ability of PAK1 to phosphorylate ER-α on serine 305 and subsequent secondary activation of serine 118. These findings prompt further investigation of how nuclear signaling by PAK1 may affect estrogen's action and whether tamoxifen resistance might be prevented or reversed by PAK1 inhibition. (Cancer Res 2006; 66(12): 5985-8)
Fas Signaling in Thyroid Carcinomas Is Diverted from Apoptosis to Proliferation
Authors: Mitsiades Constantine S. , Poulaki Vassiliki , Fanourakis Galinos , Sozopoulos Elias , McMillin Douglas , Wen Zhaoqin , Voutsinas Gerassimos , Tseleni-Balafouta Sophia , Mitsiades Nicholas
Published: June 2006

Purpose: The death receptor Fas is present in thyroid carcinomas, yet fails to trigger apoptosis. Interestingly, Fas has been reported to be actually overexpressed in papillary thyroid carcinomas, suggesting that it may confer a survival advantage.

Experimental Design: We investigated the expression and activation status of Fas pathway mediators in thyroid carcinoma cell lines and tumor specimens.

Results: All cell lines tested express Fas-associated death domain, procaspase-8, procaspase-9, and procaspase-3; resistance to Fas-mediated apoptosis could not be attributed to lack of any of these apoptosis mediators. Moreover, Fas death domain mutations were not found in our study. The proteasome inhibitors MG132 and PS-341 (bortezomib, Velcade), which lead to accumulation of the nuclear factor κB (NF-κB) inhibitor IκB, did not sensitize SW579 cells to Fas-mediated apoptosis, suggesting that resistance to Fas-mediated apoptosis is not due to proteasome or NF-κB activity. Cross-linking of Fas in vitro induced recruitment of Fas-associated death domain–like interleukin-1β–converting enzyme inhibitory protein (FLIP) instead of procaspase-8. Inhibition of FLIP expression with a FLIP antisense oligonucleotide resulted in significant sensitization to Fas-mediated apoptosis. Fas cross-linking promoted BrdUrd incorporation; activated the mitogen-activated protein kinase/extracellular signal–regulated kinase kinase/extracellular signal–regulated kinase, NF-κB, and activator protein-1 pathways in thyroid carcinoma cells in vitro; and protected cells from tumor necrosis factor–related apoptosis-inducing ligand–induced apoptosis. We also found that good prognosis papillary thyroid carcinoma specimens exhibited higher immunoreactivity for cleaved (activated) caspase-8 than poor prognosis tumors.

Conclusions: In thyroid carcinomas, the proteolytic cleavage and activation of caspase-8 depends on the balance between expression levels for procaspase-8 and FLIP and correlates with favorable clinical prognosis. Fas may actually stimulate proliferation and confer a survival advantage to thyroid cancer cells.
Human In vivo Dose-Response to Controlled, Low-Dose Low Linear Energy Transfer Ionizing Radiation Exposure
Authors: Goldberg Zelanna , Rocke David M. , Schwietert Chad , Berglund Susanne R. , Santana Alison , Jones Angela , Lehmann Jörg , Stern Robin , Lu Ruixiao , Hartmann Siantar Christine
Published: June 2006

Purpose: The effect of low doses of low–linear energy transfer (photon) ionizing radiation (LDIR, <10 cGy) on human tissue when exposure is under normal physiologic conditions is of significant interest to the medical and scientific community in therapeutic and other contexts. Although, to date, there has been no direct assessment of the response of human tissue to LDIR when exposure is under normal physiologic conditions of intact three-dimensional architecture, vasculature, and cell-cell contacts (between epithelial cells and between epithelial and stromal cells).

Experimental Design: In this article, we present the first data on the response of human tissue exposed in vivo to LDIR with precisely controlled and calibrated doses. We evaluated transcriptomic responses to a single exposure of LDIR in the normal skin of men undergoing therapeutic radiation for prostate cancer (research protocol, Health Insurance Portability and Accountability Act–compliant, Institutional Review Board–approved). Using newly developed biostatistical tools that account for individual splice variants and the expected variability of temporal response between humans even when the outcome is measured at a single time, we show a dose-response pattern in gene expression in a number of pathways and gene groups that are biologically plausible responses to LDIR.

Results: Examining genes and pathways identified as radiation-responsive in cell culture models, we found seven gene groups and five pathways that were altered in men in this experiment. These included the Akt/phosphoinositide-3-kinase pathway, the growth factor pathway, the stress/apoptosis pathway, and the pathway initiated by transforming growth factor-β signaling, whereas gene groups with altered expression included the keratins, the zinc finger proteins and signaling molecules in the mitogen-activated protein kinase gene group. We show that there is considerable individual variability in radiation response that makes the detection of effects difficult, but still feasible when analyzed according to gene group and pathway.

Conclusions: These results show for the first time that low doses of radiation have an identifiable biosignature in human tissue, irradiated in vivo with normal intact three-dimensional architecture, vascular supply, and innervation. The genes and pathways show that the tissue (a) does detect the injury, (b) initiates a stress/inflammatory response, (c) undergoes DNA remodeling, as suggested by the significant increase in zinc finger protein gene expression, and (d) initiates a “pro-survival” response. The ability to detect a distinct radiation response pattern following LDIR exposure has important implications for risk assessment in both therapeutic and national defense contexts.
In vitroPeptide Immunization of Target Tax Protein Human T-Cell Leukemia Virus Type 1–Specific CD4+ Helper T Lymphocytes
Authors: Kobayashi Hiroya , Ngato Toshihiro , Sato Keisuke , Aoki Naoko , Kimura Shoji , Tanaka Yuetsu , Aizawa Hitoshi , Tateno Masatoshi , Celis Esteban
Published: June 2006

Purpose: Adult T-cell leukemia/lymphoma induced by human T-cell leukemia virus type 1 (HTLV-1) is usually a fatal lymphoproliferative malignant disease. HTLV-1 Tax protein plays a critical role in HTLV-1-associated leukemogenesis and is an attractive target for vaccine development. Although HTLV-1 Tax is the most dominant antigen for HTLV-1-specific CD8+ CTLs in HTLV-1-infected individuals, few epitopes recognized by CD4+ helper T lymphocytes in HTLV-1 Tax protein have been described. The aim of the present study was to study T-helper-cell responses to HTLV-1 Tax and to identify naturally processed MHC class II–restricted epitopes that could be used for vaccine development.

Experimental Design: An MHC class II binding peptide algorithm was used to predict potential T-helper cell epitope peptides from HTLV-1 Tax. We assessed the ability of the corresponding peptides to elicit helper T-cell responses by in vitro vaccination of purified CD4+ T lymphocytes.

Results: Peptides Tax191-205 and Tax305-319 were effective in inducing T-helper-cell responses. Although Tax191-205 was restricted by the HLA-DR1 and DR9 alleles, responses to Tax305-319 were restricted by either DR15 or DQ9. Both these epitopes were found to be naturally processed by HTLV-1+ T-cell lymphoma cells and by autologous antigen-presenting cells that were pulsed with HTLV-1 Tax+ tumor lysates. Notably, the two newly identified helper T-cell epitopes are found to lie proximal to known CTL epitopes, which will facilitate the development of prophylactic peptide–based vaccine capable of inducing simultaneous CTL and T-helper responses.

Conclusion: Our data suggest that HTLV-1 Tax protein could serve as tumor-associated antigen for CD4+ helper T cells and that the present epitopes might be used for T-cell-based immunotherapy against tumors expressing HTLV-1.
Targeting the c-Met Signaling Pathway in Cancer
Authors: Peruzzi Benedetta , Bottaro Donald P.
Published: June 2006

On binding to the cell surface receptor tyrosine kinase (TK) known as c-Met, hepatocyte growth factor (HGF) stimulates mitogenesis, motogenesis, and morphogenesis in a wide range of cellular targets including, epithelial and endothelial cells, hematopoietic cells, neurons, melanocytes, and hepatocytes. These pleiotropic actions are fundamentally important during development, homeostasis, and tissue regeneration. HGF signaling also contributes to oncogenesis and tumor progression in several human cancers and promotes aggressive cellular invasiveness that is strongly linked to tumor metastasis. Our present understanding of c-Met oncogenic signaling supports at least three avenues of pathway selective anticancer drug development: antagonism of ligand/receptor interaction, inhibition of TK catalytic activity, and blockade of intracellular receptor/effector interactions. Potent and selective preclinical drug candidates have been developed using all three strategies, and human clinical trials in two of the three areas are now under way.
p53 Transgenic Mice Are Highly Susceptible to 4-Nitroquinoline-1-Oxide-Induced Oral Cancer
Authors: Zhang Zhongqiu , Wang Yian , Yao Ruisheng , Lubet Ronald A. , You Ming
Published: June 2006

In this study, we did a bioassay employing mice with a dominant-negative p53 mutation (p53Val135/WT) to assess whether a germ-line p53 mutation predisposed mice toward the development of squamous cell carcinomas (SCC) in the oral cavity. Treatment of the mouse oral cavity with 4-nitroquinoline-1-oxide produced a 66%, 91%, and 20% tumor incidence in the oral cavity, esophagus, and forestomach/stomach, respectively, in p53Val135/WT mice. In contrast, only a 25%, 58%, and 4% tumor incidence was observed in oral cavity, esophagus, and forestomach/stomach, respectively, in wild-type littermates (p53WT/WT). The most striking difference between p53Val135/WT and p53WT/WT mice following the carcinogen treatment was the higher prevalence and more rapid development of SSC in p53Val135/WT mice than in wild-type mice. To identify the precise genes or pathways involved in these differences during tumor development, we examined gene expression profiles of 4-nitroquinoline-1-oxide-treated normal tongues as well as tongue SCC in p53Val135/WT and p53WT/WT mice. Microarray and GenMAPP analysis revealed that dominant-negative p53 (135Valp53) affects several cellular processes involved in SCC development. Affected processes included apoptosis and cell cycle arrest pathways, which were modulated in both tumor and normal epithelium. These results showed that reduction of p53-dependent apoptosis and increases in cell proliferation might contribute to the observed increase in oral cavity and gastroesophageal malignancies in p53Val135/WT mice as well as to the more rapid growth and progression of tumors. (Mol Cancer Res 2006;4(6):401–10)
Who Is Black in Brazil? A Timely or a False Question in Brazilian Race Relations in the Era of Affirmative Action?
Authors: Santos Sales Augusto dos
Published: June 2006

At the end of 2001 the question of race became part of the Brazilian national agenda under the pressure of black social movements for the establishment of quotas for admission of Afro-Brazilians to public universities. There was already strong resistance to this proposal. One of the principal arguments against this kind of affirmative action was and continues to be that Brazilian racial boundaries are not as rigid as those of the United States—that, given its substantial miscegenation, it is impossible to know who is black. The myth of racial democracy seriously limits realistic discussion of racism and racial identity because it prevents the identification of dysfunctional race relations. The question is not who is black but what sort of society Brazilians want to build.
Evaluating Transformational Leadership Skills of Hospice Executives
Authors: Longenecker Paul D.
Published: June 2006

Health care is a rapidly changing environment requiring a high level of leadership skills by executive level personnel. The hospice industry is experiencing the same rapid changes; however, the changes have been experienced over the brief span of 25 years. Highly skilled hospice executives are a necessity for the growth and long-term survival of hospice care. This descriptive study was conducted to evaluate the leadership skills of hospice executives. The study population consisted of hospice executives who were members of the state hospice organization in Ohio and/or licensed by the state (88 hospice providers). Three questionnaires were utilized for collecting data. These questionnaires collected data on transformational leadership skills of participants, participants’ personal demographics, and their employer’s organizational demographics. Forty-seven hospice executives responded (53%). Key findings reported were high levels of transformational leadership skills (mean, 3.39), increased use of laissez-faire skills with years of hospice experience ( P = .57), and positive reward being a frequent leadership technique utilized (mean, 3.29). In addition, this was the first study of leadership skills of hospice executives and the first formal collection of personal demographic data about hospice executives.
Home Pediatric Compassionate Extubation: Bridging Intensive and Palliative Care
Authors: Zwerdling Ted , Hamann Kevin C. , Kon Alexander A.
Published: June 2006

Compassionate home extubation for pediatric patients is a topic that seldom appears in the literature and is of unknown clinical importance. However, standards in pediatric intensive care unit (PICU) and among pediatric critical care physicians regarding end-of-life decisions are changing, including where and when patient extubation occurs. The authors’ hospice recently consulted on an infant with spinal muscular atrophy in the PICU requiring mechanical ventilation, for whom further life-sustaining care was deemed futile. In consultation with the family, nursing staff, physicians, and the ethics committee, and following protocol guidelines, arrangements were made for this infant and his parents to be transported home. Once comfortable with his family, a small amount of lorazepam was given and the endotracheal tube removed. The infant died quietly about 20 minutes later. This case prompted the authors to review the current state of published articles covering this topic, suggest a protocol for implementing home extubation, realize imposed barriers, and discuss potential solutions. A well-developed plan for home extubation procedures may improve interactions with PICU and hospice services and at the same time provide additional choices for parents and patients wishing to maximize end-of-life quality outside the hospital setting.
Homicide in the Netherlands
Authors: Bijleveld Catrien , Smit Paul
Published: June 2006

The findings of a survey of all homicides in 1998 in the Netherlands are briefly presented. After describing characteristics of the incident, the offender, and the victim, multivariate relations between these characteristics are investigated. It appears that homicide cases are structured in an interpretable way in which a previous classification can be accommodated. The analysis, however, also indicates that homicide types do not constitute distinct groups but instead rank along a circular continuum.
Association algorithm to mine the rules that govern enzyme definition and to classify protein sequences
Authors: Chiu Shih-Hau , Chen Chien-Chi , Yuan Gwo-Fang , Lin Thy-Hou
Published: June 2006

Background

The number of sequences compiled in many genome projects is growing exponentially, but most of them have not been characterized experimentally. An automatic annotation scheme must be in an urgent need to reduce the gap between the amount of new sequences produced and reliable functional annotation. This work proposes rules for automatically classifying the fungus genes. The approach involves elucidating the enzyme classifying rule that is hidden in UniProt protein knowledgebase and then applying it for classification. The association algorithm, Apriori, is utilized to mine the relationship between the enzyme class and significant InterPro entries. The candidate rules are evaluated for their classificatory capacity.

Results

There were five datasets collected from the Swiss-Prot for establishing the annotation rules. These were treated as the training sets. The TrEMBL entries were treated as the testing set. A correct enzyme classification rate of 70% was obtained for the prokaryote datasets and a similar rate of about 80% was obtained for the eukaryote datasets. The fungus training dataset which lacks an enzyme class description was also used to evaluate the fungus candidate rules. A total of 88 out of 5085 test entries were matched with the fungus rule set. These were otherwise poorly annotated using their functional descriptions.

Conclusion

The feasibility of using the method presented here to classify enzyme classes based on the enzyme domain rules is evident. The rules may be also employed by the protein annotators in manual annotation or implemented in an automatic annotation flowchart.
Identical probes on different high-density oligonucleotide microarrays can produce different measurements of gene expression
Authors: Zhang LanMin , Yoder Sean J , Enkemann Steven A
Published: June 2006

Background

There are many potential sources of variability in a microarray experiment. Variation can arise from many aspects of the collection and processing of samples for gene expression analysis. Oligonucleotide-based arrays are thought to minimize one source of variability as identical oligonucleotides are expected to recognize the same transcripts during hybridization.

Results

We demonstrate that although the probes on the U133A GeneChip arrays are identical in sequence to probes designed for the U133 Plus 2.0 arrays the values obtained from an experimental hybridization can be quite different. Nearly half of the probesets in common between the two array types can produce slightly different values from the same sample. Nearly 70% of the individual probes in these probesets produced array specific differences.

Conclusion

The context of the probe may also contribute some bias to the final measured value of gene expression. At a minimum, this should add an extra level of caution when considering the direct comparison of experiments performed in two microarray formats. More importantly, this suggests that it may not be possible to know which value is the most accurate representation of a biological sample when comparing two formats.
Can antibiotic prescriptions in respiratory tract infections be improved? A cluster-randomized educational intervention in general practice – The Prescription Peer Academic Detailing (Rx-PAD) Study [NCT00272155]
Authors: Gjelstad Svein , Fetveit Arne , Straand Jørund , Dalen Ingvild , Rognstad Sture , Lindbaek Morten
Published: June 2006

Background

More than half of all antibiotic prescriptions in general practice are issued for respiratory tract infections (RTIs), despite convincing evidence that many of these infections are caused by viruses. Frequent misuse of antimicrobial agents is of great global health concern, as we face an emerging worldwide threat of bacterial antibiotic resistance. There is an increasing need to identify determinants and patterns of antibiotic prescribing, in order to identify where clinical practice can be improved.

Methods/Design

Approximately 80 peer continuing medical education (CME) groups in southern Norway will be recruited to a cluster randomized trial. Participating groups will be randomized either to an intervention- or a control group. A multifaceted intervention has been tailored, where key components are educational outreach visits to the CME-groups, work-shops, audit and feedback. Prescription Peer Academic Detailers (Rx-PADs), who are trained GPs, will conduct the educational outreach visits. During these visits, evidence-based recommendations of antibiotic prescriptions for RTIs will be presented and software will be handed out for installation in participants PCs, enabling collection of prescription data. These data will subsequently be linked to corresponding data from the Norwegian Prescription Database (NorPD). Individual feedback reports will be sent all participating GPs during and one year after the intervention. Main outcomes are baseline proportion of inappropriate antibiotic prescriptions for RTIs and change in prescription patterns compared to baseline one year after the initiation of the tailored pedagogic intervention.

Discussion

Improvement of prescription patterns in medical practice is a challenging task. A thorough evaluation of guidelines for antibiotic treatment in RTIs may impose important benefits, whereas inappropriate prescribing entails substantial costs, as well as undesirable consequences like development of antibiotic resistance. Our hypothesis is that an educational intervention program will be effective in improving prescription patterns by reducing the total number of antibiotic prescriptions, as well as reducing the amount of broad-spectrum antibiotics, with special emphasis on macrolides.
Forebrain Overexpression of CaMKII abolishes Cingulate Long Term Depression and Reduces Mechanical Allodynia and Thermal Hyperalgesia
Authors: Wei Feng , Wang Guo-Du , Zhang Chao , Shokat Kevan M , Wang Huimin , Tsien Joe Z , Liauw Jason , Zhuo Min
Published: June 2006

Activity-dependent synaptic plasticity is known to be important in learning and memory, persistent pain and drug addiction. Glutamate NMDA receptor activation stimulates several protein kinases, which then trigger biochemical cascades that lead to modifications in synaptic efficacy. Genetic and pharmacological techniques have been used to show a role for Ca2+/calmodulin-dependent kinase II (CaMKII) in synaptic plasticity and memory formation. However, it is not known if increasing CaMKII activity in forebrain areas affects behavioral responses to tissue injury. Using genetic and pharmacological techniques, we were able to temporally and spatially restrict the over expression of CaMKII in forebrain areas. Here we show that genetic overexpression of CaMKII in the mouse forebrain selectively inhibits tissue injury-induced behavioral sensitization, including allodynia and hyperalgesia, while behavioral responses to acute noxious stimuli remain intact. CaMKII overexpression also inhibited synaptic depression induced by a prolonged repetitive stimulation in the ACC, suggesting an important role for CaMKII in the regulation of cingulate neurons. Our results suggest that neuronal CaMKII activity in the forebrain plays a role in persistent pain.
The influence of MMP-14, TIMP-2 and MMP-2 expression on breast cancer prognosis
Authors: Têtu Bernard , Brisson Jacques , Wang Chang Shu , Lapointe Hélène , Beaudry Geneviève , Blanchette Caty , Trudel Dominique
Published: June 2006

Introduction

Matrix metalloproteinase (MMP)-2 is very active at degrading extracellular matrix. It is under the influence of an activator, membrane type 1 MMP (MMP-14), and the tissue inhibitor of metalloproteases (TIMP)-2. We hypothesized that the individual expression of these three markers or their balance may help to predict breast cancer prognosis.

Methods

MMP-2, MMP-14 and TIMP-2 expression has been evaluated by 35S mRNA in situ hybridization on paraffin material of 539 breast cancers without distant metastasis at diagnosis and with a median follow-up of 9.2 years.

Results

MMP-2 and MMP-14 mRNA was detected primarily in reactive stromal cells whereas TIMP-2 mRNA was expressed by both stromal and cancer cells. Of the three molecules, an adjusted Cox model revealed that high MMP-14 mRNA (≥ 10% cells) alone predicted a significantly shorter overall survival (p = 0.031) when adjusted for clinical factors (tumor size and number of involved lymph nodes). Prognostic significance was lost when further adjusted for Her-2/neu and urokinase-type plasminogen activator (p = 0.284). Furthermore, when all three components were analyzed together, the survival was worst for patients with high MMP-2/high MMP-14/low TIMP-2 (5 year survival = 60%) and best with low MMP-2/low MMP-14/high TIMP-2 (5 year survival = 74%), but the difference did not reach statistical significance (p = 0.3285).

Conclusion

Of the MMP-14/TIMP-2/MMP-2 complex, MMP-14 was the factor most significantly associated with the outcome of breast cancer and was an independent factor of poor overall survival when adjusted for clinical prognostic factors, but not for certain ancillary markers.
Moz-dependent Hox expression controls segment-specific fate maps of skeletal precursors in the face
Authors: Crump Justin Gage , Swartz Mary E. , Eberhart Johann K. , Kimmel Charles B.
Published: June 2006

Development of the facial skeleton depends on interactions between intrinsic factors in the skeletal precursors and extrinsic signals in the facial environment. Hox genes have been proposed to act cell-intrinsically in skeletogenic cranial neural crest cells (CNC) for skeletal pattern. However,Hox genes are also expressed in other facial tissues, such as the ectoderm and endoderm, suggesting that Hox genes could also regulate extrinsic signalling from non-CNC tissues. Here we study moz mutant zebrafish in which hoxa2b and hoxb2a expression is lost and the support skeleton of the second pharyngeal segment is transformed into a duplicate of the first-segment-derived jaw skeleton. By performing tissue mosaic experiments between moz- and wild-type embryos, we show that Moz and Hox genes function in CNC, but not in the ectoderm or endoderm,to specify the support skeleton. How then does Hox expression within CNC specify a support skeleton at the cellular level? Our fate map analysis of skeletal precursors reveals that Moz specifies a second-segment fate map in part by regulating the interaction of CNC with the first endodermal pouch(p1). Removal of p1, either by laser ablation or in the itga5b926 mutant, reveals that p1 epithelium is required for development of the wild-type support but not the moz-duplicate jaw-like skeleton. We present a model in which Moz-dependent Hox expression in CNC shapes the normal support skeleton by instructing second-segment CNC to undergo skeletogenesis in response to local extrinsic signals.
calderónencodes an organic cation transporter of the major facilitator superfamily required for cell growth and proliferation ofDrosophilatissues
Authors: Herranz Héctor , Morata Ginés , Milán Marco
Published: June 2006

The adaptation of growth in response to dietary changes is essential for the normal development of all organisms. The insulin receptor (InR) signalling pathway controls growth and metabolism in response to nutrient availability. The elements of this pathway have been described, although little is known about the downstream elements regulated by this cascade. We identified calderón, a gene that encodes a protein with highest homology with organic cation transporters of the major facilitator superfamily, as a new transcriptional target of the InR pathway. These transporters are believed to function mainly in the uptake of sugars, as well as other organic metabolites. Genetic experiments demonstrate that calderón is required cell autonomously and downstream of the InR pathway for normal growth and proliferation of larval tissues. Our results indicate that growth of imaginal cells may be modulated by two distinct, but coordinated,nutrient-sensing mechanisms: one cell-autonomous and the other humoral.
C. elegansISWI and NURF301 antagonize an Rb-like pathway in the determination of multiple cell fates
Authors: Andersen Erik C. , Lu Xiaowei , Horvitz H. Robert
Published: June 2006

The class A, B and C synthetic multivulva (synMuv) genes act redundantly to negatively regulate the expression of vulval cell fates in Caenorhabditis elegans. The class B and C synMuv proteins include homologs of proteins that modulate chromatin and influence transcription in other organisms similar to members of the Myb-MuvB/dREAM, NuRD and Tip60/NuA4 complexes. To determine how these chromatin-remodeling activities negatively regulate the vulval cell-fate decision, we isolated a suppressor of the synMuv phenotype and found that the suppressor gene encodes the C. elegans homolog of Drosophila melanogaster ISWI. The C. elegans ISW-1 protein likely acts as part of a Nucleosome Remodeling Factor (NURF) complex with NURF-1, a nematode ortholog of NURF301, to promote the synMuv phenotype. isw-1 and nurf-1 mutations suppress both the synMuv phenotype and the multivulva phenotype caused by overactivation of the Ras pathway. Our data suggest that a NURF-like complex promotes the expression of vulval cell fates by antagonizing the transcriptional and chromatin-remodeling activities of complexes similar to Myb-MuvB/dREAM, NuRD and Tip60/NuA4. Because the phenotypes caused by a null mutation in the tumor-suppressor and class B synMuv gene lin-35 Rb and a gain-of-function mutation in let-60 Ras are suppressed by reduction of isw-1 function,NURF complex proteins might be effective targets for cancer therapy.