bluuebunny/crossref_metadata_2025 huggingface dataset:
Summer Diet of the Harbour Porpoise (Phocoena phocoena) in the Estuary and the Northern Gulf of St. Lawrence
Authors: Fontaine Pierre-Michel , Hammill Mike O. , Barrette Cyrille , Kingsley Michael C.
Published: April 2008

Stomach contents (n = 138) were examined in harbour porpoise (Phocoena phocoena) caught incidently by commercial fishermen in the estuary and the Gulf of St. Lawrence; 111 stomachs contained food. A total of 4423 otoliths and 11 upper beaks were collected belonging to nine species of fishes and one species of squid. Capelin (Mallotus villosus), Atlantic herring (Clupea harengus), and redfish (Sebastes marinus) were the three most important species in the diet by frequency of occurrence (83, 8, and 4.5%, respectively) and percent occurrence in the stomachs (52, 49, and 8.5%). Capelin and herring also made the greatest mass and caloric contribution to the diet of porpoise (>80%). The estimated mean mass and caloric value of the stomach contents of a nonlactating adults were 958 g and 7007 kJ, respectively.
RANDOM MATRICES: THE CIRCULAR LAW
Authors: TAO TERENCE , VU VAN
Published: April 2008

Let x be a complex random variable with mean zero and bounded variance σ2. Let Nn be a random matrix of order n with entries being i.i.d. copies of x. Let λ1, …, λn be the eigenvalues of [Formula: see text]. Define the empirical spectral distributionμn of Nn by the formula [Formula: see text]

The following well-known conjecture has been open since the 1950's:

Circular Law Conjecture: μn converges to the uniform distribution μ∞ over the unit disk as n tends to infinity.

We prove this conjecture, with strong convergence, under the slightly stronger assumption that the (2 + η)th-moment of x is bounded, for any η > 0. Our method builds and improves upon earlier work of Girko, Bai, Götze–Tikhomirov, and Pan–Zhou, and also applies for sparse random matrices.

The new key ingredient in the paper is a general result about the least singular value of random matrices, which was obtained using tools and ideas from additive combinatorics.
Gendered learning experience of engineering and technology students
Authors: Takruri-Rizk Haifa , Jensen Kathrine , Booth Kathryn
Published: April 2008

UK National statistics for science, engineering and technology studies and careers confirm the under-representation of women in these disciplines. A literature review formed the basis for developing survey questionnaires exploring issues of female students' attraction to, and retention in, engineering and technology studies. Findings indicate that having family members in the engineering or technology industry plays an important part in the students' choice of degree topic and future career. In particular, we found that female students need to be encouraged to study a "male dominated" subject, such as engineering or technology but that teachers do not contribute much to such encouragement. While at university, female students were more comfortable in small practical sessions rather than in a large lecture theatre environment and, when evaluating self-confidence in their skills at graduation, the female students were less confident than their male colleagues. In addition, the study highlights that gaining work experience through an industrial placement should be one of the priorities for engineering and technology students. A high level of determination and wanting to do engineering or technology is especially necessary for women who may be discouraged by the stereotyped image of engineering and technology studies and professions.
Cooperation creates results
Authors: Lee Maria
Published: April 2008

Cyberspace is the non-physical space by which the whole world is connected. Cyberspace is made possible by the inventions of the computer and the internet. With this interconnectivity comes danger and fear as well. In this non-physical space, people never know what could be happening on the other end. Someone at this moment could be trying to get into the nation's computer infrastructure to plan an attack against America. However, the organization of the government, cooperation with other countries, and the awareness of citizens combine to help to greatly to relieve some of the fear of the possibility of cyber attack.
Estimating the selectivity of
tf-idf
based cosine similarity predicates
Authors: Tata Sandeep , Patel Jignesh M.
Published: April 2008

An increasing number of database applications today require sophisticated approximate string matching capabilities. Examples of such application areas include data integration and data cleaning. Cosine similarity has proven to be a robust metric for scoring the similarity between two strings, and it is increasingly being used in complex queries. An immediate challenge faced by current database optimizers is to find accurate and efficient methods for estimating the selectivity of cosine similarity predicates. To the best of our knowledge, there are no known methods for this problem. In this paper, we present the first approach for estimating the selectivity of tf.idf based cosine similarity predicates. We evaluate our approach on three different real datasets and show that our method often produces estimates that are within 40% of the actual selectivity.
Intel Mash Maker
Authors: Ennals Rob , Brewer Eric , Garofalakis Minos , Shadle Michael , Gandhi Prashant
Published: April 2008

Intel® Mash Maker is an interactive tool that tracks what the user is doing and tries to infer what information and visualizations they might find useful for their current task. Mash Maker uses structured data from existing web sites to create new "mashed up" interfaces combining information from many sources.

The Intel® Mash Maker client is currently implemented as an extension to the FireFox web browser. Mash Maker adds a toolbar to the browser that shows buttons representing enhancements that Mash Maker believes the user might want to apply to the current page. An enhancement might combine the data on the page with data from another source, or visualize data in a new way. Mash Maker is intended to be an integral part of the way the user browses information, rather than being a special tool that a user uses when they want to create mashups.

In order to create mashups from normal websites, Mash Maker must first extract structured data from them. If the web site does not provide RDF data, then Mash Maker extracts structured data from the raw HTML using a community-maintained database of
extractors
, where each extractor describes how to extract structured data from a particular kind of web site.
Ricardo Baeza-Yates speaks out
Authors: Winslett Marianne , Baeza-Yates Ricardo
Published: April 2008

Welcome to this installment of
ACM SIGMOD Record'
s series of interviews with distinguished members of the database community. I'm Marianne Winslett, and today we are at the ICDE 2007 conference in Istanbul. I have here with me Ricardo Baeza-Yates, who is the vice president of Yahoo! Research in Europe and Latin America. Before that, he was a professor of computer science at the University of Chile for many years. His research interests include information retrieval, databases, algorithms, and user interfaces, and he is a co-author of one of the most widely used books on information retrieval. Ric's PhD is from the University of Waterloo. So, Ric, welcome!
Advances in Single-Molecule Fluorescence Methods for Molecular Biology
Authors: Joo Chirlmin , Balci Hamza , Ishitsuka Yuji , Buranachai Chittanon , Ha Taekjip
Published: April 2008

Ever since their introduction two decades ago, single-molecule (SM) fluorescence methods have matured and branched out to address numerous biological questions, which were inaccessible via ensemble measurements. Among the current arsenal, SM fluorescence techniques have capabilities of probing the dynamic interactions of nucleic acids and proteins via Förster (fluorescence) resonance energy transfer (FRET), tracking single particles over microns of distances, and deciphering the rotational motion of multisubunit systems. In this exciting era of transitioning from in vitro to in vivo and in situ conditions, it is anticipated that SM fluorescence methodology will become a common tool of molecular biology.
Targeted Drug-Aerosol Delivery in the Human Respiratory System
Authors: Kleinstreuer C. , Zhang Z. , Donohue J.F.
Published: April 2008

Inhalation of drug aerosols is a modern pathway to combat lung diseases. It is also becoming the preferred route for insulin delivery, pain management, cancer therapy, and nanotherapeutics. Popular delivery devices include nebulizers, metered-dose inhalers, and dry-powder inhalers. They are all nondirectional and hence have typically low particle deposition efficiencies in desired nasal or lung areas. Thus, for specific disease treatment with costly and/or aggressive medicine, it is necessary to provide targeted drug–aerosol delivery to predetermined sites in the human respiratory system. Experimental measurements and computer models of particle transport and deposition in nasal and lung airway models are presented. Furthermore, the underlying methodology and performance of pressurized metered dose inhalers as well as new smart inhaler systems are discussed. To maximize respiratory drug delivery to specific sites, an optimal combination of particle characteristics, inhalation waveform, particle release position, and drug-aerosol dosage has to be achieved.
The Second Generation in Western Europe: Education, Unemployment, and Occupational Attainment
Authors: Heath Anthony F. , Rothon Catherine , Kilpi Elina
Published: April 2008

This paper reviews recent research in ten Western European countries on the educational and labor market outcomes of second-generation minorities. Minorities from less-developed origins appear to be particularly disadvantaged in education, access to the labor market, and occupational attainment. Disadvantages are most evident with test scores early in the school career, but in some countries minorities have higher continuation rates beyond the compulsory leaving age than do majority peers with similar test scores. Entry into the labor market is a particular problem for most minorities, with substantial ethnic penalties with respect to employment in all ten countries. There is a more mixed picture for occupational attainment: In some countries, we find cumulative disadvantages, whereas in others the barriers are greatest on entry into the labor market. We review possible explanations for the differences both between minorities and between countries.
Targeting Endoplasmic Reticulum Stress and Akt with OSU-03012 and Gefitinib or Erlotinib to Overcome Resistance to Epidermal Growth Factor Receptor Inhibitors
Authors: Wang Yu-Chieh , Kulp Samuel K. , Wang Dasheng , Yang Chih-Cheng , Sargeant Aaron M. , Hung Jui-Hsiang , Kashida Yoko , Yamaguchi Mamoru , Chang Geen-Dong , Chen Ching-Shih
Published: April 2008

Preexisting and acquired resistance to epidermal growth factor receptor (EGFR) inhibitors limits their clinical usefulness in patients with advanced non–small cell lung cancer (NSCLC). This study characterizes the efficacy and mechanisms of the combination of gefitinib or erlotinib with OSU-03012, a celecoxib-derived antitumor agent, to overcome EGFR inhibitor resistance in three NSCLC cell lines, H1155, H23, and A549. The OSU-03012/EGFR inhibitor combination induced pronounced apoptosis in H1155 and H23 cells, but not in A549 cells, suggesting a correlation between drug sensitivity and basal phospho-Akt levels independently of EGFR expression status. Evidence indicates that this combination facilitates apoptosis through both Akt signaling inhibition and up-regulation of endoplasmic reticulum (ER) stress–induced, GADD153-mediated pathways. For example, ectopic expression of constitutively active Akt significantly attenuated the inhibitory effect on cell survival, and small interfering RNA–mediated knockdown of GADD153 protected cells from undergoing apoptosis in response to drug cotreatments. Furthermore, the OSU-03012/EGFR inhibitor combination induced GADD153-mediated up-regulation of death receptor 5 expression and subsequent activation of the extrinsic apoptosis pathway. It is noteworthy that the ER stress response induced by this combination was atypical in that the cytoprotective pathway was not engaged. In addition, in vivo suppression of tumor growth and modulation of intratumoral biomarkers were observed in a H1155 tumor xenograft model in nude mice. These data suggest that the concomitant modulation of Akt and ER stress pathways with the OSU-03012/EGFR inhibitor combination represents a unique approach to overcoming EGFR inhibitor resistance in NSCLC and perhaps other types of cancer with elevated basal Akt activities. [Cancer Res 2008;68(8):2820–30]
Genistein Induces the p21WAF1/CIP1 and p16INK4a Tumor Suppressor Genes in Prostate Cancer Cells by Epigenetic Mechanisms Involving Active Chromatin Modification
Authors: Majid Shahana , Kikuno Nobuyuki , Nelles Jason , Noonan Emily , Tanaka Yuichiro , Kawamoto Ken , Hirata Hiroshi , Li Long C. , Zhao Hong , Okino Steve T. , Place Robert F. , Pookot Deepa , Dahiya Rajvir
Published: April 2008

Genistein (4′,5,7-trihydroxyisoflavone) is the most abundant isoflavone found in the soybean. The effects of genistein on various cancer cell lines have been extensively studied but the precise molecular mechanisms are not known. We report here the epigenetic mechanism of the action of genistein on androgen-sensitive (LNCaP) and androgen-insensitive (DuPro) human prostate cancer cell lines. Genistein induced the expression of tumor suppressor genes p21 (WAF1/CIP1/KIP1) and p16 (INK4a) with a concomitant decrease in cyclins. There was a G0-G1 cell cycle arrest in LNCaP cells and a G2-M arrest in DuPro cells after genistein treatment. Genistein also induced apoptosis in DuPro cells. DNA methylation analysis revealed the absence of p21 promoter methylation in both cell lines. The effect of genistein on chromatin remodeling has not been previously reported. We found that genistein increased acetylated histones 3, 4, and H3/K4 at the p21 and p16 transcription start sites. Furthermore, we found that genistein treatment also increased the expression of histone acetyl transferases that function in transcriptional activation. This is the first report on epigenetic regulation of various genes by genistein through chromatin remodeling in prostate cancer. Altogether, our data provide new insights into the epigenetic mechanism of the action of genistein that may contribute to the chemopreventive activity of this dietary isoflavone and have important implications for epigenetic therapy. [Cancer Res 2008;68(8):2736–44]
Manganese Superoxide Dismutase Modulates Hypoxia-Inducible Factor-1α Induction via Superoxide
Authors: Kaewpila Suwimol , Venkataraman Sujatha , Buettner Garry R. , Oberley Larry W.
Published: April 2008

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that plays an important role in O2 homeostasis. Numerous observations suggest that changes in reactive oxygen species affect HIF-1α stabilization and HIF-1α transcriptional activation in many cell types. The antioxidant enzyme manganese superoxide dismutase (MnSOD) modulates the cellular redox environment by converting superoxide (O2•−) to hydrogen peroxide and dioxygen. Previous results from our group have shown that overexpression of MnSOD in MCF-7 cells alters stabilization of HIF-1α under hypoxic conditions; however, the underlying mechanism(s) is not known. Here, we tested the hypothesis that MnSOD regulates the expression of HIF-1α by modulating the steady-state level of O2•−. We found that decreasing MnSOD with small interfering RNA in MCF-7 cells resulted in (a) an associated increase in the hypoxic accumulation of HIF-1α immunoreactive protein, (b) a significant increase in the levels of O2•− (P < 0.01), but (c) no significant change in the steady-state level of H2O2. Removal of O2•− using spin traps (α-4-pyridyl-1-oxide-N-tert-butylnitrone and 5,5-dimethyl-1-pyrroline N-oxide) or the O2•− scavenger Tempol or an SOD mimic (AEOL10113) resulted in a decrease in HIF-1α protein, consistent with the hypothesis that O2•− is an important molecular effector responsible for hypoxic stabilization of HIF-1α. The evidence from both genetic and pharmaceutical manipulation is consistent with our hypothesis that O2•− can contribute to the stabilization of HIF-1α. [Cancer Res 2008;68(8):2781–8]
Enhancement of UVB-Induced Apoptosis by Apigenin in Human Keratinocytes and Organotypic Keratinocyte Cultures
Authors: Abu-Yousif Adnan O. , Smith Kimberly A. , Getsios Spiro , Green Kathleen J. , Van Dross Rukiyah T. , Pelling Jill C.
Published: April 2008

Topical application of the bioflavonoid 4′,5,7-trihydroxyflavone (apigenin) to mouse skin effectively reduces the incidence and size of skin tumors caused by UVB exposure. The ability to act as a chemopreventive compound indicates that apigenin treatment alters the molecular events initiated by UVB exposure; however, the effects of apigenin treatment on UVB-irradiated keratinocytes are not fully understood. In the present study, we have used three models of human keratinocytes to study the effect of apigenin treatment on UVB-induced apoptosis: HaCaT human keratinocyte cells, primary keratinocyte cultures isolated from human neonatal foreskin, and human organotypic keratinocyte cultures. Each keratinocyte model was exposed to a moderate dose of UVB (300–1,000 J/m2), then treated with apigenin (0–50 μmol/L), and harvested to assess apoptosis by Western blot analysis for poly(ADP)ribose polymerase cleavage, annexin-V staining by flow cytometry, and/or the presence of sunburn cells. Apigenin treatment enhanced UVB-induced apoptosis >2-fold in each of the models tested. When keratinocytes were exposed to UVB, apigenin treatment stimulated changes in Bax localization and increased the release of cytochrome c from the mitochondria compared with UVB exposure alone. Overexpression of the antiapoptotic protein Bcl-2 and expression of a dominant-negative form of Fas-associated death domain led to a reduction in the ability of apigenin to enhance UVB-induced apoptosis. These results suggest that enhancement of UVB-induced apoptosis by apigenin treatment involves both the intrinsic and extrinsic apoptotic pathways. The ability of apigenin to enhance UVB-induced apoptosis may explain, in part, the photochemopreventive effects of apigenin. [Cancer Res 2008;68(8):3057–65]
The Helix-Loop-Helix Protein Id1 Requires Cyclin D1 to Promote the Proliferation of Mammary Epithelial Cell Acini
Authors: Caldon C. Elizabeth , Swarbrick Alexander , Lee Christine S.L. , Sutherland Robert L. , Musgrove Elizabeth A.
Published: April 2008

Overexpression of the helix-loop-helix (HLH) protein Id1 has been associated with metastasis in breast cancer, but its role in models of early breast tumorigenesis is not well characterized. We show that the down-regulation of endogenous Id1 via proteosomal degradation and relocalization from the nucleus to the cytoplasm is an early event in the formation of mammary epithelial acini. Overexpression of Id1 in both human MCF-10A and primary mouse mammary epithelial cells disrupted normal acinar development by increasing acinar volume. This occurred in an HLH domain–dependent fashion via an increase in S phase. Id1 overexpression also increased apoptosis leading to accelerated luminal clearance, and this was reversed by coexpression of the proto-oncogene Bcl2, leading to large, disorganized structures with filled lumina. Id1 overexpression was unable to increase the volume of cyclin D1−/− acini, indicating that Id1 is dependent on cyclin D1 for its proliferative effects. In summary, Id1 may contribute to early breast cancer by promoting excessive proliferation through cyclin D1. [Cancer Res 2008;68(8):3026–36]
Analysis of the Mechanisms Mediating Tumor-Specific Changes in Gene Expression in Human Liver Tumors
Authors: Acevedo Luis G. , Bieda Mark , Green Roland , Farnham Peggy J.
Published: April 2008

There is widespread interest in efficient characterization of differences between tumor and normal samples. Here, we show an effective methodology for genome-scale characterization of tumors. Using matched normal and tumor samples from liver cancer patients, as well as non–cancer-related normal liver tissue, we first determined changes in gene expression as monitored on RNA expression arrays. We identified several hundred mRNAs that were consistently changed in the tumor samples. To characterize the mechanisms responsible for creation of the tumor-specific transcriptome, we performed chromatin immunoprecipitation on microarray experiments to assay binding of RNA polymerase II, H3me3K27, and H3me3K9 and DNA methylation in 25,000 promoter regions. These experiments identified changes in active and silenced regions of the genome in the tumor cells. Finally, we used a “virtual comparative genomic hybridization” method to identify copy number alterations in the tumor samples. Through comparison of RNA polymerase II binding, chromatin structure, DNA methylation, and copy number changes, we suggest that the major contributor to creation of the liver tumor transcriptome was changes in gene copy number. [Cancer Res 2008;68(8):2641–51]
Effect of Low-Fat Diet on Development of Prostate Cancer and Akt Phosphorylation in the Hi-Myc Transgenic Mouse Model
Authors: Kobayashi Naoko , Barnard R. James , Said Jonathan , Hong-Gonzalez Jenny , Corman Dan M. , Ku Melvin , Doan Ngan Bao , Gui Dorina , Elashoff David , Cohen Pinchas , Aronson William J.
Published: April 2008

This study evaluated the effect of dietary fat on prostate cancer development by using the Hi-Myc mouse transgenic prostate cancer model. Hi-Myc mice develop murine prostatic intraepithelial neoplasia (mPIN) as early as 2 to 4 weeks and invasive adenocarcinoma between 6 and 9 months due to the overexpression of human c-Myc in the mouse prostate. Three-week-old male Hi-Myc mice were placed on high-fat (HF; 42% Kcal) or low-fat (LF; 12% Kcal) diets, and equal caloric intake was maintained until euthanasia at 7 months. The number of mice that developed invasive adenocarcinoma at 7 months was 27% less in the LF diet group (12/28) compared with the HF diet group (23/33, P < 0.05). Epithelial cells in mPIN lesions in the LF group had a significantly lower proliferative index compared with epithelial cells in the HF group (21.7% versus 28.9%, P < 0.05). During the mPIN phase of carcinogenesis (4 months), the LF group had higher serum insulin-like growth factor (IGF) binding protein-1 levels (21.0 ± 8.9 ng/mL versus 3.2 ± 0.8 ng/mL, P < 0.05) relative to the HF group. Akt (Ser473) phosphorylation, Akt kinase activity, and phosphorylation of downstream targets of Akt in prostates were significantly reduced in the LF diet group compared with the HF group. We conclude that dietary fat reduction delays transition from mPIN to invasive cancer in this Myc-driven transgenic mouse model, possibly through suppression of the IGF-Akt pathway and decreased proliferation of mPIN epithelial cells. [Cancer Res 2008;68(8):3066–73]
Bone Marrow X Kinase–Mediated Signal Transduction in Irradiated Vascular Endothelium
Authors: Tu Tianxiang , Thotala Dinesh , Geng Ling , Hallahan Dennis E. , Willey Christopher D.
Published: April 2008

Radiation-induced activation of the phosphatidyl inositol-3 kinase/Akt signal transduction pathway requires Akt binding to phosphatidyl-inositol phosphates (PIP) on the cell membrane. The tyrosine kinase bone marrow X kinase (Bmx) binds to membrane-associated PIPs in a manner similar to Akt. Because Bmx is involved in cell growth and survival pathways, it could contribute to the radiation response within the vascular endothelium. We therefore studied Bmx signaling within the vascular endothelium. Bmx was activated rapidly in response to clinically relevant doses of ionizing radiation. Bmx inhibition enhanced the efficacy of radiotherapy in endothelial cells as well as tumor vascular endothelium in lung cancer tumors in mice. Retroviral shRNA knockdown of Bmx protein enhanced human umbilical vascular endothelial cell (HUVEC) radiosensitization. Furthermore, pretreatment of HUVEC with a pharmacologic inhibitor of Bmx, LFM-A13, produced significant radiosensitization of endothelial cells as measured by clonogenic survival analysis and apoptosis as well as functional assays including cell migration and tubule formation. In vivo, LFM-A13, when combined with radiation, resulted in significant tumor microvascular destruction as well as enhanced tumor growth delay. Bmx therefore represents a molecular target for the development of novel radiosensitizing agents. [Cancer Res 2008;68(8):2861–9]
Imaging Transgene Activity In vivo
Authors: Gade Terence P.F. , Koutcher Jason A. , Spees William M. , Beattie Bradley J. , Ponomarev Vladimir , Doubrovin Michael , Buchanan Ian M. , Beresten Tatiana , Zakian Kristen L. , Le H. Carl , Tong William P. , Mayer-Kuckuk Philipp , Blasberg Ronald G. , Gelovani Juri G.
Published: April 2008

The successful translation of gene therapy for clinical application will require the assessment of transgene activity as a measure of the biological function of a therapeutic transgene. Although current imaging permits the noninvasive detection of transgene expression, the critical need for quantitative imaging of the action of the expressed transgene has not been met. In vivo magnetic resonance spectroscopic imaging (MRSI) was applied to quantitatively delineate both the concentration and activity of a cytosine deaminase–uracil phosphoribosyltransferase (CD-UPRT) fusion enzyme expressed from a transgene. MRSI enabled the generation of anatomically accurate maps of the intratumoral heterogeneity in fusion enzyme activity. We observed an excellent association between the CD-UPRT concentration and activity and the percentage of CD-UPRT+ cells. Moreover, the regional levels of UPRT activity, as measured by imaging, correlated well with the biological affect of the enzyme. This study presents a translational imaging paradigm for precise, in vivo measurements of transgene activity with potential applications in both preclinical and clinical settings. [Cancer Res 2008;68(8):2878–84]
Targeting a Tumor-Specific Laminin Domain Critical for Human Carcinogenesis
Authors: Tran Mark , Rousselle Patricia , Nokelainen Pasi , Tallapragada Sruthi , Nguyen Ngon T. , Fincher Edgar F. , Marinkovich M. Peter
Published: April 2008

Laminin-332 is critical for squamous cell carcinoma (SCC) tumorigenesis, but targeting it for cancer therapy has been unachievable due to key role of laminin-332 in promoting tissue integrity. Here, we show that a portion of laminin-332, termed G45, which is proteolytically removed and absent in normal tissues, is prominently expressed in most human SCC tumors and plays an important role in human SCC tumorigenesis. Primary human keratinocytes lacking G45 (ΔG45) showed alterations of basal receptor organization, impaired matrix deposition, and increased migration. After SCC transformation, the absence of G45 domain in ΔG45 cells was associated with deficient extracellular signal-regulated kinase and phosphotidylinositol 3-kinase (PI3K) pathway activation, impaired invasion, deficient metalloproteinase activity, and absent tumorgenicity in vivo. Expression of G45 or activated PI3K subunit in ΔG45 cells reversed these abnormalities. G45 antibody treatment induced SCC tumor apoptosis, decreased SCC tumor proliferation, and markedly impaired human SCC tumorigenesis in vivo without affecting normal tissue adhesion. These results show a remarkable selectivity of expression and function for laminin-332 G45 in human SCC tumorigenesis and implicate it as a specific target for anticancer therapy. [Cancer Res 2008;68(8):2885–94]
Targeting CD24 for Treatment of Colorectal and Pancreatic Cancer by Monoclonal Antibodies or Small Interfering RNA
Authors: Sagiv Eyal , Starr Alex , Rozovski Uri , Khosravi Rami , Altevogt Peter , Wang Timothy , Arber Nadir
Published: April 2008

CD24 is a potential oncogene reported to be overexpressed in a large variety of human malignancies. We have shown that CD24 is overexpressed in 90% of colorectal tumors at a fairly early stage in the multistep process of carcinogenesis. Anti-CD24 monoclonal antibodies (mAb) induce a significant growth inhibition in colorectal and pancreatic cancer cell lines that express the protein. This study is designed to investigate further the effects of CD24 down-regulation using mAb or small interfering RNA in vitro and in vivo. Western blot analysis showed that anti-CD24 mAb induced CD24 protein down-regulation through lysosomal degradation. mAb augmented growth inhibition in combination with five classic chemotherapies. Xenograft models in vivo showed that tumor growth was significantly reduced in mAb-treated mice. Similarly, stable growth inhibition of cancer cell lines was achieved by down-regulation of CD24 expression using short hairpin RNA (shRNA). The produced clones proliferated more slowly, reached lower saturation densities, and showed impaired motility. Most importantly, down-regulation of CD24 retarded tumorigenicity of human cancer cell lines in nude mice. Microarray analysis revealed a similar pattern of gene expression alterations when cells were subjected to anti-CD24 mAb or shRNA. Genes in the Ras pathway, mitogen-activated protein kinase, or BCL-2 family and others of oncogenic association were frequently down-regulated. As a putative new oncogene that is overexpressed in gastrointestinal malignancies early in the carcinogenesis process, CD24 is a potential target for early intervention in the prevention and treatment of cancer. [Cancer Res 2008;68(8):2803–12]
MUC1 Expression Is Regulated by DNA Methylation and Histone H3 Lysine 9 Modification in Cancer Cells
Authors: Yamada Norishige , Nishida Yukari , Tsutsumida Hideaki , Hamada Tomofumi , Goto Masamichi , Higashi Michiyo , Nomoto Mitsuharu , Yonezawa Suguru
Published: April 2008

MUC1 is a transmembrane mucin that is highly expressed in various cancers and correlates with malignant potential. Important cancer-related genes such as p16 and E-cadherin are controlled epigenetically; however, MUC1 has been overlooked in epigenetics. Herein, we provide the first report that MUC1 gene expression is regulated by DNA methylation and histone H3 lysine 9 (H3-K9) modification of the MUC1 promoter. The recently developed MassARRAY assay was performed to investigate the DNA methylation status of 184 CpG sites from −2,753 to +263. Near the transcriptional start site, the DNA methylation level of MUC1-negative cancer cell lines (e.g., MDA-MB-453) was high, whereas that of MUC1-positive cell lines (e.g., MCF-7) was low. Histone H3-K9 modification status was also closely related to MUC1 gene expression. Furthermore, MUC1 mRNA expression in MUC1-negative cells was restored by treatment with the DNA methylation inhibitor 5-aza-2′-deoxycytidine. Our results indicate that DNA methylation and histone H3-K9 modification in the 5′ flanking region play a critical role in MUC1 gene expression, and this study defines MUC1 as a new member of the class of epigenetically controlled genes. An understanding of the epigenetic changes of MUC1 may be of importance for diagnosis of carcinogenic risk and prediction of outcome for cancer patients. [Cancer Res 2008;68(8):2708–16]
Interleukin-15/Interleukin-15Rα Complexes Promote Destruction of Established Tumors by Reviving Tumor-Resident CD8+ T Cells
Authors: Epardaud Mathieu , Elpek Kutlu G. , Rubinstein Mark P. , Yonekura Ai-ris , Bellemare-Pelletier Angelique , Bronson Roderick , Hamerman Jessica A. , Goldrath Ananda W. , Turley Shannon J.
Published: April 2008

Tumors often escape immune-mediated destruction by suppressing lymphocyte infiltration or effector function. New approaches are needed that overcome this suppression and thereby augment the tumoricidal capacity of tumor-reactive lymphocytes. The cytokine interleukin-15 (IL-15) promotes proliferation and effector capacity of CD8+ T cells, natural killer (NK) cells, and NKT cells; however, it has a short half-life and high doses are needed to achieve functional responses in vivo. The biological activity of IL-15 can be dramatically increased by complexing this cytokine to its soluble receptor, IL-15Rα. Here, we report that in vivo delivery of IL-15/IL-15Rα complexes triggers rapid and significant regression of established solid tumors in two murine models. Despite a marked expansion of IL-2/IL-15Rβ+ cells in lymphoid organs and peripheral blood following treatment with IL-15/IL-15Rα complexes, the destruction of solid tumors was orchestrated by tumor-resident rather than newly infiltrating CD8+ T cells. Our data provide novel insights into the use of IL-15/IL-15Rα complexes to relieve tumor-resident T cells from functional suppression by the tumor microenvironment and have significant implications for cancer immunotherapy and treatment of chronic infections. [Cancer Res 2008;68(8):2972–83]
Secondary BRCA1 Mutations in BRCA1-Mutated Ovarian Carcinomas with Platinum Resistance
Authors: Swisher Elizabeth M. , Sakai Wataru , Karlan Beth Y. , Wurz Kaitlyn , Urban Nicole , Taniguchi Toshiyasu
Published: April 2008

Although ovarian carcinomas with mutated BRCA1 or BRCA2 are sensitive to platinum compounds, such carcinomas eventually develop platinum resistance. Previously, we showed that acquired resistance to cisplatin in BRCA2-mutated tumors can be mediated by secondary intragenic mutations in BRCA2 that restore the wild-type BRCA2 reading frame. Here, we show that secondary mutations of BRCA1 also occur in BRCA1-mutated ovarian cancer with platinum resistance. We evaluated nine recurrent BRCA1-mutated ovarian cancers previously treated with platinum compounds, including five with acquired platinum resistance, one with primary platinum resistance, and three with platinum sensitivity. Four of the six recurrent platinum-resistant tumors had developed secondary genetic changes in BRCA1 that restored the reading frame of the BRCA1 protein, whereas none of the three platinum-sensitive recurrent tumors developed BRCA1 sequence alterations. We immunohistochemically confirmed restored expression of BRCA1 protein in two cases with secondary mutations. Intriguingly, the case with primary platinum resistance showed back mutation of BRCA1 in the primary tumor and showed another secondary mutation in the recurrent tumor. Our results suggest that secondary mutations in BRCA1 can mediate resistance to platinum in BRCA1-mutated ovarian tumors. [Cancer Res 2008;68(8):2581–6]
Noninvasive Imaging of Apoptosis and Its Application in Cancer Therapeutics
Authors: Coppola Julia M. , Ross Brian D. , Rehemtulla Alnawaz
Published: April 2008

Purpose: Activation of the apoptotic cascade plays an important role in the response of tumors to therapy. Noninvasive imaging of apoptosis facilitates optimization of therapeutic protocols regarding dosing and schedule and enables identification of efficacious combination therapies.

Experimental Design: We describe a hybrid polypeptide that reports on caspase-3 activity in living cells and animals in a noninvasive manner. This reporter, ANLucBCLuc, constitutes a fusion of small interacting peptides, peptide A and peptide B, with the NLuc and CLuc fragments of luciferase with a caspase-3 cleavage site (DEVD) between pepANLuc (ANLuc) and pepBCLuc (BCLuc). During apoptosis, caspase-3 cleaves the reporter, enabling separation of ANLuc from BCLuc. A high-affinity interaction between peptide A and peptide B restores luciferase activity by NLuc and CLuc complementation. Using a D54 glioma model, we show the utility of the reporter in imaging of apoptosis in living subjects in response to various chemotherapy and radiotherapy regimens.

Results: Treatment of live cells and mice carrying D54 tumor xenografts with chemotherapeutic agents such as temozolomide and perifosine resulted in induction of bioluminescence activity, which correlated with activation of caspase-3. Treatment of mice with combination therapy of temozolomide and radiation resulted in increased bioluminescence activity over individual treatments and increased therapeutic response due to enhanced apoptosis.

Conclusion: The data provided show the utility of the ANLucBCLuc reporter in dynamic, noninvasive imaging of apoptosis and provides a rationale for use of this technology to optimize dose and schedule of novel therapies or to develop novel combination therapies using existing drugs.
Targeting Ras in Myeloid Leukemias
Authors: Braun Benjamin S. , Shannon Kevin
Published: April 2008

Ras proteins normally relay growth-promoting signals from many activated cell surface receptors, and they are altered by oncogenic point mutations in ∼30% of human cancers. Activating KRAS and NRAS mutations are especially common in malignancies of the pancreas, lung, and colon, and in myeloid leukemia. Here, we discuss general strategies for targeting hyperactive Ras signaling in cancer cells with specific reference to myeloid malignancies.
Activation of Placenta-Specific Transcription FactorDistal-lessHomeobox 5 Predicts Clinical Outcome in Primary Lung Cancer Patients
Authors: Kato Tatsuya , Sato Nagato , Takano Atsushi , Miyamoto Masaki , Nishimura Hitoshi , Tsuchiya Eiju , Kondo Satoshi , Nakamura Yusuke , Daigo Yataro
Published: April 2008

Purpose and Experimental Design: To identify novel biomarkers and therapeutic targets for lung cancers, we screened for genes that were highly transactivated in lung cancers using a cDNA microarray representing 27,648 genes. DLX5 gene, a member of the human distal-less homeobox transcriptional factor family that is expressed during early embryonic development, was found to be overexpressed in the great majority of lung cancers. Tissue microarray consisting of archival non–small cell lung cancer samples from 369 patients was applied to examine the clinicopathologic significance of DLX5 protein. A role of DLX5 in cancer cell growth and/or survival was investigated through small interfering RNA experiments.

Results: Northern blot and immunohistochemical analyses detected expression of DLX5 only in placenta among 23 normal tissues examined. Immunohistochemical analysis showed that positive immunostaining of DLX5 was correlated with tumor size (pT classification; P = 0.0053) and poorer prognosis of non–small cell lung cancer patients (P = 0.0045). It was also shown to be an independent prognostic factor (P = 0.0415). Treatment of lung cancer cells with small interfering RNAs for DLX5 effectively knocked down its expression and suppressed cell growth.

Conclusions: These data implied that DLX5 is useful as a target for the development of anticancer drugs and cancer vaccines as well as for a prognostic biomarker in clinic.
Understanding the Biological Basis of Autofluorescence Imaging for Oral Cancer Detection: High-Resolution Fluorescence Microscopy in Viable Tissue
Authors: Pavlova Ina , Williams Michelle , El-Naggar Adel , Richards-Kortum Rebecca , Gillenwater Ann
Published: April 2008

Purpose: Autofluorescence imaging is increasingly used to noninvasively identify neoplastic oral cavity lesions. Improving the diagnostic accuracy of these techniques requires a better understanding of the biological basis for optical changes associated with neoplastic transformation in oral tissue.

Experimental Design: A total of 49 oral biopsies were considered in this study. The autofluorescence patterns of viable normal, benign, and neoplastic oral tissue were imaged using high-resolution confocal fluorescence microscopy.

Results: The autofluorescence properties of oral tissue vary significantly based on anatomic site and pathologic diagnosis. In normal oral tissue, most of the epithelial autofluorescence originates from the cytoplasm of cells in the basal and intermediate regions, whereas structural fibers are responsible for most of the stromal fluorescence. A strongly fluorescent superficial layer was observed in tissues from the palate and the gingiva, which contrasts with the weakly fluorescent superficial layer found in other oral sites. Upon UV excitation, benign inflammation shows decreased epithelial fluorescence, whereas dysplasia displays increased epithelial fluorescence compared with normal oral tissue. Stromal fluorescence in both benign inflammation and dysplasia drops significantly at UV and 488 nm excitation.

Conclusion: Imaging oral lesions with optical devices/probes that sample mostly stromal fluorescence may result in a similar loss of fluorescence intensity and may fail to distinguish benign from precancerous lesions. Improved diagnostic accuracy may be achieved by designing optical probes/devices that distinguish epithelial fluorescence from stromal fluorescence and by using excitation wavelengths in the UV range.
Effects of a Topically Applied Bioadhesive Berry Gel on Loss of Heterozygosity Indices in Premalignant Oral Lesions
Authors: Shumway Brian S. , Kresty Laura A. , Larsen Peter E. , Zwick Jared C. , Lu Bo , Fields Henry W. , Mumper Russell J. , Stoner Gary D. , Mallery Susan R.
Published: April 2008

Purpose: The aim of this study was to assess the effects of topical application of a 10% (w/w) freeze-dried black raspberry (FBR) gel on oral intraepithelial neoplasia (IEN) variables that included histologic diagnoses and loss of heterozygosity (LOH) indices. Microsatellite instability and/or LOH at tumor suppressor gene–associated chromosomal loci have been associated with a higher risk for oral IEN progression to oral squamous cell carcinoma. Previously, our laboratories have shown that FBRs are well tolerated and possess potent antioxidant, apoptotic, and differentiation-inducing properties.

Experimental Design: Each participant with IEN served as their own internal control. Before treatment, all lesions were photographed, and lesional tissue was hemisected to obtain a pretreatment diagnosis and baseline biochemical and molecular variables. Gel dosing (0.5 g applied four times daily for 6 weeks) was initiated 1 week after the initial biopsy. Genomic DNA was isolated from laser-captured basilar and suprabasilar surface epithelial cells followed by PCR amplification using primer sets that targeted known and presumed tumor suppressor gene loci associated with INK4a/ARF, p53, and FHIT. Allelic imbalance was determined by sequence analysis using normal participant tissues to establish microsatellite marker peak patterns and allele sizes.

Results: Confirming earlier phase I data, none of the 27 participants developed FBR gel–associated toxicities. Furthermore, our results show histologic regression in a subset of patients as well as statistically significant reduction in LOH at tumor suppressor gene–associated loci.

Conclusions: These preliminary data suggest that further evaluation of berry gels for oral IEN chemoprevention is warranted.
Pathologic Complete Response to Neoadjuvant Chemotherapy of Breast Carcinoma Is Associated with the Disappearance of Tumor-Infiltrating Foxp3+ Regulatory T Cells
Authors: Ladoire Sylvain , Arnould Laurent , Apetoh Lionel , Coudert Bruno , Martin Francois , Chauffert Bruno , Fumoleau Pierre , Ghiringhelli François
Published: April 2008

Purpose: T-cell infiltration is associated with good tumor prognosis in many cancers. To assess the capacity of neoadjuvant chemotherapy to affect T-cell infiltration in breast cancer, we evaluated CD3 and CD8 infiltrates, and the Foxp3 immunosuppressive T cells.

Experimental Design: CD3+, CD8+, and Foxp3+ cell infiltrates were detected by immunohistochemistry in a series of 56 breast cancer patients before and after the end of neoadjuvant chemotherapy.

Results: Poor prognostic factors (negative hormonal receptors, high tumor grade, and nodal involvement) were associated with a significantly higher number of CD3, CD8, and Foxp3 infiltrates before the beginning of chemotherapy. Chemotherapy resulted in a decrease in Foxp3 infiltrates, whereas the level of CD8 and CD3 infiltrates remained unchanged. Pathologic complete responses (pCR) had a drastic decrease of Foxp3+ cells, whereas these cells remained elevated in nonresponders. A cutoff criterion that combined high CD8 infiltration and no Foxp3 cell infiltration on surgical specimens is associated with pCR with a sensitivity of 75% and a specificity of 93%. The infiltrate of cytotoxic TiA1 and granzyme B–positive cells was dramatically enhanced after chemotherapy only in patients with pCR. By multivariate analysis, association of a high CD8 infiltration and no Foxp3 infiltration on final histologic specimens were independently associated with pCR.

Conclusion: These findings indicate that pCR to neoadjuvant chemotherapy is associated with an immunologic profile combining the absence of immunosuppressive Foxp3 cells and the presence of a high number of CD8 T cells and cytotoxic cells. These results argue for the induction of an antitumor immune response by chemotherapy.
Prediction of Broad Spectrum Resistance of Tumors towards Anticancer Drugs
Authors: Efferth Thomas , Konkimalla V. Badireenath , Wang Yi-Fen , Sauerbrey Axel , Meinhardt Silke , Zintl Felix , Mattern Jürgen , Volm Manfred
Published: April 2008

Purpose: Drug resistance is a major obstacle in cancer chemotherapy. Although the statistical probability of therapeutic success is known for larger patient groups from clinical therapy trials, it is difficult to predict the individual response of tumors. The concept of individualized therapy aims to determine in vitro the drug response of tumors beforehand to choose effective treatment options for each individual patient.

Experimental Design: We analyzed the cross-resistance profiles of different tumor types (cancers of lung, breast, and colon, and leukemia) towards drugs from different classes (anthracyclines, antibiotics, Vinca alkaloids, epipodophyllotoxins, antimetabolites, and alkylating agents) by nucleotide incorporation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Hierarchical cluster analysis and COMPARE analyses were applied.

Results: Tumors exert broad resistance profiles, e.g., tumors resistant to one drug tend to also be resistant to other drugs, whereas sensitive tumors reveal sensitivity towards many drugs. Interestingly, the broad spectrum resistance phenotype could reliably be predicted by doxorubicin alone. Expression of the ATP-binding cassette transporter P-glycoprotein (ABCB1, MDR1) and the proliferative activity of tumors were identified as underlying mechanisms of broad spectrum resistance. To find novel compounds with activity against drug-resistant tumors, a database with 2,420 natural products was screened for compounds acting independent of P-glycoprotein and the proliferative state of tumor cells.

Conclusions: Tumors exert cross-resistance profiles much broader than the classical multidrug resistance phenotype. Broad spectrum resistance can be predicted by doxorubicin due to the multifactorial mode of action of this drug. Novel cytotoxic compounds from natural resources might be valuable tools for strategies to bypass broad spectrum resistance.