bluuebunny/crossref_metadata_2025 huggingface dataset:
Technological Problems of the Processing of Used Automobile Tyres
Authors: Gubarevich V. N.
Published: September 2007

This article describes technological research and special
equipment for complex processing of used automobile tyres. It was found
during the course of the research that the following quantities of materials
can be obtained from one tonne of the processed automobile tyres: 600 to
650 kg of rubber powder, 130 to 150 kg of textile, 130 to 140 kg of metal.
New magnetic separators are designed to recover metal and its compounds
with rubber. Also, highly efficient air vibrating separators have been
developed for separation of the textile cord from powder. In the
technological testwork, the rubber powder, with particle size ranges: –0.5
mm, –1.0+0.5 mm, –1.8+1.0 mm was obtained. Concentration of the
ferromagnetic impurities in the rubber powder does not exceed 0.03%, and
of textile 2%. In comparison with other technologies, the main advantage of
our technology is lower specific consumption of material for equipment, as
well as reduced energy consumption, simplicity of the process, possibility of
obtaining fine rubber waste with highly developed surface.
Removal of Phosphorus and Enrichment of Manganese From a ComplexFerruginous Manganese Ore
Authors: Rao G. V. , Acharya B. C. , Murty B. V. R. , Mohanty J. N. , Swamy Y. V. , Chattopadhay P. , Tripathy A. K.
Published: September 2007

Attempts were made to enrich manganese content as well as Mn/Fe ratio from a complex
manganese ore from Nishikhal deposit, Orissa, India, containing 32% Mn, 18% Fe, 16%
SiO 2, 21% acid insolubles and 0.45% P by reduction roasting followed by magnetic
separation route. Interestingly the adopted route not only enriched the Mn content to
around 40%, Mn/Fe ratio to around 10 but also brought down the P to around 0.3% in the
non‐magnetic product there by making this deposit as a potential feed for ferro‐manganese
production in the country. Although the enrichment of Mn and Mn/Fe ratio is
expected by this route, 60% of the phosphorus reduction is primarily due to the presence of
P in association with goethite while the rest of the P was observed to be associated with the
manganese phases and as apatite within the silicate phases as confirmed by the optical
microscope and electron microscopic studies. The paper also discusses the limitation of
reducing the P content further in the beneficiated product.
Selection of an Expression for the Hydrodynamic Drag on a Particle in a Magnetic Separator
Authors: Mostika Yu. S. , Karmazin V. I. , Shutov V. Yu. , Grebenyuk L. Z.
Published: September 2007

The results of a numerical solution of equations of the motion of a paramagnetic particle in
the working gap of a magnetic separator for various values of magnetic induction (from
0.2 to 2 T) and the particle diameter (from 10 µm to 1 mm) show that along the particle
trajectory various types of flow modes: e.g. laminar, transitional and turbulent can be
present. It is also shown that some of the well‐known formulae approximating the
experimental dependence of the hydrodynamic drag coefficient on Reynolds number Re
(the so‐called standard hydrodynamic drag curve) as a step‐smooth function, do not
ensure the condition of continuity of the hydrodynamic drag on the boundaries of the
range of values Re for which these formulae were obtained. One of the variants of
approximation of the standard hydrodynamic drag curve for the case where along the
same trajectory various types of regimes of flow‐around a particle are present, is proposed.
Review of Magnetic Carrier Technologies for Metal Ion Removal
Authors: Broomberg J. , Gélinas S. , Finch James A. , Xu Z.
Published: September 2007

Magnetic carriers are magnetic materials designed to bind selectively on some non
‐magnetic materials to make them separable using magnetic separation. It allows magnetic
separation, a fast, efficient, high capacity and well‐developed industrial technology, to be
applied to the separation of materials that are otherwise non‐magnetic. One application is
in metal ion recovery from dilute effluents. Magnetic carrier technologies offer some
advantages over other more conventional metal ion separation techniques such as ion
exchange, carbon adsorption, and precipitation. Various magnetic carrier technologies
have been developed using different magnetic materials (for example, micro‐sized magnetite
of magnetic oils) and controlling the attachment of the carrier to the target species
through specific binding mechanisms (for example, electrostatic adsorption or chemical
affinity). A full‐scale industrial water treatment application is illustrated in the case of the
Sirofloc process. The review summarizes the efforts over the last twenty years to develop
carriers with high loading capacity and selectivity. General principles for the design of
magnetic carriers are summarized.
Removal of Iron From Fly Ash for Ceramic and Refractory Applications
Authors: Rao R. Bhima , Chattopadhyay P. , Banerjee G. N.
Published: September 2007

The natural resources of refractory raw materials are declining and at the same time the
consumption rate is increasing, particularly in iron and steel industries. Any attempt to
identify a new raw material source from the waste dumps could solve the national economy
as well as environmental problems. In view of this, fly ash from thermal power plant has
been identified for use in the ceramic/refractory industries after suitable beneficiation. For
this wet high intensity magnetic separation studies carried out on typical fly ash sample
indicate that the non‐magnetic fraction (product) containing 24% Al2O3, 67% SiO2, 1.7%
Fe2O3could be achieved with 63% recovery. This product is acceptable as a ceramic and
refractory raw material after the necessary blending.
A Novel Advantage of HGMS Ordered Matrices
Authors: Iacob Gh. , Rezlescu N.
Published: September 2007

A novel benefit of an ordered High Gradient Magnetic Separation (HGMS) matrix, made
up of parallel ferromagnetic wires is presented. One shows that the magnetic force Fm
depends on α, the angle between the wires of the matrix and the applied magnetic field H0 .
There is a relation between the tilting angles and magnetic susceptibilities of particles
pulled out from the mixture. This relation proves a practical possibility of separating a
mixture only by choosing adequate tilting angles; the method is named separation in
angular steps. Finally one shows two applications based on this principle: a separator
which extracts successively and another one which extracts concomitantly different
magnetic fractions from a granular mixture.
Bone Morphogenetic Protein 7 in the Development and Treatment of Bone Metastases from Breast Cancer
Authors: Buijs Jeroen T. , Henriquez Nico V. , van Overveld Petra G.M. , van der Horst Geertje , Que Ivo , Schwaninger Ruth , Rentsch Cyrill , ten Dijke Peter , Cleton-Jansen Anne-Marie , Driouch Keltouma , Lidereau Rosette , Bachelier Richard , Vukicevic Slobodan , Clézardin Philippe , Papapoulos Socrates E. , Cecchini Marco G. , Löwik Clemens W.G.M. , van der Pluijm Gabri
Published: September 2007

Bone morphogenetic protein 7 (BMP7) counteracts the physiological epithelial-to-mesenchymal transition (EMT), a process that is indicative of epithelial plasticity. Because EMT is involved in cancer, we investigated whether BMP7 plays a role in breast cancer growth and metastasis. In this study, we show that decreased BMP7 expression in primary breast cancer is significantly associated with the formation of clinically overt bone metastases in patients with ≥10 years of follow-up. In line with these clinical observations, BMP7 expression is inversely related to tumorigenicity and invasive behavior of human breast cancer cell lines. Moreover, BMP7 decreased the expression of vimentin, a mesenchymal marker associated with invasiveness and poor prognosis, in human MDA-MB-231 (MDA-231)-B/Luc+ breast cancer cells under basal and transforming growth factor-β (TGF-β)–stimulated conditions. In addition, exogenous addition of BMP7 to TGF-β–stimulated MDA-231 cells inhibited Smad-mediated TGF-β signaling. Furthermore, in a well-established bone metastasis model using whole-body bioluminescent reporter imaging, stable overexpression of BMP7 in MDA-231 cells inhibited de novo formation and progression of osteolytic bone metastases and, hence, their metastatic capability. In line with these observations, daily i.v. administration of BMP7 (100 μg/kg/d) significantly inhibited orthotopic and intrabone growth of MDA-231-B/Luc+ cells in nude mice. Our data suggest that decreased BMP7 expression during carcinogenesis in the human breast contributes to the acquisition of a bone metastatic phenotype. Because exogenous BMP7 can still counteract the breast cancer growth at the primary site and in bone, BMP7 may represent a novel therapeutic molecule for repression of local and bone metastatic growth of breast cancer. [Cancer Res 2007;67(18):8742–51]
The Nuclear Matrix Protein, NRP/B, Enhances Nrf2-Mediated Oxidative Stress Responses in Breast Cancer Cells
Authors: Seng Seyha , Avraham Hava Karsenty , Jiang Shuxian , Yang Suping , Sekine Masayuki , Kimelman Noam , Li Huchun , Avraham Shalom
Published: September 2007

The transcription factor NF-E2–related factor 2 (Nrf2) translocates into the nucleus and activates phase II genes encoding detoxification enzymes and antioxidant proteins, resulting in the protection of cells from oxidative insults. However, the involvement of Nrf2-mediated oxidative stress responses in breast cancer cells is largely unknown. Notably, during our study of the Nrf2 pathway in breast cancer cells, we observed that the nuclear matrix protein NRP/B was expressed and colocalized with Nrf2 in these cells, suggesting that NRP/B is involved in Nrf2-mediated oxidative stress responses. The expression level of NRP/B was variable in different breast cancer cells and breast cancer tissues, and was found to be localized in the nucleus. NRP/B expression was increased after exposure to the oxidative stress agent, hydrogen peroxide (H2O2), particularly in the highly aggressive MDA-MB-231 breast cancer cells. Association of NRP/B with Nrf2 in vitro and in vivo was observed in MDA-MB-231 breast cancer cells, and this association was up-regulated upon exposure to H2O2, but not to sodium nitroprusside, SIN-1, and DETA-NO. NRP/B also enhanced Nrf2-mediated NAD(P)H:quinine oxidoreductase 1 promoter activity. Thus, this study reveals that NRP/B enhances oxidative stress responses in breast cancer cells via the Nrf2 pathway, identifying a novel role of nuclear matrix protein(s) in oxidative stress responses. [Cancer Res 2007;67(18):8596–604]
Differential Regulation of Hypoxia-Induced CXCR4 Triggering during B-Cell Development and Lymphomagenesis
Authors: Piovan Erich , Tosello Valeria , Indraccolo Stefano , Masiero Massimo , Persano Luca , Esposito Giovanni , Zamarchi Rita , Ponzoni Maurilio , Chieco-Bianchi Luigi , Dalla-Favera Riccardo , Amadori Alberto
Published: September 2007

The chemokine receptor CXCR4 plays a central role in organ-specific homing and tumor spreading and is induced by hypoxia. B lymphocytes are exposed to low oxygen tensions during their development, but the influence of hypoxia on their physiology is poorly understood. Here, we show that hypoxia is associated with up-regulation of CXCR4 expression in human normal and malignant B cells, through both transcriptional and posttranslational mechanisms. However, a dichotomic functional response to CXCR4 triggering was observed: both peripheral B cells and lymphomas arising from mature B cells displayed increased responses to CXCR4 triggering under hypoxia, whereas germinal center (GC) B cells as well as GC-derived lymphomas showed CXCR4 receptor desensitization. This phenomenon was associated with differential modulation of key signal-transducing molecules, including mitogen-activated protein kinase phosphatase-1 and regulator of G protein signaling molecule-1. The unresponsiveness of GC-derived lymphomatous B cells to CXCR4 triggering under hypoxia may have implications for the development and pathogenesis of GC-derived lymphoid tumors. [Cancer Res 2007;67(18):8605–14]
Prostaglandin E2 Induces Breast Cancer–Related Aromatase Promoters via Activation of p38 and c-Jun NH2-Terminal Kinase in Adipose Fibroblasts
Authors: Chen Dong , Reierstad Scott , Lin Zhihong , Lu Meiling , Brooks Chris , Li Newton , Innes Joy , Bulun Serdar E.
Published: September 2007

Aromatase is the key enzyme for estrogen biosynthesis. A distal promoter, PI.4, maintains baseline levels of aromatase in normal breast adipose tissue. In contrast, malignant breast epithelial cells secrete prostaglandin E2 (PGE2), which stimulates aromatase expression via proximal promoters PI.3/PII in a cyclic AMP (cAMP)– and protein kinase C (PKC)–dependent manner in adjacent breast adipose fibroblasts (BAF), leading to increased local concentrations of estrogen. Although an effective treatment for breast cancer, aromatase inhibitors indiscriminately abolish estrogen synthesis in all tissues, causing major side effects. To identify drug targets to selectively block aromatase and estrogen production in breast cancer, we investigated PGE2-stimulated signaling pathways essential for aromatase induction downstream of cAMP and PKC in human BAFs. Here, we show that PGE2 or its surrogate hormonal mixture dibutyryl cAMP (Bt2cAMP) + phorbol diacetate (PDA) stimulated the p38, c-jun NH2-terminal kinase (JNK)-1, and extracellular signal–regulated kinase (ERK) mitogen-activated protein kinase pathways. Inhibition or small interfering RNA–mediated knockdown of p38 or JNK1, but not ERK, inhibited PGE2- or Bt2cAMP + PDA–induced aromatase activity and expression via PI.3/PII. Conversely, overexpression of wild-type p38α or JNK1 enhanced PGE2-stimulated aromatase expression via PII. PGE2 or Bt2cAMP + PDA stimulated c-Jun and activating transcription factor-2 (ATF2) phosphorylation and binding to the PI.3/PII region. Specific activation of protein kinase A (PKA) or EPAC with cAMP analogues stimulated p38 and JNK1; however, only PKA-activating cAMP analogues induced aromatase expression. The PKC activator PDA effectively stimulated p38 and JNK1 phosphorylation but not aromatase expression. Taken together, PGE2 activation of p38 and JNK1 via PKA and PKC is necessary for aromatase induction in BAFs, and p38 and JNK1 are potential new drug targets for tissue-specific ablation of aromatase expression in breast cancer. [Cancer Res 2007;67(18):8914–22]
Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?
Authors: Rassool Feyruz V. , Gaymes Terry J. , Omidvar Nader , Brady Nicola , Beurlet Stephanie , Pla Marika , Reboul Murielle , Lea Nicholas , Chomienne Christine , Thomas Nicholas S.B. , Mufti Ghulam J. , Padua Rose Ann
Published: September 2007

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of disorders characterized by ineffective hematopoiesis, with an increased propensity to develop acute myelogenous leukemia (AML). The molecular basis for MDS progression is unknown, but a key element in MDS disease progression is loss of chromosomal material (genomic instability). Using our two-step mouse model for myeloid leukemic disease progression involving overexpression of human mutant NRAS and BCL2 genes, we show that there is a stepwise increase in the frequency of DNA damage leading to an increased frequency of error-prone repair of double-strand breaks (DSB) by nonhomologous end-joining. There is a concomitant increase in reactive oxygen species (ROS) in these transgenic mice with disease progression. Importantly, RAC1, an essential component of the ROS-producing NADPH oxidase, is downstream of RAS, and we show that ROS production in NRAS/BCL2 mice is in part dependent on RAC1 activity. DNA damage and error-prone repair can be decreased or reversed in vivo by N-acetyl cysteine antioxidant treatment. Our data link gene abnormalities to constitutive DNA damage and increased DSB repair errors in vivo and provide a mechanism for an increase in the error rate of DNA repair with MDS disease progression. These data suggest treatment strategies that target RAS/RAC pathways and ROS production in human MDS/AML. [Cancer Res 2007;67(18):8762–71]
The Role of Platelet/Endothelial Cell Adhesion Molecule–1 (CD31) and CD38 Antigens in Marrow Microenvironmental Retention of Acute Myelogenous Leukemia Cells
Authors: Gallay Nathalie , Anani Ludovic , Lopez Adriana , Colombat Philippe , Binet Christian , Domenech Jorge , Weksler Babette B. , Malavasi Fabio , Herault Olivier
Published: September 2007

In acute myelogenous leukemia (AML), leukemic cell-microenvironment interactions within various niches (stromal/osteoblastic or sinusoidal endothelial cell niches) have a role in leukemia cell survival and drug resistance. The AML leukemic cells express platelet/endothelial cell adhesion molecule–1 (CD31) and CD38, two adhesion molecules that could interact with microenvironmental elements, i.e., CD31 on the surface of marrow endothelial cells (CD31/CD31 and CD38/CD31 interactions) and hyaluronate (CD38/hyaluronate interactions). We report a physical association of these two antigens on the plasma membrane of myeloid leukemic cells. In this context, in vitro experiments done using interaction-blocking anti-CD31 and anti-CD38 monoclonal antibodies (CLB-HEC75 and OKT10, respectively) indicate that an excess of CD31 on the cell membrane of leukemic cells (CD31/CD38 MFI ratio >1) promotes a homotypic interaction with marrow endothelial cells, resulting in higher transendothelial migration. Conversely, an excess of CD38 (CD31/CD38 MFI ratio <1) allows leukemic cells to be entrapped within the bone marrow microenvironment through hyaluronate adhesion. The results obtained in vitro using fluorescence resonance energy transfer, co-capping, and co-immunoprecipitation experiments, and hyaluronate adhesion and transendothelial migration assays, are supported by immunophenotypic characterization of marrow leukemic cells from 78 AML patients on which CD38 expression levels were found to be positively correlated with those of CD31. Importantly, the excess of CD31 in those samples was associated with a higher peripheral WBC count. These findings indicate that bone marrow retention of AML cells depends on CD31 and CD38 coexpression levels. [Cancer Res 2007;67(18):8624–32]
Activation of the Signal Transducers and Activators of the Transcription 3 Pathway in Alveolar Epithelial Cells Induces Inflammation and Adenocarcinomas in Mouse Lung
Authors: Li Yuan , Du Hong , Qin Yulin , Roberts Jennifer , Cummings Oscar W. , Yan Cong
Published: September 2007

The lung is an organ for host defense to clear up pathogens through innate and adaptive immunity. This process involves up-regulation of proinflammatory cytokines and chemokines that lead to activation of the signal transducers and activators of the transcription 3 (Stat3) signaling pathway. Overexpression of Stat3C in alveolar type II epithelial cells of CCSP-rtTA/(tetO)7-Stat3C bitransgenic mice leads to severe pulmonary inflammation, including immune cell infiltration and up-regulation of proinflammatory cytokines and chemokines in the lung. As a consequence, spontaneous lung bronchoalveolar adenocarcinoma was observed in bitransgenic mice. Aberrantly expressed genes in the bitransgenic model were identified and served as biomarkers for human bronchoalveolar adenocarcinoma. During tumorigenesis, genes that are critical to epithelial cell proliferation in lung development were reactivated. Therefore, Stat3 is a potent proinflammatory molecule that directly causes spontaneous lung cancer in vivo. [Cancer Res 2007;67(18):8494–503]
Lupeol Suppresses Cisplatin-Induced Nuclear Factor-κB Activation in Head and Neck Squamous Cell Carcinoma and Inhibits Local Invasion and Nodal Metastasis in an Orthotopic Nude Mouse Model
Authors: Lee Terence K. , Poon Ronnie T.P. , Wo Jana Y. , Ma Stephanie , Guan Xin-Yuan , Myers Jeffrey N. , Altevogt Peter , Yuen Anthony P.W.
Published: September 2007

A poor prognosis in head and neck squamous cell carcinoma (HNSCC) patients is commonly associated with the presence of regional metastasis. Cisplatin-based chemotherapy concurrent with radiation therapy is commonly used in the treatment of locally advanced HNSCC. However, the result is dismal due to common acquisition of chemoresistance and radioresistance. Epidemiologic studies have shown the importance of dietary substances in the prevention of HNSCC. Here, we found that lupeol, a triterpene found in fruits and vegetables, selectively induced substantial HNSCC cell death but exhibited only a minimal effect on a normal tongue fibroblast cell line in vitro. Down-regulation of NF-κB was identified as the major mechanism of the anticancer properties of lupeol against HNSCC. Lupeol alone was not only found to suppress tumor growth but also to impair HNSCC cell invasion by reversal of the NF-κB–dependent epithelial-to-mesenchymal transition. Lupeol exerted a synergistic effect with cisplatin, resulting in chemosensitization of HNSCC cell lines with high NF-κB activity in vitro. In in vivo studies, using an orthotopic metastatic nude mouse model of oral tongue squamous cell carcinoma, lupeol at a dose of 2 mg/animal dramatically decreased tumor volume and suppressed local metastasis, which was more effective than cisplatin alone. Lupeol exerted a significant synergistic cytotoxic effect when combined with low-dose cisplatin without side effects. Our results suggest that lupeol may be an effective agent either alone or in combination for treatment of advanced tumors. [Cancer Res 2007;67(18):8800–9]
RAV12 Accelerates the Desensitization of Akt/PKB Pathway of Insulin-like Growth Factor I Receptor Signaling in COLO205
Authors: Chi-Hang Li Jonathan , Li Ronghao
Published: September 2007

RAV12 is a high-affinity immunoglobulin G1 (IgG1) chimeric antibody recognizing an N-linked carbohydrate epitope expressed on a number of human carcinomas and adenocarcinomas. RAV12 is efficacious in treating colon, gastric, and pancreatic tumors in xenograft models in vivo. Insulin-like growth factor-I receptor (IGF-IR) is a protein widely overexpressed in tumor-derived cell lines that promotes cell survival and prevents apoptosis. We found the RAV12 epitope (RAAG12) decorated the IGF-IR proteins of RAV12-responsive cell lines such as COLO201, COLO205, and SNU-16. Here, we report findings of IGF-IR signaling manipulation by RAV12. We found that RAV12 caused a significantly accelerated IGF-I–mediated IGF-IR phosphorylation and desensitization in COLO205. We also observed significant changes in some of the major downstream signaling components of IGF-IR. Data suggested that RAV12 treatment accelerated the desensitization of Akt/PKB through IRS1, and such activation could be attenuated by Tyrphostin AG538 (IGF-IR inhibitor), LY294002, or Wortmannin (phosphoinositide-3-kinase inhibitor). Furthermore, RAV12-inhibited IGF-I stimulated COLO205 growth, and the inhibition could be significantly augmented by mitogen-activated protein kinase inhibitor. [Cancer Res 2007;67(18):8856–64]
Efficient p53 Activation and Apoptosis by Simultaneous Disruption of Binding to MDM2 and MDMX
Authors: Hu Baoli , Gilkes Daniele M. , Chen Jiandong
Published: September 2007

The p53 tumor suppressor plays a key role in protection against malignant transformation. MDM2 and MDMX are important regulators of the transcriptional activity and stability of p53 by binding to its NH2 terminus. Recent studies suggest that inhibition of both MDM2 and MDMX is necessary for robust activation of p53 in certain tumor cells. However, small-molecule MDM2 inhibitors such as Nutlin fail to inhibit MDMX despite significant homology between the two proteins. The therapeutic efficacy of such compounds may be compromised by MDMX overexpression. To evaluate the feasibility and biological effects of simultaneously disrupting p53 binding to MDM2 and MDMX, we used phage display to identify a novel peptide that can inhibit p53 interactions with MDM2 (IC50 = 10 nmol/L) and MDMX (IC50 = 100 nmol/L). Expression of a scaffold protein (thioredoxin) displaying this peptide sequence by adenovirus disrupts both MDM2 and MDMX interaction with p53, resulting in efficient p53 activation, cell cycle arrest, and apoptosis of tumor cells overexpressing MDM2 and MDMX. Intratumoral injection of the adenovirus also induces growth suppression of tumor xenografts in mice in a p53-dependent fashion. These results show the therapeutic potential of targeting both MDM2 and MDMX in cancer, and provide a novel structural motif for the design of potent p53 activators. [Cancer Res 2007;67(18):8810–7]
Topoisomerase IIβ–Mediated DNA Double-Strand Breaks: Implications in Doxorubicin Cardiotoxicity and Prevention by Dexrazoxane
Authors: Lyu Yi Lisa , Kerrigan John E. , Lin Chao-Po , Azarova Anna M. , Tsai Yuan-Chin , Ban Yi , Liu Leroy F.
Published: September 2007

Doxorubicin is among the most effective and widely used anticancer drugs in the clinic. However, cardiotoxicity is one of the life-threatening side effects of doxorubicin-based therapy. Dexrazoxane (Zinecard, also known as ICRF-187) has been used in the clinic as a cardioprotectant against doxorubicin cardiotoxicity. The molecular basis for doxorubicin cardiotoxicity and the cardioprotective effect of dexrazoxane, however, is not fully understood. In the present study, we showed that dexrazoxane specifically abolished the DNA damage signal γ-H2AX induced by doxorubicin, but not camptothecin or hydrogen peroxide, in H9C2 cardiomyocytes. Doxorubicin-induced DNA damage was also specifically abolished by the proteasome inhibitors bortezomib and MG132 and much reduced in top2β−/− mouse embryonic fibroblasts (MEF) compared with TOP2β+/+ MEFs, suggesting the involvement of proteasome and DNA topoisomerase IIβ (Top2β). Furthermore, in addition to antagonizing Top2 cleavage complex formation, dexrazoxane also induced rapid degradation of Top2β, which paralleled the reduction of doxorubicin-induced DNA damage. Together, our results suggest that dexrazoxane antagonizes doxorubicin-induced DNA damage through its interference with Top2β, which could implicate Top2β in doxorubicin cardiotoxicity. The specific involvement of proteasome and Top2β in doxorubicin-induced DNA damage is consistent with a model in which proteasomal processing of doxorubicin-induced Top2β-DNA covalent complexes exposes the Top2β-concealed DNA double-strand breaks. [Cancer Res 2007;67(18):8839–46]
Aberrant Huntingtin Interacting Protein 1 in Lymphoid Malignancies
Authors: Bradley Sarah V. , Smith Mitchell R. , Hyun Teresa S. , Lucas Peter C. , Li Lina , Antonuk Danielle , Joshi Indira , Jin Fang , Ross Theodora S.
Published: September 2007

Huntingtin interacting protein 1 (HIP1) is an inositol lipid, clathrin, and actin binding protein that is overexpressed in a variety of epithelial malignancies. Here, we report for the first time that HIP1 is elevated in non–Hodgkin's and Hodgkin's lymphomas and that patients with lymphoid malignancies frequently had anti-HIP1 antibodies in their serum. Moreover, p53-deficient mice with B-cell lymphomas were 13 times more likely to have anti-HIP1 antibodies in their serum than control mice. Furthermore, transgenic overexpression of HIP1 was associated with the development of lymphoid neoplasms. The HIP1 protein was induced by activation of the nuclear factor-κB pathway, which is frequently activated in lymphoid malignancies. These data identify HIP1 as a new marker of lymphoid malignancies that contributes to the transformation of lymphoid cells in vivo. [Cancer Res 2007;67(18):8923–31]
Integrative Genomic Analysis of Phosphatidylinositol 3′-Kinase Family Identifies PIK3R3 as a Potential Therapeutic Target in Epithelial Ovarian Cancer
Authors: Zhang Lin , Huang Jia , Yang Nuo , Greshock Joel , Liang Shun , Hasegawa Kosei , Giannakakis Antonis , Poulos Nikolaos , O'Brien-Jenkins Ann , Katsaros Dionyssios , Butzow Ralf , Weber Barbara L. , Coukos George
Published: September 2007

Purpose: The phosphatidylinositol 3′-kinase (PI3K) family plays a key regulatory role in various cancer-associated signal transduction pathways. Here, we investigated the genomic alterations and gene expression of most known PI3K family members in human epithelial ovarian cancer.

Experimental Design: The DNA copy number of PI3K family genes was screened by a high-resolution array comparative genomic hybridization in 89 human ovarian cancer specimens. The mRNA expression level of PI3K genes was analyzed by microarray retrieval approach, and further validated by real-time reverse transcription-PCR. The expression of p55γ protein in ovarian cancer was analyzed on tissue arrays. Small interfering RNA was used to study the function of PIK3R3 in ovarian cancer.

Results: In ovarian cancer, 6 of 12 PI3K genes exhibited significant DNA copy number gains (>20%), including PIK3CA (23.6%), PIK3CB (27.0%), PIK3CG (25.8%), PIK3R2 (29.2%), PIK3R3 (21.3%), and PIK3C2B (40.4%). Among those, only PIK3R3 had significantly up-regulated mRNA expression level in ovarian cancer compared with normal ovary. Up-regulated PIK3R3 mRNA expression was also observed in liver, prostate, and breast cancers. The PIK3R3 mRNA expression level was significantly higher in ovarian cancer cell lines (n = 18) than in human ovarian surface epithelial cells (n = 6, P = 0.002). Overexpression of p55γ protein in ovarian cancer was confirmed by tissue array analysis. In addition, we found that knockdown of PIK3R3 expression by small interfering RNA significantly increased the apoptosis in cultured ovarian cancer cell lines.

Conclusion: We propose that PIK3R3 may serve as a potential therapeutic target in human ovarian cancer.
Prognostic Value of Preoperative Serum Cell-Free Circulating DNA in Men with Prostate Cancer Undergoing Radical Prostatectomy
Authors: Bastian Patrick J. , Palapattu Ganesh S. , Yegnasubramanian Srinivasan , Lin Xiaohui , Rogers Craig G. , Mangold Leslie A. , Trock Bruce , Eisenberger Mario , Partin Alan W. , Nelson William G.
Published: September 2007

Purpose: We evaluated the association of preoperative serum cell-free circulating DNA concentration in men with clinically localized prostate cancer who underwent radical prostatectomy with prostate-specific antigen (PSA) recurrence.

Experimental Design: One hundred and ninety-two men with clinically localized prostate cancer, who underwent radical prostatectomy at the Johns Hopkins Hospital and had preoperative serum available for analyses constituted our study population. All serum samples were collected before prostate biopsy or at least 4 months after prostate biopsy. The total amount of serum cell-free circulating DNA from each sample was calculated using a standard curve generated via quantitative real-time PCR. PSA recurrence was defined as a single postoperative PSA level of ≥0.2. The natural logarithm (ln) of the DNA concentration was used for statistical analyses.

Results: Of the 192 men in our study, 56 (29%) experienced PSA recurrence within the study period (median time to PSA recurrence 2 years). The median follow-up time for men free of disease at last follow-up was 3 years. The median serum cell-free DNA concentration of all men in the study was 5.3 ng/mL (mean 18.05 ng/mL; range 0.2-320 ng/mL). The mean serum DNA concentration for men who recurred and for those who did not was 3.8 ± 34.1 and 13.7 ± 33.6 ng/mL, respectively (P = 0.001). In a univariate analysis, ln DNA concentration was significantly associated with PSA recurrence (hazard ratio, 1.49; 95% confidence interval, 1.3-1.8; P < 0.001). In the multivariate model, ln DNA concentration was significantly associated with PSA recurrence (hazard ratio, 2.56; 95% confidence interval, 1.1-1.6; P = 0.003). Using bootstrap analyses, serum cell-free DNA concentrations ≥5.75 ng/mL were associated with an increased risk of PSA recurrence within 2 years of radical prostatectomy.

Conclusion: Our study suggests that preoperative serum cell-free DNA concentration may be a useful prognostic biomarker for men with clinically localized prostate cancer treated with radical prostatectomy.
Comparison of Gene Sets for Expression Profiling: Prediction of Metastasis from Low-Malignant Breast Cancer
Authors: Thomassen Mads , Tan Qihua , Eiriksdottir Freyja , Bak Martin , Cold Søren , Kruse Torben A.
Published: September 2007

Purpose: In the low-risk group of breast cancer patients, a subgroup experiences metastatic recurrence of the disease. The aim of this study was to examine the performance of gene sets, developed mainly from high-risk tumors, in a group of low-malignant tumors.

Experimental Design: Twenty-six tumors from low-risk patients and 34 low-malignant T2 tumors from patients with slightly higher risk have been examined by genome-wide gene expression analysis. Nine prognostic gene sets were tested in this data set.

Results: A 32-gene profile (HUMAC32) that accurately predicts metastasis has previously been developed from this data set. In the present study, six of the eight other gene sets have prognostic power in the low-malignant patient group, whereas two have no prognostic value. Despite a relatively small overlap between gene sets, there is high concordance of classification of samples. This, together with analysis of functional gene groups, indicates that the same pathways may be represented by several of the gene sets. However, the results suggest that low-risk patients may be classified more accurately with gene signatures developed especially for this patient group.

Conclusion: Several gene sets, mainly developed in high-risk cancers, predict metastasis from low-malignant cancer.
ATM, CTLA4, MNDA, andHEM1in High versus Low CD38–Expressing B-Cell Chronic Lymphocytic Leukemia
Authors: Joshi Avadhut D. , Hegde Ganapati V. , Dickinson John D. , Mittal Amit K. , Lynch James C. , Eudy James D. , Armitage James O. , Bierman Philip J. , Bociek R. Gregory , Devetten Marcel P. , Vose Julie M. , Joshi Shantaram S.
Published: September 2007

Purpose: In B-cell chronic lymphocytic leukemia (CLL), high CD38 expression has been associated with unfavorable clinical course, advanced disease, resistance to therapy, shorter time to first treatment, and shorter survival. However, the genes associated with CLL patient subgroups with high and low CD38 expression and their potential role in disease progression is not known.

Experimental Design: To identify the genes associated with the clinical disparity in CLL patients with high versus low CD38 expression, transcriptional profiles were obtained from CLL cells from 39 different patients using oligonucleotide microarray. Gene expression was also compared between CLL cells and B cells from healthy individuals.

Results: Gene expression analysis identified 76 differentially expressed genes in CD38 high versus low groups. Out of these genes, HEM1, CTLA4, and MNDA were selected for further studies and their differential expression was confirmed by real-time PCR. HEM1 overexpression was associated with poor outcome, whereas the overexpression of CTLA4 and MNDA was associated with good outcome. Down-regulation of HEM1 expression in patient CLL cells resulted in a significant increase in their susceptibility to fludarabine-mediated killing. In addition, when gene expression patterns in CD38 high and low CLL cells were compared with normal B-cell profiles, ATM expression was found to be significantly lower in CD38 high compared with CD38 low CLL as confirmed by real-time reverse transcription-PCR.

Conclusions: These results identify the possible genes that may be involved in cell proliferation and survival and, thus, determining the clinical behavior of CLL patients expressing high or low CD38.
Pravastatin Inhibits the Rho/CCN2/Extracellular Matrix Cascade in Human Fibrosis Explants and Improves Radiation-Induced Intestinal Fibrosis in Rats
Authors: Haydont Valérie , Bourgier Céline , Pocard Marc , Lusinchi Antoine , Aigueperse Jocelyne , Mathé Denis , Bourhis Jean , Vozenin-Brotons Marie-Catherine
Published: September 2007

Purposes: Intestinal complications after radiotherapy are caused by transmural fibrosis and impair the quality of life of cancer survivors. Radiation fibrosis was considered permanent and irreversible, but recently, its dynamic nature was shown, providing new opportunities for the development of antifibrotic therapies. Among these new targets, we identified the Rho/ROCK pathway and thought to investigate whether pravastatin treatment inhibits Rho pathway activation and elicits an antifibrotic action.

Experimental Design: Rho and ROCK activities were monitored in human explants presenting radiation fibrosis remodeling after incubation with pravastatin. Subsequent modulation of CCN2, type I collagen, and fibronectin expression were assessed ex vivo and in intestinal smooth muscle cells derived from radiation enteropathy. Then, the therapeutic relevance of the antifibrotic action of pravastatin was explored in vivo in a rat model of chronic radiation fibrosis (19 Gy X-rays) treated with 30 mg/kg/d pravastatin in the drinking water.

Results: The results obtained with human explants show that pravastatin specifically inhibits Rho activity in submucosal mesenchymal cells. Pravastatin also elicits ROCK inhibition, and subsequent CCN2 production in human explants and smooth muscle cells isolated from radiation enteropathy. Inhibition of type I collagen and fibronectin does occur, showing that pravastatin modulates the secretory phenotype of mesenchymal cells. Lastly, curative pravastatin administration improves radiation enteropathy in rats. This structural improvement is associated with decreased deposition of CCN2 and subsequent decreased extracellular matrix deposition.

Conclusion: Targeting established fibrosis with pravastatin is an efficient and safe antifibrotic strategy in radiation-induced enteropathy, and is easily transferable into the clinic.
In vivo Targeting of Dead Tumor Cells in a Murine Tumor Model Using a Monoclonal Antibody Specific for the La Autoantigen
Authors: Al-Ejeh Fares , Darby Jocelyn M. , Pensa Katherine , Diener Kerrilyn R. , Hayball John D. , Brown Michael P.
Published: September 2007

Purpose: To investigate the potential of the La-specific monoclonal antibody (mAb) 3B9 as an in vivo tumor-targeting agent.

Experimental Design: The murine EL4 lymphoma cell line was used for in vitro studies and the EL4 model in which apoptosis was induced with cyclophosphamide and etoposide was used for in vivo studies. In vitro studies compared 3B9 binding in the EL4 cell with that in its counterpart primary cell type of the thymocyte. For in vivo studies, 3B9 was intrinsically or extrinsically labeled with carbon-14 or 1,4,7,10-tetra-azacylododecane-N,N′,N″,N″″-tetraacetic acid–indium-111, respectively, and biodistribution of the radiotracers was investigated in EL4 tumor-bearing mice, which were treated or not with chemotherapy.

Results: La-specific 3B9 mAb bound EL4 cells rather than thymocytes, and binding was detergent resistant. 3B9 binding to dead EL4 cells in vitro was specific, rapid, and saturable. Significantly, more 3B9 bound dead EL4 tumor explant cells after host mice were treated with chemotherapy, which suggested that DNA damage induced 3B9 binding. Tumor binding of 3B9 in vivo was antigen specific and increased significantly after chemotherapy. Tumor accumulation of 3B9 peaked at ∼50% of the injected dose per gram of tumor 72 h after chemotherapy and correlated with increased tumor cell death. Tumor/organ ratios of 3B9 biodistribution, which included the tumor/blood ratio, exceeded unity 48 or more hours after chemotherapy.

Conclusions: La-specific mAb selectively targeted dead tumor cells in vivo, and targeting was augmented by cytotoxic chemotherapy. This novel cell death radioligand may be useful both for radioimmunoscintigraphy and radioimmunotherapy.
Bortezomib Sensitizes Non–Hodgkin's Lymphoma Cells to Apoptosis Induced by Antibodies to Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand (TRAIL) Receptors TRAIL-R1 and TRAIL-R2
Authors: Smith Mitchell R. , Jin Fang , Joshi Indira
Published: September 2007

Non–Hodgkin's lymphoma (NHL) is an increasingly common disease that, despite advances in antibody-targeted therapy, still requires novel therapeutic approaches. Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) activates a major nonmitochondrial pathway for tumor cell killing through binding to a receptor family, some activating and some decoy. Agonistic antibodies to the receptors TRAIL-R1 and TRAIL-R2 can mimic many of the effects of TRAIL. We are investigating the effects of such agonistic antibodies, mapatumumab directed at TRAIL-R1 and lexatumumab directed at TRAIL-R2, on NHL cell lines. These antibodies induce apoptosis through caspase-8 but also activate BID to involve the mitochondrial pathway and activate caspase-9. In addition, we find signaling through both the nuclear factor-κB and c-Jun NH2-terminal kinase pathways. Because the proteasome inhibitor bortezomib also affects these pathways, we have investigated the combination of TRAIL-R antibodies and bortezomib and show enhanced apoptosis and signaling as well as enhanced killing of NHL cells in a severe combined immunodeficient mouse/human NHL cell line xenograft system. The combination of bortezomib and TRAIL signaling warrants further investigation as a therapeutic regimen. Understanding the multiple intracellular pathways of TRAIL activation may lead to rationally designed therapeutic trials.
The B7 Family and Cancer Therapy: Costimulation and Coinhibition
Authors: Zang Xingxing , Allison James P.
Published: September 2007

The activation and development of an adaptive immune response is initiated by the engagement of a T-cell antigen receptor by an antigenic peptide-MHC complex. The outcome of this engagement is determined by both positive and negative signals, costimulation and coinhibition, generated mainly by the interaction between the B7 family and their receptor CD28 family. The importance of costimulation and coinhibition of T cells in controlling immune responses is exploited by tumors as immune evasion pathways. Absence of the expression of costimulatory B7 molecules renders tumors invisible to the immune system, whereas enhanced expression of inhibitory B7 molecules protects them from effective T cell destruction. Therefore, the manipulation of these pathways is crucial for developing effective tumor immunotherapy. Translation of our basic knowledge of costimulation and coinhibition into early clinical trials has shown considerable promise.
Binding Activities and Antitumor Properties of a New Mouse/Human Chimeric Antibody Specific for GD2 Ganglioside Antigen
Authors: Alvarez-Rueda Nidia , Leprieur Stéphanie , Clémenceau Béatrice , Supiot Stéphane , Sébille-Rivain Véronique , Faivre-Chauvet Alain , Davodeau François , Paris François , Barbet Jacques , Aubry Jacques , Birklé Stéphane
Published: September 2007

Purpose: We previously generated a mouse monoclonal antibody (mAb) specific for the tumor-associated GD2 ganglioside antigen. Here, we describe the development of a chimeric anti-GD2 mAb for more effective tumor immunotherapy.

Experimental Design: We cloned the cDNA encoding the immunoglobulin light and heavy chains of the 60C3 anti-GD2 mAb, and constructed chimeric genes by linking the cDNA fragments of the variable regions of the murine light and heavy chains to cDNA fragments of the human κ and γ1 constant regions, respectively.

Results: The resultant chimeric anti-GD2 mAb, c.60C3, showed identical binding affinity and specificity to that of its murine counterpart. Both c.60C3 and 60C3 were rapidly internalized by tumor cells at 37°C. When human serum and human natural killer cells were used as effectors in complement-mediated cytotoxicity and antibody-dependent cell cytotoxicity, respectively, c.60C3 was more effective in killing GD2-expressing tumor cells. However, c.60C3 was ineffective at inducing cell death by apoptosis, although binding of 60C3 induced apoptotic death in vitro. In an in vivo, GD2-expressing, syngeneic tumor model, i.v. injection of c.60C3, but not of 60C3, significantly suppressed tumor growth in mice (P < 0.0005).

Conclusion: Immune effector functions mediated by this antibody and its potentially reduced immunogenicity make chimeric c.60C3 a promising therapeutic agent against neuroectodermic tumors.
Selective High-Affinity Ligand Antibody Mimics for Cancer Diagnosis and Therapy: Initial Application to Lymphoma/Leukemia
Authors: Balhorn Rod , Hok Saphon , Burke Patricia A. , Lightstone Felice C. , Cosman Monique , Zemla Adam , Mirick Gary , Perkins Julie , Natarajan Arutselvan , Corzett Michele , DeNardo Sally J. , Albrecht Huguette , Gregg Jeff P. , DeNardo Gerry L.
Published: September 2007

Purpose: More than two decades of research and clinical trials have shown radioimmunotherapy to be a promising approach for treating various forms of cancer. Lym-1 antibody, which binds selectively to HLA-DR10 on malignant B-cell lymphocytes, has proved to be effective in delivering radionuclides to non–Hodgkin's lymphoma and leukemia. Using a new approach to create small synthetic molecules that mimic the targeting properties of the Lym-1 antibody, a prototype, selective high-affinity ligand (SHAL), has been developed to bind to a unique region located within the Lym-1 epitope on HLA-DR10.

Experimental Design: Computer docking methods were used to predict two sets of small molecules that bind to neighboring cavities on the β subunit of HLA-DR10 surrounding a critical amino acid in the epitope, and the ligands were confirmed to bind to the protein by nuclear magnetic resonance spectroscopy. Pairs of these molecules were then chemically linked together to produce a series of bidentate and bisbidentate SHALs.

Results: These SHALs bind with nanomolar to picomolar Kd's only to cell lines expressing HLA-DR10. Analyses of biopsy sections obtained from patients also confirmed that SHAL bound to both small and large cell non–Hodgkin's lymphomas mimicking the selectivity of Lym-1.

Conclusions: These results show that synthetic molecules less than 1/50th the mass of an antibody can be designed to exhibit strong binding to subtle structural features on cell surface proteins similar to those recognized by antibodies. This approach offers great potential for developing small molecule therapeutics that target other types of cancer and disease.
Transforming Growth Factor-β and the Immune Response: Implications for Anticancer Therapy
Authors: Wrzesinski Stephen H. , Wan Yisong Y. , Flavell Richard A.
Published: September 2007

Immune homeostasis is a delicate balance between the immune defense against foreign pathogens and suppression of the immune system to maintain self-tolerance and prevent autoimmune disease. Maintenance of this balance involves several crucial networks of cytokines and various cell types. Among these regulators, transforming growth factor-β (TGF-β) is a potent cytokine with diverse effects on hematopoietic cells. Its pivotal function within the immune system is to maintain tolerance via the regulation of lymphocyte proliferation, differentiation, and survival. In addition, TGF-β controls the initiation and resolution of inflammatory responses through the regulation of chemotaxis and activation of leukocytes in the periphery, including lymphocytes, natural killer cells, dendritic cells, macrophages, mast cells, and granulocytes. Through its pleiotropic effects on these immune cells, TGF-β prevents the development of autoimmune diseases without compromising immune responses to pathogens. However, overactivation of this pathway can lead to several immunopathologies under physiologic conditions including cancer progression, making it an attractive target for antitumor therapies. This review discusses the biological functions of TGF-β and its effects on the immune system and addresses how immunosuppression by this cytokine can promote tumorigenesis, providing the rationale for evaluating the immune-enhancing and antitumor effects of inhibiting TGF-β in cancer patients.