bluuebunny/crossref_metadata_2025_split huggingface dataset:
HIV Protease Inhibitors Block Akt Signaling and Radiosensitize Tumor Cells Both In vitro and In vivo
Authors: Gupta Anjali K. , Cerniglia George J. , Mick Rosemarie , McKenna W. Gillies , Muschel Ruth J. 
Published: September 2005

Abstract
In tumor cells with mutations in epidermal growth factor receptor (SQ20B), H-Ras (T24), or K-Ras (MIAPACA2 and A549), the inhibition of Akt phosphorylation increases radiation sensitivity in clonogenic assays, suggesting that Akt is a potential molecular target when combined with therapeutic radiation. Insulin resistance and diabetes are recognized side effects of HIV protease inhibitors (HPIs), suggesting that these agents may inhibit Akt signaling. Because activation of the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway is common in human cancers, we hypothesized that HPIs can inhibit Akt activity resulting in increased tumor cell sensitivity to ionizing radiation–induced cell death. Five first-generation HPIs were subsequently tested and three of the five (amprenavir, nelfinavir, and saquinavir but not ritonavir or indinavir) inhibited Akt phosphorylation at Ser473 at serum concentrations routinely achieved in HIV patients. In both tumor cell colony formation assays and tumor regrowth delay experiments, combinations of drug and radiation exerted synergistic effects compared with either modality alone. In addition, in vivo, doses of amprenavir or nelfinavir comparable with the therapeutic levels achieved in HIV patients were sufficient to down-regulate phosphorylation of Akt in SQ20B and T24 xenografts. Finally, overexpression of active PI3K in cells without activation of Akt resulted in radiation resistance that could be inhibited with HPIs. Because there is abundant safety data on HPIs accumulated in thousands of HIV patients over the last 5 years, these agents are excellent candidates to be tested as radiation sensitizers in clinical trials.
A Mouse Model Recapitulating Molecular Features of Human Mesothelioma
Authors: Altomare Deborah A. , Vaslet Charles A. , Skele Kristine L. , De Rienzo Assunta , Devarajan Karthik , Jhanwar Suresh C. , McClatchey Andrea I. , Kane Agnes B. , Testa Joseph R. 
Published: September 2005

Abstract
Malignant mesothelioma has been linked to asbestos exposure and generally has a poor prognosis because it is often diagnosed in advanced stages and is refractory to conventional therapy. Human malignant mesotheliomas accumulate multiple somatic genetic alterations, including inactivation of the NF2 and CDKN2A/ARF tumor suppressor genes. To better understand the significance of NF2 inactivation in malignant mesothelioma and identify tumor suppressor gene alterations that cooperate with NF2 loss of function in malignant mesothelioma pathogenesis, we treated Nf2 (+/−) knockout mice with asbestos to induce malignant mesotheliomas. Asbestos-exposed Nf2 (+/−) mice exhibited markedly accelerated malignant mesothelioma tumor formation compared with asbestos-treated wild-type (WT) littermates. Loss of the WT Nf2 allele, leading to biallelic inactivation, was observed in all nine asbestos-induced malignant mesotheliomas from Nf2 (+/−) mice and in 50% of malignant mesotheliomas from asbestos-exposed WT mice. For a detailed comparison with the murine model, DNA analyses were also done on a series of human malignant mesothelioma samples. Remarkably, similar to human malignant mesotheliomas, tumors from Nf2 (+/−) mice showed frequent homologous deletions of the Cdkn2a/Arf locus and adjacent Cdkn2b tumor suppressor gene, as well as reciprocal inactivation of Tp53 in a subset of tumors that retained the Arf locus. As in the human disease counterpart, malignant mesotheliomas from the Nf2 (+/−) mice also showed frequent activation of Akt kinase, which plays a central role in tumorigenesis and therapeutic resistance. Thus, this murine model of environmental carcinogenesis faithfully recapitulates many of the molecular features of human malignant mesothelioma and has significant implications for the further characterization of malignant mesothelioma pathogenesis and preclinical testing of novel therapeutic modalities.
Cyclooxygenase-2 Functions as a Downstream Mediator of Lysophosphatidic Acid to Promote Aggressive Behavior in Ovarian Carcinoma Cells
Authors: Symowicz Jaime , Adley Brian P. , Woo Michelle M.M. , Auersperg Nelly , Hudson Laurie G. , Stack M. Sharon 
Published: September 2005

Abstract
Elevated levels of the bioactive lipid lysophosphatidic acid (LPA) are detectable in the majority of patients with both early- and late-stage ovarian cancer, suggesting that LPA promotes early events in ovarian carcinoma dissemination. LPA contributes to the development, progression, and metastasis of ovarian cancer in part by inducing the expression of genes that contribute to proliferation, survival, or invasion, including cyclooxgenase-2 (COX-2) and matrix metalloproteinase–2 (MMP-2). We have previously shown that LPA promotes proMMP-2 activation and MMP-2–dependent migration and invasion in ovarian cancer cells. The purpose of the current study was to determine whether the effect of LPA on acquisition of the metastatic phenotype in ovarian cancer cells is mediated via a COX-2–dependent mechanism. Immunohistochemical analysis of 173 ovarian tumors showed strong COX-2 immunoreactivity in 63% of tumor specimens, including 50% of borderline tumors. LPA increased COX-2 protein expression in a time- and concentration-dependent manner in two of three immortalized borderline ovarian epithelial cells as well as in four of six ovarian cancer cell lines. This was accomplished by both activation of the Edg/LPA receptor and LPA-mediated transactivation of the epidermal growth factor receptor, which increased COX-2 expression via the Ras/mitogen-activated protein kinase pathway. COX-2 also played a role in LPA-induced invasion and migration, as treatment with the COX-2 specific inhibitor NS-398 reduced LPA-induced proMMP-2 protein expression and activation and blocked MMP-dependent motility and invasive activity. These data show that COX-2 functions as a downstream mediator of LPA to potentiate aggressive cellular behavior.
Inhibition of p38 Mitogen-Activated Protein Kinase and Phosphatidylinositol 3-Kinase Decreases UVB-Induced Activator Protein-1 and Cyclooxygenase-2 in a SKH-1 Hairless Mouse Model
Authors: Bachelor Michael A. , Cooper Simon J. , Sikorski Ewa T. , Bowden G. Timothy 
Published: September 2005

Abstract
Activation of activator protein-1 (AP-1) and increased expression of cyclooxygenase-2 (COX-2) have been clearly shown to play a functional role in UVB-induced skin tumor promotion. In this study, we examined UVB-induced signal transduction pathways in SKH-1 mouse epidermis leading to increases in COX-2 expression and AP-1 activity. We observed rapid increases in p38 mitogen-activated protein kinase (MAPK) signaling through activation of p38 MAPK and its downstream target, MAPK activated protein kinase-2. UVB also increased phosphatidylinositol 3-kinase (PI3K) signaling as observed through increases in AKT and GSK-3β phosphorylation. Activation of the p38 MAPK and PI3K pathways results in the phosphorylation of cyclic AMP–responsive element binding protein, which was also observed in UVB-irradiated SKH-1 mice. Topical treatment with SB202190 (a specific inhibitor of p38 MAPK) or LY294002 (a specific inhibitor of PI3K) significantly decreased UVB-induced AP-1 activation by 84% and 68%, respectively, as well as COX-2 expression. Our data show that in mouse epidermis, UVB activation of the p38 MAPK and PI3K pathways leads to AP-1 activation and COX-2 expression.
Transactivation Functions of the Tumor-Specific HMGA2/LPP Fusion Protein Are Augmented by Wild-Type HMGA2
Authors: Crombez Koen R.M.O. , Vanoirbeek Els M.R. , Van de Ven Wim J.M. , Petit Marleen M.R. 
Published: September 2005

Abstract
The gene encoding the architectural transcription factor HMGA2 is frequently rearranged in several benign tumors of mesenchymal origin. The lipoma preferred partner (LPP) gene is the most frequent translocation partner of HMGA2 in a subgroup of lipomas, which are benign tumors of adipose tissue. In these lipomas, HMGA2/LPP fusion transcripts are expressed, which encode for the three AT-hooks of HMGA2 followed by the two most carboxyl-terminal LIM domains (protein-protein interaction domains) of LPP. Identical fusion transcripts are also expressed in other benign mesenchymal tumors. Previous studies revealed that the LIM domains of LPP have transcriptional activation capacity in GAL4-based luciferase reporter assays. Here, we show that the HMGA2/LPP fusion protein retains the transactivation functions of the LPP LIM domains and thus functions as transcription factor. The HMGA2/LPP fusion protein activates transcription from the well-characterized PRDII element, which is a part of the IFN-β enhancer and which is known to bind to HMGA2. We also show that HMGA2/LPP activates transcription from the BAT-1 element of the rhodopsin promoter, a HMGA1-binding element. HMGA1 is a closely related family member of HMGA2. Finally, in a number of lipomas, HMGA2/LPP and HMGA2 are coexpressed, and HMGA2 augments the transactivation functions of HMGA2/LPP. These results support the concept that the transactivation functions of the novel HMGA2/LPP transcription factor contribute to lipomagenesis.
Analysis of Tumor-Host Interactions by Gene Expression Profiling of Lung Adenocarcinoma Xenografts Identifies Genes Involved in Tumor Formation
Authors: Creighton Chad J. , Bromberg-White Jennifer L. , Misek David E. , Monsma David J. , Brichory Frank , Kuick Rork , Giordano Thomas J. , Gao Weimin , Omenn Gilbert S. , Webb Craig P. , Hanash Samir M. 
Published: September 2005

Abstract
Tumor cell lines are relied on extensively for cancer investigations, yet cultured cells in an in vitro environment differ considerably in behavior compared with those of the same cancer cells that proliferate and form tumors in vivo. To uncover gene expression changes related to tumor formation, gene expression profiles of human lung adenocarcinoma (A549) cells grown as lung tumors in immune-compromised mice were compared with profiles of the same cells grown in vitro. Additionally, profiles of uninvolved adjacent mouse tissue were determined. A profound interplay between cancer cells and the host was shown that affected a complex protein interaction network involving processes of extracellular interaction, growth factor signaling, hemostasis, immune response, and transcriptional regulation. Growth in vivo of A549 cells, which carry an activating k-ras mutation, induced changes in gene expression that corresponded highly to a pattern characteristic of human lung tumors with k-ras mutation. Cytokines interleukin-4, interleukin-6, and IFN-γ each induced distinct in vitro genomic responses in cancer cells that emulated many of the changes in gene expression observed in vivo. Genes that were both selectively induced in vivo and overexpressed in human lung adenocarcinoma tumors included CSPG2, which has not been associated previously with tumor formation. Knockdown in A549 of CSPG2 by RNA interference significantly inhibited tumor growth in vivo but not in vitro. Thus, analysis of tumor xenografts by gene expression profiling has the potential for identifying genes involved in tumor development that may not be expressed in cancer cells grown in vitro.
Enhanced G2-M Arrest by Nuclear Factor-κB-Dependent p21waf1/cip1 Induction
Authors: Wuerzberger-Davis Shelly M. , Chang Pei-Yun , Berchtold Craig , Miyamoto Shigeki 
Published: September 2005

Abstract
The transcription factor nuclear factor-κB (NF-κB) regulates cell survival pathways, but the molecular mechanisms involved are not completely understood. Here, we developed a NF-κB reporter cell system derived from CEM T leukemic cells to monitor the consequences of NF-κB activation following DNA damage insults. Cells that activated NF-κB in response to ionizing radiation or etoposide arrested in the G2-M phase for a prolonged time, which was followed by increased cell cycle reentry and survival. In contrast, those that failed to activate NF-κB underwent transient G2-M arrest and extensive cell death. Importantly, p21waf1/cip1 was induced in S-G2-M phases in a NF-κB-dependent manner, and RNA interference of this cell cycle regulator reduced the observed NF-κB-dependent phenotypes. Thus, cell cycle–coupled induction of p21waf1/cip1 by NF-κB represents a resistance mechanism in certain cancer cells.
Proteasome Structures Affected by Ionizing Radiation
Authors: Pervan Milena , Iwamoto Keisuke S. , McBride William H. 
Published: September 2005

Abstract
Exposure of cells to ionizing radiation slows the rate of degradation of substrates through the proteasome. Because the 26S proteasome degrades most short-lived cellular proteins, changes in its activity might significantly, and selectively, alter the life span of many signaling proteins and play a role in promoting the biological consequences of radiation exposure, such as cell cycle arrest, DNA repair, and apoptosis. Experiments were therefore undertaken to identify the radiation target that is associated with the proteasome. Regardless of whether they were irradiated before or after extraction and purification from human prostate cancer PC3 cells, 26S proteasomes remained intact but showed a rapid 30% to 50% dose-independent decrease in their three major enzymatic activities following exposure to 1 to 20 Gy. There was no effect on 20S proteasomes, suggesting that the radiation-sensitive target is located in the 19S cap of the 26S proteasome, rather than in the enzymatically active core. Because the base of the 19S cap contains an ATPase ring that mediates substrate unfolding, pore opening, and translocation of substrates into the catalytic chamber, we examined whether the ATPase activity of purified 26S proteasomes was affected. In fact, in vitro irradiation of proteasomes enhanced their ATPase activity. Furthermore, pretreatment with low concentrations of the free radical scavenger tempol was able to prevent both the radiation-induced decrease in proteolytic activity and the increase in ATP utilization, indicating that free radicals are mediators of these radiation-induced phenomena. Finally, we have shown that cell irradiation results in the accumulation of proteasome substrates: polyubiquitinated proteins and ornithine decarboxylase, indicating that the observed decrease in proteasome function is physiologically relevant.
Two N-Myristoyltransferase Isozymes Play Unique Roles in Protein Myristoylation, Proliferation, and Apoptosis
Authors: Ducker Charles E. , Upson John J. , French Kevin J. , Smith Charles D. 
Published: September 2005

Abstract
N-myristoyltransferases (NMT) add myristate to the NH2 termini of certain proteins, thereby regulating their localization and/or biological function. Using RNA interference, this study functionally characterizes the two NMT isozymes in human cells. Unique small interfering RNAs (siRNA) for each isozyme were designed and shown to decrease NMT1 or NMT2 protein levels by at least 90%. Ablation of NMT1 inhibited cell replication associated with a loss of activation of c-Src and its target FAK as well as reduction of signaling through the c-Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase pathway. Terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling assays showed that depletion of either NMT isozyme induced apoptosis, with NMT2 having a 2.5-fold greater effect than NMT1. Western blot analyses revealed that loss of NMT2 shifted the expression of the BCL family of proteins toward apoptosis. Finally, intratumoral injection of siRNA for NMT1 or for both NMT1 and NMT2 inhibited tumor growth in vivo, whereas the same treatment with siRNA for NMT2 or negative control siRNA did not. Overall, the data indicate that NMT1 and NMT2 have only partially overlapping functions and that NMT1 is critical for tumor cell proliferation.
Metabolic side effects of atypical antipsychotics in children: a literature review
Authors: Fedorowicz Valérie J. , Fombonne Eric 
Published: September 2005

The objective of this review is to summarize the data about metabolic side effects of atypical antipsychotics in children. Original research articles about side effects of atypical antipsychotics used in children were reviewed. The data was obtained mainly through Medline searches, identifying articles focusing on the use of atypical antipsychotics in children. Forty studies that addressed the issue of metabolic side effects were selected. The use of atypical antipsychotics in children has been consistently associated with weight gain and moderate prolactin elevation, while only a few case reports address the issue of glucose dysregulation and dyslipidaemia. The risk of weight gain and hyperprolactinaemia might be higher in younger children. Other risk factors have also been associated with antipsychotic-induced metabolic disturbances. These changes seem to be reversible, at least in some cases. Metabolic side effects of atypical antipsychotics could lead to serious complications in children who are prescribed these medications. Serious considerations should be given before initiating treatment and consistent clinical monitoring is essential. More research is needed, especially regarding glucose dysregulation and dyslipidaemia.
Influence of the type of factor VIII concentrate on the incidence of factor VIII inhibitors in previously untreated patients with severe hemophilia A
Authors: Goudemand Jenny , Rothschild Chantal , Demiguel Virginie , Vinciguerrat Christine , Lambert Thierry , Chambost Hervé , Borel-Derlon Annie , Claeyssens Ségolène , Laurian Yves , Calvez Thierry ,   the members of the FVIII-LFB and Recombinant FVIII study groups
Published: September 2005

Abstract
Inhibitor development is the major treatment complication in children with severe hemophilia A. It is not clear whether the risk of inhibitors is higher with recombinant factor VIII or with plasma-derived factor VIII. We used multivariate analysis to compare 2 cohorts of previously untreated patients (PUPs) with severe hemophilia A: 62 patients treated with the same brand of high-purity plasma-derived FVIII (pFVIII) containing von Willebrand factor (VWF) and 86 patients treated with full-length recombinant FVIII (rFVIII). In addition to the usual end points (all inhibitors, high inhibitors), we also examined a third end point (high inhibitors and/or immune tolerance induction). The risk of inhibitor development was higher in patients treated with rFVIII than in patients treated with pFVIII, regardless of other risk factors (F8 genotype; nonwhite origin; history of inhibitors in patients with a family history of hemophilia; age at first FVIII infusion). The adjusted relative risk (RRa) for inhibitor development with rFVIII versus pFVIII was 2.4 (all inhibitors), 2.6 (high inhibitors), and 3.2 (high inhibitors and/or immune tolerance induction), respectively, depending on the end point (above). The pathophysiology of this large effect must be understood in order to improve the characteristics of recombinant products and to reduce the incidence of inhibitors to FVIII.
High rates of early HBeAg seroconversion and relapse in Indian patients of chronic hepatitis B treated with Lamivudine: results of an open labeled trial
Authors: Alexander George , Baba Chalamalasetty S , Chetri Kamal , Negi TS , Choudhuri Gourdas 
Published: September 2005

Abstract
Background
The use of Lamivudine in chronic hepatitis B (CHB) is well known, however the reported rate of HBeAg sero-conversion and its durability post-treatment have varied considerably. We undertook the present study to study the effect of Lamivudine on HBeAg loss and seroconversion rates in Indian patients of CHB in relation to frequency, predictors and durability.

Methods
We treated 60 patients of e antigen positive CHB (with active viral replication and ongoing necro-inflammatory activity) with Lamivudine. They were followed up by monthly aminotransferases, and 3 monthly HBeAg and anti-HBe. Those who attained HBeAg sero-conversion were advised to discontinue Lamivudine after 6 months and followed up every 3 months thereafter, to see for relapse. Treatment was given for maximum of 3 years if not sero-converted.

Results
The annual incremental loss of HBeAg in patients receiving Lamivudine was 25 (41.6%) at end of 1st year, 33 (55%) at 2nd year and 35 (58.3%) at 3rd year. The corresponding rates for full sero-conversion were 17/60 (28.6%), 22/60 (36.6%) and 24/60 (40%) in the 3 years. HBeAg loss correlated with increased pre-therapy ALT levels (p = 0.002) and decreased pretreatment HBV-DNA levels (p = 0.004). The presence of cirrhosis had no influence on the rate of HBeAg loss. Relapse occurred in 35% (7/20) post-treatment at median time of 6 months.

Conclusion
Indian patients showed a higher rate of HBeAg sero-conversion in the first year of Lamivudine treatment. This correlated with baseline ALT and inversely with HBV-DNA levels. Relapse rate after treatment was high and occurred soon after stopping treatment.
Concurrence of Plasmodium falciparum dhfr and crt mutations in northern Ghana
Authors: Mockenhaupt Frank P , Bousema J Teun , Eggelte Teunis A , Ehrhardt Stephan , Otchwemah Rowland N , Sauerwein Robert W , Bienzle Ulrich 
Published: September 2005

Abstract

Background
Both chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) are failing drugs in much of sub-Saharan Africa. Previous findings suggest an association between resistance to CQ and to SP in vivo, in vitro, and on the molecular level.

Methods
In 126 Ghanaian children with uncomplicated malaria, associations between mutations conferring resistance in the Plasmodium falciparum dihydrofolate reductase (dhfr; SP) and chloroquine resistance transporter (crt; CQ) genes, concentrations of residual antimalarial drugs, and gametocyte carriage were examined.

Results
Mutant dhfr alleles and the CQ-resistance allele crt T76 were strongly associated with each other. Isolates exhibiting the dhfr triple mutation seven times more likely also contained crt T76 parasites as compared to isolates without the dhfr triple variant (P = 0.0001). Moreover, both, isolates with the dhfr triple mutation (adjusted OR, 3.2 (95%CI, 1.0–10.4)) and with crt T76 (adjusted OR, 14.5 (1.4–150.8)) were associated with an increased likelihood of pre-treatment gametocytaemia. However, crt T76 did not correlate with gametocytaemia following SP treatment and no selection of crt T76 in SP treatment failure isolates was observed.

Conclusion
These results confirm an association between CQ and SP resistance markers in isolates from northern Ghana. This could indicate accelerated development of resistance to SP if CQ resistance is already present, or vice versa. Considering the enhanced transmission potential as reflected by the increased proportion of isolates containing gametocytes when resistant parasites are present, co-resistance can be expected to spread in this area. However, the underlying mechanism leading to this constellation remains obscure.