bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation‐Induced Alteration of Pain‐Related Signals in an Animal Model with Bone Invasion from Cancer
Authors: SEONG JINSIL , PARK HEE CHUL , KIM JIYOUNG , KIM UN JUNG , LEE BAE WHAN
Published: January 2005

Abstract: Although radiotherapy is highly effective in relieving bone pain from cancer invasion, the mechanism of pain relief remains unclear. To explore the mechanism of radiotherapy‐induced analgesia, we have developed an animal model of bone pain resulting from cancer invasion. Using this animal model system, radiation‐induced pain response and pain‐related signals in the spinal cord were analyzed. The hind paw model of bone pain from cancer invasion was developed by injecting transplantable hepatocellular carcinoma, HCa‐1, into the periosteal membrane of the foot dorsum in C3H/HeJ mice. Bony invasion from HCa‐1 cells was confirmed by histopathological examinations. We also measured the development of pain‐associated behaviors. In this model, changes in the objective level of pain response after irradiation of the tumor were analyzed. Expression of pain‐related host signals in the spinal cord, such as calcitonin gene‐related peptide (CGRP), substance P, and c‐fos, was investigated with immunohistochemical staining. In the histopathological examinations, bone invasion from HCa‐1 cells was seen from day 7 and was evident at day 14 after injection. Measurable pain‐associated behaviors were developed from day 7. In this model, mice treated with radiotherapy showed decreased objective levels of pain with a higher threshold to graded mechanical stimulation than did control mice from day 3 after irradiation. After irradiation of tumors, significant decreases in the expression of CGRP were shown in the spinal cord, whereas neither substance P nor c‐fos showed any alteration. We developed a novel hind paw model of bone pain from cancer invasion that was confirmed by histopathological examination and measurable pain‐associated behaviors. Radiotherapy decreased the objective level of pain and the underlying mechanism involved in the alteration of pain‐related host signal, CGRP, in the spinal cord.
Analysis of the Signal Transduction Pathway Leading to Human Immunodeficiency Virus‐1‐Induced Interferon Regulatory Factor‐1 Upregulation
Authors: SGARBANTI MARCO , MARSILI GIULIA , REMOLI ANNA LISA , RIDOLFI BARBARA , STELLACCI EMILIA , BORSETTI ALESSANDRA , ENSOLI BARBARA , BATTISTINI ANGELA
Published: January 2005

Abstract: Interferon (IFN) regulatory factors (IRFs) constitute a family of transcriptional activators and repressors involved in the regulation of immune system, host defense, and cell growth. All members share conserved DNA‐binding domains that recognize DNA sequences termed IRF‐binding elements/IFN‐stimulated response elements (IRF‐E/ISRE) present on the promoter of IFN‐α/β and IFN‐stimulated genes. An ISRE has been identified downstream of the transcription start site of the long terminal repeat (LTR) of human immunodeficiency virus‐1 (HIV‐1). Our previous results showed that among the IRF factors, IRF‐1 is able to stimulate HIV‐1 LTR transcription and its expression is induced by HIV‐1, early, upon infection and before the expression of Tat. In this study we investigated the signal transduction pathway leading to HIV‐1‐induced IRF‐1 expression. Key IRF‐1 promoter elements that mediate the activation of transcription upon induction by inflammatory cytokines are IFN‐γ‐activated sequences that bind members of the signal transducer and activator of transcription (STAT) family and binding sites for nuclear factor κB (NF‐κB). Both STAT‐1 and NF‐κB activation were examined to determine putative molecular targets whose inhibition resulted in the inhibition of HIV‐1 replication. The results show that at early time points after HIV‐1 infection, NF‐κB but not STAT‐1 is activated. Moreover, a significant decrease in HIV‐1 replication was observed upon de novo infection of Jurkat T cells expressing an NF‐κB super‐repressor (IκB‐α 2NΔ4). These results suggest that in early phases of HIV‐1 infection, before detectable cytokine production, NF‐κB seems responsible for HIV‐1‐induced IRF‐1 expression.
Enhanced Expression of Natural Resistance‐Associated Macrophage Protein 1 in Atherosclerotic Lesions May Be Associated with Oxidized Lipid‐Induced Apoptosis
Authors: LI WEI , HELLSTEN ANNA , NYHALAH JEROME DINGA , YUAN XI‐MING
Published: January 2005

Abstract: The natural resistance‐associated macrophage proteins (Nramps) can modulate inflammatory reactions. Nramps are not only responsible for intracellular divalent metal transport but also determine the macrophage functions in inflammatory processes. In the present study we tested whether Nramp1 is involved in macrophage apoptosis induced by oxidized lipids in atherogenesis. Arterial segments of Watanabe heritable hyperlipidemic rabbits were used for an examination of Nramp1 mRNA by in situ RT‐PCR and macrophage immunohistochemistry. Annexin V/PI staining and terminal dUTP nick‐end labeling (TUNEL) techniques were used for apoptosis detection. We found that, in macrophage‐rich areas (positive to RMA‐11) of the rabbit atherosclerotic aorta, there were lesion‐dependent increases in Nramp1 mRNA, which are mainly apoptotic foamy macrophages that are positive to TUNEL staining. U937 cells were treated with 7β‐hydroxycholesterol (7β‐OH) in the presence or absence of the redox‐active iron chelator desferrioxamine (DFO) or 1,10‐phenanthroline. The cellular iron chelators considerably reduced, whereas iron compounds enhanced, 7β‐OH‐induced apoptosis and necrosis. DFO also decreased mRNA levels of Nramp1, whereas both iron compounds and 7β‐OH dramatically enhanced the expression of Nramp1 mRNA, particularly among 7β‐OH‐induced apoptotic cells. We conclude that the enhanced expression of Nramp1 in macrophage regions of atherosclerotic lesions may be associated with ferrous iron‐enhanced, oxidized lipid‐induced apoptosis. This finding reveals a novel function of Nramp1 in atherogenesis.
Role of Constitutively Activated and Insulin‐Like Growth Factor‐Stimulated ERK1/2 Signaling in Human Hepatoma Cell Proliferation and Apoptosis: Evidence for Heterogeneity of Tumor Cell Lines
Authors: ALEXIA CATHERINE , LASFER MALIKA , GROYER ANDRÉ
Published: January 2005

Abstract: Enhanced insulin‐like growth factor II (IGF‐II) and type I IGF receptor (IGF‐IR) gene expression in liver tumors and the development of liver tumors in transgenic mice overexpressing IGF‐II in the liver suggest that the IGFs and underlying signaling cascades may play auto/paracrine roles in the control of hepatocarcinoma (HCC) cell proliferation and in their protection against apoptosis. We have focused on the role of mitogen‐activated protein kinase (ERK1/2) signaling on human HepG2 and Huh‐7 hepatoma cell proliferation and on the protection of these cells against drug‐induced apoptosis. Physiological concentrations of IGF‐I stimulated DNA replication in HepG2 cells (1.5‐fold) but not in Huh‐7 cells, and this effect was abolished by PD98059 (MEK‐1 inhibitor). Doxorubicin or cisplatin treatment induced apoptosis (caspase‐dependent poly[ADP‐ribose]polymerase cleavage) in both cell lines, but dose‐dependent reversion of drug‐induced apoptosis (57–84%) by IGF‐I was only observed in HepG2 cells. The very low level of IGF‐IR at the plasma membrane of Huh‐7 cells may account for their unresponsiveness to IGF‐I. We have shown that drug treatment enhanced (17‐fold) or did not modify constitutive ERK1/2 activity in cultured HepG2 or Huh‐7 cells, respectively. In both cell lines, inhibition of constitutive and drug‐induced ERK1/2 activity by PD98059 yielded a complete inhibition of drug‐induced apoptosis. Altogether, our data demonstrate the heterogeneous response of human hepatoma cells to an IGF stimulus and suggest (1) that auto/paracrine effects of IGF‐I/‐II might contribute to the proliferation of HCC cells and to their protection against apoptosis in vivo and (2) that drug‐induced activation of ERK1/2 plays a role in drug‐induced apoptosis in human hepatoma cells.
Cooperative Effects between Protein Kinase A and p44/p42 Mitogen‐Activated Protein Kinase to Promote cAMP‐Responsive Element Binding Protein Activation after β Cell Stimulation by Glucose and Its Alteration Due to Glucotoxicity
Authors: COSTES SAFIA , LONGUET CHRISTINE , BROCA CHRISTOPHE , FARUQUE OMAR , HANI EL HABIB , BATAILLE DOMINIQUE , DALLE STEPHANE
Published: January 2005

Abstract: Long‐term hyperglycemia, a major characteristic of the diabetic state, contributes to the deterioration of the β cell function, a concept known as β cell glucotoxicity. We used the MIN6 β cell line and isolated rat islets to clarify the signaling mechanism(s) used by glucose to activate cAMP‐responsive element binding protein (CREB), a transcription factor crucial for β cell biology, and to evaluate the possible downregulation of this mechanism mediated by long‐term hyperglycemia. We report that glucose (10 mM) induces an increase in cytosolic calcium concentration that leads to cAMP‐induced protein kinase A (PKA) activation, promoting nuclear translocation of activated ERK1/2. The observation that glucose‐induced CREB phosphorylation was totally inhibited by the PKA inhibitor H89 (2 μM) and reduced by 50% with the ERK1/2 inhibitor PD98059 (20 μM) indicates that ERK1/2, located downstream of PKA, cooperates with PKA and is responsible for half of the PKA‐mediated CREB phosphorylation elicited by glucose in MIN6 β cells. We also found that exposure of μ cells for 24 h to high glucose (25 mM) induced a 70% decrease in cellular ERK1/2 and a 50% decrease in CREB content. In high‐glucose‐treated, ERK1/2‐ and CREB‐downregulated β cells, there was a loss of glucose (10 mM, 5 min)‐stimulated ERK1/2 and CREB phosphorylation that was associated with nuclear apoptotic characteristics. Since we have shown that activation of ERK1/2 is crucial for CREB phosphorylation, loss of the ERK1/2‐CREB signaling pathway in β cells due to long‐term hyperglycemia is likely to exacerbate β cell failure in diabetic states by affecting physiologically relevant gene expression and by inducing apoptosis.
p42/p44 Mitogen‐Activated Protein Kinase Signal Transduction Pathway: A Novel Target for the Treatment of Hormone‐Resistant Prostate Cancer?
Authors: KOUL HARI K. , MARONI PAUL D. , MEACHAM RANDALL B. , CRAWFORD DAVID , KOUL SWEATY
Published: January 2005

Abstract: Prostate cancer is the second leading cause of cancer deaths in men. Conventional therapies produce a high rate of cure for patients with localized prostate cancer, but there is no cure once the disease has spread beyond the prostate. Androgen withdrawal remains the only treatment for these men with clinically advanced disease; however, most of these men, who initially respond to hormone ablation therapy, fail and the disease progresses. There is at present no effective treatment for hormone‐independent prostate cancer. Several lines of evidence suggest a role of p42/p44 mitogen‐activated protein kinase (p42/p44 MAP kinase) signal transduction pathways in prostate cancer. At the molecular level, a variety of genetic alterations lead to an epigenetic mechanism by which a feedback autocrine loop between membrane receptors and associated ligands serves as an essential component of the growth, proliferation, and metastasis of prostate cancer at an advanced and androgen‐independent stage. Peptide growth factors are known to exert their effects by a complex array of mechanisms primarily mediated by the p42/p44 MAP kinase signal transduction pathway. Thus, we hypothesized that MAP kinase signal transduction pathways could serve as new and novel targets in prostate cancer therapy. In this article we provide an overview of the role played by MAP kinase signal transduction in the prostate.
Functional Characterization of Amyloid β Precursor Protein Regulatory Elements: Rationale for the Identification of Genetic Polymorphism
Authors: LAHIRI DEBOMOY K.
Published: January 2005

Abstract: Alzheimer's disease (AD) is characterized by the formation of senile plaques of the amyloid peptide (Aβ) derived from a large Aβ precursor protein (APP). Autosomally inherited or “familial” AD has only been previously demonstrated in connection with coding sequence missense mutations. Abnormal regulation of APP gene expression has been demonstrated to play a role in AD. Genome screen and linkage analysis suggest that the APP locus may predispose to AD. The aim is to characterize genetic variability in the APP gene within its upstream regulatory region and to determine whether that variability is associated with AD and affects the expression of APP. This article describes the rationale and strategy for identifying genetic polymorphisms in the APP regulatory region, including its promoter, to associate any variability with the disease.
Role of the APP Promoter in Alzheimer's Disease: Cell Type‐Specific Expression of the β‐Amyloid Precursor Protein
Authors: LAHIRI DEBOMOY K. , GE YUAN‐WEN
Published: January 2005

Abstract: One of the major hallmarks in Alzheimer's disease (AD) is amyloid deposition in the brain of afflicted subjects. This tissue‐specific deposition of the amyloid β‐protein (Aβ) is the major characteristic of AD. Aβ is proteolytically derived from a large Aβ precursor protein (APP). An apparent overexpression of the APP gene in certain areas of the AD brain indicates that abnormalities in gene regulation might be an important factor in AD pathology. The mechanism of expression of APP in different cell types is poorly understood. To understand the contribution of different cell types, such as neuronal, glial, and epithelial cells, APP expression was studied at the message and protein levels. Levels of APP expression, both message and protein, were greater in human neuroblastoma (NB) and PC12 cells than in glial and HeLa cells. DNA transfection experiments suggest that the relative activities of different promoter regions varied according to cell type. Although the upstream regulatory element in the promoter region is necessary for activity in PC12 and HeLa cells, this is not the case for NB cells. A 30‐bp proximal promoter region was found to be important for cell type‐specific APP gene expression.
Inhibition of B16 Mouse Melanoma Cell Growth and Induction of Apoptotic Cell Death with 8‐Chloroadenosine‐3′,5′‐monophosphate and Tiazofurin
Authors: KORIĆANAC LELA B. , TODOROVIĆ DANIJELA V. , POPOVIĆ NATAŠA M. , DEMAJO MIROSLAV A. , RUŽDIJIĆ SABERA D. , RISTI‐FIRA ALEKSANDRA M.
Published: January 2005

Abstract: Novel antineoplastic agents, 8‐chloroadenosine 3′,5′‐monophosphate (8‐Cl‐cAMP) and tiazofurin (TR), have been shown to be effective against different malignant cells. Through specific mechanisms of action they modulate the cellular signal transduction pathway, thereby causing growth inhibition, cell differentiation, and apoptosis. The aim of this work was the in vitro study of either 8‐Cl‐cAMP or TR effects on B16/F10 and B16/C3 mouse melanoma cell growth and cell death. Significant cell growth inhibition was obtained after the application of 8‐Cl‐cAMP or TR. The presence and number of apoptotic cells was evaluated using agarose gel electrophoresis and flow cytometry. The number of apoptotic nuclei, after treatment with antineoplastic agents, did not significantly change in B16/F10 cells, although it did show a significant increase in B16/C3 cells. The expression of c‐myc did not significantly change in B16/F10 cells after treatment with 8‐Cl‐cAMP or TR. The same results were obtained in B16/C3 cells after treatment with 8‐Cl‐cAMP. The level of c‐myc expression showed a significant increase in B16/C3 cells after treatment with TR. Concerning the effects that the analyzed agents exhibited on melanoma cells and other cancer cells, further preclinical studies of these drugs will potentially lead to better understanding of the molecular mechanisms of their action and finally more efficient therapeutic approaches to malignant diseases.
Proapoptotic Potentials of Genistein Under Growth Stimulation by Estrogen
Authors: JIN PARK OCK , SHIN JANG‐IN
Published: January 2005

Abstract: In mammary carcinogenesis, hormonal effects have been reported to be important factors. Estrogens are known to regulate the proliferation of breast cancer cells, whereas genistein has been shown to induce apoptosis in mammary tumor cells. This study examined genistein‐induced apoptosis through the regulation of bcl‐2 and bax expression in the presence of estrogen. MCF‐7 cells were treated with either genistein (25, 50, and 100 μM) or in the presence of 17β‐estradiol (12.5, 25, and 50 nM) for 48 h. DNA ladder analysis and Western blot analysis of bcl‐2, bax, cyclin B1, p21, and p53 were carried out. For comparison, the in vivo system was employed using estrogen‐deficient and estrogen‐sufficient female rats at two different concentrations of genistein. In MCF‐7 cells, DNA fragmentation was evident by the treatment of genistein in the absence and presence of estrogen. Downregulation of bcl‐2 and upregulation of bax by genistein were observed. However, genistein showed no proapoptotic properties in the presence of estrogen except with the lowest concentration of estrogen. In the presence of estrogen, p21 and p53 protein expression were upregulated by high concentrations of genistein. Bcl‐2/bax ratios were decreased by genistein treatment in the presence or absence of estrogen in female rats. These results demonstrate that the proapoptotic property of genistein might be influenced greatly by the concentration of estrogen in vitro, but that this influence by estrogen is not evident in vivo.
Inhibition of Cyclooxygenase‐2 Expression and Restoration of Gap Junction Intercellular Communication in H‐ras‐Transformed Rat Liver Epithelial Cells by Caffeic Acid Phenethyl Ester
Authors: LEE KI WON , CHUN KYUNG‐SOO , LEE JEONG‐SANG , KANG KYUNG‐SUN , SURH YOUNG‐JOON , LEE HYONG JOO
Published: January 2005

Abstract: One of the most frequent defects in human cancers is the uncontrolled activation of the ras signaling pathways. Increased expression of cyclooxygenase‐2 (COX‐2) and inhibition of gap junction intercellular communication (GJIC) have been frequently observed in several forms of human malignancies. The present study investigated the effects of caffeic acid phenethyl ester (CAPE), a chemopreventive phytochemical derived from honey propolis, on COX‐2 expression and GJIC in Harvey‐ras‐transformed WB‐F344 rat liver epithelial cells (H‐ras WB cells). H‐ras induced COX‐2 expression in WB‐F344 rat liver epithelial cells (WB cells). H‐ras WB cells also exhibited complete inhibition of GJIC and predominant unphosphorylation of connexin 43 (Cx43), a major protein modulating GJIC. CAPE significantly inhibited the constitutive expression of COX‐2 and restored the disrupted GJIC through the phosphorylation of Cx43 at a concentration of 12.5 μM in H‐ras WB cells. Although the molecular basis for the cancer chemopreventive activity of CAPE is not completely understood, several studies suggest that CAPE is a potent and specific inhibitor of the transcription factor nuclear factor κB (NF‐κB) activation. We also found that CAPE significantly inhibited H‐ras‐induced NF‐κB DNA‐binding activity without affecting the activation of extracellular signal‐regulated kinase and p38 mitogen‐activated protein kinase, which are major intracellular molecules involved in the Ras signaling pathways. In conclusion, CAPE may exert cancer chemopreventive effects through the inhibition of COX‐2 expression and the restoration of disrupted GJIC induced by H‐ras, possibly by targeting NF‐κB.
The Hinge Region of the Androgen Receptor Plays a Role in Proteasome‐Mediated Transcriptional Activation
Authors: TANNER TAMZIN , CLAESSENS FRANK , HAELENS ANNEMIE
Published: January 2005

Abstract: To investigate the function of the hinge region in transcriptional activation by the androgen receptor, we compared the actions of the wild‐type receptor with a mutant receptor, deleted of amino acids 628–646 of the hinge. The role of the proteasome on the expression and activity of these two proteins was investigated. The deletion mutant demonstrated a threefold increase in transcriptional activity when compared to the wild‐type receptor protein. Furthermore, we found that hormone‐dependent stabilization of the receptor protein was more enhanced for the deletion mutant. In addition, experiments using the proteasome inhibitor, MG132, demonstrated that the deletion mutant is more sensitive to proteasome‐mediated degradation than the wild‐type receptor. However, inhibition of the proteasome had a negative effect on the transcriptional activity of the deletion mutant. Taken together, our results suggest that the hinge region not only plays an important role in controlling the transactivation potential of the androgen receptor but also in determining the influence of the proteasome on androgen receptor‐mediated transcriptional activation.
Polynucleosomal Synthesis of Poly(ADP‐ribose) Causes Chromatin Unfolding as Determined by Micrococcal Nuclease Digestion
Authors: PEREZ‐LAMIGUEIRO MARIA A. , ALVAREZ‐GONZALEZ RAFAEL
Published: January 2005

Abstract: We have evaluated the influence of protein poly(ADP‐ribosyl)ation in the relaxation of chromatin by exposing a rat liver polynucleosomal extract to micrococcal nuclease (MNase) digestion. The kinetic susceptibility of polynucleosomes to endonuclease digestion was determined as a function of the time of incubation as well as endonuclease concentration. To validate our assay, we also ran control experiments with protein‐free calf thymus DNA as the opposite of polynucleosomal DNA. Rat liver chromatin was also incubated in the absence or presence of exogenously added 200 μM βNAD+, the poly(ADP‐ribosyl)ation substrate, before MNase digestion. For incubations in the presence of βNAD+, the synthesis of polynucleosomal poly(ADP‐ribose) was stopped with 1 mM benzamide. After addition of MNase, endonuclease digestion was blocked with EDTA to chelate the Mg2+ ions needed for enzymatic activation, and the samples were subjected to electrophoresis through 1.5% agarose gels. As expected, a faster degradation of chromatin into oligonucleosomal DNA ladders was observed upon protein poly(ADP‐ribosyl)ation when the chromatin extract was preincubated with 200 μM βNAD+. Thus, our results are consistent with the conclusion that the covalent poly(ADP‐ribosyl)ation of polynucleosomal proteins favors a more “relaxed” or “open” structure, which renders chromatin more susceptible to MNase digestion.
Repetitive Treatments of Colon HT‐29 Cells with Diallyl Disulfide Induce a Prolonged Hyperacetylation of Histone H3 K14
Authors: DRUESNE NATHALIE , PAGNIEZ ANTHONY , MAYEUR CAMILLE , THOMAS MURIEL , CHERBUY CLAIRE , DUÉE PIERRE‐HENRI , MARTEL PAULE , CHAUMONTET CATHERINE
Published: January 2005

Abstract: Diallyl disulfide (DADS) is a sulfur compound derived from garlic. Several studies carried out in rodents have revealed protective effects of DADS against colon carcinogenesis. The antipromoting effects of DADS may be partly related to its ability to inhibit tumoral cell proliferation. In a previous study, we have shown that in two human colon tumor cell lines (HT‐29 and Caco‐2) seeded at a low density (0.2 × 106 cells/100‐mm petri dish), DADS antiproliferative effects were associated with a transient increase of histone H3 K14 acetylation. Moreover, DADS could inhibit nuclear histone deacetylase activity. Therefore, in the present study, we examined the possible effects of different experimental conditions (HT‐29 cells at high density, repetitive treatments with DADS) on the pattern of DADS‐induced histone hyperacetylation. Using HT‐29 cells seeded at a higher density (5 × 106 cells/100‐mm petri dish), we found that DADS induced histone H3 K14 hyperacetylation rapidly (3 h). When administrated as single treatments, the DADS effect on histone H3 K14 remained transient. In contrast, repetitive treatment with DADS resulted in a prolonged hyperacetylation of histone H3 K14. Whatever the cell culture conditions were, DADS had no effect on histone H4 acetylation. Thus, in vitro, the cell density and pattern of DADS treatment influenced the HT‐29 nuclear response to DADS. DADS belongs to food‐borne molecules that may play a role in chromatin remodeling and contribute to the nutritional modulation of gene expression.
Plants Contain a High Number of Proteins Showing Sequence Similarity to the Animal SUV39H Family of Histone Methyltransferases
Authors: ZHAO ZHONG , SHEN WEN‐HUI
Published: January 2005

Abstract: The SET domain, first identified within and named after proteins encoded by three Drosophila genes [Su(var)3–9, E(z), and Trithorax], is recognized as a signature motif for histone methyltransferases that are involved in epigenetic processes. The SUV39H family of SET domain proteins methylate specifically the residue lysine 9 of histone H3, creating a code for gene silencing. This family of proteins contain at their C termini a unique catalytic domain consisting of pre‐SET, SET, and post‐SET domains. Sequence homology‐based searches identified 15 Arabidopsis, 14 maize, and 12 rice proteins that can be assigned to the SUV39H family. These high numbers in plants are in marked contrast to the situation in animals, in which each species appears to contain only two to three proteins of this family. Our phylogenetic analyses revealed that plant proteins can be classified into seven orthology groups. Representative members of each group can be found in single plant species, suggesting that different group members are evolutionarily conserved to perform specific functions.
Systematic Review of Microsatellite Instability and Colorectal Cancer Prognosis
Authors: Popat S. , Hubner R. , Houlston R.S.
Published: January 2005

Purpose

A number of studies have investigated the relationship between microsatellite instability (MSI) and colorectal cancer (CRC) prognosis. Although many have reported a better survival with MSI, estimates of the hazard ratio (HR) among studies differ. To derive a more precise estimate of the prognostic significance of MSI, we have reviewed and pooled data from published studies.

Methods

Studies stratifying survival in CRC patients by MSI status were eligible for analysis. The principal outcome measure was the HR. Data from eligible studies were pooled using standard techniques.

Results

Thirty-two eligible studies reported survival in a total of 7,642 cases, including 1,277 with MSI. There was no evidence of publication bias. The combined HR estimate for overall survival associated with MSI was 0.65 (95% CI, 0.59 to 0.71; heterogeneity P = .16; I2 = 20%). This benefit was maintained restricting analyses to clinical trial patients (HR = 0.69; 95% CI, 0.56 to 0.85) and patients with locally advanced CRC (HR = 0.67; 95% CI, 0.58 to 0.78). In patients treated with adjuvant fluorouracil (FU) CRCs with MSI had a better prognosis (HR = 0.72; 95% CI, 0.61 to 0.84). However, while data are limited, tumors with MSI derived no benefit from adjuvant FU (HR = 1.24; 95% CI, 0.72 to 2.14).

Conclusion

CRCs with MSI have a significantly better prognosis compared to those with intact mismatch repair. Additional studies are needed to further define the benefit of adjuvant chemotherapy in locally advanced tumors with MSI.
Randomized Phase II Study of Two Doses of Gefitinib in Hormone-Refractory Prostate Cancer: A Trial of the National Cancer Institute of Canada-Clinical Trials Group
Authors: Canil C.M. , Moore M.J. , Winquist E. , Baetz T. , Pollak M. , Chi K.N. , Berry S. , Ernst D.S. , Douglas L. , Brundage M. , Fisher B. , McKenna A. , Seymour L.
Published: January 2005

Purpose

Overexpression of the epidermal growth factor receptor has been demonstrated in advanced prostate cancer and is associated with a poor outcome. A multi-institutional, randomized, phase II study was undertaken by the National Cancer Institute of Canada-Clinical Trials Group to evaluate the efficacy and toxicity of two doses of oral gefitinib in patients with minimally symptomatic, hormone-refractory prostate cancer (HRPC).

Patients and Methods

Between July and November 2001, 40 patients with HRPC and increasing prostate-specific antigen (PSA) or progression in measurable disease who had not received prior chemotherapy were randomly assigned to 250 mg (n = 19) or 500 mg (n = 21) oral gefitinib daily continuously. The primary end points were PSA response rate and objective measurable response. Functional Assessment of Cancer Therapy Prostate Cancer Subscale (FACT-P) quality-of-life questionnaires were completed at baseline and during treatment.

Results

None of the patients demonstrated a PSA or objective measurable response. Five (14.3%) of 35 assessable patients had stable PSA (one patient at 250 mg and four patients at 500 mg), and five patients (14.3%) had a best response of stable disease (duration, 2.5 to 16.8 months). No significant effect on the rate of increase in PSA was seen. The most common drug-related nonhematologic toxicities observed were grade 1 to 2 diarrhea (250 mg, 65%; 500 mg, 56%), fatigue (250 mg, 29%; 500 mg, 33%), and grade 1 to 2 skin rash (250 mg, 24%; 500 mg, 39%). FACT-P scores decreased during treatment, indicating worsening of symptoms compared with baseline.

Conclusion

Gefitinib did not result in any responses in PSA or objective measurable disease at either dose level. Gefitinib has minimal single-agent activity in HRPC.
Role of Anti-Hepatitis C Virus (HCV) Treatment in HCV-Related, Low-Grade, B-Cell, Non-Hodgkin's Lymphoma: A Multicenter Italian Experience
Authors: Vallisa Daniele , Bernuzzi Patrizia , Arcaini Luca , Sacchi Stefano , Callea Vittorio , Marasca Roberto , Lazzaro Antonio , Trabacchi Elena , Anselmi Elisa , Arcari Anna Lisa , Moroni Carlo , Bertè Raffaella , Lazzarino Mario , Cavanna Luigi
Published: January 2005

Purpose

Hepatitis C virus (HCV) is endemic in some areas of Northwestern Europe and the United States. HCV has been shown to play a role in the development of both hepatocellular carcinoma and B-cell non-Hodgkin's lymphoma (B-NHL). The biologic mechanisms underlying the lymphomagenic activity of the virus so far are under investigation. In this study, the role of antiviral (anti-HCV) treatment in B-NHL associated with HCV infection is evaluated.

Patients and Methods

Thirteen patients with histologically proven low-grade B-NHL characterized by an indolent course (ie, doubling time no less than 1 year, no bulky disease) and carrying HCV infection were enrolled on the study. All patients underwent antiviral treatment alone with pegilated interferon and ribavirin. Response assessment took place at 6 and 12 months.

Results

Of the twelve assessable patients, seven (58%) achieved complete response and two (16%) partial hematologic response at 14.1 ± 9.7 months (range, 2 to 24 months, median follow-up, 14 months), while two had stable disease with only one patient experiencing progression of disease. Hematologic responses (complete and partial, 75%) were highly significantly associated to clearance or decrease in serum HCV viral load following treatment (P = .005). Virologic response was more likely to be seen in HCV genotype 2 (P = .035), while hematologic response did not correlate with the viral genotype. Treatment-related toxicity did not cause discontinuation of therapy in all but two patients, one of whom, however, achieved complete response.

Conclusion

This experience strongly provides a role for antiviral treatment in patients affected by HCV-related, low-grade, B-cell NHL.
Phase I Clinical Trial of Mafosfamide in Infants and Children Aged 3 Years or Younger With Newly Diagnosed Embryonal Tumors: A Pediatric Brain Tumor Consortium Study (PBTC-001)
Authors: Blaney Susan M. , Boyett James , Friedman Henry , Gajjar Amar , Geyer Russ , Horowtiz Marc , Hunt Daniel , Kieran Mark , Kun Larry , Packer Roger , Phillips Peter , Pollack Ian F. , Prados Michael , Heideman Richard
Published: January 2005

Purpose

A phase I trial of intrathecal (IT) mafosfamide was performed to determine the optimal dose, dose-limiting toxicities, and incidence and severity of other toxicities when administered in association with concomitant multiagent systemic chemotherapy to children younger than 3 years with newly diagnosed embryonal tumors.

Patients and Methods

Twenty-five assessable patients received IT mafosfamide at one of six dose levels ranging from 5 mg to 17 mg. Patients were premedicated with dexamethasone (0.15 mg/kg) and morphine (0.1 mg/kg) before receiving IT mafosfamide. Serial samples of CSF for pharmacokinetic studies were obtained in a subset of patients with Ommaya reservoirs.

Results

Irritability, presumably secondary to pain or headache during mafosfamide administration, was dose limiting in two of three patients at the 17-mg dose level. The maximum-tolerated dose of IT mafosfamide following premedication with dexamethasone and morphine was 14 mg.

Conclusion

The maximum tolerated dose and recommended phase II dose of IT mafosfamide in patients younger than 3 years with newly diagnosed embryonal CNS tumors is 14 mg. A trial to assess the efficacy of regional therapy with IT mafosfamide administered with intensive systemic chemotherapy in children younger than 3 years with primary intracranial embryonal tumors is now in progress.
Advanced-Stage Large-Cell Lymphoma in Children and Adolescents: Results of a Randomized Trial Incorporating Intermediate-Dose Methotrexate and High-Dose Cytarabine in the Maintenance Phase of the APO Regimen: A Pediatric Oncology Group Phase III Trial
Authors: Laver Joseph H. , Kraveka Jacqueline M. , Hutchison Robert E. , Chang Myron , Kepner James , Schwenn Molly , Tarbell Nancy , Desai Sunil , Weitzman Sheila , Weinstein Howard J. , Murphy Sharon B.
Published: January 2005

Purpose

The Pediatric Oncology Group adopted a histology-based approach to non-Hodgkin's lymphoma and treated patients with advanced large-cell lymphoma on a separate protocol (doxorubicin, vincristine, prednisone, 6-mercaptopurin, and methotrexate; APO regimen). In this study, we assessed the effects of an intense antimetabolite therapy alternating with APO on overall survival (OS) and event-free survival (EFS) and looked into biologic correlates.

Patients and Methods

From December 1994 to April 2000, we enrolled 180 eligible pediatric patients with stage III/IV large-cell lymphoma (LCL); 90 patients were randomly assigned to the intermediate-dose methotrexate (IDM) and high-dose cytarabine (HiDAC) arm, 85 patients to the APO arm, and five patients directly to the APO arm by study design due to CNS involvement. Planned therapy duration was 12 months.

Results

The 4-year EFS for all patients was 67.4% (SE, 4.2%), and OS was 80.1% (SE, 3.6%) without any significant difference between the two arms. The 4-year EFS and OS were 71.8% (SE, 6.1%) and 88.1% (SE, 4.4%), respectively, for patients with anaplastic large-cell lymphoma, and 63.8% (SE, 10.3%) and 70.3% (SE, 9.0%), respectively, for patients with diffuse large B-cell lymphoma. Only 11 patients required radiation (due to unresponsive bulky disease or CNS involvement). The IDM/HiDAC arm was associated with more toxicity.

Conclusion

The efficacy of incorporating IDM/HiDAC in the treatment plan of pediatric and adolescent patients with advanced-stage LCL was inconclusive as to its effect on EFS, regardless of the lymphoma phenotype. It cannot be excluded that with a higher number of patients, one treatment could prove superior and future studies will build on these data.
Platinum-Etoposide Chemotherapy in Elderly Patients With Small-Cell Lung Cancer: Results of a Randomized Multicenter Phase II Study Assessing Attenuated-Dose or Full-Dose With Lenograstim Prophylaxis—A Forza Operativa Nazionale Italiana Carcinoma Polmonare and Gruppo Studio Tumori Polmonari Veneto (FONICAP-GSTPV) Study
Authors: Ardizzoni Andrea , Favaretto Adolfo , Boni Luca , Baldini Editta , Castiglioni Federico , Antonelli Paola , Pari Franca , Tibaldi Carmelo , Altieri Alfonso M. , Barbera Sante , Cacciani Giancarlo , Raimondi Mario , Tixi Lucia , Stefani Micaela , Monfardini Silvio , Antilli Antonio , Rosso Riccardo , Paccagnella Adriano
Published: January 2005

Purpose

Small-cell lung cancer (SCLC) is increasingly diagnosed in elderly patients, who are at higher risk of treatment-related morbidity and mortality. We conducted a randomized two-stage phase II study to assess the therapeutic index of two different platinum/etoposide regimens, attenuated-dose (AD) and full-dose (FD) plus prophylactic lenograstim.

Patients and Methods

SCLC patients older than 70 years were randomized to receive four courses of cisplatin 25 mg/m2 on days 1 and 2, and etoposide 60 mg/m2 on days 1, 2, and 3 every 3 weeks (AD); or cisplatin 40 mg/m2 on days 1 and 2, and etoposide 100 mg/m2 on days 1, 2, and 3 every 3 weeks, plus lenograstim 5 mg/kg days 5 through 12, every 3 weeks (FD). A combined primary end point named therapeutic success (TS), which took into account activity, toxicity, and compliance, was used.

Results

Ninety-five patients were enrolled. Seventy-five percent and 72% of the patients in the AD and FD arms, respectively, completed the treatment as per protocol. Response rate was 39% and 69% in the AD and FD arms, respectively, and 1-year survival probability was 18% and 39%, respectively. Treatment was well tolerated in both groups, with no grade 3 to 4 myelotoxicity in the AD arm, and 12% myelotoxicity in the FD arm. Overall, the observed TSs were 10 (36%) of 28 patients and 42 (63%) of 67 patients for AD and FD treatments, respectively.

Conclusion

In elderly patients with SCLC a full-dose cisplatin/etoposide regimen combined with prophylactic lenograstim is active and feasible, while attenuated doses of the same regimen are associated with a poor therapeutic outcome.
Quality-of-Life Assessment in the Symptom Management Trials of the National Cancer Institute-Supported Community Clinical Oncology Program
Authors: Buchanan David R. , O'Mara Ann M. , Kelaghan Joseph W. , Minasian Lori M.
Published: January 2005

Purpose

To examine how quality of life (QOL) is prospectively conceptualized, defined, and measured in the symptom management clinical trials supported by the National Cancer Institute Community Clinical Oncology Program (CCOP).

Methods

All QOL research objectives, rationales, assessment instruments, symptoms treated, and types of interventions from the CCOP symptom management portfolio of clinical trials were extracted and analyzed.

Results

QOL assessments were proposed in 68 (52%) of the 130 total CCOP symptom management trials initiated since 1987. A total of 22 global QOL instruments were identified. Both the frequency of symptom management trials and the frequency of QOL assessment have increased significantly over time. The Functional Assessment of Cancer Therapy and Uniscale instruments were the most widely used QOL instruments, included in 55% of trials assessing QOL. The conceptual framework for QOL inclusion was limited to univariate relationships between symptom relief and global improvements in QOL. No consistent associations were found between QOL assessment and either the symptoms targeted or types of interventions.

Conclusion

To advance the state of the science, research protocols need to provide more explicit rationales for assessing QOL in symptom management trials and for the selection of the QOL instrument(s) to be used. Conceptual frameworks that specify the hypothesized links between the specific symptom(s) being managed, interactions with other symptoms, different domains of QOL, and global QOL also need to be more precisely described. Methodologic and conceptual advances in QOL symptom management trials are critical to fulfill the promise of alleviating suffering and improving the QOL of cancer patients.
Satellite DNA binding and cellular localisation of RNA helicase P68
Authors: Enukashvily Natella , Donev Rossen , Sheer Denise , Podgornaya Olga
Published: January 2005

We purified a 68-kDa protein from the mouse nuclear matrix using ion exchange and affinity chromatography. Column fractions were tested for specific binding to mouse minor satellite DNA using a gel mobility shift assay. The protein was identified by mass spectrometry as RNA helicase P68. In fixed cells, P68 was found to shuttle in and out of SC35 domains, forming fibres and granules in a cell-cycle dependent manner. Analysis of the P68 sequence revealed a short potential coiled-coil domain that might be involved in the formation of P68 fibres. Contacts between centromeres and P68 granules were observed during all phases of the cycle but they were most prominent in mitosis. At this stage, P68 was found in both the centromeric regions and the connections between chromosomes. Direct interaction of P68/DEAD box RNA helicase with satellite DNAs in vitro has not been demonstrated for any other members of the RNA helicase family.
Induction of apoptosis by TNF receptor 2 in a T-cell hybridoma is FADD dependent and blocked by caspase-8 inhibitors
Authors: Depuydt Bart , Van Loo Geert , Vandenabeele Peter , Declercq Wim
Published: January 2005

Previously we reported that both human TNFR1 and TNFR2 mediate TNF-induced apoptosis in the transfected rat/mouse T cell hybridoma PC60. We show here that TNFR2-mediated apoptosis in PVC60 cells can be blocked by the broad-spectrum caspase inhibitor zVAD-fmk, the caspase-8 inhibitor zIETD-fmk and by CrmA, a viral inhibitor of caspase-1 and caspase-8. This suggests an involvement of caspase-8 in TNFR2-mediated apoptosis. The upstream adaptor of caspase-8, FADD, is also involved in TNFR2-induced cell death, since transient overexpression of a dominant negative deletion mutant of FADD inhibited apoptosis induced by this receptor. TNFR2-induced apoptosis is independent of endogenous TNF or other death-inducing ligand production and subsequent activation of TNFR1 or other death receptors. Furthermore, TNFR2 stimulation does not enhance sensitivity for a subsequent TNFR1-induced apoptotic signal, as has been reported for Jurkat cells. TRAF2 downregulation, which has been proposed as the mechanism by which TNFR2 enhances TNFR1 signaling, was observed in PC60 cells, but the TNRF1 signal was not modulated. These data confirm the capacity of TNFR2 to generate an apoptotic cell death signal independent of TNFR1.
Integrin-dependent PLC-γ1 phosphorylation mediates fibronectin-dependent adhesion
Authors: Tvorogov Denis , Wang Xue-Jie , Zent Roy , Carpenter Graham
Published: January 2005

Although integrin engagement initiates signaling events such as focal-adhesion kinase (FAK) and Src kinase activation, the role of phosphoinositide turnover in cell adhesion is less clear. To assess PLC-γ1 function in this process, Plcg1-/- fibroblasts (Null) were compared with the same fibroblasts in which PLC-γ1 was re-expressed (Null+). Following plating on fibronectin, Null cells displayed a significantly impaired rate of adhesion compared with Null+ cells. This defect was detected at low concentrations of fibronectin; at high fibronectin concentrations, the Null and Null+ cells displayed equivalent adhesion characteristics. The differences were not due to PLC-γ1-dependent changes in integrin subunit expression, nor was integrin receptor clustering impaired with the absence of PLC-γ1. Experiments with site-specific antibodies and PLC-γ1 mutants showed that fibronectin selectively increased phosphorylation of Tyr783 and that mutagenesis of this residue, but not Tyr771 or Tyr1253, abrogated fibronectin-dependent adhesion. The SH2 domains of PLC-γ1 were also required for maximal adhesion on fibronectin. Adhesion to fibronectin induced PLC-γ1 tyrosine phosphorylation that was inhibited by a Src-kinase inhibitor, but not an epidermal-growth-factor-receptor kinase inhibitor. Moreover, in cells null for Src family members, but not in cells null for FAK family members, integrin-dependent PLC-γ1 tyrosine phosphorylation was greatly reduced. Finally, the data demonstrated that PLC-γ1 co-immunoprecipitated with Src following fibronectin-induced integrin activation, and this association did not depend on FAK expression.
The snRNP 15.5K protein folds its cognate K-turn RNA: A combined theoretical and biochemical study
Authors: COJOCARU VLAD , NOTTROTT STEPHANIE , KLEMENT REINHARD , JOVIN THOMAS M.
Published: January 2005

The human 15.5K protein binds to the 5′ stem–loop of U4 snRNA, promotes the assembly of the spliceosomal U4/U6 snRNP, and is required for the recruitment of the 61K protein and the 20/60/90K protein complex to the U4 snRNA. In the crystallographic structure of the 15.5K–U4 snRNA complex, the conformation of the RNA corresponds to the family of kink-turn (K-turn) structural motifs. We simulated the complex and the free RNA, showing how the protein binding and the intrinsic flexibility contribute to the RNA folding process. We found that the RNA is significantly more flexible in the absence of the 15.5K protein. Conformational transitions such as the interconversion between alternative purine stacking schemes, the loss of G-A base pairs, and the opening of the K-turn occur only in the free RNA. Furthermore, the stability of one canonical G-C base pair is influenced both by the binding of the 15.5K protein and the nature of the adjacent structural element in the RNA. We performed chemical RNA modification experiments and observed that the free RNA lacks secondary structure elements, a result in excellent agreement with the simulations. Based on these observations, we propose a protein-assisted RNA folding mechanism in which the RNA intrinsic flexibility functions as a catalyst.
A selenocysteine tRNA and SECIS element in Plasmodium falciparum
Authors: MOURIER TOBIAS , PAIN ARNAB , BARRELL BART , GRIFFITHS-JONES SAM
Published: January 2005

The molecular machinery for incorporating selenocysteine into proteins is present in both prokaryotes and eukaryotes. Although selenocysteine insertion has been reported in animals, plants, and protozoans, known eukaryotic selenocysteine tRNA sequences and selenocysteine insertion sequences are limited to animals and plants. Here we present clear indications of the presence of selenocysteine-tRNA and a selenocysteine insertion sequence in Plasmodium falciparum. To our knowledge, this is the first report of an identification of protozoan selenocysteine insertion machinery at the sequence level.
NMR structure of the apoB mRNA stem–loop and its interaction with the C to U editing APOBEC1 complementary factor
Authors: MARIS CHRISTOPHE , MASSE JAMES , CHESTER ANN , NAVARATNAM NAVEENAN , ALLAIN FRÉDÉRIC H.-T.
Published: January 2005

We have solved the NMR structure of the 31-nucleotide (nt) apoB mRNA stem–loop, a substrate of the cytidine deaminase APOBEC1. We found that the edited base located at the 5′ end of the octa-loop is stacked between two adenosines in both the unedited (cytidine 6666) and the edited (uridine 6666) forms and that the rest of the loop is unstructured. The 11-nt “mooring” sequence essential for editing is partially flexible although it is mostly in the stem of the RNA. The octa-loop and the internal loop in the middle of the stem confer this flexibility. These findings shed light on why APOBEC1 alone cannot edit efficiently the cytidine 6666 under physiological conditions, the editing base being buried in the loop and not directly accessible. We also show that APOBEC1 does not specifically bind apoB mRNA and requires the auxiliary factor, APOBEC1 complementary factor (ACF), to edit specifically cytidine 6666. The binding of ACF to both the mooring sequence and APOBEC1 explains the specificity of the reaction. Our NMR study lead us to propose a mechanism in which ACF recognizes first the flexible nucleotides of the mooring sequence (the internal loop and the 3′ end octa-loop) and subsequently melts the stem–loop, exposing the amino group of the cytidine 6666 to APOBEC1. Thus, the flexibility of the mooring sequence plays a central role in the RNA recognition by ACF.