bluuebunny/crossref_metadata_2025 huggingface dataset:
Tagging Single-Nucleotide Polymorphisms in Antioxidant Defense Enzymes and Susceptibility to Breast Cancer
Authors: Cebrian Arancha , Pharoah Paul D. , Ahmed Shahana , Smith Paula L. , Luccarini Craig , Luben Robert , Redman Karen , Munday Hannah , Easton Douglas F. , Dunning Alison M. , Ponder Bruce A.J.
Published: January 2006

It is generally believed that the initiation of breast cancer is a consequence of cumulative genetic damage leading to genetic alterations and provoking uncontrolled cellular proliferation and/or aberrant programmed cell death, or apoptosis. Reactive oxygen species have been related to the etiology of cancer as they are known to be mitogenic and therefore capable of tumor promotion. The aim of this study was to assess the role of common variation in 10 polymorphic genes coding for antioxidant defense enzymes in modulating individual susceptibility to breast cancer using a case-control study (N cases = 4,474 and N controls = 4,580). Both cases and controls were from the East Anglian region of the United Kingdom. We have identified a set of 54 single nucleotide polymorphisms (SNPs) that efficiently tag all the known SNPs in the 10 genes and are also expected to tag any unknown SNPs in each gene. We found no evidence for association of common variants in SOD1, SOD2, GPX1, GPX4, GSR, TXNRD1, and TXN2. There was borderline evidence for association of variants in CAT g27168a {P [2 degrees of freedom (df)] = 0.05}, TXN t2715c [P (2 df) = 0.007], and TXNRD2 A66S and TXNRD2 g23524a (Ptrend = 0.074 and 0.046, respectively). For TXNRD2 A66S [AS versus AA: odds ratio (OR), 1.05; 95% confidence intervals (95% CI), 0.96-1.15; SS versus AA: OR, 1.12; 95% CI, 0.98-1.29], there are bioinformatics data to suggest that it is functional but confirmation in independent data sets is required before they can be regarded as definitive breast cancer susceptibility alleles. Even if confirmed, these four alleles would account for just 0.32% of the excess familial risk of breast cancer. (Cancer Res 2006; 66(2): 1225-33)
De novo CpG Island Methylation in Human Cancer Cells
Authors: Jair Kam-Wing , Bachman Kurtis E. , Suzuki Hiromu , Ting Angela H. , Rhee Ina , Yen Ray-Whay Chiu , Baylin Stephen B. , Schuebel Kornel E.
Published: January 2006

A major obstacle toward understanding how patterns of abnormal mammalian cytosine DNA methylation are established is the difficulty in quantitating the de novo methylation activities of DNA methyltransferases (DNMT) thought to catalyze these reactions. Here, we describe a novel method, using native human CpG island substrates from genes that frequently become hypermethylated in cancer, which generates robust activity for measuring de novo CpG methylation. We then survey colon cancer cells with genetically engineered deficiencies in different DNMTs and find that the major activity against these substrates in extracts of these cells is DNMT1, with minor contribution from DNMT 3b and none from DNMT3a, the only known bona fide de novo methyltransferases. The activity of DNMT1 against unmethylated CpG rich DNA was further tested by introducing CpG island substrates and DNMT1 into Drosophila melanogaster cells. The exogenous DNMT1 methylates the integrated mammalian CpG islands but not the Drosophila DNA. Additionally, in human cancer cells lacking DNMT1 and DNMT3b and having nearly absent genomic methylation, gene-specific de novo methylation can be initiated by reintroduction of DNMT1. Our studies provide a new assay for de novo activity of DNMTs and data suggesting a potential role for DNMT1 in the initiation of promoter CpG island hypermethylation in human cancer cells. (Cancer Res 2006; 66(2): 682-92)
Cisplatin Mimics ARF Tumor Suppressor Regulation of RelA (p65) Nuclear Factor-κB Transactivation
Authors: Campbell Kirsteen J. , Witty James M. , Rocha Sonia , Perkins Neil D.
Published: January 2006

The RelA (p65) nuclear factor-κB (NF-κB) subunit can contribute towards tumor cell survival through inducing the expression of a variety of antiapoptotic genes. However, the NF-κB response can show great diversity and is not always antiapoptotic. Here, we find that cisplatin, a DNA cross-linking agent and commonly used anticancer compound, does not affect RelA nuclear translocation but modulates its transcriptional activity. Similar to other genotoxic agents, such as daunorubicin and UV light, cisplatin treatment in the U-2 OS osteosarcoma cell line represses RelA activity and inhibits expression of the NF-κB antiapoptotic target gene Bcl-xL. The mechanism through which cisplatin achieves these effects is different to daunorubicin and UV light but shows great similarity to the RelA regulatory pathway induced by the ARF tumor suppressor: cisplatin regulation of RelA requires ATR/Chk1 activity, represses Bcl-xL but not XIAP expression, and results in phosphorylation of RelA at Thr505. In contrast to these results, another chemotherapeutic drug etoposide activates NF-κB and induces expression of these target genes. Thus, within a single tumor cell line, there is great heterogeneity in the NF-κB response to different, commonly used chemotherapeutic drugs. These observations suggest that it might be possible to minimize the ability of RelA to inhibit cancer therapy by diagnostically predicting the type of chemotherapeutic drug most compatible with NF-κB functionality in a tumor cell type. Moreover, our data indicate that at least with respect to RelA, cisplatin functions as an ARF mimic. Other drugs capable of mimicking this aspect of ARF function might therefore have therapeutic potential. (Cancer Res 2006; 66(2): 929-35)
Intracellular Signaling Pathways Involved in the Cell Growth Inhibition of Glioma Cells by Melatonin
Authors: Martín Vanesa , Herrera Federico , Carrera-Gonzalez Pilar , García-Santos Guillermo , Antolín Isaac , Rodriguez-Blanco Jezabel , Rodriguez Carmen
Published: January 2006

Melatonin is an indolamine mostly produced in the pineal gland, soluble in water, and highly lipophilic, which allows it to readily cross the blood-brain barrier. Melatonin possesses antioxidant properties and its long-term administration in rodents has not been found to cause noteworthy side effects. In the present work, we found that millimolar concentrations of this indolamine reduced cell growth of C6 glioma cells by 70% after 72 hours of treatment, inhibiting cell progression from G1 to S phase of the cell cycle. Intraperitoneal administration of 15 mg/kg body weight of melatonin to rats previously injected in the flank with C6 glioma cells reduces tumor growth by 50% 2 weeks after the implant. Inhibition of cell growth does not depend on melatonin membrane receptor activation whereas it seemingly relates to the reduction of intracellular basal free radical levels by 30%. Increase of basal redox state of the cells and constitutive activation of tyrosine kinase receptor [receptor tyrosine kinase (RTK)] pathways, including the extracellular signal–regulated kinase 1/2 (ERK1/2) and the Akt and protein kinase C (PKC) signaling pathways, contribute to the progression of the gliomas leading to the constitutive activation of the redox-dependent survival transcription factor nuclear factor κB (NF-κB). The antioxidant effect of melatonin in C6 cells is associated to inhibition of NF-κB and Akt, but not of ERK1/2. The antiproliferative effect of the indolamine on these cells is partially abolished when coincubated with the PKC activator 12-O-tetradecanoylphorbol-13-acetate, thus indicating that the ability of melatonin to change cellular redox state may be inactivating the pathway RTK/PKC/Akt/NF-κB. (Cancer Res 2006; 66(2): 1081-8)
Thymosin β4 Is a Determinant of the Transformed Phenotype and Invasiveness of S-Adenosylmethionine Decarboxylase–Transfected Fibroblasts
Authors: Nummela Pirjo , Yin Miao , Kielosto Mari , Leaner Virna , Birrer Michael J. , Hölttä Erkki
Published: January 2006

S-adenosylmethionine decarboxylase (AdoMetDC) is a key enzyme in the synthesis of polyamines essential for cell growth and proliferation. Its overexpression induces the transformation of murine fibroblasts in both sense and antisense orientations, yielding highly invasive tumors in nude mice. These cell lines hence provide a good model to study cell invasion. Here, the gene expression profiles of these cells were compared with their normal counterpart by microarray analyses (Incyte Genomics, Palo Alto, CA, and Affymetrix, Santa Clara, CA). Up-regulation of the actin sequestering molecule thymosin β4 was the most prominent change in both cell lines. Tetracycline-inducible expression of thymosin β4 antisense RNA caused a partial reversal of the transformed phenotype. Further, reversal of transformation by dominant-negative mutant of c-Jun (TAM67) caused reduction in thymosin β4 mRNA. Interestingly, a sponge toxin, latrunculin A, which inhibits the binding of thymosin β4 to actin, was found to profoundly affect the morphology and proliferation of the AdoMetDC transformants and to block their invasion in three-dimensional Matrigel. Thus, thymosin β4 is a determinant of AdoMetDC-induced transformed phenotype and invasiveness. Up-regulation of thymosin β4 was also found in ras-transformed fibroblasts and metastatic human melanoma cells. These data encourage testing latrunculin A–like and other agents interfering with thymosin β4 for treatment of thymosin β4–overexpressing tumors with high invasive and metastatic potential. (Cancer Res 2006; 66(2): 701-12)
Protein Kinase C-δ and Mitogen-Activated Protein/Extracellular Signal–Regulated Kinase-1 Control GLI Activation in Hedgehog Signaling
Authors: Riobo Natalia A. , Haines Gwendolyn M. , Emerson Charles P.
Published: January 2006

One third of all lethal cancers are associated with excessive activation of the Hedgehog (HH) pathway by mutations of its signaling components or by increased responsiveness of cells to the HH ligand. HH signaling through the GLI transcription factors leads to increased cell proliferation by up-regulation of the extracellular regulated kinase (ERK) pathway and by expression of S phase cyclins. In this study, we have tested the hypothesis that the HH pathway can integrate ERK signaling to modulate the activity of GLI. Using NIH 3T3 cells, we show that phorbol esters, acting through protein kinase C-δ (PKCδ) and mitogen-activated protein/extracellular signal–regulated kinase-1 (MEK-1), fully stimulate the transcriptional activity of endogenous and overexpressed GLI proteins, as assessed by GLI-luciferase reporter assays, and induce the expression of endogenous GLI1 and PTCH-1 target genes, as assessed by reverse transcription-PCR. Moreover, activation of GLI elicited by Sonic Hedgehog also requires PKCδ and MEK-1 function. Remarkably, coexpression of activated MEK-1 and GLI1 or GLI2 induced a 10-fold synergistic increase in GLI-luciferase activity that was totally blocked by PD98059. The NH2-terminal region of GLI1 (amino acids 1-130) is required for sensing the ERK pathway, as deletion of this domain produces active GLI1 protein with greatly reduced response to activation by MEK-1. Basic fibroblast growth factor activation of the ERK pathway also stimulated GLI1 activity through its NH2-terminal domain. Our results identify PKCδ and MEK-1 as essential, positive regulators of GLI-mediated HH signaling. Furthermore, our findings suggest that tumors with deregulated HH and ERK synergize to stimulate cell proliferation pathways. (Cancer Res 2006; 66(2): 839-45)
Chaperoning Function of Stress Protein grp170, a Member of the hsp70 Superfamily, Is Responsible for its Immunoadjuvant Activity
Authors: Park Jun-Eui , Facciponte John , Chen Xing , MacDonald Ian , Repasky Elizabeth A. , Manjili Masoud H. , Wang Xiang-Yang , Subjeck John R.
Published: January 2006

When used as vaccines, tumor-derived stress proteins can elicit antitumor immune responses. For members of the hsp70 superfamily, like grp170, this seems to be due to (a) the chaperoning of antigenic peptide by the stress protein and (b) the binding of the stress protein to receptor(s) on antigen-presenting cells (APC) and subsequent antigen presentation. This suggests that domains exist on the stress protein for each function. In this study, we determine the ability of grp170 and its structural domains to (a) bind to and present melanoma-associated antigen gp100 to the immune system and (b) to bind to receptors on APCs. A direct correlation between chaperone function, binding to APCs in a receptor-like manner, and antitumor immunity was observed. Two mutants that share no common sequence, yet are both effective in their antitumor activities, compete with one another for APC binding. Studies of other members of the hsp70 superfamily, hsp110 and hsp70, or their domain deletion mutants, further confirmed that APC binding segregates with chaperoning function and not sequence. Therefore, these studies suggest that molecular chaperoning is involved in stress protein interactions with APCs, antigen binding, and in eliciting antitumor immunity, thus bridging this ancient function of stress proteins in prokaryotes to their ability to elicit immunity in higher organisms. (Cancer Res 2006; 66(2): 1161-8)
DNA Methylation Alterations in the Pancreatic Juice of Patients with Suspected Pancreatic Disease
Authors: Matsubayashi Hiroyuki , Canto Marcia , Sato Norihiro , Klein Alison , Abe Tadayoshi , Yamashita Keishi , Yeo Charles J. , Kalloo Anthony , Hruban Ralph , Goggins Michael
Published: January 2006

Molecular markers of pancreatic neoplasia could aid in the evaluation of visible pancreatic lesions and indicate neoplasia invisible to imaging. We evaluated methylation-specific PCR (MSP) assays that detect aberrantly methylated DNA for their use as markers of pancreatic neoplasia. Methylation analysis was done on pancreatic juice collected endoscopically or surgically from 155 individuals with suspected pancreatic disease: 56 patients had pancreatic ductal adenocarcinoma, 17 had intraductal papillary mucinous neoplasms, 26 had symptomatic chronic pancreatitis, 12 controls lacked evidence of pancreatic disease, and 44 were asymptomatic individuals at increased risk of developing familial pancreatic cancer undergoing screening for pancreatic neoplasia. Pancreatic juice DNA was analyzed for promoter methylation using conventional MSP assays for 17 genes. For six genes, pancreatic juice methylation was quantified using real-time quantitative MSP (QMSP; Cyclin D2, FOXE1, NPTX2, ppENK, p16, and TFPI2). Quantifying pancreatic juice methylation using QMSP with a cutoff of >1% methylated DNA could better predict pancreatic cancer than detecting methylation using conventional MSP. In the endoscopic group, 9 of 11 patients with pancreatic cancer, but none of 64 individuals without neoplasia had ≥1% methylation for two or more of the best five QMSP assays (82% sensitivity and 100% specificity; P < 0.0001). The prevalence of pancreatic juice methylation in patients with chronic pancreatitis was less than in patients with pancreatic cancer but higher than in controls and similar to high-risk individuals. The detection and quantification of aberrantly methylated DNA in pancreatic juice is a promising approach to the diagnosis of pancreatic cancer. (Cancer Res 2006; 66(2): 1208-17)
Combined Inhibitory Effects of Curcumin and Phenethyl Isothiocyanate on the Growth of Human PC-3 Prostate Xenografts in Immunodeficient Mice
Authors: Khor Tin Oo , Keum Young-Sam , Lin Wen , Kim Jung-Hwan , Hu Rong , Shen Guoxiang , Xu Changjiang , Gopalakrishnan Avanthika , Reddy Bandaru , Zheng Xi , Conney Allan H. , Kong Ah-Ng Tony
Published: January 2006

Earlier studies using prostate cancer cells in culture showed that phenethyl isothiocyanate (PEITC) and curcumin have significant chemopreventive and possibly chemotherapeutic effects. However, their in vivo effects are still lacking. Hence, this study was undertaken to determine the possible in vivo efficacy of prostate cancer-prevention as well as cancer-therapeutic treatment by PEITC and curcumin alone or in combination. We evaluated the effects on tumor growth in vivo, using NCr immunodeficient (nu/nu) mice bearing s.c. xenografts of PC-3 human prostate cancer cells. Molecular biomarkers representing proliferation and apoptosis were determined. Continued i.p. injection of curcumin or PEITC (6 and 5 μmol; thrice a week for 28 days), beginning a day before tumor implantation significantly retarded the growth of PC-3 xenografts. Combination of i.p. administration of PEITC (2.5 μmol) and curcumin (3 μmol) showed stronger growth-inhibitory effects. Next, we evaluated the cancer-therapeutic potential of curcumin and PEITC in mice with well-established tumors, and the results showed that PEITC or curcumin alone had little effect, whereas combination of curcumin and PEITC significantly reduced the growth of PC-3 xenografts. Immunohistochemistry staining and Western blot analysis revealed that the inhibition of Akt and nuclear factor-κB signaling pathways could contribute to the inhibition of cell proliferation and induction of apoptosis. Taken together, our results show that PEITC and curcumin alone or in combination possess significant cancer-preventive activities in the PC-3 prostate tumor xenografts. Furthermore, we found that combination of PEITC and curcumin could be effective in the cancer-therapeutic treatment of prostate cancers. (Cancer Res 2006; 66(2): 613-21)
Angiostatin Is Directly Cytotoxic to Tumor Cells at Low Extracellular pH: A Mechanism Dependent on Cell Surface–Associated ATP Synthase
Authors: Chi Sulene L. , Pizzo Salvatore V.
Published: January 2006

Angiostatin, a proteolytic fragment of plasminogen, is a potent angiogenesis inhibitor able to suppress tumor growth and metastasis through inhibition of endothelial cell proliferation and migration. Previously, we showed that angiostatin binds and inhibits F1Fo ATP synthase on the endothelial cell surface and that anti-ATP synthase antibodies reduce endothelial cell proliferation. ATP synthase also occurs on the extracellular surface of a variety of cancer cells, where its function is as yet unknown. Here, we report that ATP synthase is present and active on the tumor cell surface, and angiostatin, or antibody directed against the catalytic β-subunit of ATP synthase, inhibits the activity of the synthase. We show that tumor cell surface ATP synthase is more active at low extracellular pH (pHe). Low pHe is a unique characteristic of the tumor microenvironment. Although the mechanism of action of angiostatin has not been fully elucidated, angiostatin treatment in combination with acidosis decreases the intracellular pH (pHi) of endothelial cells, leading to cell death. We also find that, at low pHe, angiostatin and anti-β-subunit antibody induce intracellular acidification of A549 cells, as well as a direct cytotoxicity that is absent in tumor cells with low levels of extracellular ATP synthase. These results establish angiostatin as an antitumorigenic and antiangiogenic agent through a mechanism implicating tumor cell surface ATP synthase. Furthermore, these data provide evidence that extracellular ATP synthase plays a role in regulating pHi in cells challenged by acidosis. (Cancer Res 2006; 66(2): 875-82)
Deregulation of the HOXA10 Homeobox Gene in Endometrial Carcinoma: Role in Epithelial-Mesenchymal Transition
Authors: Yoshida Hiroyuki , Broaddus Russell , Cheng Wenjun , Xie SuSu , Naora Honami
Published: January 2006

Homeobox genes encode transcription factors that control cell differentiation and play essential roles in developmental patterning. Increasing evidence indicates that many homeobox genes are aberrantly expressed in cancers, and that their deregulation significantly contributes to tumor progression. The homeobox gene HOXA10 controls uterine organogenesis during embryonic development and functional endometrial differentiation in the adult. We investigated whether HOXA10 expression is deregulated in endometrial carcinomas, and how counteracting this aberrant expression modifies tumor behavior. We found that down-regulation of HOXA10 expression in endometrial carcinomas strongly correlates with increased tumor grade and is associated with methylation of the HOXA10 promoter. Enforced expression of HOXA10 in endometrial carcinoma cells inhibited invasive behavior in vitro and tumor dissemination in nude mice. The inhibitory effect of HOXA10 on invasive behavior was attributable at least in part to the ability of HOXA10 to induce expression of the epithelial cell adhesion molecule E-cadherin by down-regulating expression of Snail, a repressor of E-cadherin gene transcription. These findings reveal a novel role for HOXA10 deregulation in the progression of endometrial carcinoma by promoting epithelial-mesenchymal transition. (Cancer Res 2006; 66(2): 889-97)
Tumor Cell Lines Expressing the Proteasome Subunit Isoform LMP7E1 Exhibit Immunoproteasome Deficiency
Authors: Heink Sylvia , Fricke Benjamin , Ludwig Daniela , Kloetzel Peter-M. , Krüger Elke
Published: January 2006

The immune system can recognize antigenic peptides derived from tumors by their presentation on MHC class I complexes to CTLs. Immunoproteasomes (i20S) can substantially enhance the MHC class I peptide repertoire, making down-regulation of i20S an important strategy of tumor cells in manipulating immune surveillance. Here, we report that human cancer cells express the nonfunctional immunosubunit-variant LMP7E1, in addition to, or instead of LMP7E2, in response to IFN-γ. This preferential expression of LMP7E1 and the consequent down-regulation of LMP7E2 results in i20S deficiency. The molecular explanation for this phenomenon is the incapacity of LMP7E1 to interact efficiently with the proteasome maturation protein, which regularly recruits LMP7E2 into nascent i20S precursor complexes. In contrast to previous reports, i20S formation in these cancer cells cannot be restored by IFN-γ treatment. However, expression of LMP7E2 in these cells restores the i20S-deficient phenotype. Thus, our data describe a novel mechanism that contributes to the process of oncogenesis. (Cancer Res 2006; 66(2):649-52)
OSI-930: A Novel Selective Inhibitor of Kit and Kinase Insert Domain Receptor Tyrosine Kinases with Antitumor Activity in Mouse Xenograft Models
Authors: Garton Andrew J. , Crew Andrew P.A. , Franklin Maryland , Cooke Andrew R. , Wynne Graham M. , Castaldo Linda , Kahler Jennifer , Winski Shannon L. , Franks April , Brown Eric N. , Bittner Mark A. , Keily John F. , Briner Paul , Hidden Chris , Srebernak Mary C. , Pirrit Carrie , O'Connor Matthew , Chan Anna , Vulevic Bojana , Henninger Dwight , Hart Karen , Sennello Regina , Li An-Hu , Zhang Tao , Richardson Frank , Emerson David L. , Castelhano Arlindo L. , Arnold Lee D. , Gibson Neil W.
Published: January 2006

OSI-930 is a novel inhibitor of the receptor tyrosine kinases Kit and kinase insert domain receptor (KDR), which is currently being evaluated in clinical studies. OSI-930 selectively inhibits Kit and KDR with similar potency in intact cells and also inhibits these targets in vivo following oral dosing. We have investigated the relationships between the potency observed in cell-based assays in vitro, the plasma exposure levels achieved following oral dosing, the time course of target inhibition in vivo, and antitumor activity of OSI-930 in tumor xenograft models. In the mutant Kit–expressing HMC-1 xenograft model, prolonged inhibition of Kit was achieved at oral doses between 10 and 50 mg/kg and this dose range was associated with antitumor activity. Similarly, prolonged inhibition of wild-type Kit in the NCI-H526 xenograft model was observed at oral doses of 100 to 200 mg/kg, which was the dose level associated with significant antitumor activity in this model as well as in the majority of other xenograft models tested. The data suggest that antitumor activity of OSI-930 in mouse xenograft models is observed at dose levels that maintain a significant level of inhibition of the molecular targets of OSI-930 for a prolonged period. Furthermore, pharmacokinetic evaluation of the plasma exposure levels of OSI-930 at these effective dose levels provides an estimate of the target plasma concentrations that may be required to achieve prolonged inhibition of Kit and KDR in humans and which would therefore be expected to yield a therapeutic benefit in future clinical evaluations of OSI-930. (Cancer Res 2006; 66(2): 1015-24)
Critical Roles for Polymerase ζ in Cellular Tolerance to Nitric Oxide–Induced DNA Damage
Authors: Wu Xiaohua , Takenaka Katsuya , Sonoda Eiichiro , Hochegger Helfrid , Kawanishi Shosuke , Kawamoto Takuo , Takeda Shunichi , Yamazoe Mitsuyoshi
Published: January 2006

Nitric oxide (NO), a signal transmitter involved in inflammation and regulation of smooth muscle and neurons, seems to cause mutagenesis, but its mechanisms have remained elusive. To gain an insight into NO-induced genotoxicity, we analyzed the effect of NO on a panel of chicken DT40 clones deficient in DNA repair pathways, including base and nucleotide excision repair, double-strand break repair, and translesion DNA synthesis (TLS). Our results show that cells deficient in Rev1 and Rev3, a subunit essential for DNA polymerase ζ (Polζ), are hypersensitive to killing by two chemical NO donors, spermine NONOate and S-nitroso-N-acetyl-penicillamine. Mitotic chromosomal analysis indicates that the hypersensitivity is caused by a significant increase in the level of induced chromosomal breaks. The data reveal the critical role of TLS polymerases in cellular tolerance to NO-induced DNA damage and suggest the contribution of these error-prone polymerases to accumulation of single base substitutions. (Cancer Res 2006; 66(2): 748-54)
Cranking the Immunologic Engine with Chemotherapy: Using Context to Drive Tumor Antigen Cross-Presentation towards Useful Antitumor Immunity
Authors: van der Most Robbert G. , Currie Andrew , Robinson Bruce W.S. , Lake Richard A.
Published: January 2006

This review shows how tumor antigen cross-presentation is affected by the major therapeutic modalities including chemotherapy, radiotherapy, and surgery. We argue that this process could affect the way that a tumor works as its own cellular vaccine, and that it is differentially modulated by the choice of treatment. (Cancer Res 2006; 66(2): 601-4)
The P2X7 Receptor Sustains the Growth of Human Neuroblastoma Cells through a Substance P–Dependent Mechanism
Authors: Raffaghello Lizzia , Chiozzi Paola , Falzoni Simonetta , Di Virgilio Francesco , Pistoia Vito
Published: January 2006

P2X7 is a receptor for extracellular nucleotides expressed by different normal cell types. P2X7 triggering may result in stimulation of cell proliferation or induction of apoptosis depending on the level of activation. P2X7 expression and function in B-cell chronic lymphocytic leukemia has been shown to correlate with disease severity. Here, we have asked the question of whether P2X7 is expressed and functional in neuroblastoma, a pediatric tumor of neuroectodermal origin. P2X7 was detected both in primary neuroblastoma tumors and in neuroblastoma cell lines. In the latter cells, P2X7 stimulation by ATP was found to trigger (a) increased intracellular calcium fluxes, (b) plasma membrane depolarization, and (c) formation of a nonselective plasma membrane permeable pore. In contrast to the usual response typically observed in the majority of cell types, P2X7 in vitro stimulation did not induce caspase-3 activation or apoptosis of neuroblastoma cells but rather supported their proliferation. Growth stimulation was partially due to substance P release from nucleotide-activated neuroblastoma cells. Therefore, neuroblastoma cells seem to have molded P2X7 function to their advantage in two ways (i.e., by silencing P2X7 proapoptotic activity and by coupling P2X7 stimulation to release of locally acting trophic factors). (Cancer Res 2006; 66(2): 907-14)
Prostaglandin E2 Impairs CD4+ T Cell Activation by Inhibition of lck: Implications in Hodgkin's Lymphoma
Authors: Chemnitz Jens M. , Driesen Julia , Classen Sabine , Riley James L. , Debey Svenja , Beyer Marc , Popov Alexey , Zander Thomas , Schultze Joachim L.
Published: January 2006

Many tumors, including Hodgkin's lymphoma, are associated with decreased cellular immunity and elevated levels of prostaglandin E2 (PGE2), a known inhibitor of CD4+ T cell activation, suggested to be involved in immune deviation in cancer. To address the molecular mechanisms tumor-derived PGE2 might have on primary human CD4+ T cells, we used a whole genome-based transcriptional approach and show that PGE2 severely limited changes of gene expression induced by signaling through the T cell receptor and CD28. This data suggests an interference of PGE2 at an early step of T cell receptor signaling: indeed, PGE2 stimulation of T cells leads to inactivation of lck and reduced phosphorylation of ZAP70. Antiapoptotic genes escaped PGE2-induced inhibition resulting in partial protection from apoptosis in response to irradiation or Fas-mediated signaling. As a functional consequence, PGE2-treated CD4+ T cells are arrested in the cell cycle associated with up-regulation of the cyclin/cyclin-dependent kinase inhibitor p27kip1. Most importantly, CD4+ T cells in Hodgkin's lymphoma show similar regulation of genes that were altered in vitro by PGE2 in T cells from healthy individuals. These data strongly suggest that PGE2 is an important factor leading to CD4+ T cell impairment observed in Hodgkin's lymphoma. (Cancer Res 2006; 66(2): 1114-22)
In utero Exposure of Mice to Dibenzo[a,l]Pyrene Produces Lymphoma in the Offspring: Role of the Aryl Hydrocarbon Receptor
Authors: Yu Zhen , Loehr Christiane V. , Fischer Kay A. , Louderback Mandy A. , Krueger Sharon K. , Dashwood Roderick H. , Kerkvliet Nancy I. , Pereira Clifford B. , Jennings-Gee Jamie E. , Dance Stephanie T. , Miller Mark Steven , Bailey George S. , Williams David E.
Published: January 2006

Lymphoma and leukemia are the most common cancers in children and young adults; in utero carcinogen exposure may contribute to the etiology of these cancers. A polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP), was given to pregnant mice (15 mg/kg body weight, gavage) on gestation day 17. Significant mortalities in offspring, beginning at 12 weeks of age, were observed due to an aggressive T-cell lymphoblastic lymphoma. Lymphocytes invaded numerous tissues. All mice surviving 10 months, exposed in utero to DBP, exhibited lung tumors; some mice also had liver tumors. To assess the role of the aryl hydrocarbon receptor (AHR) in DBP transplacental cancer, B6129SF1/J (AHRb-1/d, responsive) mice were crossed with strain 129S1/SvIm (AHRd/d, nonresponsive) to determine the effect of maternal and fetal AHR status on carcinogenesis. Offspring born to nonresponsive mothers had greater susceptibility to lymphoma, irrespective of offspring phenotype. However, when the mother was responsive, an AHR-responsive phenotype in offspring increased mortality by 2-fold. In DBP-induced lymphomas, no evidence was found for TP53, β-catenin, or Ki-ras mutations but lung adenomas of mice surviving to 10 months of age had mutations in Ki-ras codons 12 and 13. Lung adenomas exhibited a 50% decrease and a 35-fold increase in expression of Rb and p19/ARF mRNA, respectively. This is the first demonstration that transplacental exposure to an environmental PAH can induce a highly aggressive lymphoma in mice and raises the possibility that PAH exposures to pregnant women could contribute to similar cancers in children and young adults. (Cancer Res 2006; 66(2): 755-62)
Effect of Rapamycin on Mouse Chronic Lymphocytic Leukemia and the Development of Nonhematopoietic Malignancies in Eμ-TCL1 Transgenic Mice
Authors: Zanesi Nicola , Aqeilan Rami , Drusco Alessandra , Kaou Mohamed , Sevignani Cinzia , Costinean Stefan , Bortesi Laura , La Rocca Gaspare , Koldovsky Pavel , Volinia Stefano , Mancini Rita , Calin George , Scott Charles P. , Pekarsky Yuri , Croce Carlo M.
Published: January 2006

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the world. The TCL1 gene, responsible for prolymphocytic T cell leukemia, is also overexpressed in human B cell malignancies and overexpression of the Tcl1 protein occurs frequently in CLL. Aging transgenic mice that overexpress TCL1 under control of the μ immunoglobulin gene enhancer, develop a CD5+ B cell lymphoproliferative disorder mimicking human CLL and implicating TCL1 in the pathogenesis of CLL. In the current study, we exploited this transgenic mouse to investigate two different CLL-related issues: potential treatment of CLL and characterization of neoplasms that accompany CLL. We successfully transplanted CLL cells into syngeneic mice that led to CLL development in the recipient mice. This approach allowed us to verify the involvement of the Tcl1/Akt/mTOR biochemical pathway in the disease by testing the ability of a specific pharmacologic agent, rapamycin, to slow CLL. We also showed that 36% of these transgenic mice were affected by solid malignancies, in which the expression of the Tcl1 protein was absent. These findings indicate that other oncogenic mechanism(s) may be involved in the development of solid tumors in Eμ-TCL1 transgenic mice. (Cancer Res 2006: 66(2): 915–20)
Altered Expression and Localization of Creatine Kinase B, Heterogeneous Nuclear Ribonucleoprotein F, and High Mobility Group Box 1 Protein in the Nuclear Matrix Associated with Colon Cancer
Authors: Balasubramani Manimalha , Day Billy W. , Schoen Robert E. , Getzenberg Robert H.
Published: January 2006

Identification of biomarkers could lead to the development of effective screening tests for colorectal cancer. A previous study from our laboratory showed specific alterations of nuclear structure in colon cancer. In an effort to characterize these biomarkers, protein spots were selected from separations made by two-dimensional gel electrophoresis, which were analyzed by mass spectrometry. The sequences obtained from the isolated spots revealed that they have close similarity to creatine kinase B (CKB) isoforms, heterogeneous nuclear ribonucleoprotein F (hnRNP F) and high mobility group box 1 protein (HMGB1) isoforms. To determine the expression of these proteins in colon cancer, expression was studied in 9 tumor and matched adjacent normal pairs, 5 donor colons, 16 polyps, 4 metastatic liver lesions and matched adjacent normal pairs, and 3 liver donors. CKB and hnRNP F were expressed in 78% and 89% of colon tumors, respectively. hnRNP F had a higher frequency of expression than CKB in premalignant polyps. With the establishment of differential expression of the proteins in colon cancer, their subcellular localization was analyzed. The subcellular fractions studied both showed high protein levels of hnRNP F in colon tumors compared with normal colon tissues. Surprisingly, subcellular levels of CKB were decreased in colon tumors, suggesting that the observed high CKB levels in nuclear matrix extracts are caused by the enhanced localization of CKB to the nuclear matrix during colon tumorigenesis. These results suggest an involvement of hnRNP F and CKB in colorectal cancer. Additionally, they suggest that hnRNP F is a potential marker for colorectal cancer progression. (Cancer Res 2006; 66(2): 763-9)
Frontline Therapy with Early Intensification and Autologous Stem Cell Transplantation versus Conventional Chemotherapy in Unselected High-Risk, Aggressive Non-Hodgkin’s Lymphoma Patients: A Prospective Randomized GEMOH Report
Authors: Baldissera R.C. , Nucci M. , Vigorito A.C. , Maiolino A. , Simões B.P. , Lorand-Metze I. , Aranha F.J.P. , Miranda E.C.M. , Pagnano K.B.B. , Ruiz M.A. , Moraes A.A.J.G. , de Souza C.A.
Published: January 2006

This prospective multicenter randomized trial compares conventional with early intensification with high-dose sequential chemotherapy (HDS) and autologous stem cell transplantation (ASCT) as frontline therapy in high-risk non-Hodgkin lymphomas (NHL). Newly diagnosed patients with aggressive high-risk [intermediate-high (HI) and high-risk (HR)] NHL according to the international prognosis index (IPI) were randomized to receive 12-week VACOP-B (arm A, 27 patients) or 6-week VACOP-B followed by HDS and ASCT (arm B, 29 patients). Complete remission rate was52% in arm A and 55% in B. Nine patients (16%) died early due to progression. According to intention-to-treat, with a median follow-up of 23 months, the 5-year actuarial overall survival, progression-free survival and disease-free survival in arms A and B were 47 and 40% (p = nonsignificant), 47 and 30% (p = nonsignificant), and 97 and 47% (p = 0.02), respectively. Abbreviated chemotherapy followed by intensification with HDS-ASCT does not seem to be superior to conventional chemotherapy in HI/HR aggressive NHL.
Costs of Chemotherapy for Indolent Follicular Non-Hodgkin’s Lymphoma in the UK: An Observational Study
Authors: Hutchinson Julia , Lloyd Adam , Gray Alastair , Gale Rupert , Hancock Barry
Published: January 2006

Non-Hodgkin’s lymphoma (NHL) is the sixth most common cancer in the United Kingdom (UK). This analysis assessed the health service costs of patients receiving chemotherapy for indolent follicular NHL based on a retrospective analysis of patient records in the UK. Each patient was followed up for a period of 3 years or until death. The analysis included 181 patients, who received a total of 187 treatment periods. Costs were estimated from the perspective of the UK National Health Service. The study found the cost of providing treatment with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) or fludarabine to patients with indolent follicular NHL to be lower than previously reported.
Side Effects of Oral Iron Prophylaxis in Pregnancy – Myth or Reality?
Authors: Milman Nils , Byg Keld-Erik , Bergholt Thomas , Eriksen Lisbeth
Published: January 2006

Background: It is a common belief among women that iron compounds have unpleasant gastrointestinal side effects. Objective: To assess the gastrointestinal side effects of iron prophylaxis in pregnancy. Methods: A randomized, double-blind study comprising 404 healthy pregnant women allocated to four groups taking ferrous iron supplement (as fumarate) in doses of 20 (n = 99), 40 (n = 100), 60 (n = 102) and 80 mg (n = 103) daily from 18 weeks of gestation to delivery. Iron supplement was predominantly taken at bedtime. Gastrointestinal symptoms (nausea, vomiting, epigastric pain, eructation, pyrosis, meteorism, borborygmi, colic pain, flatulence, constipation, thin feces, diarrhea), black feces, and use of laxatives were recorded by interview at 18, 32 and 39 weeks of gestation. Results: The frequencies of gastrointestinal symptoms were not significantly different in the four iron supplement groups either at inclusion or at 32 and 39 weeks of gestation and thus not related to the iron dose. Conclusion: This study shows that a supplement of 20–80 mg ferrous iron (as fumarate), taken between meals, has no clinically significant gastrointestinal side effects. The implementation of iron prophylaxis to pregnant women should not be compromised by undue concern of non-existing side effects.
Pregnancy and Oral Contraceptives in Congenital Bleeding Disorders of the Vitamin K- Dependent Coagulation Factors
Authors: Girolami Antonio , Randi Maria Luigia , Ruzzon Elisabetta , Lombardi Anna Maria , Girolami Bruno , Fabris Fabrizio
Published: January 2006

Pregnancies and deliveries represent important hemostatic challenges for congenital coagulation disorders. The same is true for the assumption of oral contraceptives. Available information mainly deals with von Willebrand’s disease, factor XI (FXI) deficiency and carriers of hemophilia A. Data concerning patients with congenital prothrombin complex factor deficiencies are very scanty. In the present study, data of a total of 27 women are presented, 11 patients with homozygous or double heterozygous deficiencies of FII, FVII and FX, together with 16 cases of hemophilia B carriers. The patients with FII, FVII or FX defects had a total of 14 pregnancies and often needed transfusion therapy. Proper management resulted in a decrease in postpartum bleeding and satisfactory fetal outcome. Elective cesarean delivery seems indicated only in recent years. Carriers of hemophilia B had a total of 19 pregnancies but showed no bleeding and needed no substitutive therapy. Searching the literature, we discovered only 9 additional patients with prothrombin deficiency or FX deficiency, having a total of 16 pregnancies. On the contrary, there were at least 17 additional patients with FVII deficiency, with a total of 21 pregnancies. The management of the diseases has been variable, but in substantial agreement with the personal observations. Oral contraceptive therapy was administered in some of our patients and in a few additional cases described in the literature. Medication was always well tolerated and patients who took it for a long period of time showed a decrease in menometrorrhagia and an improvement in hematocrit levels. This led to a decrease in transfusional needs and to improved general conditions.
Von Willebrand Factor 1 and Factor 2 Alleles (Intron 40) Are Suitable Markers for Carrier Detection in von Willebrand Disease Families in the Indian Population
Authors: Trasi Sucheta , Mohanty Dipika , Pathare Anil , Shetty Shrimati , Ghosh Kanjaksha
Published: January 2006

The efficacy of the two von Willebrand factor (vWF) intron 40 variable number of tandem repeat (VNTR) markers, vWF1 and vWF2, in the genetic diagnosis of von Willebrand disease (vWD) in Indian patients was studied. Three hundred and sixty-five unrelated normal individuals and 100 vWD patients (type 1: 18; type 2: 21; type 3: 61) were analyzed for the two vWF intron 40 VNTR markers. Polymerase chain reaction of the two markers vWF1 and vWF2 was done using specific primers followed by electrophoresis on 10% polyacrylamide gel. VNTR analysis revealed the presence of VNTR9 and VNTR15 along with the eight alleles VNTR6 to VNTR14 in the vWF1 marker. Furthermore, apart from the six alleles, VNTR1 to VNTR6 of the vWF2 marker, two new alleles, VNTR7 and VNTR8, were also found. The heterozygosity rates were 75 and 74% for vWF1 and vWF2, respectively. Overall, the heterozygosity rate, i.e. when both vWF1 and vWF2 were considered in combination, was 81%. These data were successfully applied for the detection of carriers in 10 severe type 3 vWD families. The high heterozygosity of the two vWF intron 40 VNTR markers and the simplicity of the technique without much cost being involved suggest the practical feasibility of this technique in developing countries like India.
Thrombotic Thrombocytopenic Purpura Associated with Systemic Lupus Erythematosus
Authors: Aleem Aamer , Al-Sugair Saleh
Published: January 2006

Thrombotic thrombocytopenic purpura (TTP) occurring in patients with systemic lupus erythematosus (SLE) is rare and can be difficult to diagnose because of overlapping features of the two disorders. The aim of this study is to further characterize this uncommon association in terms of presenting features, diagnostic difficulties and treatment outcome. This is the largest series from a single centre with 6 patients diagnosed over a 6-year period. Two thirds of the patients had a simultaneous diagnosis of TTP and SLE. Half of the patients had a positive Coombs test along with clear features of TTP. Five patients received plasmapheresis as initial treatment while 1 patient received plasma infusions only. Four out of 5 patients responded to plasmapheresis and only 1 patient required cytotoxic therapy. TTP in association with SLE appears to be underdiagnosed and a positive Coombs test is not against the diagnosis of TTP in this setting. Most of the patients respond well to plasmapheresis. In case of a poor response, cytotoxic drugs should be considered early.
Aberrant CD8 Expression in B-Chronic Lymphocytic Leukemia: Report of Five Cases
Authors: Parisi-Duchêne E. , Mazurier I. , Moskovtchenko P.
Published: January 2006

The expression of T cell-associated antigens on B cell non-Hodgkin lymphoma is rare. We describe 5 cases of B-chronic lymphocytic leukemia (B-CLL) with aberrant expression of CD8 on B cells. These B-CLL presented a typical immunophenotype CD19+, CD23+, FMC7– and CD5+ (except for 1 case) with a monotypic expression of surface immunoglobulin light chain kappa. The CD8 expression was confirmed on B-CLL cells by two-color flow cytometry staining. We could not find coexpression of CD3 or CD4 on B-CLL cells. The clinical implications, the sensitivity to therapy and the prognostic outcome of this aberrant expression remains to be determined.
Hemochromatosis and Severe Iron Overload Associated with Compound Heterozygosity for TFR2 R455Q and Two Novel Mutations TFR2 R396X and G792R
Authors: Lee Pauline L. , Barton James C.
Published: January 2006

We report three mutations of transferrin receptor 2 (TFR2) – R396X (exon 9; nt 1186C→T), R455Q (exon 10; nt 1364G→A) and G792R (exon 18; nt 2374G→A) – in a man of Scottish descent with hemochromatosis and severe iron overload. He was also heterozygous for the common HFE H63D polymorphism. The patient did not have coding region mutations in HAMP,FPN1,HJV or ALAS2. We conclude that this patient represents another example of hemochromatosis due to mutations of the gene encoding transferrin receptor 2.
A Juvenile Hemochromatosis Patient Homozygous for a Novel Deletion of cDNA Nucleotide 81 of Hemojuvelin
Authors: Lee Pauline , Promrat Kittichai , Mallette Carol , Flynn Maura , Beutler Ernest
Published: January 2006

Background: A 25-year-old woman of English/Irish background was diagnosed with hemochromatosis. She manifested hypogonadotrophic hypogonadism and congestive heart failure. Although there were abnormal liver function tests, no cirrhosis was present. The patient has been treated intermittently by phlebotomy for 24 years. The aim of this study was to investigate the genetic basis of the patient’s iron overload disease. Methods: Genetic analysis was performed by direct sequencing of the genes for hemojuvelin, HFE, hepcidin, fer- roportin and transferrin receptor 2. Results and Con clusions: Molecular analysis showed that the patient was homozygous for a previously undescribed mutation of HJV, the gene encoding hemojuvelin. This mutation, nt 81G deletion, causes a frameshift encoding 23 additional irrelevant amino acids and premature termination. No mutations were found in the other hemochromatosis genes, hepcidin, HFE, ferroportin or transferrin receptor 2, which might have contributed to her iron overload.
Ser/Thr/Tyr Protein Phosphorylation in Bacteria – For Long Time Neglected, Now Well Established
Authors: Deutscher Josef , Saier Jr. Milton H.
Published: January 2006

The first clearly established example of Ser/Thr/Tyr phosphorylation of a bacterial protein was isocitrate dehydrogenase. In 1979, 25 years after the discovery of protein phosphorylation in eukaryotes, this enzyme was reported to become phosphorylated on a serine residue. In subsequent years, numerous other bacterial proteins phosphorylated on Ser, Thr or Tyr were discovered and the corresponding protein kinases and P-protein phosphatases were identified. These protein modifications regulate all kinds of physiological processes. Ser/Thr/Tyr phosphorylation in bacteria therefore seems to play a similar important role as in eukaryotes. Surprisingly, many bacterial protein kinases do not exhibit any similarity to eukaryotic protein kinases, but rather resemble nucleotide-binding proteins or kinases phosphorylating diverse low-molecular-weight substrates.