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Showing papers by "University of Texas Southwestern Medical Center published in 2001"


Journal ArticleDOI
Eric S. Lander1, Lauren Linton1, Bruce W. Birren1, Chad Nusbaum1  +245 moreInstitutions (29)
15 Feb 2001-Nature
TL;DR: The results of an international collaboration to produce and make freely available a draft sequence of the human genome are reported and an initial analysis is presented, describing some of the insights that can be gleaned from the sequence.
Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

22,269 citations


Journal ArticleDOI
TL;DR: Nonenzymatic mechanisms that impact MAP kinase functions and findings from gene disruption studies are highlighted and particular emphasis is on ERK1/2.
Abstract: Mitogen-activated protein (MAP) kinases comprise a family of ubiquitous proline-directed, protein-serine/threonine kinases, which participate in signal transduction pathways that control intracellular events including acute responses to hormones and major developmental changes in organisms. MAP kinases lie in protein kinase cascades. This review discusses the regulation and functions of mammalian MAP kinases. Nonenzymatic mechanisms that impact MAP kinase functions and findings from gene disruption studies are highlighted. Particular emphasis is on ERK1/2.

4,040 citations


Journal ArticleDOI
09 Nov 2001-Science
TL;DR: In cultured mammalian cells, inappropriate accumulation of HIF caused by forced expression of the HIF-1α subunit under normoxic conditions was attenuated by coexpression of HPH, indicating that HPH is an essential component of the pathway through which cells sense oxygen.
Abstract: Mammalian cells respond to changes in oxygen availability through a conserved pathway that is regulated by the hypoxia-inducible factor (HIF). The alpha subunit of HIF is targeted for degradation under normoxic conditions by a ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF. We identified a conserved family of HIF prolyl hydoxylase (HPH) enzymes that appear to be responsible for this posttranslational modification. In cultured mammalian cells, inappropriate accumulation of HIF caused by forced expression of the HIF-1α subunit under normoxic conditions was attenuated by coexpression of HPH. Suppression of HPH in cultured Drosophila melanogaster cells by RNA interference resulted in elevated expression of a hypoxia-inducible gene (LDH, encoding lactate dehydrogenase) under normoxic conditions. These findings indicate that HPH is an essential component of the pathway through which cells sense oxygen.

2,453 citations


Journal Article
TL;DR: The complexity of the apoptotic program began to increase with the discovery of Bcl-2, a gene whose product causes resistance to apoptosis in lymphocytes, and the complex role of mitochondria in apoptosis came into focus when biochemical studies identified several mitochondrial proteins that are able to activate cellular apoptotic programs directly.
Abstract: The initial insight into the genetic basis of apoptosis, or programmed cell death, was gained from ingenious studies of the roundworm Caenorhabditis elegans (for review, see Horvitz 1999). These studies revealed a linear pathway whereby the products of two genes, designated Ced-3 andCed-4, were necessary and sufficient to trigger the perfectly timed and orchestrated death of 131 preordained cells during development. The relevance of this pathway to higher animals was established by the discovery of apparent mammalian orthologs of these genes and the demonstration that the mammalian Ced-3-related genes encode proteases (designated caspases) whose activities are responsible for the morphological changes characteristic of apoptosis (for review, see Hengartner 2000). The complexity of the apoptotic program began to increase with the discovery of Bcl-2, a gene whose product causes resistance to apoptosis in lymphocytes (Vaux et al. 1988; McDonnell et al. 1989). Bcl-2 was shown to correct partially the phenotype of a C. elegans mutation in Ced-9, a cell survival gene that functions upstream of Ced-4 and Ced-3 (Vaux et al. 1992). This finding suggested an apparent one-for-one correlation between the C. elegans and mammalian proand antiapoptotic pathways. However, this correlation did not explain two observations made in mammalian cells. First, the Bcl-2 protein was found on the membrane of mitochondria, which were not implicated in C. elegans apoptosis; and second, apoptotic changes could be produced in Xenopus laevis oocyte extracts only when a membrane fraction enriched in mitochondria was present (Hockenberry et al. 1990; Newmeyer et al. 1994). The complex role of mitochondria in mammalian cell apoptosis came into focus when biochemical studies identified several mitochondrial proteins that are able to activate cellular apoptotic programs directly (Liu et al. 1996; Susin et al. 1999; Du et al. 2000; Verhagen et al. 2000; Li et al. 2001). Normally, these proteins reside in the intermembrane space of mitochondria. In response to a variety of apoptotic stimuli, they are released to the cytosol and/or the nucleus. They promote apoptosis either by activating caspases and nucleases or by neutralizing cytosolic inhibitors of this process. A complex picture has emerged in which mitochondrial and cytosolic proapoptotic proteins interact with antiapoptotic proteins with each cell’s life or death hanging in the balance. This review summarizes the recent data on the expanding and complex role of mitochondria in apoptosis.

2,439 citations


Journal ArticleDOI
19 Jul 2001-Nature
TL;DR: The purification and identification of TRIKA2, which is composed of TAK1, TAB1 and TAB2, a protein kinase complex previously implicated in IKK activation through an unknown mechanism, indicate that ubiquitination has an important regulatory role in stress response pathways, including those of IKK and JNK.
Abstract: TRAF6 is a signal transducer that activates IkappaB kinase (IKK) and Jun amino-terminal kinase (JNK) in response to pro-inflammatory mediators such as interleukin-1 (IL-1) and lipopolysaccharides (LPS). IKK activation by TRAF6 requires two intermediary factors, TRAF6-regulated IKK activator 1 (TRIKA1) and TRIKA2 (ref. 5). TRIKA1 is a dimeric ubiquitin-conjugating enzyme complex composed of Ubc13 and Uev1A (or the functionally equivalent Mms2). This Ubc complex, together with TRAF6, catalyses the formation of a Lys 63 (K63)-linked polyubiquitin chain that mediates IKK activation through a unique proteasome-independent mechanism. Here we report the purification and identification of TRIKA2, which is composed of TAK1, TAB1 and TAB2, a protein kinase complex previously implicated in IKK activation through an unknown mechanism. We find that the TAK1 kinase complex phosphorylates and activates IKK in a manner that depends on TRAF6 and Ubc13-Uev1A. Moreover, the activity of TAK1 to phosphorylate MKK6, which activates the JNK-p38 kinase pathway, is directly regulated by K63-linked polyubiquitination. We also provide evidence that TRAF6 is conjugated by the K63 polyubiquitin chains. These results indicate that ubiquitination has an important regulatory role in stress response pathways, including those of IKK and JNK.

2,075 citations


Journal ArticleDOI
30 Nov 2001-Science
TL;DR: Some general principles that govern the actions of this class of bioactive lipids and their nuclear receptors are considered here, and the scheme that emerges reveals a complex molecular script at work.
Abstract: Cholesterol, fatty acids, fat-soluble vitamins, and other lipids present in our diets are not only nutritionally important but serve as precursors for ligands that bind to receptors in the nucleus. To become biologically active, these lipids must first be absorbed by the intestine and transformed by metabolic enzymes before they are delivered to their sites of action in the body. Ultimately, the lipids must be eliminated to maintain a normal physiological state. The need to coordinate this entire lipid-based metabolic signaling cascade raises important questions regarding the mechanisms that govern these pathways. Specifically, what is the nature of communication between these bioactive lipids and their receptors, binding proteins, transporters, and metabolizing enzymes that links them physiologically and speaks to a higher level of metabolic control? Some general principles that govern the actions of this class of bioactive lipids and their nuclear receptors are considered here, and the scheme that emerges reveals a complex molecular script at work.

2,008 citations


Journal ArticleDOI
05 Jul 2001-Nature
TL;DR: The identification and characterization of another nuclease that is specifically activated by apoptotic stimuli and is able to induce nucleosomal fragmentation of DNA in fibroblast cells from embryonic mice lacking DFF is reported.
Abstract: Nucleosomal fragmentation of DNA is a hallmark of apoptosis (programmed cell death), and results from the activation of nucleases in cells undergoing apoptosis. One such nuclease, DNA fragmentation factor (DFF, a caspase-activated deoxyribonuclease (CAD) and its inhibitor (ICAD)), is capable of inducing DNA fragmentation and chromatin condensation after cleavage by caspase-3 (refs 2,3,4). However, although transgenic mice lacking DFF45 or its caspase cleavage site have significantly reduced DNA fragmentation, these mice still show residual DNA fragmentation and are phenotypically normal. Here we report the identification and characterization of another nuclease that is specifically activated by apoptotic stimuli and is able to induce nucleosomal fragmentation of DNA in fibroblast cells from embryonic mice lacking DFF. This nuclease is endonuclease G (endoG), a mitochondrion-specific nuclease that translocates to the nucleus during apoptosis. Once released from mitochondria, endoG cleaves chromatin DNA into nucleosomal fragments independently of caspases. Therefore, endoG represents a caspase-independent apoptotic pathway initiated from the mitochondria.

1,798 citations


Journal ArticleDOI
13 Sep 2001-Nature
TL;DR: The results implicate PGC-1 as a key modulator of hepatic gluconeogenesis and as a central target of the insulin–cAMP axis in liver.
Abstract: Blood glucose levels are maintained by the balance between glucose uptake by peripheral tissues and glucose secretion by the liver. Gluconeogenesis is strongly stimulated during fasting and is aberrantly activated in diabetes mellitus. Here we show that the transcriptional coactivator PGC-1 is strongly induced in liver in fasting mice and in three mouse models of insulin action deficiency: streptozotocin-induced diabetes, ob/ob genotype and liver insulin-receptor knockout. PGC-1 is induced synergistically in primary liver cultures by cyclic AMP and glucocorticoids. Adenoviral-mediated expression of PGC-1 in hepatocytes in culture or in vivo strongly activates an entire programme of key gluconeogenic enzymes, including phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase, leading to increased glucose output. Full transcriptional activation of the PEPCK promoter requires coactivation of the glucocorticoid receptor and the liver-enriched transcription factor HNF-4alpha (hepatic nuclear factor-4alpha) by PGC-1. These results implicate PGC-1 as a key modulator of hepatic gluconeogenesis and as a central target of the insulin-cAMP axis in liver.

1,797 citations


Journal ArticleDOI
TL;DR: There has been considerable progress in identifying the mechanisms that contribute to long-lived neural and behavioural plasticity related to addiction, including drug-induced changes in gene transcription, in RNA and protein processing, and in synaptic structure.
Abstract: Studies of human addicts and behavioural studies in rodent models of addiction indicate that key behavioural abnormalities associated with addiction are extremely long lived. So, chronic drug exposure causes stable changes in the brain at the molecular and cellular levels that underlie these behavioural abnormalities. There has been considerable progress in identifying the mechanisms that contribute to long-lived neural and behavioural plasticity related to addiction, including drug-induced changes in gene transcription, in RNA and protein processing, and in synaptic structure. Although the specific changes identified so far are not sufficiently long lasting to account for the nearly permanent changes in behaviour associated with addiction, recent work has pointed to the types of mechanism that could be involved.

1,688 citations


Journal ArticleDOI
TL;DR: This review will highlight the origin and unique markers of the satellite cell population, the regulation by growth factors, and the response to physiological and pathological stimuli, and identify future research goals for the study of satellite cell biology.
Abstract: Adult skeletal muscle has a remarkable ability to regenerate following myotrauma. Because adult myofibers are terminally differentiated, the regeneration of skeletal muscle is largely dependent on a small population of resident cells termed satellite cells. Although this population of cells was identified 40 years ago, little is known regarding the molecular phenotype or regulation of the satellite cell. The use of cell culture techniques and transgenic animal models has improved our understanding of this unique cell population; however, the capacity and potential of these cells remain ill-defined. This review will highlight the origin and unique markers of the satellite cell population, the regulation by growth factors, and the response to physiological and pathological stimuli. We conclude by highlighting the potential therapeutic uses of satellite cells and identifying future research goals for the study of satellite cell biology.

1,647 citations


Journal ArticleDOI
04 Oct 2001-Nature
TL;DR: In this article, the ADAMTS family of zinc metalloproteinase genes (ADAMTS13) was identified as the molecular mechanism responsible for TTP, and it was shown that the deficiency of ADADTS13 is the molecular mechanisms responsible for the development of TTP.
Abstract: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening systemic illness of abrupt onset and unknown cause. Proteolysis of the blood-clotting protein von Willebrand factor (VWF) observed in normal plasma is decreased in TTP patients. However, the identity of the responsible protease and its role in the pathophysiology of TTP remain unknown. We performed genome-wide linkage analysis in four pedigrees of humans with congenital TTP and mapped the responsible genetic locus to chromosome 9q34. A predicted gene in the identified interval corresponds to a segment of a much larger transcript, identifying a new member of the ADAMTS family of zinc metalloproteinase genes (ADAMTS13). Analysis of patients' genomic DNA identified 12 mutations in the ADAMTS13 gene, accounting for 14 of the 15 disease alleles studied. We show that deficiency of ADAMTS13 is the molecular mechanism responsible for TTP, and suggest that physiologic proteolysis of VWF and/or other ADAMTS13 substrates is required for normal vascular homeostasis.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss cellular genes and disease states associated with activation of the NF-κB pathway and consider therapeutic strategies to prevent the prolonged activation of this pathway, such as glucocorticoids and aspirin.
Abstract: NF-κB comprises a family of inducible transcription factors that serve as important regulators of the host immune and inflammatory response. In addition, NF-κB is also involved in protecting cells from undergoing apoptosis in response to DNA damage or cytokine treatment. Stimulation of the NF-κB pathway is mediated by diverse signal transduction cascades. These signals activate the IκB kinases, IKKα and IKKβ, which phosphorylate inhibitory proteins known as IκB to result in their ubiquitination and degradation by the proteasome. The degradation of IκB results in the translocation of NF-κB from the cytoplasm to the nucleus where it activates the expression of specific cellular genes. As we better understand the regulation of the NF-κB pathway, the potential for inhibiting this pathway has received attention. Agents that inhibit this pathway, such as glucocorticoids and aspirin, can reduce the inflammatory response, while other agents such as dominant negative IκB proteins potentiate the effects of chemotherapy and radiation therapy in the treatment of cancer. Here, we discuss cellular genes and disease states associated with activation of the NF-κB pathway and consider therapeutic strategies to prevent the prolonged activation of the NF-κB pathway.

Journal ArticleDOI
TL;DR: The differential distribution of oxin receptors is consistent with the proposed multifaceted roles of orexin in regulating homeostasis and may explain the unique role of the OX2R receptor in regulating sleep state stability.
Abstract: Orexins (hypocretins) are neuropeptides synthesized in the central nervous system exclusively by neurons of the lateral hypothalamus. Orexin-containing neurons have widespread projections and have been implicated in complex physiological functions including feeding behavior, sleep states, neuroendocrine function, and autonomic control. Two orexin receptors (OX1R and OX2R) have been identified, with distinct expression patterns throughout the brain, but a systematic examination of orexin receptor expression in the brain has not appeared. We used in situ hybridization histochemistry to examine the patterns of expression of mRNA for both orexin receptors throughout the brain. OX1R mRNA was observed in many brain regions including the prefrontal and infralimbic cortex, hippocampus, paraventricular thalamic nucleus, ventromedial hypothalamic nucleus, dorsal raphe nucleus, and locus coeruleus. OX2R mRNA was prominent in a complementary distribution including the cerebral cortex, septal nuclei, hippocampus, medial thalamic groups, raphe nuclei, and many hypothalamic nuclei including the tuberomammillary nucleus, dorsomedial nucleus, paraventricular nucleus, and ventral premammillary nucleus. The differential distribution of orexin receptors is consistent with the proposed multifaceted roles of orexin in regulating homeostasis and may explain the unique role of the OX2R receptor in regulating sleep state stability. J. Comp. Neurol. 435:6–25, 2001. © 2001 Wiley-Liss, Inc.

Journal ArticleDOI
11 May 2001-Science
TL;DR: The structures of the catalytic portion of human HMGR complexed with six different statins are determined, which show several catalytically relevant residues are disordered in the enzyme-statin complexes.
Abstract: HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase (HMGR) catalyzes the committed step in cholesterol biosynthesis. Statins are HMGR inhibitors with inhibition constant values in the nanomolar range that effectively lower serum cholesterol levels and are widely prescribed in the treatment of hypercholesterolemia. We have determined structures of the catalytic portion of human HMGR complexed with six different statins. The statins occupy a portion of the binding site of HMG-CoA, thus blocking access of this substrate to the active site. Near the carboxyl terminus of HMGR, several catalytically relevant residues are disordered in the enzyme-statin complexes. If these residues were not flexible, they would sterically hinder statin binding.

Journal ArticleDOI
01 May 2001-Neuron
TL;DR: Evidence is provided that orexin-containing neurons play important roles in regulating vigilance states and energy homeostasis and the pathophysiology and treatment of narcolepsy.

Journal ArticleDOI
TL;DR: The notion that in biomembranes selected lipids could laterally aggregate to form more ordered, detergent-resistant lipid rafts into which glycosphingolipid- and cholesterol-rich lipid domains partition is strongly supported by this study.

Journal ArticleDOI
16 Nov 2001-Science
TL;DR: The capacity of SLE patients' serum to induce DC differentiation correlated with disease activity and depended on the actions of interferon-α (IFN-α), suggesting unabated induction of DCs by IFN- α may drive the autoimmune response in SLE.
Abstract: Dendritic cells (DCs) are important in regulating both immunity and tolerance. Hence, we hypothesized that systemic lupus erythematosus (SLE), an autoimmune disease characterized by autoreactive B and T cells, may be caused by alterations in the functions of DCs. Consistent with this, monocytes from SLE patients' blood were found to function as antigen-presenting cells, in vitro. Furthermore, serum from SLE patients induced normal monocytes to differentiate into DCs. These DCs could capture antigens from dying cells and present them to CD4-positive T cells. The capacity of SLE patients' serum to induce DC differentiation correlated with disease activity and depended on the actions of interferon-alpha (IFN-alpha). Thus, unabated induction of DCs by IFN-alpha may drive the autoimmune response in SLE.

Journal ArticleDOI
06 Jul 2001-Science
TL;DR: It is demonstrated that the cytoplasmic tail of APP forms a multimeric complex with the nuclear adaptor protein Fe65 and the histone acetyltransferase Tip60 that stimulates transcription via heterologous Gal4- or LexA-DNA binding domains, suggesting that release of the cytopsized tail ofAPP by γ-cleavage may function in gene expression.
Abstract: Amyloid-β precursor protein (APP), a widely expressed cell-surface protein, is cleaved in the transmembrane region by γ-secretase. γ-Cleavage of APP produces the extracellular amyloid β-peptide of Alzheimer's disease and releases an intracellular tail fragment of unknown physiological function. We now demonstrate that the cytoplasmic tail of APP forms a multimeric complex with the nuclear adaptor protein Fe65 and the histone acetyltransferase Tip60. This complex potently stimulates transcription via heterologous Gal4- or LexA-DNA binding domains, suggesting that release of the cytoplasmic tail of APP by γ-cleavage may function in gene expression.

Journal ArticleDOI
TL;DR: Tie2-Cre transgenic mice are a new genetic tool for the analyses of endothelial cell-lineage and endothelialcell-specific gene targeting and lacZ staining in Tie2- Cre;CAG-CAT-Z embryos is consistent with endocardial-mesenchymal transformation in the atrioventricular canal and outflow tract regions.

Journal ArticleDOI
TL;DR: The diverse biological roles of the LRP include functions in lipid metabolism, and also in the homeostasis of proteinases and proteinase inhibitors, cellular entry of viruses and toxins, activation of lysosomal enzymes, cellular signal transduction, and neurotransmission.
Abstract: The LDL receptor–related protein (LRP) is larger than but structurally similar to other members of the LDL receptor gene family, an ancient family of endocytic receptors (1–3). Whereas the LDL receptor, the founding member of this family, appears to act solely in lipoprotein metabolism, the LRP and other members of this family appear to have other distinct functions. In this article, we will focus on the diverse biological roles of the LRP, which include functions in lipid metabolism, and also in the homeostasis of proteinases and proteinase inhibitors, cellular entry of viruses and toxins, activation of lysosomal enzymes, cellular signal transduction, and neurotransmission.

Journal ArticleDOI
20 Jul 2001-Science
TL;DR: The reduced forms of the redox cofactors, NAD(H) and NADP(H), strongly enhance DNA binding of the Clock:BMal1 and NPAS2:BMAL1 heterodimers, whereas the oxidized forms inhibit, raising the possibility that food, neuronal activity, or both may entrain the circadian clock by direct modulation of cellular redox state.
Abstract: Clock:BMAL1 and NPAS2:BMAL1 are heterodimeric transcription factors that control gene expression as a function of the light-dark cycle. Although built to fluctuate at or near a 24-hour cycle, the clock can be entrained by light, activity, or food. Here we show that the DNA-binding activity of the Clock:BMAL1 and NPAS2:BMAL1 heterodimers is regulated by the redox state of nicotinamide adenine dinucleotide (NAD) cofactors in a purified system. The reduced forms of the redox cofactors, NAD(H) and NADP(H), strongly enhance DNA binding of the Clock:BMAL1 and NPAS2:BMAL1 heterodimers, whereas the oxidized forms inhibit. These observations raise the possibility that food, neuronal activity, or both may entrain the circadian clock by direct modulation of cellular redox state.

Journal ArticleDOI
01 Mar 2001-Nature
TL;DR: A point mutation in synaptotagmin I is studied that causes a twofold decrease in overall Ca2+ affinity without inducing structural or conformational changes and participates in triggering neurotransmitter release at the synapse.
Abstract: In all synapses, Ca2+ triggers neurotransmitter release to initiate signal transmission. Ca2+ presumably acts by activating synaptic Ca2+ sensors, but the nature of these sensors--which are the gatekeepers to neurotransmission--remains unclear. One of the candidate Ca2+ sensors in release is the synaptic Ca2+-binding protein synaptotagmin I. Here we have studied a point mutation in synaptotagmin I that causes a twofold decrease in overall Ca2+ affinity without inducing structural or conformational changes. When introduced by homologous recombination into the endogenous synaptotagmin I gene in mice, this point mutation decreases the Ca2+ sensitivity of neurotransmitter release twofold, but does not alter spontaneous release or the size of the readily releasable pool of neurotransmitters. Therefore, Ca2+ binding to synaptotagmin I participates in triggering neurotransmitter release at the synapse.

Journal ArticleDOI
05 Oct 2001-Science
TL;DR: Findings indicate that APOAV is an important determinant of plasma triglyceride levels, a major risk factor for coronary artery disease.
Abstract: Comparison of genomic DNA sequences from human and mouse revealed a new apolipoprotein (APO) gene (APOAV) located proximal to the well-characterized APOAI/CIII/AIV gene cluster on human 11q23. Mice expressing a human APOAV transgene showed a decrease in plasma triglyceride concentrations to one-third of those in control mice; conversely, knockout mice lacking Apoav had four times as much plasma triglycerides as controls. In humans, single nucleotide polymorphisms (SNPs) across the APOAV locus were found to be significantly associated with plasma triglyceride levels in two independent studies. These findings indicate that APOAV is an important determinant of plasma triglyceride levels, a major risk factor for coronary artery disease.

Journal ArticleDOI
29 Jun 2001-Cell
TL;DR: Myocardin is the founding member of a class of muscle transcription factors and provides a mechanism whereby SRF can convey myogenic activity to cardiac muscle genes.

Journal ArticleDOI
TL;DR: Changes in cholesterol balance across the whole body may, in some way, cause alterations in sterol recycling and apolipoprotein E expression within the central nervous system, which, in turn, may affect neuron and myelin integrity.
Abstract: The central nervous system accounts for only 2% of the whole body mass but contains almost a quarter of the unesterified cholesterol present in the whole individual. This sterol is largely present in two pools comprised of the cholesterol in the plasma membranes of glial cells and neurons and the ch


Journal ArticleDOI
TL;DR: RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung and breast cancers through hypermethylation of its promoter region and is associated with impaired patient survival.
Abstract: Background: The recently identified RASSF1 locus is located within a 120-kilobase region of chromosome 3p21.3 that frequently undergoes allele loss in lung and breast cancers. We explored the hypothesis that RASSF1 encodes a tumor suppressor gene for lung and breast cancers. Methods: We assessed expression of two RASSF1 gene products, RASSF1A and RASSF1C, and the methylation status of their respective promoters in 27 non-small-cell lung cancer (NSCLC) cell lines, in 107 resected NSCLCs, in 47 small-cell lung cancer (SCLC) cell lines, in 22 breast cancer cell lines, in 39 resected breast cancers, in 104 nonmalignant lung samples, and in three breast and lung epithelial cultures. We also transfected a lung cancer cell line that lacks RASSF1A expression with vectors containing RASSF1A complementary DNA to determine whether exogenous expression of RASSF1A would affect in vitro growth and in vivo tumorigenicity of this cell line. All statistical tests were two-sided. Results: RASSF1A messenger RNA was expressed in nonmalignant epithelial cultures but not in 100% of the SCLC, in 65% of the NSCLC, or in 60% of the breast cancer lines. By contrast, RASSF1C was expressed in all nonmalignant cell cultures and in nearly all cancer cell lines. RASSF1A promoter hypermethylation was detected in 100% of SCLC, in 63% of NSCLC, in 64% of breast cancer lines, in 30% of primary NSCLCs, and in 49% of primary breast tumors but in none of the nonmalignant lung tissues. RASSF1A promoter hypermethylation in resected NSCLCs was associated with impaired patient survival (P = .046). Exogenous expression of RASSF1A in a cell line lacking expression decreased in vitro colony formation and in vivo tumorigenicity. Conclusion: RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung and breast cancers through hypermethylation of its promoter region.

Journal ArticleDOI
TL;DR: Locked nucleic acid is an RNA derivative in which the ribose ring is constrained by a methylene linkage between the 2'-oxygen and the 4'-carbon that increases binding affinity for complementarity sequences and provides an exciting new chemical approach for the control of gene expression and optimization of microarrays.

Journal ArticleDOI
TL;DR: Data support an anti-inflammatory effect of these drugs on levels of high-sensitive CRP in patients with combined hyperlipidemia, and there was no relationship between reductions in hs-CRP and LDL cholesterol.
Abstract: Background —Prospective studies indicate that baseline levels of C-reactive protein (CRP), the prototypic marker of inflammation, are associated with an increased risk for cardiovascular events. Limited studies have examined therapies that influence high-sensitive CRP (hs-CRP) levels, especially in hyperlipidemic patients. Thus, we tested the effects of 3 hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins), simvastatin (20 mg/d), pravastatin (40 mg/d), and atorvastatin (10 mg/d), on levels of hs-CRP in a randomized, double-blind, crossover trial of 22 patients with combined hyperlipidemia (LDL cholesterol >130 mg/dL and triglycerides of 200 to 600 mg/dL). Methods and Results —After 6 weeks of an American Heart Association Step 1 diet, fasting blood samples were drawn at baseline and after 6 weeks of therapy with each drug. hs-CRP levels were significantly decreased after treatment with all 3 statins compared with baseline (median values: baseline, 2.6 mg/L; atorvastatin, 1.7 mg/L; simvastatin, 1.7 mg/L; and pravastatin, 1.9 mg/L; P <0.025). The reductions obtained with the 3 statins were similar. In addition, there was no significant effect on either plasma interleukin-6 or interleukin-6 soluble receptor levels. There was no relationship between reductions in hs-CRP and LDL cholesterol. Conclusions —Pravastatin, simvastatin, and atorvastatin significantly decreased levels of hs-CRP. These data support an anti-inflammatory effect of these drugs.

Journal ArticleDOI
TL;DR: The endothelin system consists of two G-protein-coupled receptors, three peptide ligands, and two activating peptidases, which have a variety of physiological and pathophysiological roles in the vessels and brain.
Abstract: The endothelin system consists of two G-protein-coupled receptors, three peptide ligands, and two activating peptidases. Its pharmacological complexity is reflected by the diverse expression patter...