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1.
Mol Psychiatry ; 23(2): 467-475, 2018 02.
Article in English | MEDLINE | ID: mdl-27752079

ABSTRACT

Mice lacking DIX domain containing-1 (DIXDC1), an intracellular Wnt/ß-catenin signal pathway protein, have abnormal measures of anxiety, depression and social behavior. Pyramidal neurons in these animals' brains have reduced dendritic spines and glutamatergic synapses. Treatment with lithium or a glycogen synthase kinase-3 (GSK3) inhibitor corrects behavioral and neurodevelopmental phenotypes in these animals. Analysis of DIXDC1 in over 9000 cases of autism, bipolar disorder and schizophrenia reveals higher rates of rare inherited sequence-disrupting single-nucleotide variants (SNVs) in these individuals compared with psychiatrically unaffected controls. Many of these SNVs alter Wnt/ß-catenin signaling activity of the neurally predominant DIXDC1 isoform; a subset that hyperactivate this pathway cause dominant neurodevelopmental effects. We propose that rare missense SNVs in DIXDC1 contribute to psychiatric pathogenesis by reducing spine and glutamatergic synapse density downstream of GSK3 in the Wnt/ß-catenin pathway.


Subject(s)
Dendritic Spines/genetics , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/physiology , Animals , Anxiety , Anxiety Disorders , Dendritic Spines/metabolism , Depression , Depressive Disorder , Glutamate Plasma Membrane Transport Proteins/metabolism , Glycogen Synthase Kinase 3/metabolism , Mental Disorders/genetics , Mice , Mice, Knockout , Polymorphism, Single Nucleotide/genetics , Pyramidal Cells/physiology , Social Behavior , Synapses/metabolism , Wnt Signaling Pathway/physiology , beta Catenin/metabolism
2.
Prog Mol Biol Transl Sci ; 144: 277-320, 2016.
Article in English | MEDLINE | ID: mdl-27865460

ABSTRACT

With a dismal 5-year survival rate of only 8%, pancreatic cancer still remains a very lethal disease. As with most cancers, pancreatic cancer is treated with different combinations of chemotherapeutic drugs which result in side effects and potential drug resistance leading in many cases to the unfortunate demise of the patient. Over recent years, a number of therapies have been developed against numerous molecular targets in cancers. Kinase inhibitors and monoclonal antibodies have been shown to target numerous kinases, growth factor receptors, and cell signaling pathways. This can lead to effects on tumor cell growth, angiogenesis, apoptosis, and the microenvironment. Most recent findings are very promising as they relate to the use of immunotherapy to treat certain cancers. Immune checkpoint inhibitors and cancer vaccines are currently being investigated. In this review, we will highlight some novel molecular targeted strategies that are being used or considered as potential therapeutics to treat patients with pancreatic cancer.


Subject(s)
Molecular Targeted Therapy/trends , Pancreatic Neoplasms/therapy , Animals , Antineoplastic Agents/therapeutic use , Chemoprevention , Epigenesis, Genetic , Humans , Immunotherapy , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/prevention & control
3.
Dalton Trans ; 45(16): 6909-19, 2016 Apr 28.
Article in English | MEDLINE | ID: mdl-26979820

ABSTRACT

Mixed actinide(III,IV) oxalates of the general formula M2.2UAn(C2O4)5·nH2O (An = Pu or Am and M = H3O(+) and N2H5(+)) have been quantitatively precipitated by oxalic precipitation in nitric acid medium (yield >99%). Thorough multiscale structural characterization using XRD and XAS measurements confirmed the existence of mixed actinide oxalate solid solutions. The XANES analysis confirmed that the oxidation states of the metallic cations, tetravalent for uranium and trivalent for plutonium and americium, are maintained during the precipitation step. EXAFS measurements show that the local environments around U(+IV), Pu(+III) and Am(+III) are comparable, and the actinides are surrounded by ten oxygen atoms from five bidentate oxalate anions. The mean metal-oxygen distances obtained by XAS measurements are in agreement with those calculated from XRD lattice parameters.

4.
Transl Psychiatry ; 3: e301, 2013 Sep 03.
Article in English | MEDLINE | ID: mdl-24002087

ABSTRACT

Wnt signaling, which encompasses multiple biochemical pathways that regulate neural development downstream of extracellular Wnt glycoprotein ligands, has been suggested to contribute to major psychiatric disorders including autism spectrum disorders (ASD). We used next-generation sequencing and Sequenom genotyping technologies to resequence 10 Wnt signaling pathway genes in 198 ASD patients and 240 matched controls. Results for single-nucleotide polymorphisms (SNPs) of interest were confirmed in a second set of 91 ASD and 144 control samples. We found a significantly increased burden of extremely rare missense variants predicted to be deleterious by PolyPhen-2, distributed across seven genes in the ASD sample (3.5% in ASD vs 0.8% in controls; Fisher's exact test, odds ratio (OR)=4.37, P=0.04). We also found a missense variant in WNT1 (S88R) that was overrepresented in the ASD sample (8 A/T in 267 ASD (minor allele frequency (MAF)=1.69%) vs 1 A/T in 377 controls (MAF=0.13%), OR=13.0, Fisher's exact test, P=0.0048; OR=8.2 and P=0.053 after correction for population stratification). Functional analysis revealed that WNT1-S88R is more active than wild-type WNT1 in assays for the Wnt/ß-catenin signaling pathway. Our findings of a higher burden in ASD of rare missense variants distributed across 7 of 10 Wnt signaling pathway genes tested, and of a functional variant at the WNT1 locus associated with ASD, support that dysfunction of this pathway contributes to ASD susceptibility. Given recent findings of common molecular mechanisms in ASD, schizophrenia and affective disorders, these loci merit scrutiny in other psychiatric conditions as well.


Subject(s)
Child Development Disorders, Pervasive/genetics , Wnt Signaling Pathway/genetics , Wnt1 Protein/genetics , Case-Control Studies , Gene Frequency , Genotype , Humans , Mutation, Missense/genetics , Polymorphism, Single Nucleotide , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/genetics
5.
Eur J Cancer ; 48(16): 2954-61, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22658808

ABSTRACT

BACKGROUND: Currently, the benefit of chemotherapy (CT) in node-negative breast carcinoma (NNBC) is discussed. The evaluation of classical clinical and histological factors is limited to assess individual outcome. A statistical model was developed to improve the prognostic accuracy of NNBC. METHODS: A total of 305 node-negative breast carcinomas who underwent surgery (+/- radiotherapy) but no adjuvant treatment were selected. Putative prognosis factors including age, tumour size, oestrogen receptor (ER), progesterone receptor (PgR), Scarff-Bloom-Richardon (SBR) grading, urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1) and thymidine kinase (TK) were evaluated. The developed model was internally validated using Harrell's concordance index. A prognosis index (PI) was proposed and compared with Adjuvant! Online program. RESULTS: Age (p < 0.001), pathological tumour size (pT) (p < 0.001), PgR (p = 0.02), and PAI-1 (p ≤ 0.001) were included in the Cox regression model predicting Breast cancer specific survival (BCSS) at 5-years. Internal validation revealed a concordance index of 0.71. A PI score was derived from our nomogram. The PI score was significantly associated with BCSS (hazard ratio (HR): 4.1 for intermediate, p=0.02, HR: 8.8, p < 0.001 for high group) as compared to Adjuvant! Online score (HR: 1.4, p=0.14). CONCLUSION: A nomogram can be used to predict probability survival curves for individual breast cancer patients.


Subject(s)
Breast Neoplasms/surgery , Carcinoma/surgery , Decision Support Techniques , Lymph Nodes/pathology , Mastectomy, Modified Radical , Mastectomy, Segmental , Nomograms , Age Factors , Biomarkers, Tumor/analysis , Breast Neoplasms/chemistry , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Carcinoma/chemistry , Carcinoma/mortality , Carcinoma/pathology , Chemotherapy, Adjuvant , Disease-Free Survival , Female , France , Humans , Kaplan-Meier Estimate , Lymph Node Excision , Mastectomy, Modified Radical/adverse effects , Mastectomy, Modified Radical/mortality , Mastectomy, Segmental/adverse effects , Mastectomy, Segmental/mortality , Middle Aged , Multivariate Analysis , Patient Selection , Plasminogen Activator Inhibitor 1/analysis , Proportional Hazards Models , Radiotherapy, Adjuvant , Receptors, Progesterone/analysis , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Tumor Burden
6.
Transl Psychiatry ; 1: e43, 2011 Sep 27.
Article in English | MEDLINE | ID: mdl-22832659

ABSTRACT

Disrupted-in-Schizophrenia-1 (DISC1) is a genetic susceptibility locus for major mental illness, including schizophrenia and depression. The Disc1 protein was recently shown to interact with the Wnt signaling protein, DIX domain containing 1 (Dixdc1). Both proteins participate in neural progenitor proliferation dependent on Wnt signaling, and in neural migration independently of Wnt signaling. Interestingly, their effect on neural progenitor proliferation is additive. By analogy to Disc1, mutations in Dixdc1 may lead to abnormal behavior in mice, and to schizophrenia or depression in humans. To explore this hypothesis further, we generated mice mutant at the Dixdc1 locus and analyzed their behavior. Dixdc1(-/-) mice had normal prepulse inhibition, but displayed decreased spontaneous locomotor activity, abnormal behavior in the elevated plus maze and deficits in startle reactivity. Our results suggest that Dixdc1(-/-) mice will be a useful tool to elucidate molecular pathophysiology involving Disc1 in major mental illnesses.


Subject(s)
Behavior, Animal/physiology , Intracellular Signaling Peptides and Proteins/genetics , Microfilament Proteins/genetics , Nerve Tissue Proteins/genetics , Animals , Epistasis, Genetic/genetics , Humans , Male , Mice , Mice, 129 Strain , Mice, Mutant Strains , Mice, Transgenic
7.
Br J Cancer ; 104(2): 332-7, 2011 Jan 18.
Article in English | MEDLINE | ID: mdl-21179039

ABSTRACT

PURPOSE: Although a potential role of the Epstein-Barr virus (EBV) in the pathogenesis of breast cancer (BC) has been underlined, results remain conflicting. Particularly, the impact of EBV infection on biological markers of BC has received little investigation. METHODS: In this study, we established the frequency of EBV-infected BC using real-time quantitative PCR (RT-PCR) in 196 BC specimens. Biological and pathological characteristics according to EBV status were evaluated. RESULTS: EBV DNA was present in 65 of the 196 (33.2%) cases studied. EBV-positive BCs tended to be tumours with a more aggressive phenotype, more frequently oestrogen receptor negative (P=0.05) and with high histological grade (P=0.01). Overexpression of thymidine kinase activity was higher in EBV-infected BC (P=0.007). The presence of EBV was weakly associated with HER2 gene amplification (P=0.08). CONCLUSION: Our study provides evidence for EBV-associated BC undergoing distinct carcinogenic processes, with more aggressive features.


Subject(s)
Biomarkers, Tumor/isolation & purification , Breast Neoplasms/pathology , Herpesvirus 4, Human/isolation & purification , Base Sequence , Biomarkers, Tumor/genetics , Breast Neoplasms/virology , DNA Primers , DNA, Viral/analysis , Female , Genes, erbB-2 , Genome, Viral , Herpesvirus 4, Human/genetics , Humans , Middle Aged , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Reverse Transcriptase Polymerase Chain Reaction
8.
Bull Cancer ; 97(2): 181-9, 2010 Feb.
Article in French | MEDLINE | ID: mdl-20051347

ABSTRACT

Biobanks in general, and specifically tumour banks, are considered as essential tools for the development of translational and clinical research in biology and oncology. Biobank tasks include the collection and preservation of biological samples, and their association with information that will be essential for further scientific use ("annotations" that allow for the "qualification" of biological samples in biological resource). A collection is made of a series of biological resource that are representative of a homogeneous group of individuals or patients that are defined on the basis of clinical or biological information. Collections are used by scientists that are aware of their existence. In the absence of a published catalogue, this awareness is most often limited to research teams that are geographically close, or to investigators who already established collaborative projects with medical teams within the hospital that operates the tumour bank. Publications of catalogues, especially digitalized and online catalogues, should foster the development of high-level, large-scale and multicentric scientific projects. In addition, tumour banks will formalize rules that allow publication of collections, and upstream, rules that are used to qualify biological samples in biological resource: this should translate in an improved overall quality of samples and annotations. Tumour bank catalogues remain relatively few; however, some recent achievements established the "proof of concept" and already raise questions regarding rules for publication. It will be important to demonstrate that these high expectations translate into measurable benefits.


Subject(s)
Neoplasms , Tissue Banks/statistics & numerical data , Catalogs as Topic , Humans
9.
J Investig Allergol Clin Immunol ; 19 Suppl 2: 56-60, 2009.
Article in English | MEDLINE | ID: mdl-19530420

ABSTRACT

BACKGROUND: There are infrequent or unspecific diseases that occupy an important part of time in the job of the allergists. OBJECTIVE: We sought to evaluate the frequency and to determine the characteristics of uncommon or unspecific diseases seen by allergists in Spain, and to compare these data with findings obtained in a similar study undertaken in 1992. MATERIAL AND METHODS: An observational, prospective and cross-sectional study named "Alergológica 2005" was carried out in Spain. A part of this study analyzed the demographic, healthcare and clinical aspects of infrequent or unspecific diseases categorized as "Other allergic diseases" (OAD) or "Other non-allergic diseases" (ONAD). RESULTS: The survey comprised 4991 patients. In OAD, 45 patients were included. In ONAD, 290 patients were included. Significant diagnoses were gastroallergic anisakiasis (10 patients), idiopathic anaphylaxis (7 patients), and hypersensitivity pneumonitis (2 patients). In the ONAD group, non allergic respiratory diseases were the most frequent diagnosis. Mean time spent to reach a diagnosis was 14.2 days. However, the median of this time was only 1 day. Main diagnostic methods employed were a clinical history/physical examination in 86% of patients and skin tests in 73.7%. CONCLUSION: Several unspecific diseases affected more than 60% of patients in the two groups together. Findings show the current knowledge of allergic disorders due to Anisakis simplex. Diagnoses of hypersensitivity pneumonitis seem to be as frequent as previously published. Idiopathic anaphylaxis seems to be less frequent. The wide-range of times needed to reach a diagnosis was in agreement with the mixture of diseases included in both groups.


Subject(s)
Hypersensitivity/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Hypersensitivity/diagnosis , Hypersensitivity/therapy , Infant , Male , Middle Aged , Prevalence , Quality of Life , Spain/epidemiology
10.
Rev Neurol (Paris) ; 164(12): 1057-62, 2008 Dec.
Article in French | MEDLINE | ID: mdl-19041107

ABSTRACT

Myelination was a major step in the evolution of the nervous system. Appearing first in jaw fish, myelination allows the fast and secure propagation of action potentials at a low energetic cost, and without exaggerated increase in axonal diameter. In the peripheral nervous system of mammals, myelination results from the tight interactions between Schwann cells and axons, leading to the formation of highly differentiated domains along the axon. The molecular determinants of these interactions are starting to be well identified. Their understanding provides a precise framework to interpret the defects, which occur in pathological circumstances. This review summarizes the present state of knowledge concerning axoglial interactions in peripheral nerves.


Subject(s)
Axons/physiology , Axons/ultrastructure , Schwann Cells/physiology , Schwann Cells/ultrastructure , Animals , Axons/pathology , Cell Differentiation , Energy Metabolism , Humans , Myelin Sheath/physiology , Peripheral Nerves/physiology , Peripheral Nerves/ultrastructure , Ranvier's Nodes/physiology , Ranvier's Nodes/ultrastructure , Schwann Cells/pathology
11.
Neurochirurgie ; 54(6): 750-6, 2008 Dec.
Article in French | MEDLINE | ID: mdl-18760426

ABSTRACT

UNLABELLED: The recurrence and progression of treated intracranial meningiomas highlights the problem of the type of follow-up that should be used and whether early complementary treatment is indicated. The aim of this study was to evaluate different biochemical markers involved in cell proliferation and transformation to identify new prognostic factors in intracranial meningiomas. Between 1989 and 2003, 120 intracranial meningiomas were studied biochemically. The levels of estrogen receptors (RE), progesterone receptors (RP), cathepsin B (CB), cathepsin L (CL), stefin A (ATA), stefin B (STB), cystatin C (CYSC), urokinase (u-PA), type 1 plasminogen activator inhibitors (PAI-1), cathepsin D (CD) and thymidine kinase activity (TK) were measured in tumor extracts using biochemical assays. RESULTS: Out of 120 meningiomas, 73 were grade I, 39 grade II and eight grade III according to the WHO classification. Of these patients, 17 showed recurrence. The mean follow-up was 47 months. Monofactorial analysis showed that expression of progesterone receptors (RP) had an inverse correlation with recurrence (p=0.0025 %) and that thymidine kinase activity (TK), cathepsin L (CL), the WHO grade and the degree of tumor resection correlated with recurrence (p<0.05). Principal component analysis and linear discriminant analysis confirmed these results. The results of this study confirm the importance of biological parameters (PR, CL, TK) as prognostic factors for the risk of recurrence in intracranial meningiomas.


Subject(s)
Meningeal Neoplasms/surgery , Meningioma/surgery , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/analysis , Discriminant Analysis , Female , Humans , Male , Meningeal Neoplasms/pathology , Meningioma/pathology , Middle Aged , Neoplasm Recurrence, Local/epidemiology , Prognosis , Retrospective Studies , Young Adult
12.
Eur J Neurol ; 15(7): 649-59, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18582342

ABSTRACT

Acute bacterial meningitis (ABM) is a potentially life-threatening neurological emergency. An agreed protocol for early, evidence-based and effective management of community-acquired ABM is essential for best possible outcome. A literature search of peer-reviewed articles on ABM was used to collect data on the management of ABM in older children and adults. Based on the strength of published evidence, a consensus guideline was developed for initial management, investigations, antibiotics and supportive therapy of community-acquired ABM. Patients with ABM should be rapidly hospitalized and assessed for consideration of lumbar puncture (LP) if clinically safe. Ideally, patients should have fast-track brain imaging before LP, but initiation of antibiotic therapy should not be delayed beyond 3 h after first contact of patient with health service. In every case, blood sample must be sent for culture before initiating antibiotic therapy. Laboratory examination of cerebrospinal fluid is the most definitive investigation for ABM and whenever possible, the choice of antibiotics, and the duration of therapy, should be guided by the microbiological diagnosis. Parenteral therapy with a third-generation cephalosporin is the initial antibiotics of choice in the absence of penicillin allergy and bacterial resistance; amoxicillin should be used in addition if meningitis because of Listeria monocytogenes is suspected. Vancomycin is the preferred antibiotic for penicillin-resistant pneumococcal meningitis. Dexamethasone should be administered both in adults and in children with or shortly before the first dose of antibiotic in suspected cases of Streptococcus pneumoniae and H. Influenzae meningitis. In patients presenting with rapidly evolving petechial skin rash, antibiotic therapy must be initiated immediately on suspicion of Neisseria meningitidis infection with parenteral benzyl penicillin in the absence of known history of penicillin allergy.


Subject(s)
Community-Acquired Infections/diagnosis , Community-Acquired Infections/therapy , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/therapy , Adolescent , Adult , Advisory Committees , Child , Humans
13.
Oncogene ; 27(4): 506-18, 2008 Jan 17.
Article in English | MEDLINE | ID: mdl-17637748

ABSTRACT

Neuroendocrine (NE) differentiation in prostate cancer (CaP) has been reported to be an early marker associated with the development of androgen independence. The mechanisms by which CaP acquires NE properties are poorly understood. In this study, a putative role of adrenomedullin (AM) in the NE differentiation was investigated. The expression of AM and AM receptors (calcitonin receptor-like receptor (CRLR)/receptor activity modifying protein-2 and -3 (RAMP2 and RAMP3) was evaluated after experimental manipulation of androgen status. Levels of AM mRNA and immunoreactive AM (ir-AM) increased four- to sevenfold in androgen-sensitive LNCaP cells after androgen withdrawal in vitro and in LNCaP xenografts in animals after castration. Treatment of LNCaP cells with androgen analogue (dihydrotestosterone; 10(-9) M) prevented the increase in AM mRNA and ir-AM levels. Interestingly, the expression of CRLR, RAMP2 and RAMP3 is not regulated by androgen status. We demonstrate that in the presence of serum, AM is able to induce an NE phenotype in LNCaP cells via CRLR/RAMP2 and RAMP3, which includes extension of neuritic processes and expression of the neuron-specific enolase (NSE), producing cGMP in a dose-dependent manner, which is mediated by a pertussis toxin-sensitive GTP-binding protein. 8-Bromo-cGMP mimicked the effects of AM on cell differentiation. We demonstrate that AM induces a G-kinase Ialpha translocation to the nucleus. The protein kinase G inhibitor KT-5823 inhibited the neurite outgrowth induced by both AM and 8-bromo-cGMP. In noncastrated animals, administration of AM enhanced expression of NSE and chromogranin A in LNCaP xenografts with a significant increase of NSE levels in serum and no changes in tumor growth. In castrated animals, intraperitoneal injection of AM resulted in a 240+/-18% (P<0.001) increase in tumor volume 36 days after treatment, indicating that the nature of effect of AM in CaP depends on the presence or absence of endogenous androgen. Together, these results demonstrate that AM may function as a mediator of NE-like differentiation in culture as well as in vivo and indicate that its production may be important for tumor resurgence following androgen ablation.


Subject(s)
Adrenomedullin/physiology , Androgens/pharmacology , Antineoplastic Agents, Hormonal/therapeutic use , Carcinoma, Neuroendocrine/pathology , Prostatic Neoplasms/pathology , Withholding Treatment , Adrenomedullin/genetics , Adrenomedullin/metabolism , Adrenomedullin/therapeutic use , Androgens/therapeutic use , Animals , Autocrine Communication/drug effects , Autocrine Communication/physiology , Biomarkers, Tumor/analysis , Carcinoma, Neuroendocrine/drug therapy , Cell Differentiation , Cell Proliferation/drug effects , Disease Progression , Gene Expression Regulation, Neoplastic , Humans , Male , Mice , Mice, Nude , Neoplasms, Hormone-Dependent/drug therapy , Neoplasms, Hormone-Dependent/pathology , Paracrine Communication/drug effects , Paracrine Communication/physiology , Phenotype , Prostatic Neoplasms/drug therapy , Receptors, Adrenomedullin , Receptors, Peptide/genetics , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
14.
Biochim Biophys Acta ; 1768(11): 2690-7, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17692818

ABSTRACT

Recently, we cloned two Na(+)-coupled lactate transporters from mouse kidney, a high-affinity transporter (SMCT1 or slc5a8) and a low-affinity transporter (SMCT2 or slc5a12). Here we report on the cloning and functional characterization of human SMCT2 (SLC5A12) and compare the immunolocalization patterns of slc5a12 and slc5a8 in mouse kidney. The human SMCT2 cDNA codes for a protein consisting of 618 amino acids. When expressed in mammalian cells or Xenopus oocytes, human SMCT2 mediates Na(+) -coupled transport of lactate, pyruvate and nicotinate. The affinities of the transporter for these substrates are lower than those reported for human SMCT1. Several non-steroidal anti-inflammatory drugs inhibit human SMCT2-mediated nicotinate transport, suggesting that NSAIDs interact with the transporter as they do with human SMCT1. Immunofluorescence microscopy of mouse kidney sections with an antibody specific for SMCT2 shows that the transporter is expressed predominantly in the cortex. Similar studies with an anti-SMCT1 antibody demonstrate that SMCT1 is also expressed mostly in the cortex. Dual-labeling of SMCT1 and SMCT2 with 4F2hc (CD98), a marker for basolateral membrane of proximal tubular cells in the S1 and S2 segments of the nephron, shows that both SMCT1 and SMCT2 are expressed in the apical membrane of the tubular cells. These studies also show that while SMCT2 is broadly expressed along the entire length of the proximal tubule (S1/S2/S3 segments), the expression of SMCT1 is mostly limited to the S3 segment. These studies suggest that the low-affinity transporter SMCT2 initiates lactate absorption in the early parts of the proximal tubule followed by the participation of the high-affinity transporter SMCT1 in the latter parts of the proximal tubule.


Subject(s)
Kidney/chemistry , Monocarboxylic Acid Transporters/analysis , Monocarboxylic Acid Transporters/genetics , Amino Acid Sequence , Animals , Cloning, Molecular , DNA, Complementary/chemistry , Fluorescent Antibody Technique , Humans , Male , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Monocarboxylic Acid Transporters/physiology , Symporters , Xenopus laevis
15.
Oncogene ; 26(3): 407-14, 2007 Jan 18.
Article in English | MEDLINE | ID: mdl-16832347

ABSTRACT

Previously, we have shown that PKC-eta (protein kinase C-eta) positively regulates glioblastoma proliferation and confers resistance to irradiation-induced apoptosis. In this study, we investigated the efficacy of rapamycin in inhibiting cell proliferation in two glioblastoma cell lines U-251MG (PKC-eta expressing) and U-1242MG (PKC-eta deficient) following PKC-eta activation. In U-251MG cells, rapamycin (10 nM) treatment was less effective as an antiproliferative agent when cells were concurrently stimulated with 10% serum and phorbol 12-myristate 13-acetate (PMA, 100 nM), a potent activator of PKC isozymes. Rapamycin-insensitive growth was owing to PKC-eta, as U-1242MG and U-251MG cells infected with a kinase-dead form of PKC-eta (U-251kr) were susceptible to rapamycin-induced inhibition of cell proliferation. Furthermore, U-251MG cells transfected with PKC-eta antisense oligonucleotides were sensitive to rapamycin. PKC-eta-expressing cells stimulated with PMA maintained p70S6K phosphorylation on Thr389 and phosphorylation of rpS6 (ser235/36), suggesting p70S6K kinase activity was still intact. Inhibition of p70S6K expression with small interfering RNA oligonucleotides inhibited cell proliferation greater than 50% in the presence of a combination of PMA and serum. Additionally, p70S6K co-precipitated with PKC-eta, suggesting a physical interaction between PKC-eta and p70S6K regulates the observed phosphorylation. Taken together, these data demonstrate that rapamycin-insensitive glioblastoma proliferation involves PKC-eta signaling.


Subject(s)
Cell Proliferation/drug effects , Glioblastoma/pathology , Immunosuppressive Agents/pharmacology , Protein Kinase C/metabolism , Serum , Sirolimus/pharmacology , Tetradecanoylphorbol Acetate/pharmacology , Blotting, Western , Carcinogens/pharmacology , Drug Synergism , Enzyme Inhibitors/pharmacology , Glioblastoma/enzymology , Humans , Immunoprecipitation , Oligonucleotides, Antisense/pharmacology , Phosphorylation/drug effects , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/genetics , RNA, Small Interfering/pharmacology , Ribosomal Protein S6 Kinases, 70-kDa/antagonists & inhibitors , Ribosomal Protein S6 Kinases, 70-kDa/genetics , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Signal Transduction , Tumor Cells, Cultured
16.
Oncogene ; 26(20): 2885-93, 2007 May 03.
Article in English | MEDLINE | ID: mdl-17146445

ABSTRACT

Glioblastoma multiforme (GBM) is the highest grade of astrocytoma. GBM pathogenesis has been linked to receptor tyrosine kinases and kinases further down signal-transduction pathways - in particular, members of the protein kinase C (PKC) family. The expression and activity of various PKC isoforms are increased in malignant astrocytomas, but not in non-neoplastic astrocytes. This suggests that PKC activity contributes to tumor progression. The level of PKC-eta expressed correlates with the degree of phorbol-12-myristate-13-acetate (PMA)-induced proliferation of two glioblastoma cell lines, U-1242 MG and U-251 MG. Normally, U-1242 cells do not express PKC-eta, and PMA inhibits their proliferation. Conversely, PMA increases proliferation of U-1242 cells that are stably transfected with PKC-eta (U-1242-PKC-eta). PMA treatment also stimulates proliferation of U-251 cells, which express PKC-eta. Here, we determined that extracellular signal-regulated kinase (ERK) and Elk-1 are downstream targets of PKC-eta. Elk-1-mediated transcriptional activity correlates with the PKC-eta-mediated mitogenic response. Pretreatment of U-1242-PKC-eta cells with inhibitors of PKC or MAPK/ERK kinase (MEK) (bisindolyl maleimide (BIM) or U0126, respectively) blocked both PMA-induced Elk-1 transcriptional activity and PMA-stimulated proliferation. An overexpressed dominant-negative PKC-eta reduced the mitogenic response in U-251 cells, as did reduction of Elk-1 by small interfering RNA. Taken together, these results strongly suggest that PKC-eta-mediated glioblastoma proliferation involves MEK/mitogen-activated protein (MAP) kinase phosphorylation, activation of ERK and subsequently of Elk-1. Elk-1 target genes involved in GBM proliferative responses have yet to be identified.


Subject(s)
Cell Proliferation , Extracellular Signal-Regulated MAP Kinases/physiology , Glioblastoma/pathology , Protein Kinase C/physiology , ets-Domain Protein Elk-1/physiology , Cell Line, Tumor , Cell Proliferation/drug effects , Epidermal Growth Factor/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , Genes, fos/physiology , Genes, jun/physiology , Humans , Isoenzymes/physiology , Models, Biological , Phosphorylation , Signal Transduction , Tetradecanoylphorbol Acetate/pharmacology , Transcription Factor AP-1/genetics , Transcription, Genetic/genetics , Transfection
17.
Int J Biol Markers ; 21(1): 30-9, 2006.
Article in English | MEDLINE | ID: mdl-16711511

ABSTRACT

The assessment of ERa, PgR and HER2 status is routinely performed today to determine the endocrine responsiveness of breast cancer samples. Such determination is usually accomplished by means of immunohistochemistry and in case of HER2 amplification by means of fluorescent in situ hybridization (FISH). The analysis of these markers can be improved by simultaneous measurements using quantitative real-time PCR (Qrt-PCR). In this study we compared Qrt-PCR results for the assessment of mRNA levels of ERa, PgR, and the members of the human epidermal growth factor receptor family, HER1, HER2, HER3 and HER4. The results were obtained in two independent laboratories using two different methods, SYBR Green I and TaqMan probes, and different primers. By linear regression we demonstrated a good concordance for all six markers. The quantitative mRNA expression levels of ERa, PgR and HER2 also strongly correlated with the respective quantitative protein expression levels prospectively detected by EIA in both laboratories. In addition, HER2 mRNA expression levels correlated well with gene amplification detected by FISH in the same biopsies. Our results indicate that both Qrt-PCR methods were robust and sensitive tools for routine diagnostics and consistent with standard methodologies. The developed simultaneous assessment of several biomarkers is fast and labor effective and allows optimization of the clinical decision-making process in breast cancer tissue and/or core biopsies.


Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/metabolism , Estrogen Receptor alpha/analysis , Polymerase Chain Reaction/methods , Receptor, ErbB-2/analysis , Receptors, Progesterone/analysis , ErbB Receptors/analysis , Female , Humans , In Situ Hybridization, Fluorescence , RNA, Messenger/metabolism , Receptor, ErbB-3/analysis , Receptor, ErbB-4 , Reproducibility of Results
18.
Int J Biol Markers ; 21(1): 20-9, 2006.
Article in English | MEDLINE | ID: mdl-16711510

ABSTRACT

There is an increasing demand for the evaluation of HER2 status in breast cancer. In this study, sections from fixed tissues and triton extracts of tissue homogenates were obtained from 163 malignant breast tumors and analyzed in parallel using immunohistochemistry combined with fluorescence in situ hybridization, as gold standard tests, and an ELISA test (c-erbB2/c-neu Rapid Format ELISA, Oncogene Research Products, USA). Tumor DNA was employed to evaluate two quantitative PCR methods: the HER2/neu DNA Quantification Kit (Roche Diagnostics GmbH, Germany), which uses the gastrin chromosome 17 reference gene, and our recently developed Oncolab qPCR assay, where both a chromosome 17 gene (somatostatin receptor type II (SSTR2)) and a non-chromosome 17 reference gene (glyceraldehyde-3-phosphate deshydrogenase (GAPDH)) were used to detect an increase in HER2 gene copy number and to evaluate the aneusomy of chromosome 17, respectively. By IHC/FISH and ELISA, HER2 was overexpressed in 27 (16.6%) and 24 (14.7%) samples, respectively. With the Roche and Oncolab qPCR assays, 29 (17.8%) samples showed a ratio of HER2/gastrin > or = 2.0 and 26 (16.0%) showed a ratio of HER2/SSTR2 > or = 2.0, respectively. In samples presenting HER2/SSTR2 <2.0 and HER2/GAPDH > or = 2.0, which was indicative of a chromosome 17 polysomy, we observed a modest increase in HER2 protein expression. Complete agreement between the four methods for HER2 status determination was obtained for 154 (94.5%) samples. Overall, these results demonstrate that quantitative PCR is a reliable method for analyzing HER2 status and chromosome 17 polysomy.


Subject(s)
Breast Neoplasms/genetics , Chromosome Aberrations , Chromosomes, Human, Pair 17/genetics , Genes, erbB-2 , Polymerase Chain Reaction/methods , Biomarkers, Tumor/analysis , Breast Neoplasms/pathology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Prospective Studies , Receptor, ErbB-2/biosynthesis , Receptors, Estrogen/analysis , Sensitivity and Specificity
19.
Oncogene ; 25(49): 6510-9, 2006 Oct 19.
Article in English | MEDLINE | ID: mdl-16715138

ABSTRACT

Adrenomedullin (AM) is a multifunctional regulatory peptide with important angiogenic and mitogenic properties. Here we identify a region of stable secondary structure in the 5'-untranslated region (5' UTR) of human AM mRNA. Reverse transcriptase-polymerase chain reaction of the 5' UTR consistently resulted, in addition to the product with the expected size of 155 base pair (bp), in a second product with an approximately 65-bp deletion from the central region of the 5' UTR, suggesting the presence of a secondary structure. The presence of a stem-loop structure was confirmed by probing the 5' UTR with RNases with selectivity for single- or double-stranded RNA. We investigated the role of this stem-loop structure in expression of luciferase reporter gene in cultured cell lines. Reporter assays using a chimeric mRNA that combined luciferase and the 5' UTR of AM mRNA demonstrated a dramatic decrease of the reporter activity owing to a decreased translation, whereas the deletion of the stem-loop structure localized between nt +31 and +95 from the cap site led to the recovery of activity. Gel migration shift assays using cytosolic extracts from mammalian cell lines demonstrate a specific binding of a cytosolic protein to riboprobes containing the 5' UTR of AM but not to riboprobes either corresponding to other areas of the message or containing the 5' UTR but lacking the region of secondary structure. Although we conclude that the 5' UTR of the human AM mRNA can modulate the translation of AM mRNA in vivo, and that the predicted stem-loop structure is necessary for this inhibition, the functional consequences of the cis element-binding activity remain to be determined.


Subject(s)
5' Untranslated Regions/chemistry , Peptides/chemistry , Protein Biosynthesis/physiology , RNA, Messenger/chemistry , Adrenomedullin , Base Sequence , Cells, Cultured , DNA, Complementary/chemistry , Genes, Reporter , Humans , Molecular Sequence Data , Nucleic Acid Conformation , Peptides/metabolism , RNA-Binding Proteins/metabolism , Sequence Alignment
20.
Science ; 311(5769): 1911-4, 2006 Mar 31.
Article in English | MEDLINE | ID: mdl-16574864

ABSTRACT

We demonstrated short segments of a superconducting wire that meets or exceeds performance requirements for many large-scale applications of high-temperature superconducting materials, especially those requiring a high supercurrent and/or a high engineering critical current density in applied magnetic fields. The performance requirements for these varied applications were met in 3-micrometer-thick YBa2Cu3O(7-delta) films epitaxially grown via pulsed laser ablation on rolling assisted biaxially textured substrates. Enhancements of the critical current in self-field as well as excellent retention of this current in high applied magnetic fields were achieved in the thick films via incorporation of a periodic array of extended columnar defects, composed of self-aligned nanodots of nonsuperconducting material extending through the entire thickness of the film. These columnar defects are highly effective in pinning the superconducting vortices or flux lines, thereby resulting in the substantially enhanced performance of this wire.

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