Latest PUBLICATIONS

  • PTEN regulates plasma membrane expression of glucose transporter 1 and glucose uptake in thyroid cancer cells.
    Publication Date: 01/10/2014, on Journal of molecular endocrinology
    by Morani F, Phadngam S, Follo C, Titone R, Aimaretti G, Galetto A, Alabiso O, Isidoro C
    DOI: 10.1530/JME-14-0118

    Glucose represents an important source of energy for the cells. Proliferating cancer cells consume elevated quantity of glucose, which is converted into lactate regardless of the presence of oxygen. This phenomenon, known as the Warburg effect, has been proven to be useful for imaging metabolically active tumours in cancer patients by (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Glucose is internalised in the cells by glucose transporters (GLUTs) belonging to the GLUT family. GLUT1 (SLC2A1) is the most prevalent isoform in more aggressive and less differentiated thyroid cancer histotypes. In a previous work, we found that loss of expression of PTEN was associated with increased expression of GLUT1 on the plasma membrane (PM) and probability of detecting thyroid incidentalomas by FDG-PET. Herein, we investigated the molecular pathways that govern the expression of GLUT1 on the PM and the glucose uptake in WRO (expressing WT PTEN) and FTC133 (PTEN null) follicular thyroid cancer cells cultured under glucose-depleted conditions. The membrane expression of GLUT1 was enhanced in glucose-deprived cells. Through genetic manipulations of PTEN expression, we could demonstrate that the lack of this oncosuppressor has a dominant effect on the membrane expression of GLUT1 and glucose uptake. We conclude that loss of function of PTEN increases the probability of cancer detection by FDG-PET or other glucose-based imaging diagnosis.

  • The role of copper(II) in the aggregation of human amylin.
    Publication Date: 01/10/2014, on Metallomics : integrated biometal science
    by Sinopoli A, Magrì A, Milardi D, Pappalardo M, Pucci P, Flagiello A, Titman JJ, Nicoletti VG, Caruso G, Pappalardo G, Grasso G
    DOI: 10.1039/c4mt00130c

    Amylin is a 37-residue peptide hormone produced by the islet β-cells of pancreas and the formation of amylin aggregates is strongly associated with β-cell degeneration in type 2 diabetes, as demonstrated by more than 95% of patients exhibiting amylin amyloid upon autopsy. It is widely recognized that metal ions such as copper(II) have been implicated in the aggregation process of amyloidogenic peptides such as Aβ and α-synuclein and there is evidence that amylin self-assembly is also largely affected by copper(II). For this reason, in this work, the role of copper(II) in the aggregation of amylin has been investigated by several different experimental approaches. Mass spectrometric investigations show that copper(II) induces significant changes in the amylin structure, which decrease the protein fibrillogenesis as observed by ThT measurements. Accordingly, solid-state NMR experiments together with computational analysis carried out on a model amylin fragment confirmed the non-fibrillogenic nature of the copper(II) induced aggregated structure. Finally, the presence of copper(II) is also shown to have a major influence on amylin proneness to be degraded by proteases and cytotoxicity studies on different cell cultures are reported.

  • 5-HTTLPR, anxiety and gender interaction moderates right amygdala volume in healthy subjects.
    Publication Date: 01/10/2014, on Social cognitive and affective neuroscience
    by Cerasa A, Quattrone A, Piras F, Mangone G, Magariello A, Fagioli S, Girardi P, Muglia M, Caltagirone C, Spalletta G
    DOI: 10.1093/scan/nst144

    Genetic variants within the serotonin transporter gene (5-HTTLPR) impact the neurobiology and risk for anxiety-related behaviours. There are also gender differences in the prevalence of anxiety-related behaviours. Although numerous studies have investigated the influence of 5-HTTLPR genotype on the neural systems involved in emotional regulation, none have investigated how these effects are modulated by gender and anxiety. We investigated this issue using two complementary region of interest-based structural neuroimaging approaches (voxel-based morphometry and Freesurfer) in 138 healthy individuals categorized into 'no anxiety' and 'subclinical anxiety' groups based on the Hamilton Rating Scale for Anxiety (HAM-A). Preliminarily, using anxiety as a continuous variable, we found a significant interaction effect of genotype by gender on anxiety. Females homozygous for the Short allele showed the highest HAM-A scores and males the lowest. In addition, a three-way significant interaction among genotype, gender and anxiety category was found for the right amygdala volume. Post hoc tests revealed that homozygous females carrying the Short variant with a subclinical anxiety condition had larger volume. The reported interaction effects demonstrate that gender strongly modulates the relationship between 5-HTTLPR genotype and subclinical expression of anxiety acting on amygdala, one region of the emotional neural network specifically involved in the anxiety-like behaviours.

  • Metabolic syndrome-breast cancer link varies by intrinsic molecular subtype.
    Publication Date: 26/09/2014, on Diabetology & metabolic syndrome
    by Capasso I, Esposito E, de Laurentiis M, Maurea N, Cavalcanti E, Botti G, Petrillo A, Montella M, D'Aiuto M, Coppola C, Crispo A, Grimaldi M, Frasci G, Fucito A, Ciliberto G, D'Aiuto G
    DOI: 10.1186/1758-5996-6-105

    Metabolic syndrome (MS) has been shown to increase the risk of breast cancer. Existing data suggest that the strength of metabolic syndrome-breast cancer link varies by intrinsic molecular subtype, but results from worldwide literature are controversial. Primary endpoint of the study was to assess whether MS is a predictor of specific breast cancer (BC) subtype. Secondary endpoint was to determine whether components of MS can individually increase the risk of specific breast cancer subtype.

  • Monitoring reversal of MET-mediated resistance to EGFR tyrosine kinase inhibitors in non-small cell lung cancer using 3'-deoxy-3'-[18F]-fluorothymidine positron emission tomography.
    Publication Date: 15/09/2014, on Clinical cancer research : an official journal of the American Association for Cancer Research
    by Iommelli F, De Rosa V, Gargiulo S, Panico M, Monti M, Greco A, Gramanzini M, Ortosecco G, Fonti R, Brunetti A, Del Vecchio S
    DOI: 10.1158/1078-0432.CCR-14-0264

    MET amplification is one of the mechanisms underlying acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non-small cell lung cancer (NSCLC). Here, we tested whether 3'-deoxy-3'-[(18)F]-fluorothymidine ([(18)F]FLT) positron emission tomography/computerized tomography (PET/CT) can detect MET-mediated resistance to EGFR TKIs and monitor the effects of MET inhibitors in NSCLC.

  • The serotonin receptor 7 and the structural plasticity of brain circuits.
    Publication Date: 12/09/2014, on Frontiers in behavioral neuroscience
    by Volpicelli F, Speranza L, di Porzio U, Crispino M, Perrone-Capano C
    DOI: 10.3389/fnbeh.2014.00318

    Serotonin (5-hydroxytryptamine, 5-HT) modulates numerous physiological processes in the nervous system. Together with its function as neurotransmitter, 5-HT regulates neurite outgrowth, dendritic spine shape and density, growth cone motility and synapse formation during development. In the mammalian brain 5-HT innervation is virtually ubiquitous and the diversity and specificity of its signaling and function arise from at least 20 different receptors, grouped in 7 classes. Here we will focus on the role 5-HT7 receptor (5-HT7R) in the correct establishment of neuronal cytoarchitecture during development, as also suggested by its involvement in several neurodevelopmental disorders. The emerging picture shows that this receptor is a key player contributing not only to shape brain networks during development but also to remodel neuronal wiring in the mature brain, thus controlling cognitive and emotional responses. The activation of 5-HT7R might be one of the mechanisms underlying the ability of the CNS to respond to different stimuli by modulation of its circuit configuration.

  • The gap between the physiological and therapeutic roles of mesenchymal stem cells.
    Publication Date: 01/09/2014, on Medicinal research reviews
    by Galderisi U, Giordano A
    DOI: 10.1002/med.21322

    Several investigators have cultivated marrow stromal cells and have identified a population of mesenchymal stem cells (MSCs). These cells expand extensively in vitro and exhibit multilineage differentiation potential. The lack of MSC-specific markers impedes identification of MSC functions. Further in vivo studies of these cells may elucidate the nature of MSCs. Although the nature of MSCs remains unclear, nonclonal stromal cultures are used as a source of putative MSCs for therapeutic purposes. Preclinical studies and clinical trials assumed that transplanted MSCs exert their effects through their differentiation properties or through the release of molecules that restore tissue functions and modulate immune cells. These studies reported contradictory results and failed to meet expectations. Thus, it is important to note that current protocols for MSC therapy are primarily based on the use of in vitro expanded nonclonal MSCs. Clearly defining the physiological features of in situ MSCs and the in vitro and in vivo properties of nonclonal cultures of stromal cells, which are often misidentified as pure stem cell cultures, may explain the reported failures of MSC therapy. This review will address these issues.

  • Noncanonical DNA secondary structures as drug targets: the prospect of the i-motif.
    Publication Date: 01/09/2014, on ChemMedChem
    by Amato J, Iaccarino N, Randazzo A, Novellino E, Pagano B
    DOI: 10.1002/cmdc.201402153

    Under certain conditions, specific DNA sequences have the potential to adopt noncanonical secondary structures, such as i-motifs. Interestingly, these DNA stretches are not randomly located throughout the genome but rather frequently clustered in regulatory regions of oncogenes and in telomeres, the terminal regions of chromosomes. Recent evidences suggest that i-motif DNA structures exist in living cells and could be involved in a variety of biological processes, such as replication, regulation of oncogene expression, and telomere functions. Therefore, the targeting of i-motif DNA is an emerging research area in medicinal chemistry. Bringing these noncanonical structures into focus as targets for anticancer drug design and gene regulation processes could be crucial for a better understanding of their biological functions and to open the way to new, effective strategies for cancer treatment.

  • Structure, stability, and IgE binding of the peach allergen Peamaclein (Pru p 7).
    Publication Date: 01/09/2014, on Biopolymers
    by Tuppo L, Spadaccini R, Alessandri C, Wienk H, Boelens R, Giangrieco I, Tamburrini M, Mari A, Picone D, Ciardiello MA
    DOI: 10.1002/bip.22530

    Knowledge of the structural properties of allergenic proteins is a necessary prerequisite to better understand the molecular bases of their action, and also to design targeted structural/functional modifications. Peamaclein is a recently identified 7 kDa peach allergen that has been associated with severe allergic reactions in sensitive subjects. This protein represents the first component of a new allergen family, which has no 3D structure available yet. Here, we report the first experimental data on the 3D-structure of Peamaclein. Almost 75% of the backbone resonances, including two helical stretches in the N-terminal region, and four out of six cysteine pairs have been assigned by 2D-NMR using a natural protein sample. Simulated gastrointestinal digestion experiments have highlighted that Peamaclein is even more resistant to digestion than the peach major allergen Pru p 3. Only the heat-denatured protein becomes sensitive to intestinal proteases. Similar to Pru p 3, Peamaclein keeps its native 3D-structure up to 90°C, but it becomes unfolded at temperatures of 100-120°C. Heat denaturation affects the immunological properties of both peach allergens, which lose at least partially their IgE-binding epitopes. In conclusion, the data collected in this study provide a first set of information on the molecular properties of Peamaclein. Future studies could lead to the possible use of the denatured form of this protein as a vaccine, and of the inclusion of cooked peach in the diet of subjects allergic to Peamaclein.

  • Pathogenesis and treatment of falls in elderly.
    Publication Date: 01/09/2014, on Clinical cases in mineral and bone metabolism : the official journal of the Italian Society of Osteoporosis, Mineral Metabolism, and Skeletal Diseases
    by Pasquetti P, Apicella L, Mangone G
    DOI:

    Falls in the elderly are a public health problem. Consequences of falls are increased risk of hospitalization, which results in an increase in health care costs. It is estimated that 33% of individuals older than 65 years undergoes falls. Causes of falls can be distinguished in intrinsic and extrinsic predisposing conditions. The intrinsic causes can be divided into age-related physiological changes and pathological predisposing conditions. The age-related physiological changes are sight disorders, hearing disorders, alterations in the Central Nervous System, balance deficits, musculoskeletal alterations. The pathological conditions can be Neurological, Cardiovascular, Endocrine, Psychiatric, Iatrogenic. Extrinsic causes of falling are environmental factors such as obstacles, inadequate footwear. The treatment of falls must be multidimensional and multidisciplinary. The best instrument in evaluating elderly at risk is Comprehensive Geriatric Assessment (CGA). CGA allows better management resulting in reduced costs. The treatment should be primarily preventive acting on extrinsic causes; then treatment of chronic and acute diseases. Rehabilitation is fundamental, in order to improve residual capacity, motor skills, postural control, recovery of strength. There are two main types of exercises: aerobic and muscular strength training. Education of patient is a key-point, in particular through the Back School. In conclusion falls in the elderly are presented as a "geriatric syndrome"; through a multidimensional assessment, an integrated treatment and a rehabilitation program is possible to improve quality of life in elderly.

  • S-Glutathionylation at Cys328 and Cys542 impairs STAT3 phosphorylation.
    Publication Date: 15/08/2014, on ACS chemical biology
    by Butturini E, Darra E, Chiavegato G, Cellini B, Cozzolino F, Monti M, Pucci P, Dell'Orco D, Mariotto S
    DOI: 10.1021/cb500407d

    STAT3 is a latent transcription factor that promotes cell survival and proliferation and is often constitutively active in cancers. Although many reports provide evidence that STAT3 is a direct target of oxidative stress, its redox regulation is poorly understood. Under oxidative conditions STAT3 activity can be modulated by S-glutathionylation, a reversible redox modification of cysteine residues. This suggests the possible cross-talk between phosphorylation and glutathionylation and points out that STAT3 is susceptible to redox regulation. Recently, we reported that decreasing the GSH content in different cell lines induces inhibition of STAT3 activity through the reversible oxidation of thiol groups. In the present work, we demonstrate that GSH/diamide treatment induces S-glutathionylation of STAT3 in the recombinant purified form. This effect was completely reversed by treatment with the reducing agent dithiothreitol, indicating that S-glutathionylation of STAT3 was related to formation of protein-mixed disulfides. Moreover, addition of the bulky negatively charged GSH moiety impairs JAK2-mediated STAT3 phosphorylation, very likely interfering with tyrosine accessibility and thus affecting protein structure and function. Mass mapping analysis identifies two glutathionylated cysteine residues, Cys328 and Cys542, within the DNA-binding domain and the linker domain, respectively. Site direct mutagenesis and in vitro kinase assay confirm the importance of both cysteine residues in the complex redox regulatory mechanism of STAT3. Cells expressing mutant were resistant in this regard. The data presented herein confirmed the occurrence of a redox-dependent regulation of STAT3, identified the more redox-sensitive cysteines within STAT3 structure, and may have important implications for development of new drugs.

  • Antagonistic role of CotG and CotH on spore germination and coat formation in Bacillus subtilis.
    Publication Date: 12/08/2014, on PloS one
    by Saggese A, Scamardella V, Sirec T, Cangiano G, Isticato R, Pane F, Amoresano A, Ricca E, Baccigalupi L
    DOI: 10.1371/journal.pone.0104900

    Spore formers are bacteria able to survive harsh environmental conditions by differentiating a specialized, highly resistant spore. In Bacillus subtilis, the model system for spore formers, the recently discovered crust and the proteinaceous coat are the external layers that surround the spore and contribute to its survival. The coat is formed by about seventy different proteins assembled and organized into three layers by the action of a subset of regulatory proteins, referred to as morphogenetic factors. CotH is a morphogenetic factor needed for the development of spores able to germinate efficiently and involved in the assembly of nine outer coat proteins, including CotG. Here we report that CotG has negative effects on spore germination and on the assembly of at least three outer coat proteins. Such negative action is exerted only in mutants lacking CotH, thus suggesting an antagonistic effect of the two proteins, with CotH counteracting the negative role of CotG.

  • Haptoglobin increases with age in rat hippocampus and modulates Apolipoprotein E mediated cholesterol trafficking in neuroblastoma cell lines.
    Publication Date: 05/08/2014, on Frontiers in cellular neuroscience
    by Spagnuolo MS, Maresca B, Mollica MP, Cavaliere G, Cefaliello C, Trinchese G, Esposito MG, Scudiero R, Crispino M, Abrescia P, Cigliano L
    DOI: 10.3389/fncel.2014.00212

    Alteration in cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative disorders. Apolipoprotein E (ApoE) is the major component of brain lipoproteins supporting cholesterol transport. We previously reported that the acute-phase protein Haptoglobin (Hpt) binds ApoE, and influences its function in blood cholesterol homeostasis. Major aim of this study was to investigate whether Hpt influences the mechanisms by which cholesterol is shuttled from astrocytes to neurons. In detail it was studied Hpt effect on ApoE-dependent cholesterol efflux from astrocytes and ApoE-mediated cholesterol incorporation in neurons. We report here that Hpt impairs ApoE-mediated cholesterol uptake in human neuroblastoma cell line SH-SY5Y, and limits the toxicity of a massive concentration of cholesterol for these cells, while it does not affect cholesterol efflux from the human glioblastoma-astrocytoma cell line U-87 MG. As aging is the most important non-genetic risk factor for various neurodegenerative disorders, and our results suggest that Hpt modulates ApoE functions, we evaluated the Hpt and ApoE expression profiles in cerebral cortex and hippocampus of adolescent (2 months), adult (5 and 8 months), and middle-aged (16 months) rats. Hpt mRNA level was higher in hippocampus of 8 and 16 month-old than in 2-month old rats (p < 0.05), and Hpt concentration increased with the age from adolescence to middle-age (p < 0.001). ApoE concentration, in hippocampus, was higher (p < 0.001) in 5 month-old rats compared to 2 month but did not further change with aging. No age-related changes of Hpt (protein and mRNA) were found in the cortex. Our results suggest that aging is associated with changes, particularly in the hippocampus, in the Hpt/ApoE ratio. Age-related changes in the concentration of Hpt were also found in human cerebrospinal fluids. The age-related changes might affect neuronal function and survival in brain, and have important implications in brain pathophysiology.

  • Vascular-homing peptides for targeted drug delivery and molecular imaging: meeting the clinical challenges.
    Publication Date: 01/08/2014, on Biochimica et biophysica acta
    by D'Onofrio N, Caraglia M, Grimaldi A, Marfella R, Servillo L, Paolisso G, Balestrieri ML
    DOI: 10.1016/j.bbcan.2014.03.004

    The vasculature of each organ expresses distinct molecular signatures critically influenced by the pathological status. The heterogeneous profile of the vascular beds has been successfully unveiled by the in vivo phage display, a high-throughput tool for mapping normal, diseased, and tumor vasculature. Specific challenges of this growing field are targeted therapies against cancer and cardiovascular diseases, as well as novel bioimaging diagnostic tools. Tumor vasculature-homing peptides have been extensively evaluated in several preclinical and clinical studies both as targeted-therapy and diagnosis. To date, results from several Phase I and II trials have been reported and many other trials are currently ongoing or recruiting patients. In this review, advances in the identification of novel peptide ligands and their corresponding receptors on tumor endothelium through the in vivo phage display technology are discussed. Emphasis is given to recent findings in the clinical setting of vascular-homing peptides selected by in vivo phage display for the treatment of advanced malignancies and their altered vascular beds.

  • Recurrent glioblastoma multiforme versus radiation injury: a multiparametric 3-T MR approach.
    Publication Date: 01/08/2014, on La Radiologia medica
    by Di Costanzo A, Scarabino T, Trojsi F, Popolizio T, Bonavita S, de Cristofaro M, Conforti R, Cristofano A, Colonnese C, Salvolini U, Tedeschi G
    DOI: 10.1007/s11547-013-0371-y

    The discrimination between recurrent glioma and radiation injury is often a challenge on conventional magnetic resonance imaging (MRI). We verified whether adding and combining proton MR spectroscopic imaging ((1)H-MRSI), diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) information at 3 Tesla facilitate such discrimination.