Latest PUBLICATIONS

  • BAG3 mRNA is present in synaptosomal polysomes of rat brain.
    Publication Date: 01/01/2014, on Cell cycle (Georgetown, Tex.)
    by Bruno AP, Cefaliello C, D'Auria R, Crispino M, Rosati A, Giuditta A, Nori SL
    DOI: 10.4161/cc.28655

  • A new design for nucleolipid-based Ru(III) complexes as anticancer agents.
    Publication Date: 28/12/2013, on Dalton transactions (Cambridge, England : 2003)
    by Montesarchio D, Mangiapia G, Vitiello G, Musumeci D, Irace C, Santamaria R, D'Errico G, Paduano L
    DOI: 10.1039/c3dt52320a

    In continuation with our studies concerning the synthesis, characterization and biological evaluation of nucleolipidic Ru(III) complexes, a novel design for this family of potential anticancer agents is presented here. As a model compound, a new uridine-based nucleolipid has been prepared, named HoUrRu, following a simple and versatile synthetic procedure, and converted into a Ru(III) salt. Stable formulations of this highly functionalized Ru(III) complex have been obtained by co-aggregation with either the zwitterionic lipid POPC or the cationic DOTAP, which have been subjected to an in-depth microstructural characterization, including DLS, SANS and EPR measurements. The in vitro bioactivity profile of HoUrRu, as a pure compound or in formulation with POPC or DOTAP, reveals high antiproliferative activity against MCF-7 and WiDr human cancer cell lines.

  • Ion transport through lipid bilayers by synthetic ionophores: modulation of activity and selectivity.
    Publication Date: 17/12/2013, on Accounts of chemical research
    by De Riccardis F, Izzo I, Montesarchio D, Tecilla P
    DOI: 10.1021/ar4000136

    The ion-coupled processes that occur in the plasma membrane regulate the cell machineries in all the living organisms. The details of the chemical events that allow ion transport in biological systems remain elusive. However, investigations of the structure and function of natural and artificial transporters has led to increasing insights about the conductance mechanisms. Since the publication of the first successful artificial system by Tabushi and co-workers in 1982, synthetic chemists have designed and constructed a variety of chemically diverse and effective low molecular weight ionophores. Despite their relative structural simplicity, ionophores must satisfy several requirements. They must partition in the membrane, interact specifically with ions, shield them from the hydrocarbon core of the phospholipid bilayer, and transport ions from one side of the membrane to the other. All these attributes require amphipathic molecules in which the polar donor set used for ion recognition (usually oxygens for cations and hydrogen bond donors for anions) is arranged on a lipophilic organic scaffold. Playing with these two structural motifs, donor atoms and scaffolds, researchers have constructed a variety of different ionophores, and we describe a subset of interesting examples in this Account. Despite the ample structural diversity, structure/activity relationships studies reveal common features. Even when they include different hydrophilic moieties (oxyethylene chains, free hydroxyl, etc.) and scaffolds (steroid derivatives, neutral or polar macrocycles, etc.), amphipathic molecules, that cannot span the entire phospholipid bilayer, generate defects in the contact zone between the ionophore and the lipids and increase the permeability in the bulk membrane. Therefore, topologically complex structures that span the entire membrane are needed to elicit channel-like and ion selective behaviors. In particular the alternate-calix[4]arene macrocycle proved to be a versatile platform to obtain 3D-structures that can form unimolecular channels in membranes. In these systems, the selection of proper donor groups allows us to control the ion selectivity of the process. We can switch from cation to anion transport by substituting protonated amines for the oxygen donors. Large and stable tubular structures with nanometric sized transmembrane nanopores that provide ample internal space represent a different approach for the preparation of synthetic ion channels. We used the metal-mediated self-assembly of porphyrin ligands with Re(I) corners as a new method for producing to robust channel-like structures. Such structures can survive in the complex membrane environment and show interesting ionophoric behavior. In addition to the development of new design principles, the selective modification of the biological membrane permeability could lead to important developments in medicine and technology.

  • Autophagy and thyroid carcinogenesis: genetic and epigenetic links.
    Publication Date: 16/12/2013, on Endocrine-related cancer
    by Morani F, Titone R, Pagano L, Galetto A, Alabiso O, Aimaretti G, Isidoro C
    DOI: 10.1530/ERC-13-0271

    Thyroid cancer is the most common cancer of the endocrine system and is responsible for the majority of deaths from endocrine malignancies. Although a large proportion of thyroid cancers belong to well differentiated histologic subtypes, which in general show a good prognosis after surgery and radioiodine ablation, the treatment of radio-resistant papillary-type, of undifferentiated anaplastic, and of medullary-type thyroid cancers remains unsatisfactory. Autophagy is a vesicular process for the lysosomal degradation of protein aggregates and of damaged or redundant organelles. Autophagy plays an important role in cell homeostasis, and there is evidence that this process is dysregulated in cancer cells. Recent in vitro preclinical studies have indicated that autophagy is involved in the cytotoxic response to chemotherapeutics in thyroid cancer cells. Indeed, several oncogenes and oncosuppressor genes implicated in thyroid carcinogenesis also play a role in the regulation of autophagy. In addition, some epigenetic modulators involved in thyroid carcinogenesis also influence autophagy. In this review, we highlight the genetic and epigenetic factors that mechanistically link thyroid carcinogenesis and autophagy, thus substantiating the rationale for an autophagy-targeted therapy of aggressive and radio-chemo-resistant thyroid cancers.

  • Exploring the chemical space of G-quadruplex binders: discovery of a novel chemotype targeting the human telomeric sequence.
    Publication Date: 12/12/2013, on Journal of medicinal chemistry
    by Di Leva FS, Zizza P, Cingolani C, D'Angelo C, Pagano B, Amato J, Salvati E, Sissi C, Pinato O, Marinelli L, Cavalli A, Cosconati S, Novellino E, Randazzo A, Biroccio A
    DOI: 10.1021/jm401185b

    Recent findings have unambiguously demonstrated that DNA G-rich sequences can adopt a G-quadruplex folding in living cells, thus further validating them as crucial targets for anticancer therapy. Herein, to identify new potent G4 binders as antitumor drug candidates, we have targeted a 24-nt G4-forming telomeric sequence employing a receptor-based virtual screening approach. Among the best candidates, in vitro binding experiments allowed identification of three novel G4 ligands. Among them, the best compound features an unprecedented binding selectivity for the human telomeric DNA G-quadruplex with no detectable binding for other G4-forming sequences present at different genomic sites. This behavior correlates with the detected ability to generate DNA damage response in tumor cells at the telomeric level and efficient antiproliferative effect on different tumor cell lines at low micromolar concentrations.

  • Bergamot polyphenolic fraction enhances rosuvastatin-induced effect on LDL-cholesterol, LOX-1 expression and protein kinase B phosphorylation in patients with hyperlipidemia.
    Publication Date: 10/12/2013, on International journal of cardiology
    by Gliozzi M, Walker R, Muscoli S, Vitale C, Gratteri S, Carresi C, Musolino V, Russo V, Janda E, Ragusa S, Aloe A, Palma E, Muscoli C, Romeo F, Mollace V
    DOI: 10.1016/j.ijcard.2013.08.125

    Statins are the most commonly prescribed drugs to reduce cardiometabolic risk. Besides the well-known efficacy of such compounds in both preventing and treating cardiometabolic disorders, some patients experience statin-induced side effects. We hypothesize that the use of natural bergamot-derived polyphenols may allow patients undergoing statin treatment to reduce effective doses while achieving target lipid values. The aim of the present study is to investigate the occurrence of an enhanced effect of bergamot-derived polyphenolic fraction (BPF) on rosuvastatin-induced hypolipidemic and vasoprotective response in patients with mixed hyperlipidemia.

  • Polyketide genes in the marine sponge Plakortis simplex: a new group of mono-modular type I polyketide synthases from sponge symbionts.
    Publication Date: 01/12/2013, on Environmental microbiology reports
    by Della Sala G, Hochmuth T, Costantino V, Teta R, Gerwick W, Gerwick L, Piel J, Mangoni A
    DOI: 10.1111/1758-2229.12081

    Sponge symbionts are a largely unexplored source of new and unusual metabolic pathways. Insights into the distribution and function of metabolic genes of sponge symbionts are crucial to dissect and exploit their biotechnological potential. Screening of the metagenome of the marine sponge Plakortis simplex led to the discovery of the swf family, a new group of mono-modular type I polyketide synthase/fatty acid synthase (PKS/FAS) specifically associated with sponge symbionts. Two different examples of the swf cluster were present in the metagenome of P. simplex. A third example of the cluster is present in the previously sequenced genome of a poribacterium from the sponge Aplysina aerophoba but was formerly considered orthologous to the wcb/rkp cluster. The swf cluster was also found in six additional species of sponges. Therefore, the swf cluster represents the second group of mono-modular PKS, after the supA family, to be widespread in marine sponges. The putative swf operon consists of swfA (type I PKS/FAS), swfB (reductase and sulphotransferase domains) and swfC (radical S-adenosylmethionine, or radical SAM). Activation of the acyl carrier protein (ACP) domain of the SwfA protein to its holo-form by co-expression with Svp is the first functional proof of swf type genes in marine sponges. However, the precise biosynthetic role of the swf clusters remains unknown.

  • Motor and extramotor neurodegeneration in amyotrophic lateral sclerosis: a 3T high angular resolution diffusion imaging (HARDI) study.
    Publication Date: 01/12/2013, on Amyotrophic lateral sclerosis & frontotemporal degeneration
    by Trojsi F, Corbo D, Caiazzo G, Piccirillo G, Monsurrò MR, Cirillo S, Esposito F, Tedeschi G
    DOI: 10.3109/21678421.2013.785569

    In amyotrophic lateral sclerosis (ALS), diffusion weighted magnetic resonance imaging (DW-MRI) has produced mounting evidence of a widespread white matter (WM) damage within motor and extramotor pathways. To provide novel information about the degenerative process in ALS, overcoming some of the limitations imposed by diffusion tensor imaging (DTI), we performed a high angular resolution diffusion imaging (HARDI) analysis of DW-MRI data. Generalized fractional anisotropy (GFA) was evaluated in 19 patients with ALS and 19 matched control subjects, and was correlated with clinical scores of disability, pyramidal impairment by upper motor neuron (UMN) score and frontal dysfunction by the Frontal Systems Behaviour (FrSBe) scale. Results demonstrated that ALS patients showed a significant decrease of GFA in the WM tracts underneath the left and right precentral gyri and the body of the corpus callosum (p < 0.05, corrected), where GFA was significantly related to UMN scores (p < 0.001, uncorrected); and in the left superior longitudinal fasciculus (p < 0.05, corrected), where GFA was significantly related to FrSBe scale scores (p < 0.01, uncorrected). In conclusion, this study revealed a pattern of motor and extramotor frontal diffusivity abnormalities (probably related to behavioural and cognitive dysfunctions) showing a spatial distribution similar to what was previously described in ALS - frontotemporal dementia continuum.

  • PNA as a potential modulator of COL7A1 gene expression in dominant dystrophic epidermolysis bullosa: a physico-chemical study.
    Publication Date: 01/12/2013, on Molecular bioSystems
    by Amato J, Stellato MI, Pizzo E, Petraccone L, Oliviero G, Borbone N, Piccialli G, Orecchia A, Bellei B, Castiglia D, Giancola C
    DOI: 10.1039/c3mb70283a

    Dominant diseases are single gene disorders occurring in the heterozygous state. The mutated allele exerts a dominant effect because it produces an abnormal polypeptide that interferes with the function of the normal allele product. Peptide Nucleic Acids (PNAs) offer a route for a potential therapy for dominant diseases by selectively silencing the allele carrying the dominant mutation. Here, we have synthesized and studied the properties of a 15-mer PNA fully complementary to the site of the c.5272-38T>A sequence variation, which identifies a recurrent mutant COL7A1 allele causing dominant dystrophic epidermolysis bullosa (DDEB), a mendelian disease characterized by skin blistering. The PNA was conjugated with four lysine residues at the C-terminus and a fluorescent probe at the N-terminus. Physico-chemical results proved the formation of a stable, selective PNA/mutant-DNA heteroduplex in vitro. Intriguingly, when transfected into normal human fibroblasts, the PNA correctly localized in the cell nucleus. Our results open new therapeutic possibilities for patients with DDEB.

  • Combined rod and cone transduction by adeno-associated virus 2/8.
    Publication Date: 01/12/2013, on Human gene therapy
    by Manfredi A, Marrocco E, Puppo A, Cesi G, Sommella A, Della Corte M, Rossi S, Giunti M, Craft CM, Bacci ML, Simonelli F, Surace EM, Auricchio A
    DOI: 10.1089/hum.2013.154

    Gene transfer to both cone and rod photoreceptors (PRs) is essential for gene therapy of inherited retinal degenerations that are caused by mutations in genes expressed in both PR types. Vectors based on the adeno-associated virus (AAV) efficiently transduce PRs of different species. However, these are predominantly rods and little is known about the ability of the AAV to transduce cones in combination with rods. Here we show that AAV2/8 transduces pig cones to levels that are similar to AAV2/9, and the outer nuclear layer (mainly rods) to levels that are on average higher, although not statistically significant, than both AAV2/5 and AAV2/9. We additionally found that the ubiquitous cytomegalovirus (CMV), but not the PR-specific GRK1 promoter, transduced pig cones efficiently, presumably because GRK1 is not expressed in pig cones as observed in mice and humans. Indeed, the GRK1 and CMV promoters transduce a similar percentage of murine cones with the CMV reaching the highest expression levels. Consistent with this, the AAV2/8 vectors with either the CMV or the GRK1 promoter restore cone function in a mouse model of Leber congenital amaurosis type 1 (LCA1), supporting the use of AAV2/8 for gene therapy of LCA1 as well as of other retinal diseases requiring gene transfer to both PR types.

  • The multiple forms of bovine seminal ribonuclease: structure and stability of a C-terminal swapped dimer.
    Publication Date: 29/11/2013, on FEBS letters
    by Sica F, Pica A, Merlino A, Russo Krauss I, Ercole C, Picone D
    DOI: 10.1016/j.febslet.2013.10.003

    Bovine seminal ribonuclease (BS-RNase) acquires an interesting anti-tumor activity associated with the swapping on the N-terminal. The first direct experimental evidence on the formation of a C-terminal swapped dimer (C-dimer) obtained from the monomeric derivative of BS-RNase, although under non-native conditions, is here reported. The X-ray model of this dimer reveals a quaternary structure different from that of the C-dimer of RNase A, due to the presence of three mutations in the hinge peptide 111-116. The mutations increase the hinge peptide flexibility and decrease the stability of the C-dimer against dissociation. The biological implications of the structural data are also discussed.

  • Fluorescence enhancement upon G-quadruplex folding: synthesis, structure, and biophysical characterization of a dansyl/cyclodextrin-tagged thrombin binding aptamer.
    Publication Date: 20/11/2013, on Bioconjugate chemistry
    by De Tito S, Morvan F, Meyer A, Vasseur JJ, Cummaro A, Petraccone L, Pagano B, Novellino E, Randazzo A, Giancola C, Montesarchio D
    DOI: 10.1021/bc400352s

    A novel fluorescent thrombin binding aptamer (TBA), conjugated with the environmentally sensitive dansyl probe at the 3'-end and a β-cyclodextrin residue at the 5'-end, has been efficiently synthesized exploiting Cu(I)-catalyzed azide-alkyne cycloaddition procedures. Its conformation and stability in solution have been studied by an integrated approach, combining in-depth NMR, CD, fluorescence, and DSC studies. ITC measurements have allowed us to analyze in detail its interaction with human thrombin. All the collected data show that this bis-conjugated aptamer fully retains its G-quadruplex formation ability and thrombin recognition properties, with the terminal appendages only marginally interfering with the conformational behavior of TBA. Folding of this modified aptamer into the chairlike, antiparallel G-quadruplex structure, promoted by K(+) and/or thrombin binding, typical of TBA, is associated with a net fluorescence enhancement, due to encapsulation of dansyl, attached at the 3'-end, into the apolar cavity of the β-cyclodextrin at the 5'-end. Overall, the structural characterization of this novel, bis-conjugated TBA fully demonstrates its potential as a diagnostic tool for thrombin recognition, also providing a useful basis for the design of suitable aptamer-based devices for theranostic applications, allowing simultaneously both detection and inhibition or modulation of the thrombin activity.

  • Resveratrol couples apoptosis with autophagy in UVB-irradiated HaCaT cells.
    Publication Date: 19/11/2013, on PloS one
    by Vitale N, Kisslinger A, Paladino S, Procaccini C, Matarese G, Pierantoni GM, Mancini FP, Tramontano D
    DOI: 10.1371/journal.pone.0080728

    UVB radiation causes about 90% of non-melanoma skin cancers by damaging DNA either directly or indirectly by increasing levels of reactive oxygen species (ROS). Skin, chronically exposed to both endogenous and environmental pro-oxidant agents, contains a well-organised system of chemical and enzymatic antioxidants. However, increased or prolonged free radical action can overwhelm ROS defence mechanisms, contributing to the development of cutaneous diseases. Thus, new strategies for skin protection comprise the use of food antioxidants to counteract oxidative stress. Resveratrol, a phytoalexin from grape, has gained a great interest for its ability to influence several biological mechanisms like redox balance, cell proliferation, signal transduction pathways, immune and inflammatory response. Therefore, the potential of resveratrol to modify skin cell response to UVB exposure could turn out to be a useful option to protect skin from sunlight-induced degenerative diseases. To investigate into this matter, HaCaT cells, a largely used model for human skin keratinocytes, were treated with 25 or 100 µM resveratrol for 2 and 24 hours prior to UVB irradiation (10 to 100 mJ/cm(2)). Cell viability and molecular markers of proliferation, oxidative stress, apoptosis, and autophagy were analyzed. In HaCaT cells resveratrol pretreatment: reduces UVB-induced ROS formation, enhances the detrimental effect of UVB on HaCaT cell vitality, increases UVB-induced caspase 8, PARP cleavage, and induces autophagy. These findings suggest that resveratrol could exert photochemopreventive effects by enhancing UVB-induced apoptosis and by inducing autophagy, thus reducing the odds that damaged cells could escape programmed cell death and initiate malignant transformation.

  • Structural and functional relationships of natural and artificial dimeric bovine ribonucleases: new scaffolds for potential antitumor drugs.
    Publication Date: 15/11/2013, on FEBS letters
    by Gotte G, Laurents DV, Merlino A, Picone D, Spadaccini R
    DOI: 10.1016/j.febslet.2013.09.038

    Protein aggregation via 3D domain swapping is a complex mechanism which can lead to the acquisition of new biological, benign or also malignant functions, such as amyloid deposits. In this context, RNase A represents a fascinating model system, since by dislocating different polypeptide chain regions, it forms many diverse oligomers. No other protein displays such a large number of different quaternary structures. Here we report a comparative structural analysis between natural and artificial RNase A dimers and bovine seminal ribonuclease, a natively dimeric RNase with antitumor activity, with the aim to design RNase A derivatives with improved pharmacological potential.

  • The synergistic effect of everolimus and chloroquine on endothelial cell number reduction is paralleled by increased apoptosis and reduced autophagy occurrence.
    Publication Date: 11/11/2013, on PloS one
    by Grimaldi A, Balestrieri ML, D'Onofrio N, Di Domenico G, Nocera C, Lamberti M, Tonini G, Zoccoli A, Santini D, Caraglia M, Pantano F
    DOI: 10.1371/journal.pone.0079658

    Endothelial Progenitor Cells (EPCs), a minor subpopulation of the mononuclear cell fraction in peripheral blood, play a critical role in cancer development as they contribute to angiogenesis-mediated pathological neovascularization. In response to tumor cytokines, including VEGF, EPCs mobilize from the bone marrow into the peripheral circulation and move to the tumor bed where they incorporate into sprouting neovessels. In the present study, we evaluated the effects of everolimus (Afinitor, Novartis), a rapamycin analogue, alone or in combination with chloroquine, a 4-alkylamino substituted quinoline family member, one of the autophagy inhibitors, on EPCs biological functions. We found that either everolimus or chloroquine induce growth inhibition on EPCs in a dose-dependent manner after 72 h from the beginning of incubation. The combined administration of the two drugs to EPC was synergistic in inducing growth inhibition; in details, the maximal pharmacological synergism between everolimus and chloroquine in inducing growth inhibition on EPCs cells was recorded when chloroquine was administered 24 h before everolimus. Moreover, we have studied the mechanisms of cell death induced by the two agents alone or in combination on EPCs and we have found that the synergistic effect of combination on EPC growth inhibition was paralleled by increased apoptosis induction and reduced autophagy. These effects occurred together with biochemical features that are typical of reduced autophagic death such as increased co-immunoprecipitation between Beclin 1 and Bcl-2. Chloroquine antagonized the inhibition of the activity of Akt→4EBP1 axis mediated by everolimus and at the same time it blocked the feed-back activation of Erk-1/2 induced by RAD in EPCs. These data suggest a new strategy in order to block angiogenesis in tumours in which this process plays a key role in both the sustainment and spreading of cancer cells.