Search

The engineering of chemical communication at the micro/nanoscale is a key emergent topic in micro/nanotechnology, synthetic biology, and related areas. However, the field is still in its infancy; previous advances, although scarce, have mainly focused on communication between abiotic micro/nanosystems or between microvesicles and living cells. Here, we have implemented a nanoprogrammed cross-kingdom communication involving two different microorganisms and tailor-made nanodevices acting as "nanotranslators". Information flows from the sender cells (bacteria) to the nanodevice and from the nanodevice to receiver cells (yeasts) in a hierarchical way, allowing communication between two microorganisms that otherwise would not interact.

[EN] The construction of communication models at the micro¿/nanoscale involving abiotic nanodevices and living organisms has the potential to open a wide range of applications in biomedical and communication technologies. However, this area remains almost unexplored. Herein, we report, as a proof of concept, a stimuli¿responsive interactive paradigm of communication between yeasts (as a model microorganism) and enzyme¿controlled Janus Au¿mesoporous silica nanoparticles. In the presence of the stimulus, the information flows from the microorganism to the nanodevice, and then returns from the nanodevice to the microorganism as a feedback., B.dL. is grateful to the Spanish Government for her FPU PhD fellowship. The authors wish to thank the Spanish Government (projects RTI2018-100910-B-C41 (MCUI/AEI/FEDER, UE) and CTQ2017-87954-P), the Generalitat Valenciana (project PROMETEO2018/024), the Comunidad de Madrid (Project IND2017/BMD-7642) and CIBER-BBN (NANOCOM project) for support.

[EN] Nanoparticle-cell-nanoparticle communication by stigmergy was demonstrated using two capped nanodevices. The first community of nanoparticles (i.e.S(RA)(IFN)) is loaded with 9-cis-retinoic acid and capped with interferon-gamma, whereas the second community of nanoparticles (i.e.S(sulf)(PIC)) is loaded with sulforhodamine B and capped with poly(I:C). The uptake ofS(RA)(IFN)by SK-BR-3 breast cancer cells enhanced the expression of TLR3 receptor facilitating the subsequent uptake ofS(sulf)(PIC)and cell killing., We thank the Spanish Government (projects RTI2018-100910-B-C41 and RTI2018-101599-B-C22 (MCUI/FEDER, EU)), Generalitat Valenciana (project PROMETEO2018/024) and CIBER-BBN (project NANOCOMMUNITY) for support. A. U. and C. G are grateful to the Ministry of Education, Culture and Sport for her doctoral FPU grant.

Core-shell nanoparticles comprised of Fe3O4 cores and a mesoporous silica shell with an average expanded pore size of 6.07 nm and coated with a poly(N-isopropylacrylamide) (PNIPAM) layer (CS MSNs EP PNIPAM) were prepared and characterized. The nanoparticles was loaded with (Ru(bipy)3 2+) dye or an antibacterial enzyme, lysozyme, to obtain CS MSNs EP PNIPAM Ru(bipy)3 2+ and CS MSNs EP PNIPAM Lys, respectively. The lysozyme loading was determined to be 160 mg/g of nanoparticle. It was seen that Ru(bipy)3 2+ and lysozyme release was minimal at a room temperature of 25 ºC while at physiological temperature (37 º C), abrupt release was observed. The applicability of the CS MSNs EP PNIPAM Lys was further tested with two Gram-positive bacteria samples, Bacillus cereus and Micrococcus luteus. At physiological temperature, the nanoparticles were shown to reduce bacterial growth, indicating a successful release of lysozyme from the nanoparticles. This nanoparticle system shows potential as a nanocarrier for the loading of similarly sized proteins or other species as a drug delivery platform., The authors wish to express their gratitude to the facilities at Ciudad Politecnica de la Innovacion (CPI), El Centro de Reconocimiento Molecular y Desarrollo Tecnologico (IDM), the Biotechnology Department at UPV, and the Instituto de Biologia Molecular y Celular de Plantas (IBMCP) at UPV for assistance in the materials characterization techniques and for providing the bacterial samples for antibacterial testing. Warm thanks are given to the Transatlantic Partnership for Excellence in Engineering (TEE) program, an Erasmus Mundus-Action 2 project by the European Commission, for the opportunity to undertake research at the collaborating university, UPV. The University of California Office of the President (UCOP) Lab Fees Research Program funded this research. The authors also thank the Spanish Government (Projects MAT2012-38429-C04-01 and MAT2012-38429-C04-03), the Generalitat Valenciana (Project PROMETEOII/2014/047) for support.

[EN] Apoptotic signaling pathways are altered in numerous pathologies such as cancer. In this scenario, caspase-9/PP2Ac alpha interaction constitutes a key target with pharmacological interest to re-establish apoptosis in tumor cells. Very recently, a short peptide (C9h) known to disrupt caspase-9/PP2Ac alpha interaction with subsequent apoptosis induction was described. Here, we prepared two sets of mesoporous silica nanoparticles loaded with safraninO (S2) or with C9h peptide (S4) and functionalized with epsilon-polylysine as capping unit. Aqueous suspensions of both nanoparticles showed negligible cargo release whereas in the presence of pronase, a marked delivery of safraninO or C9h was observed. Confocal microscopy studies carried out with HeLa cells indicated that both materials were internalized and were able to release their entrapped cargos. Besides, a marked decrease in HeLa cell viability (ca. 50%) was observed when treated with C9h-loaded S4 nanoparticles. Moreover, S4 provides peptide protection from degradation additionally allowing for a dose reduction to observe an apoptotic effect when compared with C9h alone or in combination with a cell-penetrating peptide (i.e., Mut3DPT-C9h). Flow cytometry studies, by means of Annexin V-FITC staining, showed the activation of apoptotic pathways in HeLa as a consequence of S4 internalization, release of C9h peptide and disruption of caspase-9/PP2Ac alpha interaction., The authors wish to express their gratitude to the Spanish government (Projects MAT2015-64139-C4-1, SAF2012-31405, SAF2015-67077-R, AGL2015-70235-C2-2-R (MINECO/FEDER)), the Generalitat Valencia (Projects PROMETEOII/2014/047, PROMETEO/2012/061) and the CIBER-BBN for their support. C.T. is grateful to the Spanish Ministry of Science and Innovation for her Ph.D. fellowship.

β-lapachone (β-lap) is a novel anticancer agent that selectively induces cell death in human cancer cells, by activation of the NQO1 NAD(P)H dehydrogenase and radical oxygen species (ROS) generation. We characterized the gene expression profile of budding yeast cells treated with β-lap using cDNA microarrays. Genes involved in tolerance to oxidative stress were differentially expressed in bβ-lap treated cells. β-lap treatment generated reactive oxygen species (ROS), which were efficiently blocked by dicoumarol, an inhibitor of NADH dehydrogenases. A yeast mutant in the mitocondrial NADH dehydrogenase Nde2p was found to be resistant to β-lap treatment, despite inducing ROS production in a WT manner. Most interestingly, DNA damage responses triggered by β-lap were abolished in the nde2D mutant. Amino acid biosynthesis genes were also induced in β-lap treated cells, suggesting that β-lap exposure somehow triggered the General Control of Nutrients (GCN) pathway. Accordingly, β-lap treatment increased phosphorylation of eIF2α subunit in a manner dependent on the Gcn2p kinase. eIF2α phosphorylation required Gcn1p, Gcn20p and Nde2p. Gcn2p was also required for cell survival upon exposure to β-lap and to elicit checkpoint responses. Remarkably, β-lap treatment increased phosphorylation of eIF2α in breast tumor cells, in a manner dependent on the Nde2p ortholog AIF, and the eIF2 kinase PERK. These findings uncover a new target pathway of β-lap in yeast and human cells and highlight a previously unknown functional connection between Nde2p, Gcn2p and DNA damage responses., This research was supported by the Ministerio de Ciencia e Innovación (SAF2010-21013)

[DE] Mit DNA verschlossene und mit Farbstoff beladene mesoporöse Siliciumdioxid-Nanopartikel wurden zum Nachweis von Mycoplasma bis zu einer Nachweisgrenze von ca. 70 genomischen DNA-Kopien pro mu-L in real kontaminierten Zellkulturmedien ohne die Hilfe von PCR-Techniken eingesetzt., Diese Arbeit wurde durch die Spanische Regierung (MAT2009-14564-C04-01 und SAF2010 15512) und die Generalitat Valenciana (PROMETEO/2009/016 und 2010/005) unterstützt. E.C. dankt dem Spanischen Bildungsministerium für ein Stipendium

The coupling of gated-indicator delivery with highly specific biochemical recognition is an innovative strategy for the detection of DNA sequences, able to compete with classical methods which need PCR amplification, in important areas such as point-of-care diagnostics or detection of specific biological contaminations with pathogens. Such comparatively simple and cheap yet highly selective and sensitive assays hold promise for use in less-developed areas of the world., Financial support from the Spanish Government (MAT2009-14564-C04-01 and SAF2010 15512), the Generalitat Valenciana (PROM-ETEO/2009/016 and 2010/005) is gratefully acknowledged. E. C. thanks the Ministerio de Educacion for a fellowship. L. M. thanks Generalitat Valenciana for her Post-Doc VALI + D contract.

[EN] A novel nanodevice consisting of mesoporous nanoparticles loaded with vancomycin and capped with epsilon-poly-L-lysine (epsilon-PL) was prepared and its interaction with different Gram-negative bacteria studied. A remarkable improvement in the efficacy of the antimicrobial drug epsilon-PL and a broadening of the antimicrobial spectrum of vancomycin is demonstrated., The authors thank the Spanish Government (project MAT2012-38429-C04-01) the Generalitat Valenciana (project PROMETEO/2009/016) and the CIBER-BBN for their support. N.M. also thanks the Ministerio de Ciencia e Innovacion for her FPI grant. L.M. also thanks Generalitat Valenciana for her post-doc VALI+D contract.

[EN] Both radiotherapy and most effective chemotherapeutic agents induce different types of DNA damage. Here we show that tungstate modulates cell response to DNA damaging agents. Cells treated with tungstate were more sensitive to etoposide, phleomycin and ionizing radiation (IR), all of which induce DNA double-strand breaks (DSBs). Tungstate also modulated the activation of the central DSB signalling kinase, ATM, in response to these agents. These effects required the functionality of the Mre11-Nbs1-Rad50 (MRN) complex and were mimicked by the inhibition of PP2A phosphatase. Therefore, tungstate may have adjuvant activity when combined with DNA-damaging agents in the treatment of several malignancies. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.

[EN] New hybrid oligonucleotide-capped mesoporous silica nanoparticles able to detect genomic DNA were designed., Financial support from the Spanish Government (Project MAT2012-38429-C04) and the Generalitat Valencia (Project PROMETEOII/2014/047) is gratefully acknowledged. Ll. P. is grateful to the Universidad Politecnica de Valencia for his grant.

[EN] The eIF2 alpha kinases integrate translation initiation rates with nutrient availability, thus allowing cells to adapt to nutrient scarcity. Recent evidence has uncovered new functions of these kinases in tumour cell biology, ranging from regulation of cell cycle progression, maintenance of genome stability, control of apoptosis, and cell survival under nutrient stress and hypoxia. Accordingly, active eIF2 alpha kinases modulate the antineoplasic activity of several antitumour drugs, either by exacerbating their cytotoxic effect or by promoting chemoresistance. Understanding of eIF2 alpha kinases molecular roles may provide mechanistic insights into how tumour cells sense and adapt to nutrient restriction, thus helping to implement more effective approaches for cancer chemotherapy.

[EN] The possibility of achieving sophisticated actions in complex biological environments using gated nanoparticles is an exciting prospect with much potential. We herein describe new gated mesoporous silica nanoparticles (MSN) loaded with an anticoagulant drug and capped with a peptide containing a thrombin-specific cleavage site. When the coagulation cascade was triggered, active thrombin degraded the capping peptidic sequence and induced the-release of anticoagulant drugs to delay the clotting process. The thrombin-dependent response was assessed and a significant increase in coagulation time in plasma from 2.6 min to 5 min was found. This work broadens the application of gated silica nanoparticles and demonstrates their ability to act as controllers in a complex scenario such as hemostasis., Authors thank Spanish Government (Project Nos. MAT2012-38429-C04, AGL2012-39597-C02-02) and Generalitat Valenciana (Project No. PROMETEOII/2014/047) for support. R.B. is thankful to Svagata.eu (Erasmus Mundus Action-II program) for his fellowship. A.R. thanks UPV for her predoctoral fellowship. N.M. thanks Spanish MINECO for her FPI fellowship. The authors also thank the Electron Microscopy Service at the UPV for support.

[EN] Multidisciplinary research at the forefront of the field of hybrid materials has paved the way to the development of endless examples of smart devices. One appealing concept in this fertile field is related to the design of gated materials. These are constructed for finely tuning the delivery of chemical or biochemical species from voids of porous supports to a solution in response to predefined stimuli. Such gated materials are composed mainly of two subunits: (i) a porous inorganic support in which a cargo is loaded and (ii) certain molecular or supramolecular entities, generally grafted onto the external surface, which can control mass transport from pores. On the basis of this concept, a large number of imaginative examples have been developed. This review intends to be a comprehensive analysis of papers published until 2014 on hybrid mesoporous gated materials. The molecules used as gates, the opening mechanisms, and controlled release behavior are detailed. We hope this review will not only help researchers who work in this field but also may open the minds of related ones to develop new advances in this fertile research area., The authors gratefully acknowledge financial support from the Spanish Government (Project MAT2012-38429-C04-01) and the Generalitat Valenciana (Project PROMETEOII/2014/047). Ll.P. and M.O. also thank the Universidad Politecnica de Valencia for their predoctoral grants.

[EN] Two-component systems (TCS) regulate diverse processes such as virulence, stress responses, metabolism and antibiotic resistance in bacteria but are absent in humans, making them promising targets for novel antibacterials. By incorporating recently described TCS histidine kinase autophosphorylation inhibitors (HKAIs) into epsilon-poly-L-lysine capped nanoparticles (NPs) we could overcome the Gram negative (Gr(-)) permeability barrier for the HKAIs. The observed bactericidal activity against Gr(-) bacteria was shown to be due to the enhanced delivery and internalization of the HKAIs and not an inhibitory or synergistic effect of the NPs. The NPs had no adverse effects on mammalian cell viability or the immune function of macrophages in vitro and showed no signs of toxicity to zebrafish larvae in vivo. These results show that HKAIs are promising antibacterials for both Gr(-) and Gr + pathogens and that NPs are a safe drug delivery technology that can enhance the selectivity and efficacy of HKAIs against bacteria. (C) 2016 Elsevier Inc. All rights reserved., This work was funded by FP7 ITN STARS-Scientific Training in Antimicrobial Research Strategies (Contract No. PITN-GA-2009-238490, J.M.W., A.M.), H2020 MSCA IF (AND-659121, N.V.), grant BIO2013-42619-P from the Ministerio de Economia y Competitividad (A.M.), grant from the Spanish Government (Project MAT2015-64139-C4-1-R,N. M., J.R.M, R.M.M.), and a grant from Generalitat Valenciana (Project PROMETEOII/2014/047, N.M.). and Prometeo II/2014/029, A.M.).

A new photosensitizer (1) based on the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) scaffold has been synthesized. 1 is water soluble and showed an intense absorption band at 490 nm (e=77600 cm-1M-1) and an emission at 514 nm. In vitro toxicity of 1 in the presence of light and in darkness has been studied with HeLa, HaCaT, MCF-7, and SCC-13 cell lines. Moreover, internalization studies of 1 in these cell lines were also performed. These results suggested that 1 is more toxic for SCC-13 and HeLa carcinoma cells than for the HaCaT noncancerous immortal human keratinocytes. Toxicity upon light irradiation was due to the formation of singlet oxygen and reactive oxygen species (ROS). Cellular co-localization experiments revealed preferential localization of the dye in the endoplasmic reticulum., Financial support from the Spanish Government (Project MAT2012-38429-C04-01) and the Generalitat Valenciana (Project PROMETEOII/2014/047) is gratefully acknowledged.

Iodinated or oxygenated nitrogen heterocycles are obtained by radical decarboxylation of β- and γ-amino acids. This mild, versatile reaction is applied to the synthesis of bioactive products, such as 4-arylpiperidines, hydroxylated piperidines, and new antifungal agents.

5 pages, 1 figure, 3 schemes.-- Printed version published Sep 6, 2004., The radical decarboxylation of β- and γ-amino acids on treatment with PhI(OAc)2–I2 is a mild and efficient methodology to synthesize halogenated or oxygenated nitrogen heterocycles. The reaction was applied to the synthesis of bioactive products, such as opioid analogues, iminosugars and new antifungic agents., This work was supported by the Investigation Programmes PPQ2000-0728 and PPQ2003-01379 of the Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, Dirección General de Investigación, Ministerio de Ciencia y Tecnología, Spain. We also acknowledge financial support from FEDER funds. Y.R. thanks Gobierno de Canarias for a fellowship.

Two novel tropolone derivatives 1 and 2 have been isolated from Goupia glabra. Their structures were determined by extensive 1D and 2D NMR spectroscopic studies. Compound 2 constitutes the first example isolated from a natural source of a Diels−Alder adduct between a tropolone and a naphthalene derivative. Compounds 1 and 2 exhibit significant toxicity towards a panel of DNA damage checkpoint defective yeast mutants, and behave as genotoxins, which highlights their potential to be used as anticancer drugs. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Cell cycle checkpoints ensure the order of cell cycle events to preserve genome integrity. Among those, the DNA damage checkpoints prevent chromosome segregation when DNA is damaged. Defects in DNA damage signalling impair the cell ability to repair DNA lesions leading to cancer predisposition in humans. Advances in budding yeast have underlined the regulatory networks for these pathways, which are conserved throughout evolution, allowing a better understanding of how these controls sense and transduce the DNA damage signal. However, the molecular basis of DNA damage recognition and the coordinated regulation of DNA repair networks by checkpoint controls still remain unclear.

In recent years, mesoporous silica nanoparticles (MSNs) have been used as effective supports for the development of controlled-release nanodevices that are able to act as multifunctional delivery platforms for the encapsulation of therapeutic agents, enhancing their bioavailability and overcoming common issues such as poor water solubility and poor stability of some drugs. In particular, redox-responsive delivery systems have attracted the attention of scientists because of the intracellular reductive environment related to a high concentration of glutathione (GSH). In this context, we describe herein the development of a GSH-responsive delivery system based on poly(ethylene glycol)- (PEG-) capped MSNs that are able to deliver safranin O and doxorubicin in a controlled manner. The results showed that the PEG-capped systems designed in this work can be maintained closed at low GSH concentrations, yet the cargo can be delivered when the concentration of GSH is increased. Moreover, the efficacy of the PEG-capped system in delivering the cytotoxic agent doxorubicin in cells was also demonstrated., The authors thank the Spanish Government (Project MAT2012-38429-C04-01), the Generalitat Valenciana (Project PROMETEOII/2014/047), and the Universitat Politecnica de Valencia (Project SP20120795) for support. C.G. and C.d.l.T also thank the Spanish Ministry of Education for their FPU grants. The authors also thank UPV electron microscopy and CIPF confocal microscopy services for technical support.

Núria Mas,1–3 Irene Galiana,3 Silvia Hurtado,† Laura Mondragón,1–3 Andrea Bernardos,1–3 Félix Sancenón,1–3 María D Marcos,1–3 Pedro Amorós,4 Nuria Abril-Utrillas,5 Ramón Martínez-Máñez,1–3 José Ramón Murguía1,3 1Centro de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Centro Mixto Universidad Politécnica de Valencia, Universidad de Valencia, Valencia, Spain; 2Departamento de Química, Universidad Politécnica de Valencia, Valencia, Spain; 3CIBER de Bioingeniería, Biomateriales y Nanomedicina, Madrid, Spain; 4Institut de Ciència del Materials (ICMUV), Universitat de València, Valencia, Spain; 5Servicio Ginecología y Obstetricia, Hospital de la Plana, Vila-real, Spain†Silvia Hurtado passed away in September 2013 Abstract: pH-sensitive gated mesoporous silica nanoparticles have been synthesized. Increased extracellular pH and internalization into living yeast cells triggered molecular gate aperture and cargo release. Proper performance of the system was demonstrated with nanodevices loaded with fluorescein or with the antifungal agent tebuconazole. Interestingly, nanodevices loaded with tebuconazole significantly enhanced tebuconazole cytotoxicity. As alterations of acidic external pH are a key parameter in the onset of fungal vaginitis, this nanodevice could improve the treatment for vaginal mycoses.Keywords: capped mesoporous nanoparticles, intracellular release, pH-responsive nanoparticles, Saccharomyces cerevisiae, tebuconazole loading

We report herein the design of a smart delivery system in which cargo delivery from capped mesoporous silica (MS) nanoparticles is controlled by an integrated enzyme-based control unit . The system consists of Janus-type nanoparticles having opposing Au and MS faces, functionalized with a pH-responsive β-cyclodextrin-based supramolecular nanovalve on the MS surface and two effectors, glucose oxidase and esterase, immobilized on the Au face. The nanodevice behaves as an enzymatic logical OR operator which is selectively fueled by the presence of D-glucose and ethyl butyrate., R.V. acknowledges a Ramon & Cajal contract from the Spanish Ministry of Science and Innovation. Financial support from the Spanish Ministry of Science and Innovation (CTQ2011-24355, CTQ2009-12650, CTQ2009-09351, MAT2012-38429-C04-01) and Comunidad de Madrid (S2009/PPQ-1642, programme AVANSENS) is gratefully acknowledged. The Generalitat Valencia (project PROMETEO/2009/016) is also acknowledged.

The classical role of the conserved Gcn2 kinase of yeast and mammals is to activate the translation of the transcription factors Gcn4 in yeast and activating transcription factor 4 in mammals by phosphorylating the eukaryotic translation initiation factor 2α. Gcn2 is activated by uncharged tRNAs in response to amino acid starvation and this regulatory system is important for tolerance to nutrient deprivation and other stresses and for development, differentiation, and normal function of mammalian organs. In the past few years, the classical Gcn2 pathway has been shown to modulate life span, tumor cell survival, and immune responses. In addition, Gcn2 modulates translation of novel mRNAs such as those of an unknown regulator of leucine transport and of sulfiredoxin SRX1 in yeast (activation of translation) and of inducible nitric oxide synthase, ErBb2, HIF1a, and 5′-terminal oligopyrimidine tract mRNAs in mammals (inhibition of translation). Finally, Gcn2 directly phosphorylates novel proteins such as methionyl-tRNA synthetase in mammals, and this triggers a pathway for DNA repair. These findings anticipate many expanding roles of Gcn2 in the future, with relevance for stress responses and human disease. © 2012 IUBMB IUBMB Life, 64(12): 971–974, 2012

[EN] Tungstate counteracts diabetes and obesity in animal models, but its molecular mechanisms remain elusive. Our Saccharomyces cerevisiae-based approach has found that tungstate alleviated the growth defect induced by nutrient stress and enhanced the activation of the GCN pathway. Tungstate relieved the sensitivity to starvation of a gcn2-507 yeast hypomorphic mutant, indicating that tungstate modulated the GCN pathway downstream of Gcn2p. Interestingly, tungstate inhibited Glc7p and PP1 phosphatase activity, both negative regulators of the GCN pathway in yeast and humans, respectively. Accordingly, overexpression of a dominant-negative Glc7p mutant in yeast mimicked tungstate effects. Therefore tungstate alleviates nutrient stress in yeast by in vivo inhibition of Glc7p. These data uncover a potential role for tungstate in the treatment of PP1 and GCN related diseases. (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved., We thank R. Serrano for providing the Delta cnb1 mutant strain. We thank A. G. Hinnebusch for the gcn2-507 and gcn2 mutant strains. The pGEX-GLC7 plasmid was kindly provided by P. Sanz. The PP1-FLAG construct was kindly provided by A. C. Gingras. We thank T. Yates and J. Calbo for critical reading of the manuscript and helpful suggestions. J. J. Guinovart's laboratory was funded by grants from the Direccion General de Investigacion Cientifica y Tecnica (BFU2008-00769), the Generalitat de Catalunya (2009 SGR 01176), the Fundacion Marcelino Botin and the CIBER de Diabetes y Enfermedades Metabolicas Asociadas (ISCIII, Ministerio de Ciencia e Innovacion). J. R. Murguia laboratory was funded by Fondo de Investigaciones Sanitarias (FIS03-0628).

Learning to let go with age: Intracellular controlled release of molecules within senescent cells was achieved using mesoporous silica nanoparticles (MSNs) capped with a galacto-oligosaccharide (GOS) to contain the cargo molecules (magenta spheres; see scheme). The GOS is a substrate of the senescent biomarker, senescence-associated β-galactosidase (SA-β-gal), and releases the cargo upon entry into SA-β-gal expressing cells., We thank the Spanish Government (projects MAT2009-14564-C04 and FIS PI11-0949) the Generalitat Valencia (project PROMETEO/2009/016), and the Universidad Politécnica de Valencia (UPV PAID-05-09) for support. We thank Fundación Ramón Areces for support. C.M.-G. is supported by CIBERER. L.M. thanks the Generalitat Valenciana for her VALI+D postdoctoral contract.

Intracellular pH conditions many cellular systems, but its mechanisms of regulation and perception are mostly unknown. We have identified two yeast genes important for tolerance to intracellular acidification caused by weak permeable acids. One corresponded to LEU2 and functions by removing the dependency of the leu2 mutant host strain on uptake of extracellular leucine. Leucine transport is inhibited by intracellular acidification, and either leucine oversupplementation or overexpression of the transporter gene BAP2 improved acid growth. Another acid-tolerance gene is GCN2, encoding a protein kinase activated by uncharged tRNAs during amino acid starvation. Gcn2 phosphorylates eIF2α (eukaryotic initiation factor 2α) (Sui2) at Ser51 and this inhibits general translation, but activates that of Gcn4, a transcription factor for amino acid biosynthetic genes. Intracellular acidification activates Gcn2 probably by inhibition of aminoacyl-tRNA synthetases because we observed accumulation of uncharged tRNAleu without leucine depletion. Gcn2 is required for leucine transport and a gcn2-null mutant is sensitive to acid stress if auxotrophic for leucine. Gcn4 is required for neither leucine transport nor acid tolerance, but a S51A sui2 mutant is acid-sensitive. This suggests that Gcn2, by phosphorylating eIF2α, may activate translation of an unknown regulator of amino acid transporters different from Gcn4., This work was funded by grants from the Spanish Ministerio de Ciencia e Innovacion (Madrid) [grant number BFU2008-00604] and the Generalitat Valenciana (Valencia) [grantnumber Prometeo/2010/038].

The network consisting of mTO R and p53 pathways is crucial to understanding a wide variety of physiological and pathological events, including cancer and aging. In addition, the HIF1α protein, a downstream target of mTO R, is a hallmark of different tumor types and was the desired strategy of many drug discovery efforts. Here we present the novel chemical entity FM19G11, a new modulator of HIF1α expression, which was used as a molecular tool to dissect and further characterize the cross-talk between these signaling cascades in human colon carcinoma cell lines. To our knowledge, FM19G11 is the first drug that triggers a DNA damage response (DDR) associated with G 1/S-phase arrest in a p53-dependent manner, due to rapid hyper-activation of the growth signaling pathway through mTO R. Assessment of colonies demonstrated that FM19G11 decreases the clonogenicity of HT29, HCT116/p53+/+ and HCT116/p53-/- cells. Moreover, FM19G11 causes significant lower colony growth in soft agar of p53-proficient human colon cancer cells. Consequently, p53 sensitizes human colon cancer cells to FM19G11 by significant reduction of their viability, lessening their colony formation capability and shrinking their anchorage-independent growth. Cell signaling studies served to assign a new mode of action to FM19G11, whose tumor-suppressant activity compromises the survival of functional p53 malignant cells. © 2010 Landes Bioscience., This research was funded by the Fondo de Investigaciones Sanitarias, the Instituto de Salud Carlos III (Spain) and the Conselleria de Sanitat of the Generalitat Valenciana (Spain). Projects PI051973 and RD06/0010/1006

Radio and chemotherapy are the election options besides surgical resection, in cancer treatment. However, resistance to chemotherapy limits the effectiveness of therapy in the clinic. An improved knowledge of the mechanisms underlying the resistance to treatment would generate new therapeutic strategies. Genetic suppressor elements (GSEs) are short, biologically active, cDNA fragments that interfere with the function of their cognate gene. By selection of genetic suppressor elements (GSEs) conferring resistance to cisplatin, we identified the GSE11, that corresponds to the hCCR4/CNOT6 gene that mediates cellular sensitivity to the drug. Expression of GSE11-hCCR4 reduces hCCR4 protein levels in cells. Targeting hCCR4 with GSE11 or with siRNA, decreases sensitivity of mammalian cells to DNA-damaging agents. Overexpression of hCCR4 targets Chk2 following exposure to cisplatin, without interfering with the upstream ATM/ATR pathway, however histone γH2AX is strongly phosphorylated in these cells compared to control cells. Our results uncover a new function for a human protein involved in chemotherapy response. This finding introduces a new pharmacological target in the treatment of solid tumours., This work was supported by grants 05/1305, 05/0834, and 06/0042 from Fondo de Investigación Sanitaria and from Mutua Madrileña Foundation. I.S.-P. and J.R.M. are in receipt of career development awards from the Ramón y Cajal program funded by the Spanish Ministerio de Educación y Ciencia.

Dyskerin gene is mutated in patients with X-linked dyskeratosis congenita (X-DC), which results in greatly reduced levels of telomerase activity. A genetic suppressor element (GSE) termed GSE24-2 has been isolated in a screening for cisplatin resistance. GSE24-2-expressing cells presented impaired telomerase inhibition following in vitro exposure to chemotherapies, such as cisplatin, or telomerase inhibitors. The promoter of the telomerase component hTERT was constitutively activated in GSE24-2 cells in a c-myc expression-dependent manner. Deletion analyses and mutagenesis of the human c-myc promoter demonstrated that the target sequence for activation was the nuclease hypersensitive element-III (NHEIII) site located upstream to the P1 region of the promoter. Further, expression of GSE24-2 in cell lines derived from patients with X-DC and in VA13 cells induced increased hTERT RNA and hTR levels and recovery of telomerase activity. Finally, expression of GSE24-2 was able to rescue X-DC fibroblasts from premature senescence. These data demonstrate that this domain of dyskerin plays an important role in telomerase maintenance following cell insults such as cisplatin treatment, and in telomerase-defective cells in patients with X-DC. The expression of this dyskerin fragment has a dominant function in X-DC cells and could provide the basis for a therapeutic approach to this disease. © 2008 by The American Society of Hematology., This work was supported by grants 04/1164 and 05/1305 from Fondo de Investigación Sauitaire (FIS) and Biologia Fundamental BFU-05-0138. R.M.-P. is supported by Fundación Genoma and grant C03/10 provided by Red Temática de Investigación de Centros de Cáncer (RTICC). I.S.-P. and J.-R.M. are Ramón y Cajal program researchers funded by Ministerio de Educación y Ciencia (MEC).

The budding yeast Saccharomyces cerevisiae is being widely used as a model for investigating fundamental processes relevant to all living organisms. Many of these processes are affected by genetic and epigenetic alterations in cancer such as cell cycle progression, DNA replication and segregation, maintenance of genomic integrity and stress responses. Therefore, yeast emerges as an attractive model for anticancer drug research. The genetic tractability of budding yeast, its ease of manipulation and the wealth of functional genomics tools available in this organism makes it ideal for genome-wide analysis of biological functions and chemical screenings. The present review will discuss some of the innovative advantages based on yeast genetics and genomics for antitumour drug target identification and drug discovery.

The discovery of genotoxic amino acids derived from phenylglycine, and possessing halogen substituents, is described. The utility of hypervalent iodine reagents in the synthesis of this class of compounds is highlighted. The mechanism of action of the (haloaryl)glycines was studied in Saccharomyces cerevisiae.

Iodinated or oxygenated nitrogen heterocycles are obtained by radical decarboxylation of β- and γ-amino acids. This mild, versatile reaction is applied to the synthesis of bioactive products, such as 4-arylpiperidines, hydroxylated piperidines, and new antifungal agents.

The immunosuppressants tacrolimus (FK506) and cyclosporin A (CsA) have increased the survival rates in organ transplantation. Both drugs inhibit the protein phosphatase calcineurin (CaN) in activated T cells, exhibiting similar side-effects. Diabetes is observed more often in FK506 than CsA therapy, probably due to inhibition of new molecular targets other than CaN. We studied FK506 toxicity in mammalian cells. FK506, but not CsA, regulated p38 activation by osmotic stress, and decreased viability in osmostressed cells. In addition, FK506 treatment strongly increased the phosphorylation of the eukaryotic initiation factor-2α (eIF-2α) subunit. eIF-2α phosphorylation, p38 inhibition and cell lethality were relieved by addition of excess amino acids to the medium, suggesting that amino acid availability mediated FK506 toxicity. Therefore, these FK506-dependent responses could be relevant to the non-therapeutic effects of FK506 therapy., This study was supported by grants from Fondo de Investigaciones Sanitarias 00/0862, 01/1094 and 01/1626 and from FEDER 1FD87-1781.

The immunosuppressant Tacrolimus (FK506) has increased the survival rates of organ transplantation. FK506 exerts its immunosuppressive effect by inhibition of the protein phosphatase calcineurin in activated T-cells. Unfortunately, FK506 therapy is associated with undesired non-therapeutic effects involving targets other than calcineurin. To identify these targets we have addressed FK506 cellular toxicity in budding yeast. We show that FK506 increased cell sensitivity upon osmotic challenge independently of calcineurin and the FK506-binding proteins Fpr1p, -2p, -3p, and -4p. FK506 also induced strong amino acid starvation and activation of the general control (GCN) pathway. Tryptophan prototrophy or excess tryptophan overcame FK506 toxicity, showing that tryptophan deprivation mediated this effect. Mutation of the GCN3 and -4 genes partially alleviated FK506 toxicity, suggesting that activation of the GCN pathway by FK506 was also involved in osmotic tolerance. FK506 enhanced osmotic stress-dependent Hog1p kinase phosphorylation that was not accompanied by induction of a Hog1p-dependent reporter. Interestingly, deletion of the GCN2 gene suppressed FK506-dependent Hog1p hyperphosphorylation and restored Hog1p-dependent reporter activity. Conversely, deletion of the HOG1 gene impaired FK506-dependent activation of Gcn2p kinase and translation of a GCN4-LacZ reporter, highlighting functional cross-talk between the Gcn2p and Hog1p protein kinases. Taken together, these data demonstrate that both FK506-induced amino acid starvation and activation of the GCN pathway contribute to cell sensitivity to osmotic stress and reveal a positive regulatory loop between the Hog1p and Gcn2p pathways. Given the conserved nature of Gcn2p and Hog1p pathways, this mechanism of FK506 toxicity could be relevant to the non-therapeutic effects of FK506 therapy., This study was supported by Grants 00/0862, 01/1094, and 01/1626 from the Fondo de Investigaciones Sanitarias and by Grant 1FD87-1781 from FEDER.

The aerial parts of Nanodea muscosa, collected in Chile, yielded two new acetylenic acids. Their structures were elucidated by spectroscopic analyses, including 2D NMR techniques, as (13E)-octadec-13-en-11-ynoic acid (1) and (2E)-octadec-2-en-4-ynedioic acid (2). Compound 2 constitutes the first example of a conjugated ene-yne fatty diacid isolated from a natural source. Compounds 1 and 2 did not exhibit toxicity toward a panel of DNA damage checkpoint defective yeast mutants or show affinity for the 5-HT 1A, 5-HT 2A , D 2 , and H 1 receptors.

DNA damage or stalled DNA replication can activate specific signal transduction pathways, termed checkpoints. Checkpoint activation can result in increased repair, induction of a transcriptional programme and inhibition of cell-cycle progression. Recent results have suggested possible mechanisms for the detection of specific DNA structures, provided further information on the organisation of the signal transduction cascade and demonstrated involvement of the checkpoint pathway in DNA repair.

Genotoxic stress triggers signalling pathways that either mediate cell killing or protection of affected cells. While induction of p53 is observed for most of the genotoxins, activation of MAPK/SAPK cascades is not a general response. The role of MAPK/SAPK activation on cell fate, seems to be dependent, in some systems, on the balanced response among both cascades. We have here examined the effect of cis and trans-DDP on the activation of ERK and JNK activities. While no significant induction of ERK was observed with the compounds, both of them are able to strongly activate JNK. Trans-DDP response is rapid and transient while the cis-DDP one is slow and persistent. In contrast with the observed nuclear translocation of JNK in response to U.V. light, none of the platinum compounds induces translocation, on the contrary, activation of JNK occurs in both the nuclear and cytoplasmic compartments. Inhibition of tyrosine phosphatases by orthovanadate pretreatment prolongs the time of JNK induction in response to both platinum compounds. The positive modulation of JNK activation correlates with an increase in toxicity that, for cis-DDP corresponds to a tenfold decrease in the IC50. A strong increase in MKP-1 levels was observed only in response to trans-DDP suggesting the involvement of this activity in the downregulation of JNK activity in response to this compound. Altogether the results suggest that the prolonged activation of JNK in response to cis-DDP contributes to cell death induction., JRM is a fellow from the AECC (Asociacioón Española contra el Cáncer) and IS-P is a fellow from DGICYT. This study was supported by grants from 95/0882 and 96/2135 from Fondo de Investigación Sanitaria (FIS) and AE00409/95 from Comunidad Autónoma de Madrid (CAM).

Random over-expression of genes in multicopy plasmids and gene disruptions have uncovered rate-limiting steps for salt tolerance in the model organism Saccharomyces cerevisiae (baker’s yeast). In cells growing in glucose media intracellular sodium toxicity is the major component of salt stress. In minimal synthetic media sodium toxicity primarily affects methionine biosynthesis. This is due to sodium inhibition of the 3′,5′-bisphosphate nucleotidase encoded by the HAL2/MET22 gene. The sodium-extrusion ATPase encoded by the ENA1/PMR2 gene is the major determinant of sodium homeostasis, together with its complex regulatory system, which includes the calcineurin and HAL3 (HAL1) pathways.

A group of cross-hybridizing DNA segments contained within the EcoRI restriction fragments U', X and J of a Vero cell-adapted strain (BA71V) of African swine fever virus (ASFV) were mapped and sequenced. Analysis of the nucleotide sequence revealed the presence of a set of long internal repeated sequences composed of five types of tandemly repeat units of about 200 bp. These tandem repeats contain a G-rich core of 10-14 nucleotides surrounded by regions with a high A + T content distributed in oligo(dA).oligo(dT) tracts. Next to the repeated sequences we detected two related open reading frames that are members of a new multigene family (multigene family 300). Comparison of DNA sequences from several virus isolates indicated that this region undergoes frequent rearrangements leading to either duplications or deletions of the repeat units. These ASFV repeated sequences share similarities with chromosomal alpha satellite DNA, the scaffold-associated region and satellite III of Drosophila. Similar tandemly repeated sequences have not been described in other viruses.

The yeast halotolerance gene HAL2 encodes a nucleotidase that dephosphorylates 3'-phosphoadenosine 5'-phosphate (PAP) and 3'- phosphoadenosine 5'-phosphosulfate (PAPS), intermediates of the sulfate assimilation pathway. This nucleotidase is inhibited by Na+ and Li+ but not by K+. Incubation of wild-type yeast cells with NaCl and LiCl, but not with KCl, increased intracellular PAP to millimolar concentrations. No depletion of the pool of adenine nucleotides (AMP, ADP, ATP) was observed. Other stresses such as heat shock or oxidative stress did not result in PAP accumulation. PAPS concentrations also increased during salt stress but remained lower than 0.5 μM. S-Adenosylmethionine concentrations decreased by 50%, reflecting inhibition of sulfate assimilation during salt stress. Salt- induced PAP accumulation was attenuated in a yeast strain overexpressing HAL2. This strain grew better than the wild type under salt stress. These results suggest that the cation sensitivity of the HAL2 nucleotidase is an important determinant of the inhibition of yeast growth by sodium and lithium salts. In addition to blocking sulfate assimilation by product inhibition of PAPS reductase, PAP accumulation may have other unidentified toxic effects., This work was supported by grants from the Biotechnology Program of the “Comisión Interministerial de Ciencia y Tecnología” (Spain) and from the Project of Technological Priority of the European Union (Brussels). J. R. M. was a fellow of the “Consejería de Educación, Universidades e Investigación” of the autonomous government of the “Pais Vasco” (Spain).