961 resultados para perylene carboximides, molecular rotor, single molecule spectroscopy, optoelectronic devices


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High performance liquid chromatography (HPLC) is the reference method for measuring concentrations of antimicrobials in blood. This technique requires careful sample preparation. Protocols using organic solvents and/or solid extraction phases are time consuming and entail several manipulations, which can lead to partial loss of the determined compound and increased analytical variability. Moreover, to obtain sufficient material for analysis, at least 1 ml of plasma is required. This constraint makes it difficult to determine drug levels when blood sample volumes are limited. However, drugs with low plasma-protein binding can be reliably extracted from plasma by ultra-filtration with a minimal loss due to the protein-bound fraction. This study validated a single-step ultra-filtration method for extracting fluconazole (FLC), a first-line antifungal agent with a weak plasma-protein binding, from plasma to determine its concentration by HPLC. Spiked FLC standards and unknowns were prepared in human and rat plasma. Samples (240 microl) were transferred into disposable microtube filtration units containing cellulose or polysulfone filters with a 5 kDa cut-off. After centrifugation for 60 min at 15000g, FLC concentrations were measured by direct injection of the filtrate into the HPLC. Using cellulose filters, low molecular weight proteins were eluted early in the chromatogram and well separated from FLC that eluted at 8.40 min as a sharp single peak. In contrast, with polysulfone filters several additional peaks interfering with the FLC peak were observed. Moreover, the FLC recovery using cellulose filters compared to polysulfone filters was higher and had a better reproducibility. Cellulose filters were therefore used for the subsequent validation procedure. The quantification limit was 0.195 mgl(-1). Standard curves with a quadratic regression coefficient > or = 0.9999 were obtained in the concentration range of 0.195-100 mgl(-1). The inter and intra-run accuracies and precisions over the clinically relevant concentration range, 1.875-60 mgl(-1), fell well within the +/-15% variation recommended by the current guidelines for the validation of analytical methods. Furthermore, no analytical interference was observed with commonly used antibiotics, antifungals, antivirals and immunosuppressive agents. Ultra-filtration of plasma with cellulose filters permits the extraction of FLC from small volumes (240 microl). The determination of FLC concentrations by HPLC after this single-step procedure is selective, precise and accurate.

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Misfolded polypeptide monomers may be regarded as the initial species of many protein aggregation pathways, which could accordingly serve as primary targets for molecular chaperones. It is therefore of paramount importance to study the cellular mechanisms that can prevent misfolded monomers from entering the toxic aggregation pathway and moreover rehabilitate them into active proteins. Here, we produced two stable misfolded monomers of luciferase and rhodanese, which we found to be differently processed by the Hsp70 chaperone machinery and whose conformational properties were investigated by biophysical approaches. In spite of their monomeric nature, they displayed enhanced thioflavin T fluorescence, non-native β-sheets, and tertiary structures with surface-accessible hydrophobic patches, but differed in their conformational stability and aggregation propensity. Interestingly, minor structural differences between the two misfolded species could account for their markedly different behavior in chaperone-mediated unfolding/refolding assays. Indeed, only a single DnaK molecule was sufficient to unfold by direct clamping a misfolded luciferase monomer, while, by contrast, several DnaK molecules were necessary to unfold the more resistant misfolded rhodanese monomer by a combination of direct clamping and cooperative entropic pulling.

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A new type of high avidity binding molecule, termed "peptabody" was created by harnessing the effect of multivalent interaction. A short peptide ligand was fused via a semi-rigid hinge region with the coiled-coil assembly domain of the cartilage oligomeric matrix protein, resulting in a pentameric multivalent binding molecule. In the first peptabody (Pab-S) described here, a peptide (S) specific for the mouse B-cell lymphoma BCL1 surface Ig idiotype, was selected from a phage display library. A fusion gene was constructed encoding peptide S, followed by the 24 aa hinge region from camel IgG and a modified 55 aa cartilage oligomeric matrix protein pentamerization domain. The Pab-S fusion protein was expressed in Escherichia coli in a soluble form at high levels and purified in a single step by metal-affinity chromatography. Pab-S specifically bound the BCL1 surface idiotype with an avidity of about 1 nM, which corresponds to a 2 x 10(5)-fold increase compared with the affinity of the synthetic peptide S itself. Biochemical characterization showed that Pab-S is a stable homopentamer of about 85 kDa, with interchain disulfide bonds. Pab-S can be dissociated under denaturing and reducing conditions and reassociated as a pentamer with full-binding activity. This intrinsic feature provides an easy way to combine Pab molecules with two different peptide specificities, thus producing heteropentamers with bispecific and/or chelating properties.

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Arenaviruses are enveloped negative single strand RNA viruses that include a number of important human pathogens. The most prevalent human pathogen among the arenaviruses is the Old World arenavirus Lassa virus (LASV) which is endemic in West Africa from Senegal to Cameroon. LASV is the etiologic agent of a severe viral hemorrhagic fever named Lassa fever whose mortality rate can reach 30% in hospitalized patients. One of the hallmarks of fatal arenavirus infection in humans is the absence of an effective innate and adaptive immune response. In nature, arenaviruses are carried by rodents which represent the natural reservoirs as well as the vectors for transmission. In their natural rodent reservoir, arenaviruses have the ability to establish persistent infection without any overt signs and symptoms of pathology. We believe that the modulation of the host cell's innate immunity by arenaviruses is a key determinant for persistence in the natural host and for the pathogenesis in man. In this thesis, we studied the interaction of arenaviruses with two main branches of the host's innate anti-viral defense, the type I interferon (IFN) system and virus-induced mitochondrial apoptosis. The arenavirus nucleoprotein (NP) is responsible for the anti-IFN activity of arenaviruses. Specifically, NP blocks the activation and the nuclear translocation of the transcription factor interferon regulatory factor 3 (IRF3) which leads to type I IFN production. LASV and the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) NPs contain a 3'-5'exoribonuclease domain in the C terminal part that has been linked to the anti-IFN activity of NP. In the first project, we sought to identify cellular component(s) of the type I IFN induction pathway targeted by the viral NP. Our study revealed that LCMV NP prevents the activation of IRF3 by blocking phosphorylation of the transcription factor. We found that LCMV NP specifically targets the IRF-activating kinase IKKs, and this specific binding is conserved within the Arenaviridae. We could also demonstrate that LCMV NP associates with the kinase domain of IKKs involving NP's C-terminal region. Lastly, we showed that the binding of LCMV NP inhibits the kinase activity of IKKs. This study allowed the discovery of a new cellular interacting partner of arenavirus NP. This newly described association may play a role in the anti-IFN activity of arenaviruses but potentially also in other aspects of arenavirus infection. For the second project, we investigated the ability of arenaviruses to avoid and/or suppress mitochondrial apoptosis. As persistent viruses, arenaviruses evolved a "hit and stay" survival strategy where the apoptosis of the host cell would be deleterious. We found that LCMV does not induce mitochondrial apoptosis at any time during infection. Specifically, no caspase activity, no cytochrome c release from the mitochondria as well as no cleavage of poly (ADP-ribose) polymerase (PARP) were detected during LCMV infection. Interestingly, we found that virus-induced mitochondrial apoptosis remains fully functional in LCMV infected cells, while the induction of type IIFN is blocked. Since both type IIFN production and virus- induced mitochondrial apoptosis critically depend on the pattern recognition receptor (PRR) RIG-I, we examined the role of RIG-I in apoptosis in LCMV infected cells. Notably, virus- induced mitochondrial apoptosis in LCMV infected cells was found to be independent of RIG- I and MDA5, but still depended on MAVS. Our study uncovered a novel mechanism by which arenaviruses alter the host cell's pro-apoptotic signaling pathway. This might represent a strategy arenaviruses developed to maintain this branch of the innate anti-viral defense in absence of type I IFN response. Taken together, these results allow a better understanding of the interaction of arenaviruses with the host cell's innate immunity, contributing to our knowledge about pathogenic properties of these important viruses. A better comprehension of arenavirus virulence may open new avenues for vaccine development and may suggest new antiviral targets for therapeutic intervention against arenavirus infections. - Les arenavirus sont des virus enveloppés à ARN simple brin qui comportent un grand nombre de pathogènes humains. Le pathogène humain le plus important parmi les arenavirus est le virus de Lassa qui est endémique en Afrique de l'Ouest, du Sénégal au Cameroun. Le virus de Lassa est l'agent étiologique d'une fièvre hémorragique sévère appelée fièvre de Lassa, et dont le taux de mortalité peut atteindre 30% chez les patients hospitalisés. L'une des caractéristiques principales des infections fatales à arenavirus chez l'Homme est l'absence de réponse immunitaire innée et adaptative. Dans la nature, les arenavirus sont hébergés par différentes espèces de rongeur, qui représentent à la fois les réservoirs naturels et les vecteurs de transmission des arenavirus. Dans leur hôte naturel, les arenavirus ont la capacité d'établir une infection persistante sans symptôme manifeste d'une quelconque pathologie. Nous pensons que la modulation de système immunitaire inné de la cellule hôte par les arenavirus est un paramètre clé pour la persistance au sein de l'hôte naturel, ainsi que pour la pathogenèse chez l'Homme. L'objectif de cette thèse était d'étudier l'interaction des arenavirus avec deux branches essentielles de la défense antivirale innée de la cellule hôte, le système interféron (IFN) de type I et l'apoptose. La nucléoprotéine virale (NP) est responsable de l'activité anti-IFN des arenavirus. Plus spécifiquement, la NP bloque 1'activation et la translocation nucléaire du facteur de transcription IRF3 qui conduit à la production des IFNs de type I. La NP du virus de Lassa et celle du virus de la chorioméningite lymphocytaire (LCMV), l'arénavirus prototypique, possèdent dans leur extrémité C-terminale un domaine 3'-5' exoribonucléase qui a été associé à l'activité anti-IFN de ces protéines. Dans un premier projet, nous avons cherché à identifier des composants cellulaires de la cascade de signalisation induisant la production d'IFNs de type I qui pourraient être ciblés par la NP virale. Nos recherches ont révélé que la NP de LCMV empêche 1'activation d'IRF3 en bloquant la phosphorylation du facteur de transcription. Nous avons découvert que la NP de LCMV cible spécifiquement la kinase IKKe, et que cette interaction spécifique est conservée à travers la famille des Arenaviridae. Notre étude a aussi permis de démontrer que la NP de LCMV interagit avec le domaine kinase d'IKKe et que l'extrémité C-terminale de la NP est impliquée. Pour finir, nous avons pu établir que l'association avec la NP de LCMV inhibe l'activité kinase d'IKKe. Cette première étude présente la découverte d'un nouveau facteur cellulaire d'interaction avec la NP des arenavirus. Cette association pourrait jouer un rôle dans l'activité anti-IFN des arénavirus, mais aussi potentiellement dans d'autres aspects des infections à arénavirus. Pour le second projet, nous nous sommes intéressés à la capacité des arénavirus à éviter et/ou supprimer l'apoptose mitochondriale. En tant que virus persistants, les arénavirus ont évolué vers une stratégie de survie "hit and stay" pour laquelle l'apoptose de la cellule hôte serait néfaste. Nous avons observé qu'à aucun moment durant l'infection LCMV n'induit l'apoptose mitochondriale. Spécifiquement, aucune activité de caspase, aucune libération mitochondriale de cytochrome c ainsi qu'aucun clivage de la polymerase poly(ADP-ribose) (PARP) n'a été détecté pendant l'infection à LCMV. Il est intéressant de noter que l'apoptose mitochondriale induite par les virus reste parfaitement fonctionnelle dans les cellules infectées par LCMV, alors que l'induction de la réponse IFN de type I est bloquée dans les mêmes cellules. La production des IFNs de type I et l'apoptose mitochondriale induite par les virus dépendent toutes deux du récepteur de reconnaissance de motifs moléculaires RIG-I. Nous avons, par conséquent, investigué le rôle de RIG-I dans l'apoptose qui a lieu dans les cellules infectées par LCMV lorsqu'on les surinfecte avec un autre virus pro-apoptotique. En particulier, l'apoptose mitochondriale induite par les surinfections s'est révélée indépendante de RIG-I et MDA5, mais dépendante de MAVS dans les cellules précédemment infectées par LCMV. Notre étude démontre ainsi l'existence d'un nouveau mécanisme par lequel les arénavirus altèrent la cascade de signalisation pro-apoptotique de la cellule hôte. Il est possible que les arénavirus aient développé une stratégie permettant de maintenir fonctionnelle cette branche de la défense antivirale innée en l'absence de réponse IFN de type I. En conclusion, ces résultats nous amènent à mieux comprendre l'interaction des arénavirus avec l'immunité innée de la cellule hôte, ce qui contribue aussi à améliorer notre connaissance des propriétés pathogéniques de ces virus. Une meilleure compréhension des facteurs de virulence des arénavirus permet, d'une part, le développement de vaccins et peut, d'autre part, servir de base pour la découverte de nouvelles cibles thérapeutiques utilisées dans le traitement des infections à arénavirus.

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Transfer of tumor antigen-specific T-cell receptors (TCRs) into human T cells aims at redirecting their cytotoxicity toward tumors. Efficacy and safety may be affected by pairing of natural and introduced TCRalpha/beta chains potentially leading to autoimmunity. We hypothesized that a novel single-chain (sc)TCR framework relying on the coexpression of the TCRalpha constant alpha (Calpha) domain would prevent undesired pairing while preserving structural and functional similarity to a fully assembled double-chain (dc)TCR/CD3 complex. We confirmed this hypothesis for a murine p53-specific scTCR. Substantial effector function was observed only in the presence of a murine Calpha domain preceded by a TCRalpha signal peptide for shuttling to the cell membrane. The generalization to a human gp100-specific TCR required the murinization of both C domains. Structural and functional T-cell avidities of an accessory disulfide-linked scTCR gp100/Calpha were higher than those of a dcTCR. Antigen-dependent phosphorylation of the proximal effector zeta-chain-associated protein kinase 70 at tyrosine 319 was not impaired, reflecting its molecular integrity in signaling. In melanoma-engrafted nonobese diabetic/severe combined immunodeficient mice, adoptive transfer of scTCR gp100/Calpha transduced T cells conferred superior delay in tumor growth among primary and long-term secondary tumor challenges. We conclude that the novel scTCR constitutes a reliable means to immunotherapeutically target hematologic malignancies.

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This minireview is meant as an introduction to the following paper. To this end, it presents the general background against which the joint paper should be understood. The first objective of the present paper is thus to clarify some concepts and related terminology, drawing a clear distinction between i) atomic diversity (i.e., atomic-property space), ii) molecular or macromolecular diversity (i.e., molecular- or macromolecular-property spaces), and iii) chemical diversity (i.e., chemical-diversity space). The first refers to the various electronic states an atom can occupy. The second encompasses the conformational and property spaces of a given (macro)molecule. The third pertains to the diversity in structure and properties exhibited by a library or a supramolecular assembly of different chemical compounds. The ground is thus laid for the content of the joint paper, which pertains to case ii, to be placed in its broader chemodiversity context. The second objective of this paper is to point to the concepts of chemodiversity and biodiversity as forming a continuum. Chemodiversity is indeed the material substratum of organisms. In other words, chemodiversity is the material condition for life to emerge and exist. Increasing our knowledge of chemodiversity is thus a condition for a better understanding of life as a process.

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Baculoviruses are insect viruses found mainly in Lepidoptera. The family Baculoviridae is taxonomically divided in two genera, Nucleopolyhedrovirus and Granulovirus, which differ by occlusion body morphology. NPVs (Nucleopolyhedroviruses) have polyhedrical inclusion bodies (PIBs) containing multiple viral particles, while GVs (Granuloviruses) appear to be generally single particles occluded in oval shaped occlusion bodies. During the life cycle, two different viral progenies are produced: BV (Budded Virus) and PDV (Polyhedra Derived Virus), which are essential for the infectious process and virus propagation in host cells. Baculoviruses are being used for pest control and they are especially safe due to their specificity and invertebrate-restricted host range. Baculoviruses have been used as vectors for high level protein expression ofheterologous genes from prokaryotic and eukaryotic organisms. Also, recombinant DNA techniques have allowed the production of genetically modified viral insecticides. This study is a review on the taxonomy, structure, replication and molecular biology of baculoviruses, as well as their use as bioinsecticides in Brazil.

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Is species diversification driven by neutral- or niche-based processes? Butterflies of the Lycaenidae family have developed mutualistic interactions with ants. This biotic requirement increased the spatial fragmentation of populations of lower effective population size (Ne) compared with autonomous species. The nearly neutral theory predicts that species with smaller Ne should fix more mutations because of the increased strength of drift. Taking into account the phylogenetic relatedness among species, this study shows that species with a stronger dependence on ants displayed more intra-specific Single Nucleotide Polymorphisms compared with species with low or no myrmecophily. This phenomenon can cause more pronounced genetic differentiation between populations and could ultimately promote speciation in a similar manner as on physical islands. The large species diversity observed in this family could be the consequence of this neutral process enhancing the diversification of lineages.

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An understanding of details of the interaction mechanisms of bacterial endotoxins (lipopolysaccharide, LPS) with the oxygen transport protein hemoglobin is still lacking, despite its high biological relevance. Here, a biophysical investigation into the endotoxin:hemoglobin interaction is presented which comprises the use of various rough mutant LPS as well as free lipid A; in addition to the complete hemoglobin molecule from fetal sheep extract, also the partial structure alpha-chain and the heme-free sample are studied. The investigations comprise the determination of the gel-to-liquid crystalline phase behaviour of the acyl chains of LPS, the ultrastructure (type of aggregate structure and morphology) of the endotoxins, and the incorporation of the hemoglobins into artificial immune cell membranes and into LPS. Our data suggest a model for the interaction between Hb and LPS in which hemoglobins do not react strongly with the hydrophilic or with the hydrophobic moiety of LPS, but with the complete endotoxin aggregate. Hb is able to incorporate into LPS with the longitudinal direction parallel to the lipid A double-layer. Although this does not lead to a strong disturbance of the LPS acyl chain packing, the change of the curvature leads to a slightly conical molecular shape with a change of the three-dimensional arrangement from unilamellar into cubic LPS aggregates. Our previous results show that cubic LPS structures exhibit strong endotoxic activity. The property of Hb on the physical state of LPS described here may explain the observation of an increase in LPS-mediating endotoxicity due to the action of Hb.

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Single amino acid substitution is the type of protein alteration most related to human diseases. Current studies seek primarily to distinguish neutral mutations from harmful ones. Very few methods offer an explanation of the final prediction result in terms of the probable structural or functional effect on the protein. In this study, we describe the use of three novel parameters to identify experimentally-verified critical residues of the TP53 protein (p53). The first two parameters make use of a surface clustering method to calculate the protein surface area of highly conserved regions or regions with high nonlocal atomic interaction energy (ANOLEA) score. These parameters help identify important functional regions on the surface of a protein. The last parameter involves the use of a new method for pseudobinding free-energy estimation to specifically probe the importance of residue side-chains to the stability of protein fold. A decision tree was designed to optimally combine these three parameters. The result was compared to the functional data stored in the International Agency for Research on Cancer (IARC) TP53 mutation database. The final prediction achieved a prediction accuracy of 70% and a Matthews correlation coefficient of 0.45. It also showed a high specificity of 91.8%. Mutations in the 85 correctly identified important residues represented 81.7% of the total mutations recorded in the database. In addition, the method was able to correctly assign a probable functional or structural role to the residues. Such information could be critical for the interpretation and prediction of the effect of missense mutations, as it not only provided the fundamental explanation of the observed effect, but also helped design the most appropriate laboratory experiment to verify the prediction results.

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The Iowa Department of Transportation used a high molecular weight methacrylate (HMWM) resin to seal a 3,340 ft. x 64 ft. bridge deck in October 1986. The sealing was necessary to prevent deicing salt brine from entering a substantial number of transverse cracks that coincided with the epoxy coated top steel and unprotected bottom steel. HMWM resin is a three component product composed of a monomer, a cumene hydroperoxide initiator and a cobalt naphthenate promoter. The HMWM was applied with a dual spray bar system and flat-fan nozzles. Initiated monomer delivered through one spray bar was mixed in the air with promoted monomer from the other spray bar. The application rate averaged 0.956 gallons per 100 square feet for the tined textured driving lanes. Dry sand was broadcast on the surface at an average coverage of 0.58 lbs. per square yard to maintain friction. Coring showed that the HMWM resin penetrated the cracks more than two inches deep. Testing of the treated deck yielded Friction Numbers averaging 33 with a treaded tire compared to 36 prior to treatment. An inspection soon after treatment found five leaky cracks in one of the 15 spans. One inspection during a steady rain showed no leakage, but leakage from numerous cracks occurred during a subsequent rain. A second HMWM application was made on two spans. Leakage through the double application occurred during a rain. Neither the single or double application were successful in preventing leakage through the cracks.

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In the last few years, a need to account for molecular flexibility in drug-design methodologies has emerged, even if the dynamic behavior of molecular properties is seldom made explicit. For a flexible molecule, it is indeed possible to compute different values for a given conformation-dependent property and the ensemble of such values defines a property space that can be used to describe its molecular variability; a most representative case is the lipophilicity space. In this review, a number of applications of lipophilicity space and other property spaces are presented, showing that this concept can be fruitfully exploited: to investigate the constraints exerted by media of different levels of structural organization, to examine processes of molecular recognition and binding at an atomic level, to derive informative descriptors to be included in quantitative structure--activity relationships and to analyze protein simulations extracting the relevant information. Much molecular information is neglected in the descriptors used by medicinal chemists, while the concept of property space can fill this gap by accounting for the often-disregarded dynamic behavior of both small ligands and biomacromolecules. Property space also introduces some innovative concepts such as molecular sensitivity and plasticity, which appear best suited to explore the ability of a molecule to adapt itself to the environment variously modulating its property and conformational profiles. Globally, such concepts can enhance our understanding of biological phenomena providing fruitful descriptors in drug-design and pharmaceutical sciences.

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Purpose: To compare the efficacy and safety of a slowly resorbable glaucoma implant, Healaflow (HF) and Healon 5 (H5) as spacers injected into failing filtration blebs at the time of bleb needlings, augmented with MMC Methods: Eighty-four glaucoma patients with filtration bleb failure following glaucoma surgery (deep sclerectomy/ trabeculectomy) underwent bleb needling using either HF (n=44) or H5 (n=40) as an intrableb viscoelastic spacer. All needlings were augmented by MMC and performed in the operating room, by a single surgeon. The choice between HF and H5 was randomised. Postoperative data for IOP, number of glaucoma medications (GMs), antimetabolite injections (AMIs), bleb morphology and all complications were recorded at day 1 (D1), weeks 1 (W1), 4 (W4), month 6 (M6) and last visit. Success was defined as IOP≤21mmHg and 20% reduction in IOP from baseline Results: Age was comparable between groups (HF vs H5; 66 vs 72 years; p=0.13*). There were no differences in mean postoperative IOP or GMs at any time point between groups (mean IOP = HF vs H5; prior to needling=19.8mmHg vs 18.7mmHg, p=0.48*; D1=10.4mmHg vs 10.2mmHg, p=0.85*; W1=12.3mmHg vs 13.8mmHg, p=0.33*; W4=15.7mmHg vs 15.1mmHg, p=0.69*; M6=14.3mmHg vs 13.8mmHg, p=0.69*. Mean GMs= HF vs H5; prior to needling=1.7 vs 1.7, p=0.96*; M6=0.9 vs 1.1, p=0.66*). Success rates were comparable between HF and H5 groups (74% vs 71%). Requirements for AMIs were similar between groups; post filtration surgery and prior to needling (mean AMIs 1.54 vs 1.65 p=0.82*) and within the first six months following needling ( 0.77 vs 0.65 p=0.70*). Complication rates were infrequent in both groups (9%, HF; 3%, H5) * two-sample t-test Conclusions: The early to mid-term success rates of needlings using intrableb spacers were high. However there were no differences observed between the use of crosslinked and high molecular weight sodium hyaluronate

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We describe 19 unrelated individuals with submicroscopic deletions involving 10p15.3 characterized by chromosomal microarray (CMA). Interestingly, to our knowledge, only two individuals with isolated, submicroscopic 10p15.3 deletion have been reported to date; however, only limited clinical information is available for these probands and the deleted region has not been molecularly mapped. Comprehensive clinical history was obtained for 12 of the 19 individuals described in this study. Common features among these 12 individuals include: cognitive/behavioral/developmental differences (11/11), speech delay/language disorder (10/10), motor delay (10/10), craniofacial dysmorphism (9/12), hypotonia (7/11), brain anomalies (4/6) and seizures (3/7). Parental studies were performed for nine of the 19 individuals; the 10p15.3 deletion was de novo in seven of the probands, not maternally inherited in one proband and inherited from an apparently affected mother in one proband. Molecular mapping of the 19 individuals reported in this study has identified two genes, ZMYND11 (OMIM 608668) and DIP2C (OMIM 611380; UCSC Genome Browser), mapping within 10p15.3 which are most commonly deleted. Although no single gene has been identified which is deleted in all 19 individuals studied, the deleted region in all but one individual includes ZMYND11 and the deleted region in all but one other individual includes DIP2C. There is not a clearly identifiable phenotypic difference between these two individuals and the size of the deleted region does not generally predict clinical features. Little is currently known about these genes complicating a direct genotype/phenotype correlation at this time. These data however, suggest that ZMYND11 and/or DIP2C haploinsufficiency contributes to the clinical features associated with 10p15 deletions in probands described in this study.

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Deregulation of the ubiquitin/proteasome system has been implicated in the pathogenesis of many human diseases, including cancer. Ubiquitin-specific proteases (USP) are cysteine proteases involved in the deubiquitination of protein substrates. Functional connections between USP7 and essential viral proteins and oncogenic pathways, such as the p53/Mdm2 and phosphatidylinositol 3-kinase/protein kinase B networks, strongly suggest that the targeting of USP7 with small-molecule inhibitors may be useful for the treatment of cancers and viral diseases. Using high-throughput screening, we have discovered HBX 41,108, a small-molecule compound that inhibits USP7 deubiquitinating activity with an IC(50) in the submicromolar range. Kinetics data indicate an uncompetitive reversible inhibition mechanism. HBX 41,108 was shown to affect USP7-mediated p53 deubiquitination in vitro and in cells. As RNA interference-mediated USP7 silencing in cancer cells, HBX 41,108 treatment stabilized p53, activated the transcription of a p53 target gene without inducing genotoxic stress, and inhibited cancer cell growth. Finally, HBX 41,108 induced p53-dependent apoptosis as shown in p53 wild-type and null isogenic cancer cell lines. We thus report the identification of the first lead-like inhibitor against USP7, providing a structural basis for the development of new anticancer drugs.