222 research outputs found

    Separase prevents genomic instability by controlling replication fork speed

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    Proper chromosome segregation is crucial for preserving genomic integrity, and errors in this process cause chromosome mis-segregation, which may contribute to cancer development. Sister chromatid separation is triggered by Separase, an evolutionary conserved protease that cleaves the cohesin complex, allowing the dissolution of sister chromatid cohesion. Here we provide evidence that Separase participates in genomic stability maintenance by controlling replication fork speed. We found that Separase interacted with the replication licensing factors MCM2-7, and genome-wide data showed that Separase co-localized with MCM complex and cohesin. Unexpectedly, the depletion of Separase increased the fork velocity about 1.5-fold and caused a strong acetylation of cohesin's SMC3 subunit and altered checkpoint response. Notably, Separase silencing triggered genomic instability in both HeLa and human primary fibroblast cells. Our results show a novel mechanism for fork progression mediated by Separase and thus the basis for genomic instability associated with tumorigenesis

    Local manifold learning and its link to domain-based physics knowledge

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    In many reacting flow systems, the thermo-chemical state-space is known or assumed to evolve close to a low-dimensional manifold (LDM). Various approaches are available to obtain those manifolds and subsequently express the original high-dimensional space with fewer parameterizing variables. Principal component analysis (PCA) is one of the dimensionality reduction methods that can be used to obtain LDMs. PCA does not make prior assumptions about the parameterizing variables and retrieves them empirically from the training data. In this paper, we show that PCA applied in local clusters of data (local PCA) is capable of detecting the intrinsic parameterization of the thermo-chemical state-space. We first demonstrate that utilizing three common combustion models of varying complexity: the Burke-Schumann model, the chemical equilibrium model and the homogeneous reactor. Parameterization of these models is known a priori which allows for benchmarking with the local PCA approach. We further extend the application of local PCA to a more challenging case of a turbulent non-premixed nn-heptane/air jet flame for which the parameterization is no longer obvious. Our results suggest that meaningful parameterization can be obtained also for more complex datasets. We show that local PCA finds variables that can be linked to local stoichiometry, reaction progress and soot formation processes

    Separase prevents genomic instability by controlling replication fork speed

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    Proper chromosome segregation is crucial for preserving genomic integrity, and errors in this process cause chromosome mis-segregation, which may contribute to cancer development. Sister chromatid separation is triggered by Separase, an evolutionary conserved protease that cleaves the cohesin complex, allowing the dissolution of sister chromatid cohesion. Here we provide evidence that Separase participates in genomic stability maintenance by controlling replication fork speed. We found that Separase interacted with the replication licensing factors MCM2-7, and genome-wide data showed that Separase co-localized with MCM complex and cohesin. Unexpectedly, the depletion of Separase increased the fork velocity about 1.5-fold and caused a strong acetylation of cohesin's SMC3 subunit and altered checkpoint response. Notably, Separase silencing triggered genomic instability in both HeLa and human primary fibroblast cells. Our results show a novel mechanism for fork progression mediated by Separase and thus the basis for genomic instability associated with tumorigenesis

    OXavidin for Tissue Targeting Biotinylated Therapeutics

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    Avidin is a glycoprotein from hen egg white that binds biotin with very high affinity. Here we describe OXavidin, a product containing aldehyde groups, obtained by ligand-assisted sugar oxidation of avidin by sodium periodate. OXavidin chemically reacts with cellular and tissue proteins through Schiff's base formation thus residing in tissues for weeks while preserving the biotin binding capacity. The long tissue residence of OXavidin as well as that of OXavidin/biotinylated agent complex occurs in normal and neoplastic tissues and immunohistochemistry shows a strong and homogenous stromal localization. Once localized in tissue/tumor, OXavidin becomes an “artificial receptor” for intravenous injected biotin allowing tumor targeting with biotinylated therapeutics like radioisotopes or toxins. Moreover, present data also suggest that OXavidin might be useful for the homing of biotinylated cells. Overall, OXavidin exhibits a remarkable potential for many different therapeutic applications

    Evidence of Reelin Signaling in GBM and Its Derived Cancer Stem Cells

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    Glioblastoma (GBM) is the most aggressive and malignant form of primary brain cancer, characterized by an overall survival time ranging from 12 to 18 months. Despite the progress in the clinical treatment and the growing number of experimental data aimed at investigating the molecular bases of GBM development, the disease remains characterized by a poor prognosis. Recent studies have proposed the existence of a population of GBM cancer stem cells (CSCs) endowed with self-renewal capability and a high tumorigenic potential that are believed to be responsible for the resistance against common chemotherapy and radiotherapy treatments. Reelin is a large secreted extracellular matrix glycoprotein, which contributes to positioning, migration, and laminar organization of several central nervous system structures during brain development. Mutations of the reelin gene have been linked to disorganization of brain structures during development and behavioral anomalies. In this study, we explored the expression of reelin in GBM and its related peritumoral tissue and performed the same analysis in CSCs isolated from both GBM (GCSCs) and peritumoral tissue (PCSCs) of human patients. Our findings reveal (i) the higher expression of reelin in GBM compared to the peritumoral tissue by immunohistochemical analysis, (ii) the mRNA expression of both reelin and its adaptor molecule Dab1 in either CSC subtypes, although at a different extent; and (iii) the contribution of CSCs-derived reelin in the migration of human primary GBM cell line U87MG. Taken together, our data indicate that the expression of reelin in GBM may represent a potential contribution to the regulation of GBM cancer stem cells behavior, further stimulating the interest on the reelin pathway as a potential target for GBM treatment

    Cystic echinococcosis in wild boars (Sus scrofa) from southern Italy: Epidemiological survey and molecular characterization.

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    Cystic Echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is one of the most important parasitic zoonotic diseases in the world and it represents an important public health and socio-economic concern. In the Mediterranean basin, CE is widespread and it is endemic in Italy, with major prevalence in southern areas. Several studies have investigated CE in domestic pigs, however, such data in wild boars are scant. In the last decades the wild boar population in Italy has increased and this ungulate could play an important role in the spreading ofCEinthewild.Here wereporton theprevalenceandfertility rateofhydatid cystsinwildboarsthat were shot during two hunting seasons (2016–2017) in the Campania region of southern Italy. For each animal, a detailed inspection of the carcass and organs (lungs, liver and spleen) was performed and when cysts were found, their number, morphology and fertility were determined by visual and microscopic examination. Cysts were classified morphologically as fertile, sterile, caseous and calcified. Protoscoleces and germinal layers were collected from individual cysts and DNA was extracted to identify different strains/genotypes of E. granulosus s.l. Outofatotalof2108wildboars93(4.4%)werefoundpositiveforCE.Infectedanimalswere45malesand48 females, aged between 1 and 8 years. The average number of cysts per wild boar was 1.3 (min 1 - max 13). The total number of cysts collected was 123, of which 118 (95.9%) in the liver, 4 (3.3%) in the lungs and 1 (0.8%) in the spleen. Of all analyzed cysts, 70 (56.9%) were fertile and 53 (43.1%) sterile/acephalous. The presence of fertile cysts in 19.4% of CE-positive animals is noteworthy. Overall, molecular diagnosis showed 19 wild boars infected with the pig strain (G7)
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