Deregulation of cyclin E in human cells interferes with prereplication complex assembly

Deregulation of cyclin E expression has been associated with a broad spectrum of human malignancies. Analysis of DNA replication in cells constitutively expressing cyclin E at levels similar to those observed in a subset of tumor-derived cell lines indicates that initiation of replication and possibly fork movement are severely impaired. Such cells show a specific defect in loading of initiator proteins Mcm4, Mcm7, and to a lesser degree, Mcm2 onto chromatin during telophase and early G1 when Mcm2–7 are normally recruited to license origins of replication. Because minichromosome maintenance complex proteins are thought to function as a heterohexamer, loading of Mcm2-, Mcm4-, and Mcm7-depleted complexes is likely to underlie the S phase defects observed in cyclin E–deregulated cells, consistent with a role for minichromosome maintenance complex proteins in initiation of replication and fork movement. Cyclin E–mediated impairment of DNA replication provides a potential mechanism for chromosome instability observed as a consequence of cyclin E deregulation

The Balance Between the Therapeutic Efficacy and Safety of [¹⁷⁷Lu]Lu-NeoB in a Preclinical Prostate Cancer Model

Purpose: Radiolabeled NeoB is a promising gastrin-releasing peptide receptor (GRPR)–targeting radiopharmaceutical for theranostics of GRPR-expressing malignancies, e.g., prostate cancer (PCa). The aim of this study was to evaluate the effect of different doses of [177Lu]Lu-NeoB on the balance between therapeutic efficacy and safety in a preclinical PCa model. Procedures: To determine the efficacy of [177Lu]Lu-NeoB, PC-3 xenografted mice received 3 sham injections (control group) or 3 injections of 30 MBq/300 pmol, 40 MBq/400 pmol, or 60 MBq/600 pmol [177Lu]Lu-NeoB (groups 1, 2, and 3, respectively) 1 week apart. To quantify tumor uptake, single-photon emission computed tomography/computed tomography (SPECT/CT) imaging was performed 4 h after the first, second, and third injection on a separate group of animals. For safety evaluations, pancreatic and renal tissues of non-tumor-bearing mice treated with the abovementioned [177Lu]Lu-NeoB doses were evaluated 12 and 24 weeks post-treatment. Results: Treatment of PC-3 tumors with all three studied [177Lu]Lu-NeoB doses was effective. Median survival times were significantly (p &lt; 0.0001) improved for treatment groups 1, 2, and 3 versus the control group (82 days, 89 days, 99 days versus 19 days, respectively). However, no significant differences were observed between treatment groups. Quantification of SPECT/CT images showed minimal differences in the average absolute radioactivity uptake, especially after the third injection. Histopathological analysis revealed no clear signs of treatment-related pancreatic toxicity. For the kidneys, atrophy and fibrosis were observed for one animal from group 1 and a chronic inflammatory response was observed for both animals from group 3 at 24 weeks post-treatment. Conclusions: Treatment with [177Lu]Lu-NeoB is effective in a preclinical PCa model. Adjusting the administered dose could positively impact the risk-benefit balance as a higher dose might not lead to an increased therapeutic effect, but it may lead to an increase in toxicological effects in healthy organs such as the kidneys.</p

Cyclin E overexpression impairs progression through mitosis by inhibiting APCCdh1

Overexpression of cyclin E, an activator of cyclin-dependent kinase 2, has been linked to human cancer. In cell culture models, the forced expression of cyclin E leads to aneuploidy and polyploidy, which is consistent with a direct role of cyclin E overexpression in tumorigenesis. In this study, we show that the overexpression of cyclin E has a direct effect on progression through the latter stages of mitotic prometaphase before the complete alignment of chromosomes at the metaphase plate. In some cases, such cells fail to divide chromosomes, resulting in polyploidy. In others, cells proceed to anaphase without the complete alignment of chromosomes. These phenotypes can be explained by an ability of overexpressed cyclin E to inhibit residual anaphase-promoting complex (APCCdh1) activity that persists as cells progress up to and through the early stages of mitosis, resulting in the abnormal accumulation of APCCdh1 substrates as cells enter mitosis. We further show that the accumulation of securin and cyclin B1 can account for the cyclin E–mediated mitotic phenotype

Targeting CD34(+) cells of the inflamed synovial endothelium by guided nanoparticles for the treatment of rheumatoid arthritis

Despite the advances in the treatment of rheumatoid arthritis (RA) achieved in the last few years, several patients are diagnosed late, do not respond to or have to stop therapy because of inefficacy and/or toxicity, leaving still a huge unmet need. Tissue-specific strategies have the potential to address some of these issues. The aim of the study is the development of a safe nanotechnology approach for tissue-specific delivery of drugs and diagnostic probes. CD34 + endothelial precursors were addressed in inflamed synovium using targeted biodegradable nanoparticles (tBNPs). These nanostructures were made of poly-lactic acid, poly-caprolactone, and PEG and then coated with a synovial homing peptide. Immunofluorescence analysis clearly demonstrated their capacity to selectively address CD34 + endothelial cells in synovial tissue obtained from human, mouse, and rat. Biodistribution studies in two different animal models of rheumatoid arthritis (antigen-induced arthritis/AIA and collagen-induced arthritis/CIA) confirmed the selective accumulation in inflamed joints but also evidenced the capacity of tBNP to detect early phases of the disease and the preferential liver elimination. The therapeutic effect of methotrexate (MTX)-loaded tBNPs were studied in comparison with conventional MTX doses. MTX-loaded tBNPs prevented and treated CIA and AIA at a lower dose and reduced administration frequency than MTX. Moreover, MTX-loaded tBNP showed a novel mechanism of action, in which the particles target and kill CD34 + endothelial progenitors, preventing neo-angiogenesis and, consequently, synovial inflammation. tBNPs represent a stable and safe platform to develop highly-sensitive imaging and therapeutic approaches in RA targeting specifically synovial neo-angiogenesis to reduce local inflammation

The pRb-related protein p130 is regulated by phosphorylation-dependent proteolysis via the protein–ubiquitin ligase SCF(Skp2)

p130 is a tumor suppressor of the pocket protein family whose expression is posttranscriptionally regulated and largely G0 restricted. The mechanism of down-regulation of p130 expression in proliferating cells was investigated. Our results indicate that the decline of p130 expression as G0 cells reenter the cell cycle is due to a decrease in protein stability. The enhancement of p130 turnover in late G1 and S phase compared with G0 and early G1 phase was dependent on Cdk4/6-specific phosphorylation of p130 on Serine 672, and independent of Cdk2 activity. The activity of the ubiquitin ligase complex Skp1–Cul1/Cdc53–F-box protein Skp2 (SCF(Skp2)) and the proteasome were necessary for p130 degradation. In vitro, recombinant Skp2 was able to bind hyperphosphorylated but not dephosphorylated p130. Furthermore, in vitro polyubiquitination of p130 by SCF(Skp2) was specifically dependent on phosphorylation of p130 on Serine 672. Thus, like the Cdk inhibitor p27(Kip1), p130 turnover is regulated by Cdk-dependent G1 phosphorylation leading to ubiquitin-dependent proteolysis

Catalogo prestazionale dei manti bituminosi superficiali

La pavimentazione stradale riveste oggi peculiare rilevanza in relazione al soddisfacimento di istanze primarie ed assolutamente generali quali la sicurezza della locomozione e la ecocompatibilità del moto, soprattutto per ciò che concerne le caratteristiche dello strato superficiale. La logica che presiede al processo di attribuzione dei requisiti si è nel contempo sempre più caratterizzata in termini di esigenza di “prestazioni” (aderenza, regolarità, portanza, ridotta contribuzione vibro-sonora, etc.), rendendo di fatto meno prioritario e cogente il sistema di vincoli compositivo-esecutivi, diffusamente usato finora nei tradizionali Capitolati Speciali d’Appalto. In tale ottica, condivisa in ambito scientifico, tecnologico e giuridico, cospicua importanza hanno acquisito i “capitolati prestazionali”, con i quali è possibile governare, in un mercato dalle regole di accesso e permanenza in continua evoluzione, i rapporti tra Committenze ed Imprese Esecutrici, sulla base di codici di “sussistenza prestazionale”, fondati su di un insieme di indicatori funzionali. Sensibili a tali istanze, nel 2001 è stato cofinanziato, ed ad oggi completato, un progetto di rilevante interesse nazionale da l titolo “Istituzione di un catalogo prestazionale dei manti bituminosi per pavimentazioni stradali”, il cui obiettivo era proprio la formalizzazione, a valle di una cospicua attività di sperimentazione, di un catalogo dei rivestimenti superficiali ove risultasse possibile accertare la corrispondenza fra protocolli di composizione, produzione e messa in opera da un lato e prestazioni risultanti dall’altro

Bioaugmentation of Novosphingobium sp. PP1Y in natural and artificial soils contaminated by PAHs and heavy metals

Polycyclic Aromatic Hydrocarbons (PAHs) are among the most widespread organic pollutants in the environment. PAHs are of great concern because some of them show strong mutagenicity and carcinogenity. Bioremediation, which involves the use of microorganisms to reduce the concentration of various chemical pollutants, has become nowadays one of the most promising approach for environmental clean-up. Unfortunately, the presence of heavy metals in environments contaminated by organic compounds often hamper the environmental restoration. Several species of bacteria have been isolated from polluted environments able to degrade recalcitrant compounds. We have recently characterized a novel Sphingomonadales, Novosphingobium sp. PP1Y, isolated from surface seawater samples collected inside the harbour of Pozzuoli (Naples, Italy). The strain PP1Y not only uses a surprisingly large number of mono and polycyclic aromatic compounds as the sole carbon and energy sources but it shows a very interesting and effective adaptation to grow on complex mixtures of aromatic compounds dissolved in oil phases like diesel-oil and gasoline. Novosphingobium sp. PP1Y showed the ability to form “biofilm” on several types of hydrophobic surfaces and, in water/oil systems. It is well known that biofilm formation make bacteria able to adhere to growing substrates and to confer the resistance towards heavy metals and organic pollutants. We investigated the biodegradation abilities of Novosphingobium sp. PP1Y in natural soil and compost, artificially contaminated by PAHs and heavy metals such as nickel, copper and zinc, in small-scale experiments. N. sp. PP1Y showed the ability to quickly remove phenanthrene from the compost after addition of the organic compound in crystal form or dissolved in oil phase. The bacterium was also able to metabolize phenanthrene in the presence of heavy metals, showing the most significant delay in phenanthrene removal only at high nickel concentration. When a mixture of PAHs in paraffin containing naphthalene, phenanthrene and pyrene, was added to the compost, the bacterium was able to remove all the three compounds, although with different rates. Furthermore, the addition of N. sp. PP1Y to a natural soil contaminated by heavy metals and PAHs, already endowed with a microbial community adapted to use PAHs in the presence of heavy metals, halved the time of natural self-purifying of the soil, thus suggesting the ability of N. sp. PP1Y to compete with the adapted endogenous microbial community.In conclusion Novosphingobium sp. PP1Y is a good candidate for the bioremediation of organic compound contaminated soils in the presence of heavy metals

Bioaugmentation of Novosphingobium sp. PP1Y in natural and artificial soils contaminated by PAHs and heavy metals

Polycyclic Aromatic Hydrocarbons (PAHs) are among the most widespread organic pollutants in the environment. PAHs are of great concern because some of them show strong mutagenicity and carcinogenity. Bioremediation, which involves the use of microorganisms to reduce the concentration of various chemical pollutants, has become nowadays one of the most promising approach for environmental clean-up. Unfortunately, the presence of heavy metals in environments contaminated by organic compounds often hamper the environmental restoration. Several species of bacteria have been isolated from polluted environments able to degrade recalcitrant compounds. We have recently characterized a novel Sphingomonadales, Novosphingobium sp. PP1Y, isolated from surface seawater samples collected inside the harbour of Pozzuoli (Naples, Italy). The strain PP1Y not only uses a surprisingly large number of mono and polycyclic aromatic compounds as the sole carbon and energy sources but it shows a very interesting and effective adaptation to grow on complex mixtures of aromatic compounds dissolved in oil phases like diesel-oil and gasoline. Novosphingobium sp. PP1Y showed the ability to form “biofilm” on several types of hydrophobic surfaces and, in water/oil systems. It is well known that biofilm formation make bacteria able to adhere to growing substrates and to confer the resistance towards heavy metals and organic pollutants. We investigated the biodegradation abilities of Novosphingobium sp. PP1Y in natural soil and compost, artificially contaminated by PAHs and heavy metals such as nickel, copper and zinc, in small-scale experiments. N. sp. PP1Y showed the ability to quickly remove phenanthrene from the compost after addition of the organic compound in crystal form or dissolved in oil phase. The bacterium was also able to metabolize phenanthrene in the presence of heavy metals, showing the most significant delay in phenanthrene removal only at high nickel concentration. When a mixture of PAHs in paraffin containing naphthalene, phenanthrene and pyrene, was added to the compost, the bacterium was able to remove all the three compounds, although with different rates. Furthermore, the addition of N. sp. PP1Y to a natural soil contaminated by heavy metals and PAHs, already endowed with a microbial community adapted to use PAHs in the presence of heavy metals, halved the time of natural self-purifying of the soil, thus suggesting the ability of N. sp. PP1Y to compete with the adapted endogenous microbial community.In conclusion Novosphingobium sp. PP1Y is a good candidate for the bioremediation of organic compound contaminated soils in the presence of heavy metals