565 research outputs found

    Synthesis of Curcumin Derivatives and Analysis of Their Antitumor Effects in Triple Negative Breast Cancer (TNBC) Cell Lines

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    We analyzed antitumor effects of a series of curcumin analogues. Some of them were obtained by reaction of substitution involving the two phenolic OH groups of curcumin while the analogues with a substituent at C-4 was prepared following an original procedure that regards the condensation of benzenesulfenic acid onto the nucleophilic central carbon of the curcumin skeleton. We analyzed cytotoxic effects of such derivatives on two TNBC (triple negative breast cancer) cell lines, SUM 149 and MDA-MB-231, but only three of them showed an IC50 in a lower micromolar range with respect to curcumin. We also focused on these three derivatives that in both cell lines exhibited a higher or at least equivalent pro-apoptotic effect than curcumin. The analysis of molecular mechanisms of action of the curcumin derivatives under study has highlighted that they decreased NF-κB transcriptional factor activity, and consequently the expression of some NF-κB targets. Our data confirmed once again that curcumin may represent a very good lead compound to design analogues with higher antitumor capacities and able to overcome drug resistance with respect to conventional ones, even in tumors difficult to treat as TNBC

    Classical-path integral adaptive resolution in molecular simulation: towards a smooth quantum-classical coupling

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    Simulations that couple different classical molecular models in an adaptive way by changing the number of degrees of freedom on the fly, are available within reasonably consistent theoretical frameworks. The same does not occur when it comes to classical-quantum adaptivity. The main reason for this is the difficulty in describing a continuous transition between the two different kind of physical principles: probabilistic for the quantum and deterministic for the classical. Here we report the basic principles of an algorithm that allows for a continuous and smooth transition by employing the path integral description of atoms.Comment: 8 pages 4 figure

    Indeterminate Thyroid Nodules: From Cytology to Molecular Testing

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    Thyroid cancer is the most common malignancy of the endocrine system. Fine-needle aspiration (FNA) biopsy of thyroid nodules has become the gold standard procedure, in terms of cost and efficacy, for guiding clinicians towards appropriate patients’ management. One challenge for cytopathologists is to accurately classify cytological specimens as benign or malignant based on cytomorphological features. In fact, with a frequency ranging from 10% to 30%, nodules are diagnosed as indeterminate. In recent years, the mutational landscape of thyroid tumors has been extensively described, and two molecular profiles have been identified: RAS-like (NRAS, HRAS, and KRAS mutations; EIF1AX mutations; BRAF K601E mutation; and PPARG and THADA fusions) and BRAFV600E-like (including BRAFV600E mutation and RET and BRAF fusions). The purpose of this review is to discuss the latest molecular findings in the context of indeterminate thyroid nodules, highlighting the role of molecular tests in patients’ management

    Epigenetic changes and nuclear factor-\u3baB activation, but not microRNA-224, downregulate Raf-1 kinase inhibitor protein in triple\u2011negative breast cancer SUM 159 cells

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    Raf-1 kinase inhibitor protein (RKIP) is a tumor suppressor and metastasis inhibitor, which enhances drug\u2011induced apoptosis of cancer cells. Downregulation of RKIP may be significant in the biology of highly aggressive and drug\u2011resistant tumors, for example triple\u2011negative breast cancers (TNBCs). Potential causes for the low levels of RKIP expressed by SUM 159 TNBC cells were investigated in the present study. Bisulphite modification, methylation specific\u2011polymerase chain reaction (PCR) and a TransAM NF-\u3baB assay were performed and the results suggested that various mechanisms, including methylation of the gene promoter, histone deacetylation and nuclear factor\u2011\u3baB (NF\u2011\u3baB) activation, but not targeting by microRNA\u2011224 (miR/miRNA\u2011224), as determined by transfection of pre\u2011miR\u2011224 miRNA precursor or anti\u2011miR\u2011224 miRNA inhibitor, may downregulate RKIP in these cells. Furthermore, reverse transcription\u2011quantitative PCR, western blotting,3\u2011(4,5\u2011dimethylthiazol\u20112\u2011yl)\u20115\u2011(3\u2011carboxymethoxyphenyl)\u20112\u2011(4\u2011sulphophenyl)\u20112H\u2011tetrazolium cell growth assay and flow cytometry revealed that in SUM 159 cells, the demethylating agent 5\u2011aza\u20112'\u2011deoxycytidine (5\u2011AZA), the histone deacetylase inhibitor trichostatin A (TSA) and the NF\u2011\u3baB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) enhanced RKIP expression and resulted in significant cell growth inhibition and induction of apoptosis. 5\u2011AZA and TSA mainly produced additive antitumor effects, while the combination of DHMEQ and TSA exhibited significant synergy in cell growth inhibition and induction of apoptosis assays. Increasing evidence that aberrant activation of NF\u2011\u3baB signaling is a frequent characteristic of TNBC highlights the fact that this transcription factor may be a useful target for treatment of such tumors. In addition to DHMEQ, proteasome inhibitors may also represent valuable therapeutic resources in this context. Notably, proteasome inhibitors, in addition to the inhibition of NF\u2011\u3baB activation, may also restore RKIP levels by inhibiting proteasome degradation of the ubiquitinated protein. The current results contribute to the understanding of the molecular mechanisms of RKIP downregulation in TNBC and suggest possible novel therapeutic approaches for the treatment of these types of cancer

    Combinatorial entropy behaviour leads to range selective binding in ligand-receptor interactions

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    From viruses to nanoparticles, constructs functionalized with multiple ligands display peculiar binding properties that only arise from multivalent effects. Using statistical mechanical modelling, we describe here how multivalency can be exploited to achieve what we dub range selectivity, that is, binding only to targets bearing a number of receptors within a specified range. We use our model to characterise the region in parameter space where one can expect range selective targeting to occur, and provide experimental support for this phenomenon. Overall, range selectivity represents a potential path to increase the targeting selectivity of multivalent constructs

    Atomic Force Microscope nanolithography on chromosomes to genrate single-cell genetic probes

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    Abstract Background Chromosomal dissection provides a direct advance for isolating DNA from cytogenetically recognizable region to generate genetic probes for fluorescence in situ hybridization, a technique that became very common in cyto and molecular genetics research and diagnostics. Several reports describing microdissection methods (glass needle or a laser beam) to obtain specific probes from metaphase chromosomes are available. Several limitations are imposed by the traditional methods of dissection as the need for a large number of chromosomes for the production of a probe. In addition, the conventional methods are not suitable for single chromosome analysis, because of the relatively big size of the microneedles. Consequently new dissection techniques are essential for advanced research on chromosomes at the nanoscale level. Results We report the use of Atomic Force Microscope (AFM) as a tool for nanomanipulation of single chromosomes to generate individual cell specific genetic probes. Besides new methods towards a better nanodissection, this work is focused on the combination of molecular and nanomanipulation techniques which enable both nanodissection and amplification of chromosomal and chromatidic DNA. Cross-sectional analysis of the dissected chromosomes reveals 20 nm and 40 nm deep cuts. Isolated single chromosomal regions can be directly amplified and labeled by the Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP-PCR) and subsequently hybridized to chromosomes and interphasic nuclei. Conclusions Atomic force microscope can be easily used to visualize and to manipulate biological material with high resolution and accuracy. The fluorescence in situ hybridization (FISH) performed with the DOP-PCR products as test probes has been tested succesfully in avian microchromosomes and interphasic nuclei. Chromosome nanolithography, with a resolution beyond the resolution limit of light microscopy, could be useful to the construction of chromosome band libraries and to the molecular cytogenetic mapping related to the investigation of genetic diseases.</p

    Pharmacogenetic considerations for optimizing tacrolimus dosing in liver and kidney transplant patients

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    The introduction of tacrolimus in clinical practice has improved patient survival after organ transplant. However, despite the long use of tacrolimus in clinical practice, the best way to use this agent is still a matter of intense debate. The start of the genomic era has generated new research areas, such as pharmacogenetics, which studies the variability of drug response in relation to the genetic factors involved in the processes responsible for the pharmacokinetics and/or the action mechanism of a drug in the body. This variability seems to be correlated with the presence of genetic polymorphisms. Genotyping is an attractive option especially for the initiation of the dosing of tacrolimus; also, unlike phenotypic tests, the genotype is a stable characteristic that needs to be determined only once for any given gene. However, prospective clinical studies must show that genotype determination before transplantation allows for better use of a given drug and improves the safety and clinical efficacy of that medication. At present, research has been able to reliably show that the CYP3A5 genotype, but not the CYP3A4 or ABCB1 ones, can modify the pharmacokinetics of tacrolimus. However, it has not been possible to incontrovertibly show that the corresponding changes in the pharmacokinetic profile are linked with different patient outcomes regarding tacrolimus efficacy and toxicity. For these reasons, pharmacogenetics and individualized medicine remain a fascinating area for further study and may ultimately become the face of future medical practice and drug dosing

    Le varietà di sorgo da granella consigliate per le semine 2017

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    Nel 33º anno di prove di confronto tra ibridi di sorgo da granella sono stati realizzati 5 campi sperimentali, 2 nel Nord, 2 in Italia centrale e 1 in Sicilia. Le rese medie sono risultate simili a quelle del 2015, pur con notevoli differenze tra i diversi areali di coltivazion

    Genotoxicity Response of Fibroblast Cells and Human Epithelial Adenocarcinoma In Vitro Model Exposed to Bare and Ozone-Treated Silica Microparticles

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    Indoor air pollutants (IAP), which can pose a serious risk to human health, include biological pollutants, nitric oxide (NO), nitrogen dioxide (NO2 ), volatile organic compounds (VOC), sulfur dioxide (SO2 ), carbon monoxide (CO), carbon dioxide (CO2 ), silica, metals, radon, and particulate matter (PM). The aim of our work is to conduct a multidisciplinary study of fine silica particles (<2.5 µm) in the presence or absence of ozone (O3 ), and evaluate their potential cytotoxicity using MTS, micronucleus, and the comet test in two cell lines. We analyzed A549 (human basal alveolar epithelial cell adenocarcinoma) and Hs27 (human normal fibroblasts) exposed to dynamic conditions by an IRC simulator under ozone flow (120 ppb) and in the presence of silica particles (40 µg/h). The viability of A549 and Hs27 cells at 48 and 72 h of exposure to silica or silica/ozone decreases, except at 72 h in Hs27 treated with silica/ozone. The micronucleus and comet tests showed a significant increase in the number of micronuclei and the % of DNA in the queue, compared to the control, in both lines in all treatments, even if in different cell times/types. We found that silica alone or with more O3 causes more pronounced genotoxic effects in A549 tumor cells than in normal Hs27 fibroblasts
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