selective ratiometric detection of h2o2 in water and in living cells with boronobenzo b quinolizinium derivatives

Fluorimetric detection of H2O2 is accomplished in water and in living cells by quantitative reaction of boronobenzo[b]quinolizinium derivatives with the analyte

The Novel Antitubulin Agent TR-764 Strongly Reduces Tumor Vasculature and Inhibits HIF-1α Activation

Tubulin binding agents (TBAs) are commonly used in cancer therapy as antimitotics. It has been described that TBAs, like combretastatin A-4 (CA-4), present also antivascular activity and among its derivatives we identified TR-764 as a new inhibitor of tubulin polymerization, based on the 2-(alkoxycarbonyl)-3-(3',4',5'-trimethoxyanilino)benzo[b]thiophene molecular skeleton. The antiangiogenic activity of TR-764 (1-10 nM) was tested in vitro on human umbilical endothelial cells (HUVECs), and in vivo, on the chick embryo chorioallantoic membrane (CAM) and two murine tumor models. TR-764 binding to tubulin triggers cytoskeleton rearrangement without affecting cell cycle and viability. It leads to capillary tube disruption, increased cell permeability, and cell motility reduction. Moreover it disrupts adherens junctions and focal adhesions, through mechanisms involving VE-cadherin/β-catenin and FAK/Src. Importantly, TR-764 is active in hypoxic conditions significantly reducing HIF-1α. In vivo TR-764 (1-100 pmol/egg) remarkably blocks the bFGF proangiogenic activity on CAM and shows a stronger reduction of tumor mass and microvascular density both in murine syngeneic and xenograft tumor models, compared to the lead compound CA-4P. Altogether, our results indicate that TR-764 is a novel TBA with strong potential as both antivascular and antitumor molecule that could improve the common anticancer therapies, by overcoming hypoxia-induced resistance mechanisms

Synthesis, in vitro and in vivo biological evaluation of substituted 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones as new potent anticancer agents

A small library of 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones has been synthesized and screened according to protocols available at the National Cancer Institute (NCI). Some derivatives were potent antiproliferative agents, showing GI50 values in the nanomolar range. Remarkably, when most active compounds against leukemia cells were tested in human peripheral blood lymphocytes from healthy donors, were 100–200 times less cytotoxic. Some compounds, selected by the Biological Evaluation Committee of NCI, were examined to determine tubulin assembly inhibition. Furthermore, flow cytometric studies performed on HeLa, HT-29, and A549 cells, showed that compounds 14 and 25 caused a block in the G2/M phase. Interestingly, these derivatives induced apoptosis through the mitochondrial death pathway, causing in parallel significant activation of both caspase-3 and -9, PARP cleavage and down-regulation of the anti-apoptotic proteins Bcl-2 and Mcl-1. Finally, compound 25 was also tested in vivo in the murine BL6-B16 melanoma and E0771 breast cancer cells, causing in both cases a significant reduction in tumor volume

Choline Kinase Alpha Inhibition by EB-3D Triggers Cellular Senescence, Reduces Tumor Growth and Metastatic Dissemination in Breast Cancer

Choline kinase (ChoK) is the first enzyme of the Kennedy pathway leading to the biosynthesis of phosphatidylcholine (PtdCho), the most abundant phospholipid in eukaryotic cell membranes. EB-3D is a novel choline kinase 1 (ChoK 1) inhibitor with potent antiproliferative activity against a panel of several cancer cell lines. ChoK 1 is particularly overexpressed and hyperactivated in aggressive breast cancer. By NMR analysis, we demonstrated that EB-3D is able to reduce the synthesis of phosphocholine, and using flow cytometry, immunoblotting, and q-RT-PCR as well as proliferation and invasion assays, we proved that EB-3D strongly impairs breast cancer cell proliferation, migration, and invasion. EB-3D induces senescence in breast cancer cell lines through the activation of the metabolic sensor AMPK and the subsequent dephosphorylation of mTORC1 downstream targets, such as p70S6K, S6 ribosomal protein, and 4E-BP1. Moreover, EB-3D strongly synergizes with drugs commonly used for breast cancer treatment. The antitumorigenic potential of EB-3D was evaluated in vivo in the syngeneic orthotopic E0771 mouse model of breast cancer, where it induces a significant reduction of the tumor mass at low doses. In addition, EB-3D showed an antimetastatic effect in experimental and spontaneous metastasis models. Altogether, our results indicate that EB-3D could be a promising new anticancer agent to improve aggressive breast cancer treatment protocols.This work was supported by funds from Istituto di Ricerca Pediatrica (IRP)-Città della Speranza and Cassa di Risparmio di Padova e Rovigo—CARIPARO Foundation (project IRP13/05) and by the University of Granada, (Cei-Biotic project CEI2013-MP-1), and Associazione Italiana per la Ricerca sul Cancro (AIRC) MFAG 18459 grant (R.R.). E.M. was supported by AIRC (21101) and V.S. by FIRC (16616) fellowships

Tratamento medicamentoso da neuralgia do trigêmeo: implicações na Odontologia

O tratamento medicamentoso para a Neuralgia Trigeminal (NT) é realizado pelo neurologista e tem como objetivo amenizar a sintomatologia da doença. Essa intervenção exige uso de medicamentos anticonvulsivantes capazes de linimentar hiperexcitações neuronais, buscando cessar dores causadas por compressão do nervo trigêmeo. O objetivo com este trabalho é conhecer as implicações do tratamento medicamentoso da NT na Odontologia. Trata-se de uma revisão de literatura embasada em artigos retirados de plataformas on-line, como SciELO e Google Academic, livros de Fisiologia, Medicina Bucal e Neurologia. Os sintomas relatados na NT variam entre pacientes, contudo, numa escala de dor, sempre atingem nota máxima, sendo considerada uma das dores mais insuportáveis já existentes. O diagnóstico da NT, por vezes, é feito pelo cirurgião-dentista, considerando que os sintomas podem se assemelhar a odontalgias. A anestesia aplicada na área determinada como “zona de gatilho” é uma manobra útil para que se estabeleça um diagnóstico diferencial, seguida por uma anamnese minuciosa e fazendo-se necessários exames complementares para a determinação final. Possui etiologias distintas, como compressão do nervo por uma artéria ou por um tumor ou, até mesmo, traumas onde seja removida a mielina da célula, fazendo com que ocorra despolarização anormal. Logo após a análise, o plano de tratamento médico é traçado. O fármaco com maior emprego é a carbamazepina e tem como seu mecanismo de ação o bloqueio de canais de sódio e cálcio, antagonização do glutamato e possui ação potencializadora GABAérgica, o que faz com que o neurônio mantenha seu potencial de ação em repouso, inibindo descargas neuronais repetitivas, mostrando resultados positivos em 60% a 80% dos pacientes que fizeram seu uso; entretanto, a xerostomia, provinda do uso do medicamento, aumenta a incidência de cáries e doenças periodontais. Assim, faz-se imprescindível na área odontológica, o estudo de neuropatias, trazendo como ferramenta principal, a dispensa de procedimentos invasivos desnecessários.Palavras-chave: Anticonvulsivantes. Carbamazepina. Neuralgia do trigêmeo. Odontologia. Tratamento farmacológico

A first-in-class Wiskott-Aldrich syndrome protein activator with anti-tumor activity in hematologic cancers

Hematological cancers are among the most common cancers in adults and children. Despite significant improvements in therapies, many patients still succumb to the disease. Therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family regulates actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations: autoinhibited or activated. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as a single agent in lymphoma, leukemia, and multiple myeloma, including models of secondary resistance to PI3K, BTK, and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization and WASp binding was demonstrated using multiple techniques. Transcriptome analysis highlighted homology with drugs-inducing actin polymerization

AKR1C enzymes sustain therapy resistance in paediatric T-ALL

BACKGROUND: Despite chemotherapy intensification, a subgroup of high-risk paediatric T-cell acute lymphoblastic leukemia (TALL) patients still experience treatment failure. In this context, we hypothesised that therapy resistance in T-ALL might involve aldo-keto reductase 1C (AKR1C) enzymes as previously reported for solid tumors.METHODS: Expression of NRF2-AKR1C signaling components has been analysed in paediatric T-ALL samples endowed with different treatment outcomes as well as in patient-derived xenografts of T-ALL. The effects of AKR1C enzyme modulation has been investigated in T-ALL cell lines and primary cultures by combining AKR1C inhibition, overexpression, and gene silencing approaches.RESULTS: We show that T-ALL cells overexpress AKR1C1-3 enzymes in therapy-resistant patients. We report that AKR1C1-3 enzymes play a role in the response to vincristine (VCR) treatment, also ex vivo in patient-derived xenografts. Moreover, we demonstrate that the modulation of AKR1C1-3 levels is sufficient to sensitise T-ALL cells to VCR. Finally, we show that T-ALL chemotherapeutics induce overactivation of AKR1C enzymes independent of therapy resistance, thus establishing a potential resistance loop during T-ALL combination treatment.CONCLUSIONS: Here, we demonstrate that expression and activity of AKR1C enzymes correlate with response to chemotherapeutics in T-ALL, posing AKR1C1-3 as potential targets for combination treatments during T-ALL therapy

Study of the mechanism of action of new molecules endowed with antitumoral activity

The microtubule system of eukaryotic cells is a critical element in a variety of fundamental cellular processes such as cell proliferation, mitotic spindle formation, maintenance of cell shape, regulation of motility, cell signaling, secretion, and intracellular transport. The important role of microtubules dynamic in mitosis progression and thus in cell proliferation, made them an attractive target for cancer therapy. Many chemically diverse compounds bind and affect tubulin-microtubule system, altering polymerization and dynamics during the particularly vulnerable mitotic stage of the cell cycle, causing alteration in the spindle organization with a delay or block at the metaphase-anaphase transition during mitosis. In this study we evaluated the antiproliferative activity of seven series of novel tubulin polymerization inhibitors deriving from three classes of colchicine site binders: combretastatin-A4, chalcones and pyrroloquinolinones. Furthermore we investigated on the inhibitory effects on tubulin polimerization, cell cycle alteration, and apoptosis induction in in vitro and in vivo models and described a possible mechanism of action. The studied compounds, showed antiproliferative activity derived from a interference with microtubule assembly similar or higher than the reference compounds. As general mechanisms of action, the interaction of such compounds with tubulin, induces cell cycle arrest in the G2/M phase, with increased expression of cyclin B1 and phosphorylation of cdc25c, that trigger to apoptosis in a time- and concentration-dependent manner with activation of caspase-3 and cleavage of PARP and reduction of Bcl-2 prosurvival protein. Moreover, several compounds was effective against cancer cell lines, characterized by high expression of glycoprotein-P and multidrug resistance-associated protein, resistant to chemotherapy drugs such as vinblastine, doxorubucine and taxol. Prelimary experiment carried out in vivo models of tumor xenograft showed a significative reduction of tumor growth suggesting a potential clinical applications for these compounds.Nelle cellule eucariotiche i microtubuli costituiscono un elemento cruciale nella regolazione di molteplici processi cellulari, tra cui la proliferazione, la formazione del fuso mitotico, il mantenimento della forma cellulare, la regolazione della motilità, il signaling cellulare, i processi di secrezione e trasporto intracellulare. Il ruolo fondamentale di tale struttura citoscheletrica nella progressione mitotica e di conseguenza nella proliferazione cellulare rende i microtubuli un ottimo target per la terapia antitumorale. Molti composti aventi struttura chimica differente sono in grado di legare il sistema tubulina-microtubuli, alterandone la polimerizzazione e la dinamica, in particolare durante la fase mitotica del ciclo cellulare, destabilizzando l'organizzazione del fuso mitotico, ritardando o bloccando la transizione metafase-anafase. In questo studio è stata valutata l'attività antiproliferativa di sette serie di nuovi inibitori della polimerizzazione della tubulina, derivati da 3 classi di composti che legano i microtubuli a livello del sito di legame della colchicina: combretastatina-A4, calconi e pirrolochinolinoni. In particolare, è stato studiato in modelli in vitro e in vivo l'effetto di tali inibitori sulla polimerizzazione della tubulina, sul ciclo cellulare e sull'attivazione dell'apoptosi per la descrizione di un possibile meccanismo d'azione. I composti testati hanno mostrato attività antiproliferativa comparabile o superiore rispetto ai composti di riferimento. Per quanto riguarda il meccanismo d'azione, in generale, l'interazione di tali composti con la tubulina induce un blocco del ciclo cellulare in fase G2/M con l'aumento dell'espressione della ciclina B1 e la fosforilazione di Cdc25c. Tale arresto della progressione mitotica porta all'attivazione del processo apoptotico in modo tempo- e concentrazione- dipendente con la attivazione di caspase-3, il taglio proteolitico di PARP e la riduzione delle proteine Bcl-2 antiapoptotiche. Inoltre, alcuni composti hanno mostrato elevata efficacia nell'indurre citotossicità in cellule tumorali multidrug resistant, esprimenti la licoproteina-P e le pompe di efflusso MDR, resistenti a chemioterapici quali vinblastina, doxorubucina e tassolo. Esperimenti preliminari, svolti in modelli murini di xenotrapianto, hanno mostrato una significativa riduzione della crescita tumorale, suggerendo una possibile applicazione clinica per alcuni dei composti studiati

Synthesis, DNA-binding and antiproliferative properties of diarylquinolizinium derivatives

A series of ten 2,7- and 2,8-diarylquinolizinium derivatives was synthesized and their DNA-binding and cytotoxic properties were investigated. Except for one nitro-substituted derivative all tested diarylquinolizinium ions bind to DNA with sufficient affinity (2 7 104 M-1-2 7 105 M-1). It was shown with photometric, fluorimetric and polarimetric titrations as well as with flow-LD analysis that the ligands bind mainly by intercalation to duplex DNA, however, depending on the ligand-DNA ratio, groove binding and backbone association were also observed with some derivatives. The biological activity was further investigated with tests of cytotoxicity and antiproliferative properties towards non-tumor cells and selected cancer cells, along with cell cycle analysis and an annexin-V assay. Notably, substrates that carry donor-functionalities in the 4-position of the phenyl substituents revealed a strong, and in some cases selective, antiproliferative activity as quantified by the growth inhibition, GI50, at very low micromolar and even submicromolar level both in leukemia and solid tumors