In vivo bioluminescence imaging using orthotopic xenografts towards patient's derived-xenograft Medulloblastoma models

BACKGROUND: Medulloblastoma is a cerebellar neoplasia of the central nervous system. Four molecular subgrups have been identified (MBWNT, MBSHH, MBgroup3 and MBgroup4) with distinct genetics and clinical outcome. Among these, MBgroup3-4 are highly metastatic with the worst prognosis. The current standard therapy includes surgery, radiation and chemotherapy. Thus, specific treatments adapted to cure those different molecular subgroups are needed. The use of orthotopic xenograft models, together with the non-invasive in vivo biolumiscence imaging (BLI) technology, is emerging during preclinical studies to test novel therapeutics for medulloblastoma treatment. METHODS: Orthotopic MB xenografts were performed by injection of Daoy-luc cells, that had been previously infected with lentiviral particles to stably express luciferase gene, into the fourth right ventricle of the cerebellum of ten nude mice. For the implantation, specific stereotactic coordinates were used. Seven days after the implantation the mice were imaged by acquisitions of bioluminescence imaging (BLI) using IVIS 3D Illumina Imaging System (Xenogen). Tumor growth was evaluated by quantifying the bioluminescence signals using the integrated fluxes of photons within each area of interest using the Living Images Software Package 3.2 (Xenogen-Perkin Elmer). Finally, histological analysis using hematoxylin-eosin staining was performed to confirm the presence of tumorigenic cells into the cerebellum of the mice. RESULTS: We describe a method to use the in vivo bioluminescent imaging (BLI) showing the potential to be used to investigate the potential antitumorigenic effects of a drug for in vivo medulloblastoma treatment. We also discuss other studies in which this technology has been applied to obtain a more comprehensive knowledge of medulloblastoma using orthotopic xenograft mouse models. CONCLUSIONS: There is a need to develop patient's derived-xenograft (PDX) model systems to test novel drugs for medulloblastoma treatment within each molecular sub-groups with a higher predictive value. Here we show how this technology should be applied with hopes on generations of new treatments to be applied then in human

Phase diagram of the XXZ ferrimagnetic spin-(1/2, 1) chain in the presence of transverse magnetic field

We investigate the phase diagram of an anisotropic ferrimagnet spin-(1/2, 1) in the presence of a non-commuting (transverse) magnetic field. We find a magnetization plateau for the isotropic case while there is no plateau for the anisotropic ferrimagnet. The magnetization plateau can appear only when the Hamiltonian has the U(1) symmetry in the presence of the magnetic field. The anisotropic model is driven by the magnetic field from the N\'{e}el phase for low fields to the spin-flop phase for intermediate fields and then to the paramagnetic phase for high fields. We find the quantum critical points and their dependence on the anisotropy of the aforementioned field-induced quantum phase transitions. The spin-flop phase corresponds to the spontaneous breaking of Z2 symmetry. We use the numerical density matrix renormalization group and analytic spin wave theory to find the phase diagram of the model. The energy gap, sublattice magnetization, and total magnetization parallel and perpendicular to the magnetic field are also calculated. The elementary excitation spectrums of the model are obtained via the spin wave theory in the three different regimes depending on the strength of the magnetic field.Comment: 14 pages, 11 eps figure

A competitive cell-permeable peptide impairs Nme-1 (NDPK-A) and Prune-1 interaction: therapeutic applications in cancer.

The understanding of protein–protein interactions is crucial in order to generate a second level of functional genomic analysis in human disease. Within a cellular microenvironment, protein–protein interactions generate new functions that can be defined by single or multiple modes of protein interactions. We outline here the clinical importance of targeting of the Nme-1 (NDPK-A)–Prune-1 protein complex in cancer, where an imbalance in the formation of this protein–protein complex can result in inhibition of tumor progression. We discuss here recent functional data using a small synthetic competitive cell-permeable peptide (CPP) that has shown therapeutic efficacy for impairing formation of the Nme-1–Prune-1 protein complex in mouse preclinical xenograft tumor models (e.g., breast, prostate, colon, and neuroblastoma). We thus believe that further discoveries in the near future related to the identification of new protein–protein interactions will have great impact on the development of new therapeutic strategies against various cancers

A Structurally Simple Vaccine Candidate Reduces Progression and Dissemination of Triple-Negative Breast Cancer

The Tn antigen is a well-known tumor-associated carbohydrate determinant, often incorporated in glycopeptides to develop cancer vaccines. Herein, four copies of a conformationally constrained mimetic of the antigen TnThr (GalNAc-Thr) were conjugated to the adjuvant CRM197, a protein licensed for human use. The resulting vaccine candidate, mime[4]CRM elicited a robust immune response in a triple-negative breast cancer mouse model, correlated with high frequency of CD4+ T cells and low frequency of M2-type macrophages, which reduces tumor progression and lung metastasis growth. Mime[4]CRM-mediated activation of human dendritic cells is reported, and the proliferation of mime[4]CRM-specific T cells, in cancer tissue and peripheral blood of patients with breast cancer, is demonstrated. The locked conformation of the TnThr mimetic and a proper presentation on the surface of CRM197 may explain the binding of the conjugate to the anti-Tn antibody Tn218 and its efficacy to fight cancer cells in mice

Cytotoxic t-lymphocyte antigen-4 in colorectal cancer: Another therapeutic side of capecitabine

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an inhibitory immune checkpoint that can be expressed in tumor-infiltrating lymphocytes and colorectal cancer (CRC) cells. This immune checkpoint can attenuate anti-tumoral immune responses and facilitate tumor growth and metastasis. Although capecitabine is an effective chemotherapeutic agent for treating CRC, its effect on the tumoral CTLA-4 expression remains unclear. In the current research, we applied the GSE110224 and GSE25070 datasets to characterize CTLA-4 expression in CRC patients. Then, we analyzed CTLA-4 expression in CRC samples, HT-29, HCT-166, and SW480 cell lines using real-time PCR. Our bioinformatic results have highlighted the overexpression of CTLA-4 in the CRC tissues compared to the adjacent non-tumoral tissues. Our in vitro studies have indicated that SW480 cells can sub-stantially overexpress CTLA-4 compared to HT-29 and HCT 116 cells. In addition, capecitabine can remarkably downregulate the expression of CTLA-4 in SW480 cells. Collectively, capecitabine can inhibit the expression of CTLA-4 in CRC cells and might bridge the immunotherapy approaches with chemotherapy

Molecular characterization and sterol profiles identify nonsynonymous mutations in ERG2 as a major mechanism conferring reduced susceptibility to amphotericin B in candida kefyr

The molecular basis of reduced susceptibility to amphotericin B (rs-AMB) among any yeasts is poorly defined. Genetic alterations in genes involved in ergosterol biosynthesis and total cell sterols were investigated among clinical Candida kefyr isolates. C. kefyr isolates (n = 81) obtained from 74 patients in Kuwait and identified by phenotypic and molecular methods were analyzed. An Etest was initially used to identify isolates with rs-AMB. Specific mutations in ERG2 and ERG6 involved in ergosterol biosynthesis were detected by PCR sequencing. Twelve selected isolates were also tested by the SensiTitre Yeast One (SYO), and total cell sterols were evaluated by gas chromatography-mass spectrometry and ERG3 and ERG11 sequencing. Eight isolates from 8 patients showed rs-AMB by Etest, including 2 isolates with additional resistance to fluconazole or to all three antifungals. SYO correctly identified 8 of 8 rs-AMB isolates. A nonsynonymous mutation in ERG2 was detected in 6 of 8 rs-AMB isolates but also in 3 of 73 isolates with a wild-type AMB pattern. One rs-AMB isolate contained a deletion (frameshift) mutation in ERG2. One or more nonsynonymous mutations was detected in ERG6 in 11 of 81 isolates with the rs-AMB or wild-type AMB pattern. Among 12 selected isolates, 2 and 2 isolates contained a nonsynonymous mutation(s) in ERG3 and ERG11, respectively. Ergosterol was undetectable in 7 of 8 rs-AMB isolates, and the total cell sterol profiles were consistent with loss of ERG2 function in 6 rs-AMB isolates and loss of ERG3 activity in another rs-AMB isolate. Our data showed that ERG2 is a major target conferring rs-AMB in clinical C. kefyr isolates

Earthquake vulnerability assessment for urban areas using an ann and hybrid swot-qspm model

Tabriz city in NW Iran is a seismic-prone province with recurring devastating earthquakes that have resulted in heavy casualties and damages. This research developed a new computational framework to investigate four main dimensions of vulnerability (environmental, social, economic and physical). An Artificial Neural Network (ANN) Model and a SWOT-Quantitative Strategic Planning Matrix (QSPM) were applied. Firstly, a literature review was performed to explore indicators with significant impact on aforementioned dimensions of vulnerability to earthquakes. Next, the twenty identified indicators were analyzed in ArcGIS, a geographic information system (GIS) software, to map earthquake vulnerability. After classification and reclassification of the layers, standardized maps were presented as input to a Multilayer Perceptron (MLP) and Self-Organizing Map (SOM) neural network. The resulting Earthquake Vulnerability Maps (EVMs) showed five categories of vulnerability ranging from very high, to high, moderate, low and very low. Accordingly, out of the nine municipality zones in Tabriz city, Zone one was rated as the most vulnerable to earthquakes while Zone seven was rated as the least vulnerable. Vulnerability to earthquakes of residential buildings was also identified. To validate the results data were compared between a Multilayer Perceptron (MLP) and a Self-Organizing Map (SOM). The scatter plots showed strong correlations between the vulnerability ratings of the different zones achieved by the SOM and MLP. Finally, the hybrid SWOT-QSPM paradigm was proposed to identify and evaluate strategies for hazard mitigation of the most vulnerable zone. For hazard mitigation in this zone we recommend to diligently account for environmental phenomena in designing and locating of sites. The findings are useful for decision makers and government authorities to reconsider current natural disaster management strategies

Metastatic group 3 medulloblastoma is driven by PRUNE1 targeting NME1-TGF-β-OTX2-SNAIL via PTEN inhibition.

Genetic modifications during development of paediatric groups 3 and 4 medulloblastoma are responsible for their highly metastatic properties and poor patient survival rates. PRUNE1 is highly expressed in metastatic medulloblastoma group 3, which is characterized by TGF-β signalling activation, c-MYC amplification, and OTX2 expression. We describe the process of activation of the PRUNE1 signalling pathway that includes its binding to NME1, TGF-β activation, OTX2 upregulation, SNAIL (SNAI1) upregulation, and PTEN inhibition. The newly identified small molecule pyrimido-pyrimidine derivative AA7.1 enhances PRUNE1 degradation, inhibits this activation network, and augments PTEN expression. Both AA7.1 and a competitive permeable peptide that impairs PRUNE1/NME1 complex formation, impair tumour growth and metastatic dissemination in orthotopic xenograft models with a metastatic medulloblastoma group 3 cell line (D425-Med cells). Using whole exome sequencing technology in metastatic medulloblastoma primary tumour cells, we also define 23 common 'non-synonymous homozygous' deleterious gene variants as part of the protein molecular network of relevance for metastatic processes. This PRUNE1/TGF-β/OTX2/PTEN axis, together with the medulloblastoma-driver mutations, is of relevance for future rational and targeted therapies for metastatic medulloblastoma group 3

PRUNE is crucial for normal brain development and mutated in microcephaly with neurodevelopmental impairment.

PRUNE is a member of the DHH (Asp-His-His) phosphoesterase protein superfamily of molecules important for cell motility, and implicated in cancer progression. Here we investigated multiple families from Oman, India, Iran and Italy with individuals affected by a new autosomal recessive neurodevelopmental and degenerative disorder in which the cardinal features include primary microcephaly and profound global developmental delay. Our genetic studies identified biallelic mutations of PRUNE1 as responsible. Our functional assays of disease-associated variant alleles revealed impaired microtubule polymerization, as well as cell migration and proliferation properties, of mutant PRUNE. Additionally, our studies also highlight a potential new role for PRUNE during microtubule polymerization, which is essential for the cytoskeletal rearrangements that occur during cellular division and proliferation. Together these studies define PRUNE as a molecule fundamental for normal human cortical development and define cellular and clinical consequences associated with PRUNE mutation

QCD ghost f(T)-gravity model

Within the framework of modified teleparallel gravity, we reconstruct a f(T) model corresponding to the QCD ghost dark energy scenario. For a spatially flat FRW universe containing only the pressureless matter, we obtain the time evolution of the torsion scalar T (or the Hubble parameter). Then, we calculate the effective torsion equation of state parameter of the QCD ghost f(T)-gravity model as well as the deceleration parameter of the universe. Furthermore, we fit the model parameters by using the latest observational data including SNeIa, CMB and BAO data. We also check the viability of our model using a cosmographic analysis approach. Moreover, we investigate the validity of the generalized second law (GSL) of gravitational thermodynamics for our model. Finally, we point out the growth rate of matter density perturbation. We conclude that in QCD ghost f(T)-gravity model, the universe begins a matter dominated phase and approaches a de Sitter regime at late times, as expected. Also this model is consistent with current data, passes the cosmographic test, satisfies the GSL and fits the data of the growth factor well as the LCDM model.Comment: 19 pages, 9 figures, 2 tables. arXiv admin note: substantial text overlap with arXiv:1111.726