45 research outputs found

    HOXB7: a key factor for tumo-associated angiogenic switch.

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    We had demonstrated previously a functional bridge between altered homebox (HOX) gene expression and tumor progression through HOXB7 transactivation of basic fibroblast growth factor. Here, we have studied whether HOXB7, in addition to basic fibroblast growth factor, may induce other genes directly or indirectly related to neoangiogenesis and tumor invasion. Parental, beta-galactosidase-transduced, and HOXB7-transduced SkBr3 cell lines were examined for the expression of several growth factors and growth factor receptors involved in the proliferative and angiogenic processes. Vascular endothelial growth factor, melanoma growth-stimulatory activity/growth-related oncogenene alpha, interleukin-8, and angiopoietin-2 were up-regulated by HOXB7 transduction. The exception was angiopoietin-1 expression that was abrogated. Additional analyses included the expression levels of enzymes such as matrix metalloprotease (MMP)-2 and MMP-9 and heparanase, capable of proteolytic degradation of extracellular matrix and basement membranes. Results showed an induction of only MMP-9. The functional implication of such a finding was tested using an in vitro coculture assay in a three-dimensional matrix. A delay of differentiation with persistent nests of proliferating cells was found in endothelial cells cocultured with HOXB7-transduced SkBr3 cells. Tumorigenicity of these cells has been evaluated in vivo. Xenograft into athymic nude mice showed that SkBr3/HOXB7 cells developed tumors in mice, either irradiated or not, whereas parental SkBr3 cells did not show any tumor take unless mice were sublethally irradiated. Comparison of tumor nodules for vascularization by CD-31 and CD-34 immunostaining revealed an increased number of blood vessels in tumors expressing HOXB7. Together, the results indicate HOXB7 as a key factor up-regulating a variety of proangiogenic stimuli. Thus, HOXB7 gene or protein is a target to aim at to inhibit tumor-associated neoangiogenesis, considering the number and the redundancy of proangiogenic molecules that should be targeted one by one to theoretically achieve the same effect

    A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

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    This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations

    A Specific Mutational Signature Associated with DNA 8-Oxoguanine Persistence in MUTYH-defective Colorectal Cancer.

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    8-Oxoguanine, a common mutagenic DNA lesion, generates G:C>T:A transversions via mispairing with adenine during DNA replication. When operating normally, the MUTYH DNA glycosylase prevents 8-oxoguanine-related mutagenesis by excising the incorporated adenine. Biallelic MUTYH mutations impair this enzymatic function and are associated with colorectal cancer (CRC) in MUTYH-Associated Polyposis (MAP) syndrome. Here, we perform whole-exome sequencing that reveals a modest mutator phenotype in MAP CRCs compared to sporadic CRC stem cell lines or bulk tumours. The excess G:C>T:A transversion mutations in MAP CRCs exhibits a novel mutational signature, termed Signature 36, with a strong sequence dependence. The MUTYH mutational signature reflecting persistent 8-oxoG:A mismatches occurs frequently in the APC, KRAS, PIK3CA, FAT4, TP53, FAT1, AMER1, KDM6A, SMAD4 and SMAD2 genes that are associated with CRC. The occurrence of Signature 36 in other types of human cancer indicates that DNA 8-oxoguanine-related mutations might contribute to the development of cancer in other organs

    HighResMIP versions of EC-Earth: EC-Earth3P and EC-Earth3P-HR - Description, model computational performance and basic validation

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    A new global high-resolution coupled climate model, EC-Earth3P-HR has been developed by the EC-Earth consortium, with a resolution of approximately 40 km for the atmosphere and 0.25° for the ocean, alongside with a standard-resolution version of the model, EC-Earth3P (80 km atmosphere, 1.0 ° ocean). The model forcing and simulations follow the High Resolution Model Intercomparison Project (HighResMIP) protocol. According to this protocol, all simulations are made with both high and standard resolutions. The model has been optimized with respect to scalability, performance, data storage and post-processing. In accordance with the HighResMIP protocol, no specific tuning for the high-resolution version has been applied. Increasing horizontal resolution does not result in a general reduction of biases and overall improvement of the variability, and deteriorating impacts can be detected for specific regions and phenomena such as some Euro-Atlantic weather regimes, whereas others such as the El Niño-Southern Oscillation show a clear improvement in their spatial structure. The omission of specific tuning might be responsible for this. The shortness of the spin-up, as prescribed by the HighResMIP protocol, prevented the model from reaching equilibrium. The trend in the control and historical simulations, however, appeared to be similar, resulting in a warming trend, obtained by subtracting the control from the historical simulation, close to the observational one

    A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

    Get PDF
    This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations

    Increased Expression of PcG Protein YY1 Negatively Regulates B Cell Development while Allowing Accumulation of Myeloid Cells and LT-HSC Cells

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    Ying Yang 1 (YY1) is a multifunctional Polycomb Group (PcG) transcription factor that binds to multiple enhancer binding sites in the immunoglobulin (Ig) loci and plays vital roles in early B cell development. PcG proteins have important functions in hematopoietic stem cell renewal and YY1 is the only mammalian PcG protein with DNA binding specificity. Conditional knock-out of YY1 in the mouse B cell lineage results in arrest at the pro-B cell stage, and dosage effects have been observed at various YY1 expression levels. To investigate the impact of elevated YY1 expression on hematopoetic development, we utilized a mouse in vivo bone marrow reconstitution system. We found that mouse bone marrow cells expressing elevated levels of YY1 exhibited a selective disadvantage as they progressed from hematopoietic stem/progenitor cells to pro-B, pre-B, immature B and re-circulating B cell stages, but no disadvantage of YY1 over-expression was observed in myeloid lineage cells. Furthermore, mouse bone marrow cells expressing elevated levels of YY1 displayed enrichment for cells with surface markers characteristic of long-term hematopoietic stem cells (HSC). YY1 expression induced apoptosis in mouse B cell lines in vitro, and resulted in down-regulated expression of anti-apoptotic genes Bcl-xl and NFκB2, while no impact was observed in a mouse myeloid line. B cell apoptosis and LT-HSC enrichment induced by YY1 suggest that novel strategies to induce YY1 expression could have beneficial effects in the treatment of B lineage malignancies while preserving normal HSCs

    Mechanical and microstructural characterisation of an aluminum friction stir-welded butt joint

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    The microstructure and the mechanical properties of a 6056 aluminium alloy Friction Stir-Welded (FSW) joint were investigated in the present study. The structure was analysed using light, scanning and transmission electron microscopy. The change in microstructure across the welded joint was found to correspond to significant variation in hardness. As in most FSW joints, the structure was characterised by the presence of a region of severely deformed grains in proximity of the weld nugget, i.e. of a region of fine recrystallised grains. Tensile tests showed that the joint material exhibited a rupture strength similar to the parent material, even though the former was significantly less ductile. This difference resulted in a reduction in ductility of the welded sheets. A T6 treatment increased tensile strength, but further reduced joint ductility. Nevertheless, the strength of the welded sheet was found to be very close (80-90%) to that of the base alloy

    HOXB7 constitutively activates basic fibroblast growth factor in melanomas.

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    Homeobox (HOX) genes control axial specification during mammalian development and also regulate skin morphogenesis. Although selected HOX genes are variably expressed in leukemias and kidney and colon cancer cell lines, their relationship with the neoplastic phenotype remains unclear. In both normal development and neoplastic transformation, HOX target genes are largely unknown. We investigated the expression and function of HOXB cluster genes in human melanoma. The HOXB7 gene was constitutively expressed in all 25 melanoma cell lines and analyzed under both normal and serum-starved conditions, as well as in in vivo primary and metastatic melanoma cells; conversely, HOXB7 was expressed in proliferating but not quiescent normal melanocytes. Treatment of melanoma cell lines with antisense oligomers targeting HOXB7 mRNA markedly inhibited cell proliferation and specifically abolished expression of basic fibroblast growth factor (bFGF) mRNA. Band shift and cotransfection experiments showed that HOXB7 directly transactivates the hFGF gene through one out of five putative homeodomain binding sites present in its promoter. These novel findings indicate a key role for constitutive HOXB7 expression in melanoma cell proliferation via bFGF. The results also raise the possibility that growth factor genes are critical HOX target genes in other developmental and/or neoplastic cell systems
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