We have studied the effects of overexpression of superoxide dismutase (SOD), a tumor suppressor protein that dismutes superoxide radical to H2O2, on breast cancer cell growth in vitro and xenograft growth in vivo. No previous work has directly compared the growth-suppressive effects of manganese SOD (MnSOD) and copper-zinc SOD (CuZnSOD). We hypothesized that either adenoviral MnSOD (AdMnSOD) or adenoviral CuZnSOD (AdCuZnSOD) gene therapy would suppress the growth of human breast cancer cells. After determining the antioxidant profiles of three human breast cell lines, MCF 10A, MDA-MB231, and MCF-7, we measured the effects of MnSOD or CuZnSOD overexpression on cell growth and survival in vitro and in vivo. Results demonstrated that infection with AdMnSOD or AdCuZnSOD increased the activity of the respective enzyme in all three cell lines. In vitro, overexpression of MnSOD or CuZnSOD decreased not only cell growth but also clonogenic survival in a dose- and transgene-dependent manner. In vivo, treatment of tumors with AdMnSOD or AdCuZnSOD decreased xenograft growth compared to controls. The first direct comparison of MnSOD to CuZnSOD overexpression indicated that CuZnSOD and MnSOD were similarly effective at suppressing cancer cell growth. 相似文献
In view of the importance of beta cells in glucose homeostasis and the profound repercussions of beta cell pathology on human
health, the acquisition of tools to study pancreatic islet function is essential for the design of alternative novel therapies
for diabetes. One promising approach toward this goal involves the modification of gene expression profile of beta cells. 相似文献
Presented here is the complete genome sequence of Thiomicrospira crunogena XCL-2, representative of ubiquitous chemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-sea hydrothermal vents. This gammaproteobacterium has a single chromosome (2,427,734 base pairs), and its genome illustrates many of the adaptations that have enabled it to thrive at vents globally. It has 14 methyl-accepting chemotaxis protein genes, including four that may assist in positioning it in the redoxcline. A relative abundance of coding sequences (CDSs) encoding regulatory proteins likely control the expression of genes encoding carboxysomes, multiple dissolved inorganic nitrogen and phosphate transporters, as well as a phosphonate operon, which provide this species with a variety of options for acquiring these substrates from the environment. Thiom. crunogena XCL-2 is unusual among obligate sulfur-oxidizing bacteria in relying on the Sox system for the oxidation of reduced sulfur compounds. The genome has characteristics consistent with an obligately chemolithoautotrophic lifestyle, including few transporters predicted to have organic allocrits, and Calvin-Benson-Bassham cycle CDSs scattered throughout the genome. 相似文献
Cephalopods (octopus, squid and cuttlefish) are known for their camouflage. Cuttlefish Sepia officinalis use chromatophores and light reflectors for color change, and papillae to change three-dimensional physical skin texture.
Papillae vary in size, shape and coloration; nine distinct sets of papillae are described here. The objective was to determine
whether cuttlefish use visual or tactile cues to control papillae expression. Cuttlefish were placed on natural substrates
to evoke the three major camouflage body patterns: Uniform/Stipple, Mottle and Disruptive. Three versions of each substrate
were presented: the actual substrate, the actual substrate covered with glass (removes tactile information) and a laminated
photograph of the substrate (removes tactile and three-dimensional information because depth-of-field information is unavailable).
No differences in Small dorsal papillae or Major lateral mantle papillae expression were observed among the three versions
of each substrate. Thus, visual (not tactile) cues drive the expression of papillae in S. officinalis. Two sets of papillae (Major lateral mantle papillae and Major lateral eye papillae) showed irregular responses; their control
requires future investigation. Finally, more Small dorsal papillae were shown in Uniform/Stipple and Mottle patterns than
in Disruptive patterns, which may provide clues regarding the visual mechanisms of background matching versus disruptive coloration. 相似文献
The Drosophila lymph gland (LG) is a model system for studying hematopoiesis and blood cell homeostasis. Here, we investigated the patterns of division and differentiation of pro-hemocytes in normal developmental conditions and response to wasp parasitism, by combining lineage analyses and molecular markers for each of the three hemocyte types. Our results show that the embryonic LG contains primordial hematopoietic cells which actively divide to give rise to a pool of pro-hemocytes. We found no evidence for the existence of bona fide stem cells and rather suggest that Drosophila pro-hemocytes are regulated as a group of cells, rather than individual stem cells. The fate-restriction of plasmatocyte and crystal cell progenitors occurs between the end of embryogenesis and the end of the first larval instar, while Notch activity is required for the differentiation of crystal cells in third instar larvae only. Upon parasitism, lamellocyte differentiation prevents crystal cell differentiation and lowers plasmatocyte production. We also found that a new population of intermediate progenitors appears at the onset of hemocyte differentiation and accounts for the increasing number of differentiated hemocytes in the third larval instar. These findings provide a new framework to identify parameters of developmental plasticity of the Drosophila lymph gland and hemocyte homeostasis in physiological conditions and in response to immunological cues. 相似文献
The adaptor protein 14-3-3 binds to and stabilizes the tumor suppressor p53 and enhances its anti-tumour activity. In the regulatory C-terminal domain of p53 several 14-3-3 binding motifs have been identified. Here, we report the crystal structure of the extreme C-terminus (residues 385-393, p53pT387) of p53 in complex with 14-3-3σ at a resolution of 1.28 Å. p53pT387 is accommodated by 14-3-3 in a yet unrecognized fashion implying a rationale for 14-3-3 binding to the active p53 tetramer. The structure exhibits a potential binding site for small molecules that could stabilize the p53/14-3-3 protein complex suggesting the possibility for therapeutic intervention.
Structured summary
MINT-7711943: 14-3-3 sigma (uniprotkb:P31947) and p53 (uniprotkb:P04637) bind (MI:0407) by X-ray crystallography (MI:0114)MINT-7711931: 14-3-3 sigma (uniprotkb:P31947) and p53 (uniprotkb:P04637) bind (MI:0407) by isothermal titration calorimetry (MI:0065) 相似文献
A survey of the endohelminth fauna of Indo-West Pacific Lutjanidae (Perciformes) revealed the presence of the species Siphoderina manilensis (Velasquez, 1961) Miller & Cribb, 2008 and S. marina (Hafeezullah & Siddiqi, 1970) Miller & Cribb, 2008 in seven Lutjanus spp. from sites off the Great Barrier Reef, the Maldives, New Caledonia and Ningaloo Reef, Western Australia. A combination
of morphological and ribosomal DNA analyses of these cryptogonimids prompted the transfer of these taxa to a new genus, Euryakaina n. g., as E. manilensis n. comb. and E. marina n. comb., based on comparative analysis with other cryptogonimid taxa. Euryakaina n. g. is distinguished from all other cryptogonimid genera by the combination of a fusiform body, the few relatively small,
widely spaced oral spines (sometimes absent), a highly lobed ovary, opposite to slightly oblique testes, vitelline follicles
that extend from the anterior margin of the testes to slightly posterior to the intestinal bifurcation, and an excretory vesicle
that bifurcates dorsal to the ovary and reunites briefly slightly posterior to the intestinal bifurcation. Morphometric analysis
of these taxa alone suggests they should be reduced to synonymy, but DNA sequence analyses and ecological niche partitioning
provide evidence that they form a cryptic species complex in sympatric lutjanids in the Indo-West Pacific. The secondary structure
of the ITS2 rDNA for species of Euryakaina was also modelled and analysed for the presences of compensatory base changes (CBCs) or hemi-CBCs in order to explore the
usefulness of these changes as a tool to help elucidate the taxonomy of this complex system. We also report what we interpret
here as intraspecific variation in the ITS2 rDNA between individuals of E. manilensis from Lutjanus vitta recovered off the Great Barrier Reef and New Caledonia. 相似文献
Parasite biodiversity of fish of the southern part of the Mediterranean sea is still incompletely explored. We describe here Microcotyle visa n. sp. from the gill filaments of the bluespotted seabream Pagrus caeruleostictus (Valenciennes) (Sparidae) collected off the Algerian coast. The identity of fish hosts was confirmed by barcoding. Microcotyle visa n. sp. is herein described and illustrated. Analysis of the cox1 gene of the monogeneans revealed minor intraspecific variation (1.4%), an order of magnitude lower than the distance between this species and other Microcotyle species (10–15 %). Microcotyle visa n. sp. is distinguished from Microcotyle erythrini van Beneden & Hesse, 1863, a congener infesting sparids, on the basis of morphological (size of clamps, number of testes) and molecular (cox1) differences. This is the fourth member of the genus known to parasitise a sparid host. A species of Paramicrocotyle sp. included in the molecular analysis was nested within a robust Microcotyle + Paramicrocotyle clade; in the absence of demonstrated molecular and morphological differences, we consider that Paramicrocotyle Caballero & Bravo-Hollis, 1972 is a junior synonym of Microcotyle van Beneden & Hesse, 1863 and transfer two species of Paramicrocotyle as Microcotyle danielcarrioni (Martinez & Barrantes, 1977) n. comb. and Microcotyle moyanoi (Villalba & Fernandes, 1986) n. comb.
Control of mobile pests frequently requires area‐wide management (AWM) that spans commercial and non‐commercial habitats. Spatial modelling of habitat suitability can guide investment and implementation of AWM, but current approaches rarely capture population drivers, including local foraging, at an appropriate spatial resolution. To support the development of AWM for the fruit fly pest, Bactrocera tryoni (Tephritidae), we developed a habitat suitability model for the three premier fruit‐growing regions in south‐eastern Australia (~34,780 km2). Expert elicitation and published literature was used to develop a Bayesian network to model the drivers of B. tryoni habitat suitability, as determined by the ability of populations to persist and increase. The effect of uncertainty was tested through sensitivity analysis. The model was then linked with spatially explicit data (at 10 m resolution) to generate risk maps, using moving windows to capture local foraging movement. Habitat suitability was most strongly influenced by host availability within a distance of 200 m. Climate stress, and soil moisture for pupation, was also limiting. Experts were uncertain regarding the relative importance of drivers of host availability (host preference, host density, fruit seasonality), but this did not greatly affect model outputs. Independent trapping data supported model predictions, but their value was limited as traps were placed almost exclusively in optimal or suitable habitat. Amenability to AWM, when assessed as the ratio of suitable or optimal habitat that was under non‐horticultural versus horticultural land‐uses, differed by region (0.15–1.17). However, risk‐mapping did identify where ratios were locally most favourable (lowest). Also, predominantly local dispersal by B. tryoni suggests AWM for pest suppression could be applied at a landscape‐scale. Results show that a relatively simple model could capture the multi‐scale drivers of population dynamics and the complexity of landscapes sufficiently to guide AWM of a mobile pest. 相似文献