Galectin-1 Promotes Metastasis in Gastric Cancer Through a Sphingosine-1-Phosphate Receptor 1-Dependent Mechanism

Background/Aims: Increased expression of galectin-1 (Gal-1) in gastric cancer (GC) promotes metastasis and correlates with poor prognosis. The mechanisms by which Gal-1 promotes GC metastasis remain unknown. Methods: Gal-1and Sphingosine-1-phosphate receptor 1 (S1PR1) were determined by immunohistochemistry(IHC) and quantitative real time polymerase chain reaction (qRT-PCR) in GC specimens. Stably transfected Gal-1 or S1PR1 into SGC7901 and MGC-803 cells, western blot and invasion assays in vitro and nude mice tumorigenicity in vivo were also employed. Results: Overexpression of Gal-1 enhanced expression of S1PR1 in SGC-7901 cells, and increased cell invasion, while knockdown Gal-1 in MGC-803 cells reduced S1PR1 expression and diminished invasion. Simultaneous knockdown of Gal-1 and overexpression of S1PR1 in MGC803 cells rescued invasive ability of MGC803 cells. S1PR1 was associated with expression of epithelial-to-mesenchymal transition (EMT) markers in vitro and in clinical samples. EMT induced in MGC-803 cells by TGF-β1 was accompanied by S1PR1 activation, while knockdown of S1PR1 reduced response to TGF-β1, suggest that Gal-1 promotes GC invasion by activating EMT through a S1PR1-dependent mechanism. Overexpression of S1PR1 promoted subcutaneous xenograft growth and pulmonary metastases, and enhanced expression of EMT markers. Conclusion: Galectin-1 promotes metastasis in gastric cancer through a S1PR1- dependent mechanism, our results indicate that targeting S1PR1 may be a novel strategy to treat GC metastasis

Ecological Environment in Terms of Human Behavior

In terms of human behavior, company and government policy, it is proposed that the ecological behavior of human being is the basis of influence on the ecological environment construction in Poyang Lake and measures to ensure the sustainable development of ecological environment in Poyang Lake

Co-expression of nitrogenase proteins in cotton (Gossypium hirsutum L.)

Chemical nitrogen fertilizer can maintain crop productivity, but overuse of chemical nitrogen fertilizers leads to economic costs and environmental pollution. One approach to reduce use of nitrogen fertilizers is to transfer nitrogenase biosynthetic pathway to non-legume plants. Fe protein encoded by nifH and MoFe protein encoded by nifD and nifK are two structural components of nitrogenase. NifB encoded by nifB is a critical maturase that catalyzes the first committed step in the biosynthesis of nitrogenase FeMo-cofactor that binds and reduces N2. Expression of the nifB, nifH, nifD and nifK is essential to generate plants that are able to fix atmospheric N2. In this study, the four genes (nifB, nifH, nifD and nifK) from Paenibacillu polymyxaWLY78 were assembled in plant expression vector pCAMBIA1301 via Cre/LoxP recombination system, yielding the recombinant expression vector pCAMBIA1301-nifBHDK. Then, the four nif genes carried in the expression vector were co-introduced into upland cotton R15 using Agrobacterium tumefaciens-mediated transformation. Homozygous transgenic cotton lines B2, B5 and B17 of T3 generation were selected by PCR and RT-PCR. qRT-PCR showed that nifB, nifH, nifD and nifK were co-expressed in the transgenic cottons at similar levels. Western blotting analysis demonstrated that NifB, NifH, NifD and NifK were co-produced in the transgenic cottons. Co-expression of the four critical Nif proteins (NifB, NifH, NifD and NifK) in cottons represents an important step in engineering nitrogenase biosynthetic pathway to non-legume plants

Knockdown of ARK5 Expression Suppresses Invasion and Metastasis of Gastric Cancer

Background/Aims: Gastric cancer (GC) is a common and lethal malignancy, and AMP-activated protein kinase-related kinase 5 (ARK5) has been discovered to promote cancer metastasis in certain types of cancer. In this study, we explored the role of ARK5 in GC invasion and metastasis. Methods: ARK5 and epithelial-mesenchymal transition (EMT)-related markers were determined by immunohistochemistry and western blot in GC specimens. Other methods including stably transfected against ARK5 into SGC7901 and AGS cells, western blot, migration and invasion assays in vitro and nude mice tumorigenicity in vivo were also employed. Results: The results demonstrated that ARK5 expression was increased and positively correlated with metastasis, EMT-related markers and poor prognosis in patients with GC. Knockdown of ARK5 expression remarkably suppressed GC cells invasion and metastasis via regulating EMT, rather than proliferation in vitro and in vivo. And knockdown of ARK5 expression in GC cells resulted in the down-regulation of the mTOR/p70S6k signals, Slug and SIP1. Conclusion: The elevated ARK5 expression was closely associated with cancer metastasis and patient survival, and it seemed to function in GC cells migration and invasion via EMT alteration, together with the alteration of the mTOR/p70S6k signals, Slug and SIP1, thus providing a potential therapeutic target for GC

High-fidelity and clean nanotransfer lithography using structure-embedded and electrostatic-adhesive carriers

Abstract Metallic nanostructures are becoming increasingly important for both fundamental research and practical devices. Many emerging applications employing metallic nanostructures often involve unconventional substrates that are flexible or nonplanar, making direct lithographic fabrication very difficult. An alternative approach is to transfer prefabricated structures from a conventional substrate; however, it is still challenging to maintain high fidelity and a high yield in the transfer process. In this paper, we propose a high-fidelity, clean nanotransfer lithography method that addresses the above challenges by employing a polyvinyl acetate (PVA) film as the transferring carrier and promoting electrostatic adhesion through triboelectric charging. The PVA film embeds the transferred metallic nanostructures and maintains their spacing with a remarkably low variation of 2), and complex 3D structures. Moreover, the thin and flexible carrier film enables transfer on highly curved surfaces, such as a single-mode optical fiber with a curvature radius of 62.5 μm. With this strategy, we demonstrate the transfer of metallic nanostructures for a compact spectrometer with Cu nanogratings transferred on a convex lens and for surface-enhanced Raman spectroscopy (SERS) characterization on graphene with reliable responsiveness