71 research outputs found

    Swainsonine Activates Mitochondria-mediated Apoptotic Pathway in Human Lung Cancer A549 Cells and Retards the Growth of Lung Cancer Xenografts

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    Swainsonine (1, 2, 8-trihyroxyindolizidine, SW), a natural alkaloid, has been reported to exhibit anti-cancer activity on several mouse models of human cancer and human cancers in vivo. However, the mechanisms of SW-mediated tumor regression are not clear. In this study, we investigated the effects of SW on several human lung cancer cell lines in vitro. The results showed that SW significantly inhibited these cells growth through induction of apoptosis in different extent in vitro. Further studies showed that SW treatment up-regulated Bax, down-regulated Bcl-2 expression, promoted Bax translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, which in turn caused the release of cytochrome c, the activation of caspase-9 and caspase-3, and the cleavage of poly (ADP-ribose) polymerase (PARP), resulting in A549 cell apoptosis. However, the expression of Fas, Fas ligand (FasL) or caspase-8 activity did not appear significant changes in the process of SW-induced apoptosis. Moreover, SW treatment inhibited Bcl-2 expression, promoted Bax translocation, cytochrome c release and caspase-3 activity in xenograft tumor cells, resulting in a significant decrease of tumor volume and tumor weight in the SW-treated xenograft mice groups in comparison to the control group. Taken together, this study demonstrated for the first time that SW inhibited A549 cancer cells growth through a mitochondria-mediated, caspase-dependent apoptotic pathway in vitro and in vivo

    Investigation of zinc-containing peptide deformylase from Leptospira interrogans by X-ray absorption near-edge spectroscopy

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    Peptide deformylase (PDF, EC 3.5.1.27) is essential for the normal growth of eubacterium but not for mammalians. Recently, PDF has been studied as a target for new antibiotics. Its activity is strongly dependent on the bound metal ion. The crystallographic studies did not show any significant structural difference upon various bound metal ions. In this paper, X-ray absorption spectroscopy was employed to determine the local structure around the zinc ion of PDF from Leptospira interrogans in dry powder. XANES (X-ray absorption near-edge structure) calculations were performed and the local geometry of the active center was reconstructed successfully. By comparing with the crystal structure of an enzyme-product complex, the results from calculations show that a water molecule has moved towards the zinc ion and lies in the distance range to coordinate with the zinc ion weakly

    Progress in Antarctic marine geophysical research by the Chinese Polar Program

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    Marine geophysical survey by the Chinese National Antarctic Research Expedition (CHINARE) began with the first science expedition in 1984/1985, although only four cruises were performed in the vicinity of the Antarctic Peninsula between then and 1991/1992. After a 20 year hiatus, Antarctic marine geophysical research was relaunched by the Chinese Polar Environmental Comprehensive Investigation and Assessment Programs (known simply as the Chinese Polar Program) in 2011/2012. Integrated geophysical surveys have been carried out annually since, in Prydz Bay and the Ross Sea. During the last 5 years, we have acquired about 5500 km of bathymetric, gravimetric, and magnetic lines; more than 1800 km of seismic reflection lines; and data from several heat flow and Ocean Bottom Seismometer (OBS) stations. This work has deepened understandings of geophysical features and their implications for geological tectonics and glacial history in Antarctica and its surrounding seas. Compiled Antarctic Bouguer and Airy isostatic gravity anomalies show different features of tectonics between the East Antarctic stability and West Antarctic activity. Calculated magnetic anomalies, heat flow anomalies and lithospheric anisotropy offshore of Prydz Bay may imply high heat capacity of mantle shielded by the continental shelf lithosphere, but high heat dissipation of mantle due to the Cretaceous breakup of Gondwana along the continent and ocean transition (COT), where large sediment ridges would be brought about by the Oligocene ice sheet retreat and would enlarge free-air gravity anomalies. In the western Ross Sea, CHINARE seismic profiles indicate northern termination of the Terror Rift and deposition time of the grounding zone wedge in the northern JOIDES Basin

    MEIS2C and MEIS2D promote tumor progression via Wnt/β-catenin and hippo/YAP signaling in hepatocellular carcinoma

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    Abstract Background MEIS2 has been identified as one of the key transcription factors in the gene regulatory network in the development and pathogenesis of human cancers. Our study aims to identify the regulatory mechanisms of MEIS2 in hepatocellular carcinoma (HCC), which could be targeted to develop new therapeutic strategies. Methods The variation of MEIS2 levels were assayed in a cohort of HCC patients. The proliferation, clone-formation, migration, and invasion abilities of HCC cells were measured to analyze the effects of MEIS2C and MEIS2D (MEIS2C/D) knockdown with small hairpin RNAs in vitro and in vivo. Chromatin immunoprecipitation (ChIP) was performed to identify MEIS2 binding site. Immunoprecipitation and immunofluorescence assays were employed to detect proteins regulated by MEIS2. Results The expression of MEIS2C/D was increased in the HCC specimens when compared with the adjacent noncancerous liver (ANL) tissues. Moreover, MEIS2C/D expression negatively correlated with the prognosis of HCC patients. On the other hand, knockdown of MEIS2C/D could inhibit proliferation and diminish migration and invasion of hepatoma cells in vitro and in vivo. Mechanistically, MESI2C activated Wnt/β-catenin pathway in cooperation with Parafibromin (CDC73), while MEIS2D suppressed Hippo pathway by promoting YAP nuclear translocation via miR-1307-3p/LATS1 axis. Notably, CDC73 could directly either interact with MEIS2C/β-catenin or MEIS2D/YAP complex, depending on its tyrosine-phosphorylation status. Conclusions Our studies indicate that MEISC/D promote HCC development via Wnt/β-catenin and Hippo/YAP signaling pathways, highlighting the complex molecular network of MEIS2C/D in HCC pathogenesis. These results suggest that MEISC/D may serve as a potential novel therapeutic target for HCC.https://deepblue.lib.umich.edu/bitstream/2027.42/152244/1/13046_2019_Article_1417.pd

    Prevalence, Diagnosis, and Vaccination Situation of Animal Chlamydiosis in China

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    Since the first case of Chlamydia infection in duck had been reported in 1956 and the first case from domestic animal had been reported in 1979 in China, the chlamydia prevalence in China was heavily according to the published data. The Chlamydia in avian prevalence has been reported at least 11 provinces, Chlamydia in sheep and goats at least 11 provinces, in swine at least 15 provinces, in cows at least 13 provinces and in yaks at least 5 provinces with result of IHA detection. Different diagnostic method such as CFT, ELISA and ABC-ELISA (avidin-biotin-complex ELISA) had been established besides IHA. The inactivated vaccines have been developed with isolated strains from sheep, goats, swine and cows. These inactivated vaccines have been used since 1980s and Chlamydia prevalence in China has been successfully controlled in domestic animal. However, the inactivated vaccines of Chlamydia isolated from avian species have not been successful, although a series of experimental vaccine have been done. Due to the unsustainable eradication plan of Chlamydia in China, sporadic outbreak in animal would happen if the vaccinations were suspended and economy lose in some farmers. Although Chlamydia prevalence in China has a long history, however, almost all published studies are in Chinese, which, in some degree, blocked scientists in other countries to understand the prevalence situation and control measures of Chlamydia in China

    Solving the Maximum Weighted Clique Problem Based on Parallel Biological Computing Model

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    The maximum weighted clique (MWC) problem, as a typical NP-complete problem, is difficult to be solved by the electronic computer algorithm. The aim of the problem is to seek a vertex clique with maximal weight sum in a given undirected graph. It is an extremely important problem in the field of optimal engineering scheme and control with numerous practical applications. From the point of view of practice, we give a parallel biological algorithm to solve the MWC problem. For the maximum weighted clique problem with m edges and n vertices, we use fixed length DNA strands to represent different vertices and edges, fully conduct biochemical reaction, and find the solution to the MVC problem in certain length range with O(n2) time complexity, comparing to the exponential time level by previous computer algorithms. We expand the applied scope of parallel biological computation and reduce computational complexity of practical engineering problems. Meanwhile, we provide a meaningful reference for solving other complex problems

    Co-combustion characteristics and kinetics of meager coal and spent cathode carbon block by TG-MS analysis

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    As a hazardous waste, the spent cathode carbon block (SCCB) has a high calorific value while it is difficult to fire, its harmless disposal is a major difficulty at present. Herein, a method of mixed combustion of meager coal and SCCB in a pulverized coal furnace for disposal of SCCB is proposed, and thermogravimetric mass spectrometry (TG-MS) is used to characterize the combustion and gas release characteristics. The effects of the heating rate and mixing ratio on combustion are analyzed as well. The result shows that the comprehensive combustibility index and combustion stability index of SCCB-5 at a heating rate of 50 °C/min are both the highest. Abundant oxygen-containing groups in SCCB promote the co-combustion process. The release of hydrogen fluoride is relatively low below 1000 °C so that the use of pulverized coal boilers meets the temperature requirement for disposal of SCCB. The good melting characteristics of ash after mixing sintering also confirm this point. Finally, the kinetic calculation results show that the combustion activation energy is the lowest when the mixing ratio is 5%, which is in good agreement with the experimental results. The highest activation energy values for the combustion of meager coal, SCCB and SCCB-5 are 46.90, 89.39, 59.87 kJ mol−1, respectively

    Genetic Characterization of Animal Brucella Isolates from Northwest Region in China

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    Animal brucellosis is a reemerging disease in China, particular in northwest China. The Brucella species (even genus) are highly conserved; therefore the use of Multilocus sequencing typing (MLST: based on conserved housekeeping loci) is more suitable for discrimination at species or biovar level on Brucella. In this study, MLST was used to analyze the characterization of Brucella from sheep and yaks during 2015 and 2016. All 66 isolates were collected from northwest China, including Inner Mongolia, Xinjiang, Qinghai, and Gansu provinces. Isolates were cultured on Brucella agar medium and identified by MLST. MLST identified five ST types: ST8 (n=55), ST7 (n=2), ST3 (n=5), ST1 (n=2), and ST14 (n=2). This analysis revealed that B. melitensis isolates exhibited high single genotypes (ST8) in the most northwest China. MLST of isolates provides helpful information on understanding genetic characterization of Brucella in northwest China

    Technological Innovation, Product Quality and Upgrading of Manufacturing Value Chain: Empirical Evidence from China

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    The aim of this research is to investigate the relationship between enterprise technological innovation, export product quality, and the upgrading of the manufacturing value chain. The study is based on panel data from Chinese manufacturing enterprises between 2000 and 2013 and uses a multi-dimensional fixed-effect method to analyze the moderating effect of enterprise export product quality on the relationship between technological innovation and the upgrading of the manufacturing value chain. The results show that technological innovation significantly promotes the upgrading of the manufacturing value chain. The regression analysis indicates that a 1% increase in enterprise technological innovation leads to a 0.28% increase in the upgrading of the manufacturing value chain. Similarly, the study demonstrates that improving the quality of exported products significantly enhances the manufacturing industry’s status in the global value chain. The regression analysis reveals that a 1% increase in the quality of exported products leads to a 0.14% increase in the upgrading of the manufacturing value chain. Moreover, the research identifies a threshold value of 0.4438 for the moderating effect of enterprise export product quality on the impact of technological innovation on the upgrading of the manufacturing value chain. When the quality of exported products is below the threshold value, it has a strong positive regulatory effect on technological innovation, promoting the upgrading of the manufacturing value chain. However, once the quality of exported products exceeds the threshold value, its regulatory effect becomes insignificant. The study’s findings have important implications for enterprises looking to overcome the “dilemma of scientific and technological innovation” and promote the intelligent development of the manufacturing industry. The research conclusions have strong reference value for promoting the combination of technology innovation and business model innovation in manufacturing enterprises. This will allow for climbing the high-end links of the global value chain and achieving sustainable development
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