5,065 research outputs found

    Baicalein inhibits cell development in papillary thyroid cancer by regulating miR-206/RAP1B pathway

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    Purpose: To investigate the therapeutic effect of baicalein on papillary thyroid cancer (PTC) cells in vitro and its underlying molecular mechanism.Methods: The human PTC cell line TPC-1 was divided into five groups and treated with distilled water or baicalein at 10, 20, 50, or 100 μM. Next, miR-206, miR-206 inhibitor, the respective negative controls of miR-206 and miR-206 inhibitor, RAP1B small interfering RNA (siRNA), and control vector siRNA were synthesized and transfected into TPC-1 cells. Cell viability, migration, and invasion were measured using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and Transwell assays. miR-206 expression and Ras-related protein (RAP1B) levels were assessed by quantitative real-time reverse transcription-polymerase chain reaction and western blotting, respectively.Results: Baicalein inhibited TPC-1 cell viability, migration and invasion, upregulated miR-206 expression, and reduced the RAP1B level in a concentration-dependent manner (p < 0.01). miR-206 negatively regulated RAP1B expression and increased the baicalein-induced reduction of RAP1B expression. Moreover, RAP1B overexpression relieved the suppression of cell viability, migration, and invasion caused by baicalein (p < 0.01).Conclusion: Baicalein suppresses cell growth in PTC cells by regulating the miR-206/RAP1B pathway, providing a new therapeutic strategy for PTC treatment. Keywords: Baicalein, Papillary thyroid cancer (PTC), miR-206, RAP1B, Cell viability, Cell invasio

    Compact Supercell Method Based on Opposite Parity for Bragg Fibers

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    The supercell- based orthonormal basis method is proposed to investigate the modal properties of the Bragg fibers. A square lattice is constructed by the whole Bragg fiber which is considered a supercell, and the periodical dielectric structure of the square lattice is decomposed using periodic functions (cosine). The modal electric field is expanded as the sum of the orthonormal set of Hermite-Gaussian basis functions based on the opposite parity of the transverse electric field. The propagation characteristics of Bragg fibers can be obtained after recasting the wave equation into an eigenvalue system. This method is implemented with very high efficiency and accuracy

    Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

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    Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario

    Janus Monolayer Transition Metal Dichalcogenides

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    A novel crystal configuration of sandwiched S-Mo-Se structure (Janus SMoSe) at the monolayer limit has been synthesized and carefully characterized in this work. By controlled sulfurization of monolayer MoSe2 the top layer of selenium atoms are substituted by sulfur atoms while the bottom selenium layer remains intact. The peculiar structure of this new material is systematically investigated by Raman, photoluminescence and X-ray photoelectron spectroscopy and confirmed by transmission-electron microscopy and time-of-flight secondary ion mass spectrometry. Density-functional theory calculations are performed to better understand the Raman vibration modes and electronic structures of the Janus SMoSe monolayer, which are found to correlate well with corresponding experimental results. Finally, high basal plane hydrogen evolution reaction (HER) activity is discovered for the Janus monolayer and DFT calculation implies that the activity originates from the synergistic effect of the intrinsic defects and structural strain inherent in the Janus structure.Comment: 22 pages, 12 figure

    An novel role of sphingosine kinase-1 (SPHK1) in the invasion and metastasis of esophageal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Treatment failure for esophageal carcinoma is frequently due to lymph node metastasis and invasion to neighboring organs. The aim of the present study was to investigate invasion- and metastasis-related genes in esophageal carcinoma cells <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>A metastasis model using a Matrigel invasion clonal selection approach was employed to establish a highly invasive subline EC9706-P4 from the esophageal carcinoma cell (ESCC) line EC9706. The differentially expressed genes of the subline and the parental cells determined by gene microarrays were further analyzed by RT-PCR and Western blotting.</p> <p>Results</p> <p>We identified <it>sphingosine kinase 1 (SPHK1) </it>as an invasion and metastasis-related gene of esophageal cancer. <it>SPHK1 </it>was overexpressed in the EC9706-P4 subline with high invasive capacity. Among six ESCC lines tested, KYSE2 and KYSE30 cells showed the highest <it>SPHK1 </it>mRNA and protein expressions as well as the most invasive phenotype. By Western blotting, in 7/12 cases (58%), SPHK1 expression was higher in esophageal carcinomas than in the companion normal tissue. In 23/30 cases (76%), SPHK1 protein expression was upregulated in the tumors compared to matched normal tissue by immunohistochemistry (IHC). Esophageal carcinoma tissue microarray analysis indicated that SPHK1 expression correlated with the depth of tumor invasion (<it>P </it>< 0.0001) and lymph node metastasis (<it>P </it>= 0.016). By Kaplan-Meier analysis, strong SPHK1 expression was significantly associated with clinical failure (<it>P </it>< 0.01), suggesting the involvement of SPHK1 in aggressiveness of human esophageal carcinoma. <it>SPHK1 </it>overexpression significantly increased the invasiveness of EC9706 cells <it>in vitro </it>and also increased EC9706 cell growth and spontaneous metastasis <it>in vivo</it>, promoting significant increases in tumor growth, tumor burden and spontaneous lung metastasis in nude mice. <it>SPHK1 </it>expression significantly correlated with the expression of many EGFR pathway genes associated with invasion of cancer cells. SPHK1 protein expression also significantly correlated with the phosphorylation of EGFR.</p> <p>Conclusion</p> <p>In summary, our data implicate <it>SPHK1 </it>in the metastasis of esophageal cancer. Our study also identified downstream mediators of SPHK1 in esophageal cancer cells that may mediate enhanced malignant behavior, and several of these mediators may be useful as therapeutic targets.</p

    ATP synthase ecto-α-subunit: a novel therapeutic target for breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Treatment failure for breast cancer is frequently due to lymph node metastasis and invasion to neighboring organs. The aim of the present study was to investigate invasion- and metastasis-related genes in breast cancer cells <it>in vitro </it>and <it>in vivo</it>. Identification of new targets will facilitate the developmental pace of new techniques in screening and early diagnosis. Improved abilities to predict progression and metastasis, therapeutic response and toxicity will help to increase survival of breast cancer patients.</p> <p>Methods</p> <p>Differential protein expression in two breast cancer cell lines, one with high and the other with low metastatic potential, was analyzed using two-dimensional liquid phase chromatographic fractionation (Proteome Lab PF 2D system) followed by matrix-assisted laser desorption/time-of-flight mass spectrometry (MALDI-TOF/MS).</p> <p>Results</p> <p>Up regulation of α-subunit of ATP synthase was identified in high metastatic cells compared with low metastatic cells. Immunohistochemical analysis of 168 human breast cancer specimens on tissue microarrays revealed a high frequency of ATP synthase α-subunit expression in breast cancer (94.6%) compared to normal (21.2%) and atypical hyperplasia (23%) breast tissues. Levels of ATP synthase expression levels strongly correlated with large tumor size, poor tumor differentiation and advanced tumor stages (<it>P </it>< 0.05). ATP synthase α-subunit over-expression was detected on the surface of a highly invasive breast cancer cell line. An antibody against the ATP synthase α-subunit inhibited proliferation, migration and invasion in these breast cancer cells but not that of a non-tumor derived breast cell line.</p> <p>Conclusions</p> <p>Over-expression of ATP synthase α-subunit may be involved in the progression and metastasis of breast cancer, perhaps representing a potential biomarker for diagnosis, prognosis and a therapeutic target for breast cancer. This finding of this study will help us to better understand the molecular mechanism of tumor metastasis and to improve the screening, diagnosis, as well as prognosis and/or prediction of responses to therapy for breast cancer.</p
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