52 research outputs found

    Small interfering RNA targeting CDC25B inhibits liver tumor growth in vitro and in vivo

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Using gene expression profiling, we previously identified CDC25B to be significantly highly expressed in hepatocellular carcinoma (HCC) compared to non-tumor liver. CDC25B is a cell cycle-activating phosphatase that positively regulates the activity of cyclin-dependent kinases, and is over-expressed in a variety of human malignancies. In this study, we validated the over-expression of CDC25B in HCC, and further investigated its potential as a therapeutic target for the management of HCC.</p> <p>Results</p> <p>Quantitative real-time polymerase chain reaction and immunohistochemical staining of patient samples confirmed the significant over-expression of CDC25B in HCC compared to non-tumor liver samples (<it>P </it>< 0.001). Thus, intefering with the expression and activity of CDC25B may be a potential way to intervene with HCC progression. We used RNA interference to study the biological effects of silencing CDC25B expression in HCC cell lines (Hep3B and Hep40), in order to validate its potential as a therapeutic target. Using small oligo siRNAs targeting the coding region of CDC25B, we effectively suppressed CDC25B expression by up to 90%. This was associatetd with significant reductions in cell growth rate, cell migration and invasion through the matrigel membrane, and caused significant cell cycle delay at the G2 phase. Finally, suppression of CDC25B significantly slowed the growth of Hep40 xenografts in nude mice.</p> <p>Conclusion</p> <p>Our data provide evidence that the inhibition of CDC25B expression and activity lead to suppression of tumor cell growth and motility, and may therefore be a feasible approach in the clinical management of HCC.</p

    Blockade of Wnt-1 signaling leads to anti-tumor effects in hepatocellular carcinoma cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is an aggressive cancer, and is the third leading cause of cancer death worldwide. Standard therapy is ineffective partly because HCC is intrinsically resistant to conventional chemotherapy. Its poor prognosis and limited treatment options make it critical to develop novel and selective chemotherapeutic agents. Since the Wnt/β-catenin pathway is essential in HCC carcinogenesis, we studied the inhibition of Wnt-1-mediated signaling as a potential molecular target in HCC.</p> <p>Results</p> <p>We demonstrated that Wnt-1 is highly expressed in human hepatoma cell lines and a subgroup of human HCC tissues compared to paired adjacent non-tumor tissues. An anti-Wnt-1 antibody dose-dependently decreased viability and proliferation of Huh7 and Hep40 cells over-expressing Wnt-1 and harboring wild type β-catenin, but did not affect normal hepatocytes with undetectable Wnt-1 expression. Apoptosis was also observed in Huh7 and Hep40 cells after treatment with anti-Wnt-1 antibody. In these two cell lines, the anti-Wnt-1 antibody decreased β-catenin/Tcf4 transcriptional activities, which were associated with down-regulation of the endogenous β-catenin/Tcf4 target genes c-Myc, cyclin D1, and survivin. Intratumoral injection of anti-Wnt-1 antibody suppressed <it>in vivo </it>tumor growth in a Huh7 xenograft model, which was also associated with apoptosis and reduced c-Myc, cyclin D1, and survivin expressions.</p> <p>Conclusion</p> <p>Our results suggest that Wnt-1 is a survival factor for HCC cells, and that the blockade of Wnt-1-mediated signaling may offer a potential pathway-specific therapeutic strategy for the treatment of a subgroup of HCC that over-expresses Wnt-1.</p

    Soluble Frizzled-7 receptor inhibits Wnt signaling and sensitizes hepatocellular carcinoma cells towards doxorubicin

    Get PDF
    Abstract Background There are limited therapeutic options for hepatocellular carcinoma (HCC), the most common liver malignancy worldwide. Recent studies have identified the Frizzled-7 receptor (FZD7), important for activation of Wnt-mediated signaling, as a potential therapeutic target for HCC and other cancers. Methods We hypothesized that the extracellular domain of FZD7 (sFZD7) would be a clinically more relevant therapeutic modality than previously studied approaches to target FZD7. We expressed and purified sFZD7 from E. coli, and tested its functional activity to interact with Wnt3, its ability to inhibit Wnt3-mediated signaling, and its potential for combinatorial therapy in HCC. Results sFZD7 pulled down Wnt3 from Huh7 cells, and decreased β-catenin/Tcf4 transcriptional activity in HCC cells. In vitro, sFZD7 dose-dependently decreased viability of three HCC cell lines (HepG2, Hep40, and Huh7, all with high FZD7 and Wnt3 mRNA), but had little effect on normal hepatocytes from three donors (all with low level FZD7 and Wnt3 mRNA). When combined with doxorubicin, sFZD7 enhanced the growth inhibitory effects of doxorubicin against HCC cells in vitro, and against Huh7 xenografts in vivo. Reduced expressions of c-Myc, cyclin D1, and survivin were observed in vitro and in vivo. Additionally, sFZD7 altered the levels of phosphorylated AKT and ERK1/2 induced by doxorubicin treatment in vitro, suggesting that several critical pathways are involved in the chemosensitizing effect of sFZD7. Conclusions We propose that sFZD7 is a feasible therapeutic agent with specific activity, which can potentially be combined with other chemotherapeutic agents for the improved management of HCC.</p

    Drying characteristics of Orthosiphon stamineus Benth by solar assisted heat pump drying

    Get PDF
    Processing methods of Misai Kucing still remain crude and lack technological advancements. In terms of drying, very few studies have attempted to apply advanced drying technology to improve Misai Kucing quality and drying time. This paper presents first attempt to improve Misai Kucing drying kinetics and product quality through solar-assisted heat pump drying and comparison was made against solar drying. Experimental results showed that solar-dried samples had the greatest total color change and loss of two bioactive ingredients as compared to solar-assisted heat pump-dried samples due to its longer time process, higher drying temperature, and chlorophyll degradation. By comparing the statistical values, it showed that the Page model had the best goodness of fit at all tested dried samples by both drying methods

    Study on retention of metabolites composition in misai kucing (orthosiphon stamineus) by heat pump assisted solar drying

    Get PDF
    In this research, the effects of different drying methods on the two biomarker compounds concentrations, such as sinensetin (SEN) and rosmarinic acid (RA) of Orthosiphon staminues Benth leaves, flowers, stems and mix were investigated. SEN and RA retention among the dehydrated samples were maximum 83.07% in leaves and 92.54% in flowers, respectively by heat pump assisted solar drying method. For heat pump assisted solar dried samples, there are no significant differences (p > .05) in the retention of SEN and RA as compared to fresh samples. However, there are significant differences (p < 0.05) in SEN and RA retention in solar dried leaves, flowers, stems and mix as compared to fresh samples. Besides, an optimization study was performed to evaluate the optimal drying conditions for obtaining high SEN yields from Misai Kucing's leaves, flowers, stems and mixes with high RA contents within the drying parameters

    Robust estimation of bacterial cell count from optical density

    Get PDF
    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

    Get PDF
    Background High myopia (HM), defined as a spherical equivalent refractive error (SER) ≤ −6.00 diopters (D), is a leading cause of sight impairment, through myopic macular degeneration (MMD). We aimed to derive an improved polygenic score (PGS) for predicting children at risk of HM and to test if a PGS is predictive of MMD after accounting for SER. Methods The PGS was derived from genome-wide association studies in participants of UK Biobank, CREAM Consortium, and Genetic Epidemiology Research on Adult Health and Aging. MMD severity was quantified by a deep learning algorithm. Prediction of HM was quantified as the area under the receiver operating curve (AUROC). Prediction of severe MMD was assessed by logistic regression. Findings In independent samples of European, African, South Asian and East Asian ancestry, the PGS explained 19% (95% confidence interval 17–21%), 2% (1–3%), 8% (7–10%) and 6% (3–9%) of the variation in SER, respectively. The AUROC for HM in these samples was 0.78 (0.75–0.81), 0.58 (0.53–0.64), 0.71 (0.69–0.74) and 0.67 (0.62–0.72), respectively. The PGS was not associated with the risk of MMD after accounting for SER: OR = 1.07 (0.92–1.24). Interpretation Performance of the PGS approached the level required for clinical utility in Europeans but not in other ancestries. A PGS for refractive error was not predictive of MMD risk once SER was accounted fo

    Balance theory and the perception of religious relationships : an application of three quantitative cognitive consistency models in Singapore.

    No full text
    This study engages a social psychological approach to explain the formation of attitudes in public opinion, seeking to understand how individuals could be driven by various social forces that impinge on them as they form attitudes towards an issue.Bachelor of Communication Studie

    Hotel selection criteria.

    No full text
    For the past three decades, tourism has made great contribution to the development of Singapore economy. Being a major portion of tourism, the contribution of hotel industry towards Singapore economy cannot be underestimated. Because overseas travellers are so valuable to our hotel industry, we need to work even harder to stay in the forefront by attracting new visitors and establishing long term relationship with the olds. It follows that correspondingly, hotels in Singapore have to upgrade their image and facilities, so as to provide the best place for foreign travellers from all aspects to stay. In this report, we hope to provide a guide to the hotel manager in designing a more effective marketing campaigns to satisfy the needs of the hotel guests and attract more new customers. The main purpose of this study is to determine the pertinent criteria that set down by tourists in their selection of local hotel during their stays in Singapore. In addition, we will be examining the various factors affecting such criteria, namely, a) purpose of visit, b) age group, c) nationality and d) gender. In the pursuit of our above objectives, the project used primary and secondary data as the sources of information which served as the foundation for the knowledge and insight into the hotel industry. Lastly, with a deeper insight and understanding of tourists and business travellers’ perceptions towards our local hotel industry through our research, the report will conclude by providing various recommendations to hoteliers. These suggestions aim to strengthen good image and further improve hotel facilities.BUSINES

    Suppression of Glypican 3 Inhibits Growth of Hepatocellular Carcinoma Cells through Up-Regulation of TGF-β2

    Get PDF
    Glypican 3 (GPC3) is a valuable diagnostic marker and a potential therapeutic target in hepatocellular carcinoma (HCC). To evaluate the efficacy of targeting GPC3 at the translational level, we used RNA interference to examine the biologic and molecular effects of GPC3 suppression in HCC cells in vitro and in vivo. Transfection of Huh7 and HepG2 cells with GPC3-specific small interfering RNA (siRNA) inhibited cell proliferation (P < .001) together with cell cycle arrest at the G1 phase, down-regulation of antiapoptotic protein (Bcl-2, Bcl-xL, and Mcl-1), and replicative senescence. Gene expression analysis revealed that GPC3 suppression significantly correlated with transforming growth factor beta receptor (TGFBR) pathway (P = 4.57e-5) and upregulated TGF-β2 at both RNA and protein levels. The effects of GPC3 suppression by siRNA can be recapitulated by addition of human recombinant TGF-β2 to HCC cells in culture, suggesting the possible involvement of TGF-β2 in growth inhibition of HCC cells. Cotransfection of siRNA-GPC3 with siRNA-TGF-β2 partially attenuated the effects of GPC3 suppression on cell proliferation, cell cycle progression, apoptosis, and replicative senescence, confirming the involvement of TGF-β2 in siRNA-GPC3-mediated growth suppression. In vivo, GPC3 suppression significantly inhibited the growth of orthotopic xenografts of Huh7 and HepG2 cells (P < .05), accompanied by increased TGF-β2 expression, reduced cell proliferation (observed by proliferating cell nuclear antigen staining), and enhanced apoptosis (by TUNEL staining). In conclusion, molecular targeting of GPC3 at the translational level offers an effective option for the clinical management of GPC3-positive HCC patients
    corecore