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Introduction: Gastric cancer is the fifth most common cancer and third leading cause of cancer-related death worldwide. There are three main ways to treat gastric cancer: surgical resection, radiation therapy, and drug therapy. Furthermore, combinations of two to three regimens can improve survival. However, the survival outcomes of chemotherapy in advanced gastric cancer patients are still unsatisfactory. Unfortunately, no widely useful biomarkers have been verified to predict the efficacy of chemotherapy for locally advanced gastric cancer. Methods: An MTT assay was used to determine the cell viability after cisplatin or oxaliplatin treatment. Western blotting and immunohistochemistry were utilized to examine the secreted frizzled-related protein 4 (sFRP4) level and associated signaling pathways. Immunofluorescence staining was utilized to analyze the location of β-catenin. Colony formation and Transwell assays were used to analyze the functions related with cisplatin, oxaliplatin, and sFRP4. Results: We have found that gastric cancer patients treated with combinations of 5-fluorouracil (5-FU) and cisplatin regimens have better survival rates than those treated with 5-FU-based chemotherapy alone. sFRP4 was selected as a potential target from stringent analysis and intersection of 5-FU and cisplatin resistance-related gene sets. sFRP4 was shown to be overexpressed in clinical gastric tumor tissues and positively correlated with a worse survival rate. In addition, sFRP4 and β-catenin were upregulated in cisplatin- and oxaliplatin-resistant gastric cancer cells compared to parental cells. Immunofluorescence staining and nuclear fractionation showed that β-catenin was translocated from the cytosol into the nucleus. Moreover, sFRP4 was detected in the conditioned medium of these resistant cells, which indicates that sFRP4 might have an extracellular role in chemotherapy resistance. Increased migration capacity and dysregulation of epithelial-mesenchymal transition-related markers, which might result from the dysregulation of sFRP4, were observed in cisplatin- and oxaliplatin-resistant gastric cancer cells. Discussion/Conclusion: In summary, sFRP4 might play a critical role in resistance to cisplatin and oxaliplatin, cell metastasis, and poor prognosis in gastric cancer via the Wnt-β-catenin pathway. Investigations of the molecular mechanism underlying sFRP4-modulated cancer progression and chemotherapeutic outcomes can provide additional therapeutic strategies for gastric cancer. [ABSTRACT FROM AUTHOR]

The purpose of this study is to examine the dilution effect on combustion characteristics of methane/nitrous oxide inverse tri-coflow diffusion flame through the addition of various dilution gases. Two diluents, namely carbon dioxide and argon, were used. To scrutinize the overall combustion characteristics, the effects of dilution on flame appearance and pollution emissions were calculated numerically and observed experimentally. In terms of flame appearance, with increasing the central oxidizer flow rate, the flame became an inner-oxidizer-injected flame structure and then converted to a double flame structure. When 40% Ar and 20% CO2 were added to the oxidizer individually, a liftoff edge flame was formed at high central oxidizer flow rate. This theoretical prediction provided a fast and preliminary explanation of the various flame structures and concurred with the trend of IDF formation observed in the experiment. Regarding the flue gas emission, the addition of Ar in CH4/N2O diffusion flame can effectively reduce the yield of CO, whereas the addition of CO2 leads to an increase of CO concentration in the flue gas. Simulation results indicated that for Ar addition, the production of NOx is dominated by the inert effect at dilution levels lower than 40%, whereas the thermal/diffusion effect dominates at dilution levels higher than 40%. CO formation is mainly dominated by the thermal/diffusion effect. In CO2 dilution, NOx formation is dominated by the inert and chemical effects at dilution levels lower than 40%. However, at dilution levels higher than 40%, the chemical effect is more dominant. Thus, CO formation is dominated mainly by the chemical effect. [ABSTRACT FROM AUTHOR]