A novel colorimetric method for H2O2 sensing and its application: Fe2+-catalyzed H2O2 prevents aggregation of AuNPs by oxidizing cysteine (FeHOAuC).

The inhibition of hydrogen peroxide (H2O2) on the cysteine-mediated aggregation of gold nanoparticles (AuNPs) has great potential to rapidly visualize H2O2 and disease-associated biomarkers. However, associated applications have been rigid due to the low cysteine-oxidation efficiency or the insufficient interference-resistance of previous catalysts. Here, we proposed a novel AuNPs colorimetric method termed Fe2+-catalyzed H2O2-preventing aggregation of AuNPs by oxidizing Cysteine (FeHOAuC) for the visible and rapid detection of H2O2 with high specificity. Formed Fe2+-cysteine composites in the beginning, Fe2+ accelerates the oxidation of cysteine by H2O2 with an intramolecular electron-transferring model, and the generated cysteine oxides (including cysteic acid or cystine, dependent on the ratio of cysteine to H2O2 molecules) lose the pro-aggregation effect on AuNPs. Notably, FeHOAuC can quantify 2-30 µM of H2O2 within 5 min, and the monitoring process works well with tolerance to the impact of dissolved oxygen. The FeHOAuC paired with lactate oxidase was successfully used for measuring lactic acids in real sweat samples with a practicable detection window (2-60 µM) and a low variable coefficient (<10%). In summary, FeHOAuC is a feasible platform for rapid and convenient detection of H2O2 and oxidase-specific substrates.

Four targeted genes for predicting the prognosis of colorectal cancer: A bioinformatics analysis case.

The molecular mechanisms underlying the development and progression of colorectal cancer (CRC) have not been clarified. The purpose of the present study was to identify key genes that may serve as novel therapeutic targets or prognostic predictors in patients with CRC using bioinformatics analysis. Four gene expression datasets were downloaded from the Gene Expression Omnibus database, which revealed 19 upregulated and 34 downregulated differentially expressed genes (DEGs). The downregulated DEGs were significantly enriched in eight pathways according to Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. A protein-protein interaction network was constructed with 52 DEGs and 458 edges. Ten key genes were identified according to the degree value, betweenness centrality and closeness centrality. Survival analysis revealed that low expression of four of the ten genes, carcinoembryonic antigen related cell adhesion molecule 7 (CEACAM7), solute carrier family 4 member 4 (SLC4A4), glucagon (GCG) and chloride channel accessory 1 (CLCA1) genes, were associated with unfavorable prognosis in CRC. Furthermore, gene set enrichment analysis revealed that two pathways were significantly enriched in the CEACAM7 low-expression group. Thus, CEACAM7, SLC4A4, GCG and CLCA1 may be prognostic markers or therapeutic targets of CRC. Low CEACAM7 expression may be associated with the activation of glycosaminoglycan biosynthesis-chondroitin sulfate and extracellular matrix receptor interaction pathways and may affect the prognosis of CRC.