Quantitative Proteomics Reveals That the Inhibition of Na⁺/K⁺‑ATPase Activity Affects S‑Phase Progression Leading to a Chromosome Segregation Disorder by Attenuating the Aurora A Function in Hepatocellular Carcinoma Cells

Many studies have shown the Na⁺/K⁺-ATPase (NKA) might be a potential target for anticancer therapy. Cardiac glycosides (CGs), as a family of naturally compounds, inhibited the NKA activity. The present study investigates the antitumor effect of ouabain and elucidates the pharmacological mechanisms of CG activity in liver cancer HepG2 cell using SILAC coupled to LC–MS/MS method. Bioinformatics analysis of 330 proteins that were changed in cells under treatment with 0.5 μmol/L ouabain showed that the biological processes are associated with an acute inflammatory response, cell cycle, oxidation reduction, chromosome segregation, and DNA metabolism. We confirmed that ouabain induced chromosome segregation disorder and S-cell cycle block by decreasing the expression of AURKA, SMC2, Cyclin D, and p-CDK1 as well as increasing the expression of p53. We found that the overexpression or inhibition of AURKA significantly reduced or enhanced the ouabain-mediated the anticancer effects. Our findings suggest that AURKA is involved in the anticancer mechanisms of ouabain in HepG2 cells

Modified Enzyme-Linked Immunosorbent Assay Strategy Using Graphene Oxide Sheets and Gold Nanoparticles Functionalized with Different Antibody Types

Gold nanoparticles (GNPs) and graphene oxide (GO) sheets are excellent nano carriers in many analytical methods. In this study, a modified enzyme-linked immunosorbent assay (ELISA) strategy was developed using antibody-functionalized GO sheets and GNPs. This modification significantly reduced the limit of detection (LOD) and cost greatly of this assay. The applicability of the method was demonstrated by detecting HSP70 in a human serum sample. This result suggests that the 3G-ELISA method is feasible to detect an antigen in a complex mixture, and the LOD is up to 64-fold and the cost is as low as one-tenth of the conventional ELISA method