APE1/Ref-1 as a Serological Biomarker for the Detection of Bladder Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that shows elevated expression in a number of cancers. We attempted to determine whether serum APE1/Ref-1 is elevated in patients with bladder cancer. MATERIALS AND METHODS: Serum APE1/Ref-1 levels were determined using enzyme-linked immunosorbent assay in serum from patients with bladder cancer who had not received chemotherapy or radiotherapy (n=51) and non-tumor controls (n=55). The area under the receiver operating characteristic area under the curve was applied to determine the correlation between clinical factors and the serum levels of APE1/Ref-1. RESULTS: Serum levels of APE1/Ref-1 in bladder cancer patients were significantly elevated compared to those of the control group (3.548+/-0.333 ng/100 muL [n=51] for bladder cancer vs. 1.547+/-0.319 ng/100 muL [n=55] for the control group), with a sensitivity and specificity of 93% and 59%, respectively. Serum APE1/Ref-1 levels are associated with tumor stage, grade, muscle invasion, and recurrence. CONCLUSION: Serum APE1/Ref-1 might be useful as a potential serologic biomarker for bladder cancer.

Rac1 regulates the release of Weibel-Palade Bodies in human aortic endothelial cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The release of Weibel-Palade Bodies (WPB) is a form of endothelial cell activation. But the signal transduction pathway leading to WPB release is not yet defined. We hypothesized that small G-protein rac1 and reactive oxygen species (ROS) mediate the ligand induced release of Weibel-Palade Bodies.</p><p><b>METHODS</b>We tested this hypothesis by using wild-type and mutant adenoviral rac1 expression vectors, and by manipulating the production and destruction of superoxide and hydrogen peroxide in human aortic endothelial cells (HAEC).</p><p><b>RESULTS</b>Thrombin (1.0 Unit, 30 min) induced the increase of WPB release by 3.7-fold in HAEC, and that H2O2 (0.1 mmol/L, 30 min) induced by 4.5-fold. These results correlated with thrombin-stimulated activation of rac-GTP binding activity by 3.5-fold, and increase of ROS production by 3.4-fold. The dominant negative adenoviral rac-N17 gene transfer dramatically inhibited the release of WPB by 64.2% (control) and 77.3% (thrombin-stimulation), and decreased ROS production by 65.5% (control) and 83.6% (thrombin-stimulation) compared with non-infected cells, respectively. Anti-oxidants, catalase and N-acetyl-cysteine significantly decreased the release of WPB by 34% and 79% in control cells, and further decreased by 63.6% and 46.7% in rac-N17 transferred cells compared with non-infected cells. We also confirmed that rac1 was located upstream of ROS in the WPB release pathway.</p><p><b>CONCLUSIONS</b>Small G-protein rac1 medicates ligand-induced release of Weibel-Palade Bodies in human aortic endothelial cells, and the signal pathway of WPB release is a rac1-dependent ROS regulating mechanism.</p>