Lung cancer is the leading cause of all cancer related deaths with a worldwide mortality of 1.2 million each year. The 5-year survival rate ranges from 80% in early stages to a dismal 5% in advanced disease. Prognosis is currently mostly determined based on the extension of disease at diagnosis. Thereby it has become evident that predicted and real outcomes can vary significantly, even for patients with the same stage of disease. Novel biomarkers with a reliable predictive significance are therefore clearly needed. In this study we implemented an activity-based, solely mass spectrometry dependent biomarker discovery platform. We investigated the role of serine hydrolase activities as potential biomarkers for human lung adenocarcinoma, the most common lung cancer subtype. Forty pairs of fresh frozen malignant and matching non-neoplastic lung tissues were analyzed and enzymatic activities linked to clinical follow-up data. We found that the activities of Abhydrolase domain-containing protein 11 and Esterase D predict the development of distant metastases and the presence of aggressive lung adenocarcinomas, respectively, in a statistically significant model. We conclude that serine hydrolase activities bear a predictive potential for human lung adenocarcinoma and that activity-based proteomics represents a powerful methodology in the search for novel disease biomarkers.
UNLABELLED: CD26/Dipeptidyl peptidase (DPP) IV is an integral membrane protein of lymphocytes that modulates the activities of chemokines, interleukins, and neuropeptides. We investigated the effect of enzymatic DPP IV inhibition on ischemia/reperfusion injury after extended ischemia prior to transplantation. MATERIALS AND METHODS: We used a syngeneic rat (Lewis) orthotopic left lung transplantation model. In the control group (group I), donor lungs were flushed and preserved in Perfadex for 18 hours at 4 degrees C, then transplanted and reperfused for 2 hours. Group II donor lungs were perfused with and stored in Perfadex +25mol/L AB192 (bis(4-acetamidophenyl) 1-(S)-prolylpyrrolidine-2(R,S)-phosphonate), a small molecular weight DPP IV inhibitor. After 2-hour reperfusion, we measured blood gas, peak airway pressure, and thiobarbituric acid reactive substances. RESULTS: Grafts from group II versus group I showed a significantly increased oxygenation capacity (II: 298.4 +/- 87.6 mm Hg vs 120.9 +/- 48.0, P < .01), lower peak airway pressure (11.8 +/- 0.9 mm Hg vs 16.0 +/- 1.4, P < .01), and less lipid peroxidation (9.3 +/- 2.0 micromol/L vs 13.8 +/- 1.8, P < .01). CONCLUSION: Inhibition of intragraft DPP IV enzymatic activity significantly reduced ischemia/reperfusion-associated pulmonary injury, allowing for successful transplantation after 18 hours of ischemia.
