Podium Presentation in Room 5 on Wednesday at 9:00 (Chair: Stephen Pennington)
Authors: Weston R Spivia (1), (1) Angela McArdle, (1) Justyna Fert-Bober, (3) Harvey Pass, (2) Haining Yang, (2) Michele Carbone, Jennifer Van Eyk
Introduction: Malignant mesothelioma (MM) is an aggressive cancer associated with exposure to asbestos and other carcinogenic mineral fibers. Recently it has been reported that High Mobility Group Box 1 (HMGB1), a damage-associated molecular pattern protein, contributes to MM. HMGB1 cellular localization and its secretion is regulated by acetylation of lysine residues located within its two nuclear localization signals sequences. Non-acetylated HMGB1 is primarily localized in the nucleus, where it binds to chromatin and stabilizes nucleosomes and alters gene transcription. Hyper-acetylated HMGB1 is sequestered into the cytoplasm followed by active secretion into the extra-cellular space where can act as a paracrine/autocrine factor.
Objective: The primary objective of this study was to discriminate MM from other non-MM cancers based on the amount of the hyper-acetylated HMGB1 secreted by MM cells in serum and pleural effusion samples.
Methods: The reliable measurement and quantification of hyper-acetylated HMGB1 in serum is technologically formidable. Potential technical restrictions are the small molecular weight of HMGB1, high basic charge, and prospective post-translational modifications. To overcome the limitation we developed a targeted MS-based method, parallel reaction monitoring (PRM), to quantify unmodified, partially acetylated, and hyper-acetylated HMGB1 in patient serum and matched pleural effusion samples.
Results: Serum and pleural effusion samples from 52 individuals diagnosed with MM or non-MM lung cancer were analyzed by a PRM-MS method. The concentration of total and hyper-acetylated HMGB1 in serum and pleural effusion samples were quantified using internal standard peptides. Lower limit of detection, lower limit of quantification as well as Intra- and interday precision were calculated for all samples based on the calibration curves. Informative patterns of fully and partially hyper-acetylated proteoforms of HMGB1 between the two nuclear translocation signals were observed in the pleural effusion samples but not in serum samples.
Conclusion: Our method can discriminate MM from non-MM patients with high sensitivity, specificity and accuracy based on the different proteoforms of hyper-acetylated HMGB1.
|Planning to mention or discuss specific products or technology of the company(ies) listed above:||