Attempted Validation of Surface Enhanced Laser Desorption Ionization-Time of Flight Derived Kinesin Biomarkers in Malignant Mesothelioma

Abstract

Surface-enhanced Laser Desorption/Ionization Time-of-flight (SELDI-TOF) mass spectrometry allows researchers to search proteomes for biomarkers of disease. Validating SELDI-TOF results using traditional methodologies has yielded mixed results. Real-time PCR, ELISA and Western blot assays were utilized in an attempt to confirm the link between asbestos related cancers and kinesin family proteins, KIF5A and KIF18A. These proteins had been identified using SELDI-TOF and Classification and Regression Tree Analysis (CART) in serum of patients with asbestos related cancers. When well-characterized asbestos fibers were used to challenge mesothelial cell lines, mixed results in KIF5A and KIF18A RNA expression were observed. Western blot analysis comparing protein levels in mesothelioma cell lines versus transformed mesothelial cells yielded inconclusive results, as did Western blot analyses of human mesothelioma and non-cancerous peritoneum that had been obtained from the same patients. These results suggest that kinesin family proteins detected by SELDI-TOF CART are unlikely to be of use as biomarkers for malignant mesothelioma.