Ricin Toxicity in BALB/C 3T3 Cells: Correlation of Total Proteins with Dose Level by Mass Spectrometry and Proteomics

摘要

This report is required for the U.S. Army Edgewood Chemical Biological Center In-House Laboratory Independent Research project 'Cell Toxicity by NMR and Mass Spectrometry.' NMR and/or mass spectrometry (MS) in combination with chemometrics analysis can yield physiological details in the form of metabolome or proteome biomarker information, but model-building with IC5o/ED50 values obtained from traditional cytotoxicity assays has been required to correlate biomarker concentration with toxicity S.V. Vulimiri, et al., Chem. Res. Toxicol. 2009, 22, 492; E.M. Lenz, et al., J. Pharm. Biomed. Anal. 2004, 35, 599. We have analyzed cellular protein extracts from BALB/c 3T3 murine fibroblasts dosed with three ricin concentrations. Using a new method whereby no adjustment is made for cell concentration as toxin dose increases, we show that the average number of cellular extract proteins identified by MS and the calculated percent inhibition are each related logarithmically, but in an inverse manner, to ricin concentration. In addition, the average number of proteins identified by MS is related linearly to the calculated percent inhibition. These results indicate that, if at least eight ricin concentrations are included as is done for typical dye-based toxicity assays, toxicity could be determined and effective dose values obtained directly from LC-MS/MS data.