SRM/MRM assay for the tubulin beta-3 chain (TUBB3) protein

摘要

The current disclosure provides for a specific peptide, and derived ionization characteristics of a peptide from the tubulin beta-3 chain protein (TUBB3) that is particularly advantageous for quantifying the TUBB3 protein directly in biological samples that have been fixed in formalin by the method of Selected Reaction Monitoring (SRM) mass spectrometry. A protein sample is prepared from a biological sample using the Liquid Tissue reagents and protocol and the TUBB3 protein is quantitated by SRM/MRM mass spectrometry analysis of the sample, where the specific peptide is quantitated. Methods of treatment are provided in which the measured level of TUBB3 in a patient tumor sample is compared with a reference level and the patient is treated with a taxane-based treatment regimen when the measured TUBB3 level is lower than the reference level. A suitable reference level is, for example, about 700 amol/μg tissue.