Imaging mass spectrometry using chemical inkjet printingreveals differential protein expression in human oralsquamous cell carcinoma

摘要

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a recentlydeveloped technique that generates molecular profiles usually of peptide and protein signals directlyfrom the surface of thin tissue sections and can be coupled with automation to generate two-dimensional ion density maps. This allows specific information to be obtained on the relativeabundance and spatial distribution of the analytes of interest. The technique has potential forapplication in many diseases including cancer with respect to elucidating the molecular pathology andidentifying potential biomarkers. In this proof-of-principle study we have evaluated inkjet printing ofthe sinapinic acid matrix used for MALDI-IMS directly onto the surface of human oral squamous cellcarcinoma biopsy specimens. This MS profiling technique produced reproducible informative chemicalimages for clinical pathology. Analysis of the resulting protein profiles of highly expressed protein insquamous cell carcinoma of the tongue reveals spectral features at 4500 and 8360 Da.