The specific molecular profiles of
ovarian cancer interface zones (IZ), the region between
tumors and normal tissues, were evaluated using a new method involving matrix-assisted
laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS). We analyzed three ovarian serous
carcinomas using MALDI-IMS. Principal component analysis (PCA) was used to evaluate the quality of tissue spatial features based on MALDI-IMS, and for analysis of large data sets of MALDI-IMS. Two-dimensional gel electrophoresis and fluorescence microscopy were used to verify interface-specific
proteins. Unique profiles were identified for the
tumors, the normal zone, and the IZ. Through MALDI analysis, two interface-specific
proteins,
plastin 2 and
peroxiredoxin 1 (PRDX 1), were identified as differentially regulated between zones. Fluorescence microscopy revealed high expression levels of
plastin 2 and PRDX 1 along the IZ of ovarian
tumors. This comparative proteomics study using tissue MALDI-IMS suggested that the IZ is different from the adjacent
tumor and normal zones, and that
plastin 2 and PRDX 1 may be interface markers specific to ovarian
tumors.