Imaging mass spectrometry to distinguish hepatocellular carcinoma from normal liver tissues. MALDI Imaging-Massenspektrometrie zur Differenzierung von HCC und normalem Lebergewebe

Aim: Recent advances in radiographic imaging allow the detection of smaller liver lesions. However, the distinction of benign lesions from well differentiated hepatocellular carcinoma (HCC) remains a challenge. In order to characterize the molecular peptide pattern of hepatocellular carcinoma, MALDI imaging mass spectrometry had been performed. Method: Fourteen HCC and eleven normal liver biopsies from different patients were included in our study. All samples were subjected to trypsin and matrix deposition using the ImagePrep device (Bruker, Bremen), and were subsequently analyzed by MALDI IMS using a Bruker Autoflex Speed mass spectrometer. Mass spectra profiles were extracted from tissue samples, and two sample groups including HCC and benign liver were then created and subjected to spectral and statistical analysis using ClinProTools 3.0 software. Peak selection was evaluated through statistical comparison (Wilcoxon/Kruskal-Wallis test). Results: Statistical comparison revealed a nearly 2-fold change alteration of eleven m/z signals (551, 582, 617, 632, 710, 829, 1314, 1483, 1607, 1705, 1706) in the benign liver tissue and a 2-fold change of three m/z signals ( 660, 944, 1325) in the HCC patients on the basis of p<0.05 and with a 99.9 confidence level. Conclusion: Our results indicate that MALDI Imaging mass spectrometry can be a useful ancillary technique for the differentiation of HCC from normal liver tissue. Further studies will involve a larger number of cases in order to provide greater statistical power and to build a classification model that can differentiate HCC from benign lesions.