Histone post-translational modifications (hPTMs) contribute to the regulation of gene expression and increasing evidence links them to the development of various pathologies, highlighting their potential as biomarkers for prognostic, diagnostic and therapeutic applications. Mass spectrometry (MS) has emerged as a powerful analytical tool for hPTM analysis, which has also been applied to the analysis of epigenetic aberrations in diseases. However, the potential offered by the MS-based hPTM analysis of clinical samples for epigenetic biomarker discovery has been left largely unexploited. This article summarizes the contribution of MS-based approaches to clinical epigenetics, with a special focus on the PAThology tissue analysis of Histones by Mass Spectrometry (PAT-H-MS) approach--which represents the first application of MS-based hPTM analysis to formalin-fixed paraffin-embedded clinical samples--discussing its strengths and limitations, as well as possible implementations.
Keywords: Biomarker; PAT-H-MS; breast cancer; epigenetics; formalin-fixed paraffin-embedded tissues; histone post-translational modifications; mass spectrometry; proteomics.