Visualization of Small Intact Proteins in Breast Cancer FFPE Tissue

• DOI: 10.1007/978-1-0716-3319-9_14
• Publication Date: 2023-07-06T13:02:56Z
• Authors: Marco Giampà; Maria K. Andersen; Sebastian Krossa; Vanna Denti; Andrew Smith; Siver Andreas Moe...
• Keywords: Proteomics; Tissue Fixation; Paraffin Embedding; Breast cancer; FFPE tissue; MALDI MSI; Protein;; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Formaldehyde; Humans; Proteins; Female; Breast Neoplasms

Molecular visualization of metabolites, lipids, and proteins by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is becoming an in-demand analytical approach to aid the histopathological analysis of breast cancer. Particularly, proteins seem to play a role in cancer progression, and specific proteins are currently used in the clinic for staging. Formalin-fixed paraffin-embedded (FFPE) tissues are ideal for correlating the molecular markers with clinical outcomes due to their long-term storage. So far, to obtain proteomic information by MSI from this kind of tissue, antigen retrieval and tryptic digestion steps are required. In this chapter, we present a protocol to spatially detect small proteins in tumor and necrotic regions of patient-derived breast cancer xenograft FFPE tissues without employing any on-tissue digestion. This protocol can be used for other kinds of FFPE tissue following specific optimization of the sample preparation phases.