title: Mass spectrometric imaging of red fluorescent protein in breast tumor xenografts.
abstract: Mass spectrometric imaging (MSI) in combination with electrospray mass spectrometry (ESI-MS) is a powerful technique for visualization and identification of a variety of different biomolecules directly from thin tissue sections. As commonly used tools for molecular reporting, fluorescent proteins are molecular reporter tools that have enabled the elucidation of a multitude of biological pathways and processes. To combine these two approaches, we have performed targeted MS analysis and MALDI-MSI visualization of a tandem dimer (td)Tomato red fluorescent protein, which was expressed exclusively in the hypoxic regions of a breast tumor xenograft model. For the first time, a fluorescent protein has been visualized by both optical microscopy and MALDI-MSI. Visualization of tdTomato by MALDI-MSI directly from breast tumor tissue sections will allow us to simultaneously detect and subsequently identify novel molecules present in hypoxic regions of the tumor. MS and MALDI-MSI of fluorescent proteins, as exemplified in our study, is useful for studies in which the advantages of MS and MSI will benefit from the combination with molecular approaches that use fluorescent proteins as reporters.
authors.affiliation: Biomolecular Imaging MS group, FOM Institute AMOLF, Amsterdam, The Netherlands.
authors.forename: Kamila
authors.initials: K
authors.lastname: Chughtai
authors.forename: Lu
authors.initials: L
authors.lastname: Jiang
authors.forename: Harm
authors.initials: H
authors.lastname: Post
authors.forename: Paul T
authors.initials: PT
authors.lastname: Winnard
authors.forename: Tiffany R
authors.initials: TR
authors.lastname: Greenwood
authors.forename: Venu
authors.initials: V
authors.lastname: Raman
authors.forename: Zaver M
authors.initials: ZM
authors.lastname: Bhujwalla
authors.forename: Ron M A
authors.initials: RM
authors.lastname: Heeren
authors.forename: Kristine
authors.initials: K
authors.lastname: Glunde
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008164:Luminescent Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D057054:Molecular Imaging / Q000379:methods*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014183:Transplantation, Heterologous; D014357:Trypsin / Q000737:chemistry; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D010446:Peptide Fragments; D014357:Trypsin; D000097573:Red Fluorescent Protein