title: Proteomic characterization of the interstitial fluid perfusing the breast tumor microenvironment: a novel resource for biomarker and therapeutic target discovery.
abstract: Clinical cancer proteomics aims at the identification of markers for early detection and predictive purposes, as well as to provide novel targets for drug discovery and therapeutic intervention. Proteomics-based analysis of traditional sources of biomarkers, such as serum, plasma, or tissue lyzates, has resulted in a wealth of information and the finding of several potential tumor biomarkers. However, many of these markers have shown limited usefulness in a clinical setting, underscoring the need for new clinically relevant sources. Here we present a novel and highly promising source of biomarkers, the tumor interstitial fluid (TIF) that perfuses the breast tumor microenvironment. We collected TIFs from small pieces of freshly dissected invasive breast carcinomas and analyzed them by two-dimensional polyacrylamide gel electrophoresis in combination with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, Western immunoblotting, as well as by cytokine-specific antibody arrays. This approach provided for the first time a snapshot of the protein components of the TIF, which we show consists of more than one thousand proteins--either secreted, shed by membrane vesicles, or externalized due to cell death--produced by the complex network of cell types that make up the tumor microenvironment. So far, we have identified 267 primary translation products including, but not limited to, proteins involved in cell proliferation, invasion, angiogenesis, metastasis, inflammation, protein synthesis, energy metabolism, oxidative stress, the actin cytoskeleton assembly, protein folding, and transport. As expected, the TIF contained several classical serum proteins. Considering that the protein composition of the TIF reflects the physiological and pathological state of the tissue, it should provide a new and potentially rich resource for diagnostic biomarker discovery and for identifying more selective targets for therapeutic intervention.
authors.affiliation: Danish Centre for Translational Breast Cancer Research, and Department of Proteomics in Cancer, Institute of Cancer Biology, The Danish Cancer Society, DK-2100 Copenhagen, Denmark. jec@cancer.dk
authors.forename: Julio E
authors.initials: JE
authors.lastname: Celis
authors.forename: Pavel
authors.initials: P
authors.lastname: Gromov
authors.forename: Teresa
authors.initials: T
authors.lastname: Cabezón
authors.forename: José M A
authors.initials: JM
authors.lastname: Moreira
authors.forename: Noona
authors.initials: N
authors.lastname: Ambartsumian
authors.forename: Kerstin
authors.initials: K
authors.lastname: Sandelin
authors.forename: Fritz
authors.initials: F
authors.lastname: Rank
authors.forename: Irina
authors.initials: I
authors.lastname: Gromova
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000737:chemistry* / Q000175:diagnosis* / Q000628:therapy; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D045604:Extracellular Fluid / Q000737:chemistry*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D010477:Perfusion; D020543:Proteome; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D010446:Peptide Fragments; D020543:Proteome