Differential exoprotease activities confer tumor-specific serum peptidome patterns

Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Journal of Clinical Investigation (Impact Factor: 13.77). 02/2006; 116(1):271-84. DOI: 10.1172/JCI26022
Source: PubMed

ABSTRACT Recent studies have established distinctive serum polypeptide patterns through mass spectrometry (MS) that reportedly correlate with clinically relevant outcomes. Wider acceptance of these signatures as valid biomarkers for disease may follow sequence characterization of the components and elucidation of the mechanisms by which they are generated. Using a highly optimized peptide extraction and matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) MS-based approach, we now show that a limited subset of serum peptides (a signature) provides accurate class discrimination between patients with 3 types of solid tumors and controls without cancer. Targeted sequence identification of 61 signature peptides revealed that they fall into several tight clusters and that most are generated by exopeptidase activities that confer cancer type-specific differences superimposed on the proteolytic events of the ex vivo coagulation and complement degradation pathways. This small but robust set of marker peptides then enabled highly accurate class prediction for an external validation set of prostate cancer samples. In sum, this study provides a direct link between peptide marker profiles of disease and differential protease activity, and the patterns we describe may have clinical utility as surrogate markers for detection and classification of cancer. Our findings also have important implications for future peptide biomarker discovery efforts.

Download full-text


Available from: Josep Villanueva, Jul 31, 2015
  • Source
    • "Many current diagnostic tests depend on individual aspects of fractionated blood components: plasma, red blood cells (RBCs), WBCs and platelets. Clean, cell-free plasma is necessary for early cancer detection via blood-borne cancer biomarkers (Bunn 1997, Li et al 2002, Villanueva et al 2006). Leukocytes are required for several hematological tests as well as for DNA sequencing. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Magnetic sorting using magnetic beads has become a routine methodology for the separation of key cell populations from biological suspensions. Due to the inherent ability of magnets to provide forces at a distance, magnetic cell manipulation is now a standardized process step in numerous processes in tissue engineering, medicine, and in fundamental biological research. Herein we review the current status of magnetic particles to enable isolation and separation of cells, with a strong focus on the fundamental governing physical phenomena, properties and syntheses of magnetic particles and on current applications of magnet-based cell separation in laboratory and clinical settings. We highlight the contribution of cell separation to biomedical research and medicine and detail modern cell-separation methods (both magnetic and non-magnetic). In addition to a review of the current state-of-the-art in magnet-based cell sorting, we discuss current challenges and available opportunities for further research, development and commercialization of magnetic particle-based cell-separation systems.
    Reports on Progress in Physics 12/2014; 78(1):016601. DOI:10.1088/0034-4885/78/1/016601 · 15.63 Impact Factor
  • Source
    • "Examples of proteolytic activities have been observed in past onco-peptidomic studies [15] [16] [17], whereby subsets of serum peptides provided class discrimination between patients with different types of solid tumors and control individuals without cancer [16]. Nearly all relevant peptides sorted into a dozen or so nested sets of sequences, each the result of exopeptidase activities that confer cancerspecific differences superimposed on the proteolytic events of the ex vivo coagulation and complement degradation pathways [16]. In addition, proteomic screens of cultured cancer cells indicated sizable panels of secreted proteases and protease inhibitors [18] [19] [20]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Proteases have been implicated in cancer progression and invasiveness. We have investigated the activities, as opposed to simple protein levels, of selected aminopeptidases in urine specimens to serve as potential novel biomarkers for urothelial cancer. The unique urinary proteomes of males and females were profiled to establish the presence of a gender-independent set of aminopeptidases. Samples were also collected from patients with urothelial cancer and matched controls. A SOP for urine processing was developed taking into account hydration variation. Five specific aminopeptidase activity assays, using fluorophoric substrates, were optimized for evaluation of marker potential. Nineteen exopeptidases and 21 other proteases were identified in urine and the top-5 most abundant aminopeptidases, identical in both genders, selected for functional studies. Depending on the enzyme, activities were consistently lower (P ≤0.05), higher or unchanged in the cancer samples as compared to controls. Two selected aminopeptidase activities used as a binary classifier resulted in a ROC curve with an AUC = 0.898. We have developed functional assays that characterize aminopeptidase activities in urine specimens with adequate technical and intra-individual reproducibility. With further testing, it could yield a reliable biomarker test for bladder cancer detection or prognostication. This article is protected by copyright. All rights reserved.
    PROTEOMICS - CLINICAL APPLICATIONS 06/2014; 8(5-6). DOI:10.1002/prca.201300118 · 2.68 Impact Factor
  • Source
    • "In metastatic thyroid carcinoma [36] 12-peptide thyroid cancer signature was obtained with respect to control samples. Ten of them had been previously assigned to other tumors [40], while one of the two newly identified peptides is a 54-amino acidlong fibrinogen-α fragment. "
    01/2014; 1(1). DOI:10.2478/ped-2014-0005
Show more