iTRAQ Identification of Candidate Serum Biomarkers Associated with Metastatic Progression of Human Prostate Cancer

Department of Human Metabolism, The Medical School, The Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom.
PLoS ONE (Impact Factor: 3.23). 02/2012; 7(2):e30885. DOI: 10.1371/journal.pone.0030885
Source: PubMed


A major challenge in the management of patients with prostate cancer is identifying those individuals at risk of developing metastatic disease, as in most cases the disease will remain indolent. We analyzed pooled serum samples from 4 groups of patients (n = 5 samples/group), collected prospectively and actively monitored for a minimum of 5 yrs. Patients groups were (i) histological diagnosis of benign prostatic hyperplasia with no evidence of cancer 'BPH', (ii) localised cancer with no evidence of progression, 'non-progressing' (iii) localised cancer with evidence of biochemical progression, 'progressing', and (iv) bone metastasis at presentation 'metastatic'. Pooled samples were immuno-depleted of the 14 most highly abundant proteins and analysed using a 4-plex iTRAQ approach. Overall 122 proteins were identified and relatively quantified. Comparisons of progressing versus non-progressing groups identified the significant differential expression of 25 proteins (p<0.001). Comparisons of metastatic versus progressing groups identified the significant differential expression of 23 proteins. Mapping the differentially expressed proteins onto the prostate cancer progression pathway revealed the dysregulated expression of individual proteins, pairs of proteins and 'panels' of proteins to be associated with particular stages of disease development and progression. The median immunostaining intensity of eukaryotic translation elongation factor 1 alpha 1 (eEF1A1), one of the candidates identified, was significantly higher in osteoblasts in close proximity to metastatic tumour cells compared with osteoblasts in control bone (p = 0.0353, Mann Whitney U). Our proteomic approach has identified leads for potentially useful serum biomarkers associated with the metastatic progression of prostate cancer. The panels identified, including eEF1A1 warrant further investigation and validation.

Download full-text


Available from: Phillip C Wright
  • Source
    • "With the completion of major genome projects, the focus in biomedical research has shifted from the analysis of the rather static genome to the highly dynamic proteome because biological functions and interactions of proteins are important in tissue development. Among the proteomic technologies used for biomarker identification, iTRAQs has the advantages of being relatively high throughput, and can simultaneously provide information on peptide quantitation and identification [24]. And endometrial biopsy samples can be used to identify molecules associated with uterine receptivity to obtain a better insight into human implantation [21]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: GnRH antagonists can suppress LH and FSH, with less initial stimulatory effect and lower risk of ovarian hyperstimulation syndrome. The effects of GnRH antagonists on embryonic implantation remain controversial. To evaluate the effects of GnRH antagonists, endometrial tissues were biopsied from 12 women with ICSI treatment, in which 4 subjects undergoing controlled ovulation stimulation with rFSH and GnRH antagonist, 4 subjects with a GnRH agonist long protocol, and 4 natural cycle controls. After iTRAQ quantification analysis, 24 proteins showed differential expression between natural cycle and agonist treatment group and 39 proteins between natural cycle and antagonist treatment group. A total of 7 proteins demonstrated differential expression only in antagonist treatment group. Bioinformatic analysis implied these proteins can function in cell processes including angiogenesis, cell proliferation, apoptosis, cell migration, and immune response. Furthermore, GnRH antagonist suppressed the function of GNAS and ANPEP, which were important for endometrial functions. Immunohistochemical staining showed that ANPEP was mainly localized in the human endometrial stroma, while ACO2, CDC5L and GNAS were mainly localized in the glands. This study could provide insights into the effect of GnRH antagonists on the endometrium, and help optimize the embryo implantation and improve the success rate for GnRH antagonist protocol.This article is protected by copyright. All rights reserved
    Full-text · Article · Oct 2014 · Proteomics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite remarkable progress in proteomic methods, including improved detection limits and sensitivity, these methods have not yet been established in routine clinical practice. The main limitations, which prevent their integration into clinics are high cost of equipment, the need for highly-trained personnel, and last, but not least, the establishment of reliable and accurate protein biomarkers or panels of protein biomarkers for detection of neoplasms. Furthermore, the complexity and heterogeneity of most solid tumours present obstacles in the discovery of specific protein signatures, which could be used for early detection of cancers, for prediction of disease outcome, and for determining the response to specific therapies. However, cancer proteome, as the end-point of pathological processes that underlie cancer development and progression, could represent an important source for the discovery of new biomarkers and molecular targets for tailored therapies.
    Full-text · Article · Jan 2013 · The Scientific World Journal
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Accurate diagnosis and proper monitoring of cancer patients remain a key obstacle for successful cancer treatment and prevention. Therein comes the need for biomarker discovery, which is crucial to the current oncological and other clinical practices having the potential to impact the diagnosis and prognosis. In fact, most of the biomarkers have been discovered utilizing the proteomics-based approaches. Although high-throughput mass spectrometry-based proteomic approaches like SILAC, 2D-DIGE, and iTRAQ are filling up the pitfalls of the conventional techniques, still serum proteomics importunately poses hurdle in overcoming a wide range of protein concentrations, and also the availability of patient tissue samples is a limitation for the biomarker discovery. Thus, researchers have looked for alternatives, and profiling of candidate biomarkers through tissue culture of tumor cell lines comes up as a promising option. It is a rich source of tumor cell-derived proteins, thereby, representing a wide array of potential biomarkers. Interestingly, most of the clinical biomarkers in use today (CA 125, CA 15.3, CA 19.9, and PSA) were discovered through tissue culture-based system and tissue extracts. This paper tries to emphasize the tissue culture-based discovery of candidate biomarkers through various mass spectrometry-based proteomic approaches.
    Full-text · Article · Mar 2013
Show more