[HTML][HTML] Proteomic profiling of exosomes leads to the identification of novel biomarkers for prostate cancer
D Duijvesz, KE Burnum-Johnson, MA Gritsenko… - PloS one, 2013 - journals.plos.org
D Duijvesz, KE Burnum-Johnson, MA Gritsenko, AM Hoogland…
PloS one, 2013•journals.plos.orgBackground Current markers for prostate cancer, such as PSA lack specificity. Therefore,
novel biomarkers are needed. Unfortunately, the complexity of body fluids often hampers
biomarker discovery. An attractive alternative approach is the isolation of small vesicles, ie
exosomes,∼ 100 nm, which contain proteins that are specific to the tissue from which they
are derived and therefore can be considered as treasure chests for disease-specific
biomarker discovery. Materials and Methods Exosomes were isolated from 2 immortalized …
novel biomarkers are needed. Unfortunately, the complexity of body fluids often hampers
biomarker discovery. An attractive alternative approach is the isolation of small vesicles, ie
exosomes,∼ 100 nm, which contain proteins that are specific to the tissue from which they
are derived and therefore can be considered as treasure chests for disease-specific
biomarker discovery. Materials and Methods Exosomes were isolated from 2 immortalized …
Background
Current markers for prostate cancer, such as PSA lack specificity. Therefore, novel biomarkers are needed. Unfortunately, the complexity of body fluids often hampers biomarker discovery. An attractive alternative approach is the isolation of small vesicles, i.e. exosomes, ∼100 nm, which contain proteins that are specific to the tissue from which they are derived and therefore can be considered as treasure chests for disease-specific biomarker discovery.
Materials and Methods
Exosomes were isolated from 2 immortalized primary prostate epithelial cells (PNT2C2 and RWPE-1) and 2 PCa cell lines (PC346C and VCaP) by ultracentrifugation. After tryptic digestion, proteomic analyses utilized a nanoLC coupled with an LTQ-Orbitrap operated in tandem MS (MS/MS) mode. Accurate Mass and Time (AMT) tag approach was employed for peptide identification and quantitation. Candidate biomarkers were validated by Western blotting and Immunohistochemistry.
Results
Proteomic characterization resulted in the identification of 248, 233, 169, and 216 proteins by at least 2 peptides in exosomes from PNT2C2, RWPE-1, PC346C, and VCaP, respectively. Statistical analyses revealed 52 proteins differently abundant between PCa and control cells, 9 of which were more abundant in PCa. Validation by Western blotting confirmed a higher abundance of FASN, XPO1 and PDCD6IP (ALIX) in PCa exosomes.
Conclusions
Identification of exosomal proteins using high performance LC-FTMS resulted in the discovery of PDCD6IP, FASN, XPO1 and ENO1 as new candidate biomarkers for prostate cancer.
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