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Malignant cell‐derived extracellular vesicles express different chromogranin epitopes compared to prostasomes
Author(s) -
Dubois Louise,
Stridsberg Mats,
Kharaziha Pedram,
Chioureas Dimitris,
Meersman Niels,
Panaretakis Theocharis,
Ronquist K. Göran
Publication year - 2015
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.22990
Subject(s) - chromogranin a , extracellular vesicles , vesicle , microvesicles , extracellular , epitope , cell , microbiology and biotechnology , chemistry , medicine , pathology , biology , antigen , immunology , biochemistry , immunohistochemistry , microrna , membrane , gene
BACKGROUND Prostasomes are nanosized extracellular vesicles exocytosed by prostate epithelial cells. They have been assigned many roles propitious to sperm in favor of fertilization. Prostatic cancer cells can also produce and secrete extracellular vesicles. METHODS We assessed using ELISA, the surface expression of chromogranin proproteins on prostasomes and malignant extracellular vesicles of four different prostate cancer cell‐lines, two hormone sensitive and two hormone refractory. We used a panel of chromogranin A and chromogranin B antibodies against peptides in‐between hypothetical cleavage sites along the proproteins. RESULTS A diverging pattern of chromogranin peptides was apparent when comparing prostasomes and malignant extracellular vesicles indicating a phenotypical change. We also compared western blot patterns (prostasomes and malignant extracellular vesicles) for selected antibodies that displayed high absorbances in the ELISA. Western blot analyses revealed various cleavage patterns of those proproteins that were analyzed in prostasomes and extracellular vesicles. CONCLUSION Chromogranins are constituents of not only prostasomes but also of malignant prostate cell‐derived extracellular vesicles with different amino acid sequences exposed at the membrane surface giving rise to a mosaic pattern. These findings may be of relevance for designing new assays for detection or even possible treatment of prostate cancers. Prostate 75:1063–1073, 2015 . © 2015 Wiley Periodicals, Inc.