Prostasomes are secreted from poorly differentiated cells of prostate cancer metastases.
BACKGROUND
Prostasomes are small (40-500 nm), granule-like bodies, found in normal epithelial cells of the prostate and secreted into the prostate duct system. Also poorly differentiated prostate cancer cells are producing prostasomes, since we could isolate and purify prostasomes from vertebral metastases with biochemical methods. To find out whether these prostasomes are secreted into extracellular sites of the metastases, we used electron microscopy.


METHODS
Small biopsies from vertebral metastases of prostate cancer, taken directly from the operating field at surgery, were immediately fixated, embedded in plastic and processed for electron microscopy.


RESULTS
We found that prostasomes could be identified extracellularly in the interstitial tissues as well as in the cytoplasm of the metastatic cells.


CONCLUSIONS
We conclude that prostasomes produced by the cells of vertebral metastases of prostate cancer are distributed both intracellularly and extracellularly in the interstitial spaces of the tissue. Thus, prostasomes of metastases could perhaps be exploited as targets for immunodiagnosis and/or immunotherapy.
Sahlén
Göran
G
Department of Urology, University Hospital, Uppsala, Sweden.
Ahlander
Anders
A
Frost
Anders
A
Ronquist
Gunnar
G
Norlén
Bo Johan
BJ
Nilsson
B Ove
BO
D001706:Biopsy; D002454:Cell Differentiation; D003546:Cysteine Endopeptidases / Q000378:metabolism* / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D022162:Cytoplasmic Vesicles / Q000648:ultrastructure; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009097:Multienzyme Complexes / Q000378:metabolism* / Q000648:ultrastructure; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000556:secondary* / Q000648:ultrastructure; D046988:Proteasome Endopeptidase Complex
D009097:Multienzyme Complexes; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex