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Selective expression of CD44, a putative prostate cancer stem cell marker, in neuroendocrine tumor cells of human prostate cancer
Author(s) -
Palapattu Ganesh S.,
Wu Chengyu,
Silvers Christopher R.,
Martin Heather B.,
Williams Karin,
Salamone Linda,
Bushnell Timothy,
Huang LiShan,
Yang Qi,
Huang Jiaoti
Publication year - 2009
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.20928
Subject(s) - prostate , cd44 , prostate cancer , cancer , pca3 , medicine , cancer stem cell , pathology , cancer research , oncology , biology , cell , genetics
BACKGROUND Hormonal therapy is effective for advanced prostate cancer (PC) but the disease often recurs and becomes hormone‐refractory. It is hypothesized that a subpopulation of cancer cells, that is, cancer stem cells (CSCs), survives hormonal therapy and leads to tumor recurrence. CD44 expression was shown to identify tumor cells with CSC features. PC contains secretory type epithelial cells and a minor population of neuroendocrine cells. Neuroendocrine cells do not express androgen receptor and are quiescent, features associated with CSCs. The purpose of the study was to determine the expression of CD44 in human PC and its relationship to neuroendocrine tumor cells. METHODS Immunohistochemistry and immunofluorescence were performed to study CD44 expression in PC cell lines, single cells from fresh PC tissue and archival tissue sections of PC. We then determined if CD44+ cells represent neuroendocrine tumor cells. RESULTS In human PC cell lines, expression of CD44 is associated with cells of NE phenotype. In human PC tissues, NE tumor cells are virtually all positive for CD44 and CD44+ cells, excluding lymphocytes, are all NE tumor cells. CONCLUSIONS Selective expression of the stem cell‐associated marker CD44 in NE tumor cells of PC, in combination with their other known features, further supports the significance of such cells in therapy resistance and tumor recurrence. Prostate 69: 787–798, 2009. © 2009 Wiley‐Liss, Inc.