Expression of Progenitor Cell Markers in Proliferating Basal Cells of Human Prostatic Explant Cultures (original) (raw)
Related papers
Prostate, 2009
BACKGROUNDAccording to the cancer stem cell hypothesis, tumor growth is sustained by a subpopulation of cancer stem/progenitor-like cells. Self-renewal and high clonogenic potential are characteristics shared by normal stem and neoplastic stem/progenitor-like cells. We investigated whether human prostate cancer specimens contain cells with these properties.According to the cancer stem cell hypothesis, tumor growth is sustained by a subpopulation of cancer stem/progenitor-like cells. Self-renewal and high clonogenic potential are characteristics shared by normal stem and neoplastic stem/progenitor-like cells. We investigated whether human prostate cancer specimens contain cells with these properties.METHODSSelf-renewal and clonogenic potential were assessed by serial passaging of spheres and colony formation, respectively. Gene expression was analyzed by real time PCR. Protein expression was detected by immunocytochemistry. The neoplastic nature of the cells was verified by detection of the TMPRSS2/ERG gene fusion expression.Self-renewal and clonogenic potential were assessed by serial passaging of spheres and colony formation, respectively. Gene expression was analyzed by real time PCR. Protein expression was detected by immunocytochemistry. The neoplastic nature of the cells was verified by detection of the TMPRSS2/ERG gene fusion expression.RESULTSThe epithelial fraction isolated from surgical specimens generated colonies in 68% (19/28) of the patients. Laminin adhesion selected for cells with high clonogenic potential. The epithelial fraction from 85% (42/49) of the patients generated primary prostaspheres. Serial passaging of prostaspheres demonstrated their self-renewal capacity, which is also supported by their expression of the stem cell markers Oct-4, Nanog, Bmi-1, and Jagged-1 mRNA. Cells derived from prostaspheres were more clonogenic than the parental epithelial fraction. The pattern of mRNA expression in prostaspheres resembled that of the basal compartment of the prostate (CK5+/CK14+/CK19high/CK18−/low/c-met+/AR−/low/PSA−/low), but also included stem cell markers (CD49b+/CD49f+/CD44+/ΔNp63+/Nestin+/CD133+). The distribution of marker expression in prostaspheres suggests their heterogeneous cell composition. Prostaspheres expressed significantly higher PSCA mRNA levels than the epithelial fraction.The epithelial fraction isolated from surgical specimens generated colonies in 68% (19/28) of the patients. Laminin adhesion selected for cells with high clonogenic potential. The epithelial fraction from 85% (42/49) of the patients generated primary prostaspheres. Serial passaging of prostaspheres demonstrated their self-renewal capacity, which is also supported by their expression of the stem cell markers Oct-4, Nanog, Bmi-1, and Jagged-1 mRNA. Cells derived from prostaspheres were more clonogenic than the parental epithelial fraction. The pattern of mRNA expression in prostaspheres resembled that of the basal compartment of the prostate (CK5+/CK14+/CK19high/CK18−/low/c-met+/AR−/low/PSA−/low), but also included stem cell markers (CD49b+/CD49f+/CD44+/ΔNp63+/Nestin+/CD133+). The distribution of marker expression in prostaspheres suggests their heterogeneous cell composition. Prostaspheres expressed significantly higher PSCA mRNA levels than the epithelial fraction.CONCLUSIONHuman prostate cancer specimens contain neoplastic cells with self-renewal and clonogenic potential, which can be enriched and perpetuated in prostaspheres. Prostaspheres should prove valuable for the identification of prostate cancer stem/progenitor-like cells. Prostate 69: 1683–1693, 2009. © 2009 Wiley-Liss, Inc.Human prostate cancer specimens contain neoplastic cells with self-renewal and clonogenic potential, which can be enriched and perpetuated in prostaspheres. Prostaspheres should prove valuable for the identification of prostate cancer stem/progenitor-like cells. Prostate 69: 1683–1693, 2009. © 2009 Wiley-Liss, Inc.
European Urology, 2008
e u r o p e a n u r o l o g y 5 3 ( 2 0 0 8 ) 5 2 4 -5 3 2 a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e u r o p e a n u r o l o g y . c o m Abstract Objectives: Questions regarding the cell source and mechanisms in the initiation and progression of prostate cancer are today still open for debate. Indeed, our knowledge regarding prostate cell regulation, self-renewal, and cytodifferentiation is presently rather limited. In this study, we investigated these processes in the normal adult human prostate. Methods: Dynamic expression patterns in prostate stem/progenitor cells, intermediate/transit-amplifying cells, and cell lineages were immunohistochemically identified in an in situ explant renewal model of the human normal/benign adult prostate (n = 6). Results: Cells with a basal phenotype proliferated significantly in explant cultures, whereas luminal cells went into apoptosis. Results further show down-regulation in tissue cultures of the basal and hypothetical stem cell marker Bcl-2 in the majority of cells, except in rare putative epithelial stem cells. Investigation of established (AC133) and novel candidate prostate stem/progenitor markers, including the cell surface receptor tyrosine kinase KIT and its ligand stem cell factor (SCF), showed that these rare epithelial cells are AC133 + /CD133 low /Bcl-2 high /cytokeratin + /vimentin À /KIT low /SCF low . In addition, we report on a stromal population that expresses the mesenchymal marker vimentin and that is AC133 À /CD133 high /Bcl-2 À /cytokeratin À /KIT high /SCF high . Conclusions: We provide evidence for epithelial renewal in response to tissue culture and for basal and epithelial stem/progenitor cell recruitment leading to an expansion of an intermediate luminal precursor phenotype. Data further suggest that SCF regulates prostate epithelial stem/progenitor cells in an autocrine manner and that all or a subset of the identified novel stromal phenotype represents prostate stromal progenitor cells or interstitial pacemaker cells or both.
Cellular and molecular biology of the prostate: stem cell biology
Urology, 2003
The normal prostate shows a high degree of cellular organization. The basal layer is populated by prostate epithelial stem cells and a population of transiently proliferating/amplifying (TP/A) cells intermediate to the stem cells and fully differentiated cells. The luminal layer is composed of fully differentiated prostate epithelial cells. Neuroendocrine cells are scattered throughout the gland. This organization is also seen in prostate cancer, where the tumor cell origin (cancer stem cells) can be traced to a normal cell type by characteristic keratin expression patterns. Basal cells showed strong expression of K-[keratin]5, but they were only weakly positive for K18. Luminal cells strongly expressed K18. A subpopulation of basal cells coexpressed K5 and K14. These keratin expression patterns changed with the degree of cell differentiation as well as location. The least differentiated stem cells in the basal layer were positive for K5 and K14, with weak expression for K18. Intermediate stages of differentiation were identified by expression of K5 and K18. Neuroendocrine cells also expressed K5 as well as typical neuroendocrine cell markers (eg, chromogranin A). Evidence supporting the hypothesis that prostate cancer arises from malignant transformation of intermediate stem cells included the presence in prostate cancers of keratin patterns associated with the intermediate stages of differentiation, androgen independence of both prostate cancers and intermediate stem cells, and expression of c-met by both the TP/A intermediate stem cells and tumor cells.
Novel method for the isolation and characterisation of the putative prostatic stem cell
Cytometry. Part A : the journal of the International Society for Analytical Cytology, 2003
Prostate stem cells, responsible for the development, maturation, and function of the prostate, have been implicated in the aetiology of both benign prostate hyperplasia (BPH) and prostate cancer (CaP). However, research has been hampered by the lack of a definitive stem cell marker. We have adapted the protocol for differential Hoechst 33342 uptake by hemopoietic stem cells to enable isolation of putative stem cells from the prostate. Prostate epithelial cells isolated from prostate tissue obtained from patients with BPH after transurethral resection of the prostate were stained with Hoechst 33342. The Hoechst 33342 Red/Blue flow cytometry profile was then determined. Hoechst 33342 and Pyronin Y staining was used to determined the cell cycle status. A verapamil-sensitive side population (SP) can be isolated from primary prostate tissue accounting for 1.38% +/- 0.07% of prostate epithelial cells. Cell cycle analysis of this SP population revealed that the majority of SP cells are in...
Stem/progenitor and intermediate cell types and the origin of human prostate cancer
Differentiation, 2005
Theories of cell lineage in human prostatic epithelium, based on protein expression, propose that basal and luminal cells: 1) are either independently capable of self-renewal or 2) arise from stem cells expressing a full spectrum of proteins (p63, cytokeratins CK5/14, CK8/18, and glutathione-S-transferase-pi [GST-pi]) similar to cells of the embryonic urogenital sinus (UGS). Such embryonic-like stem cells are thought to give rise to mature basal cells and secretory luminal cells. By single cell cloning of an immortalized, normal human prostate-derived, non-tumorigenic RWPE-1 cell line, we isolated and characterized two epithelial cell types, WPE-stem and WPE-int. WPEstem cells show: i) strong, sixfold greater nuclear expression of p63; ii) nearly twofold greater expression of CK14; iii) threefold less CK18, and iv) low androgen receptor (AR) expression as compared with WPE-int cells. WPE-stem cells are androgen-independent for growth and survival. WPE-int cells express very low p63 and CK5/14, and high CK18. WPE-int cells are androgen-independent for growth and survival but are highly responsive as shown by androgen induction of AR and prostate specific antigen (PSA). Compared with WPE-int cells, WPE-stem cells are smaller and show more rapid growth. WPE-stem cells can grow in an anchorage-independent manner in agar with 4.5-fold greater cloning efficiency and as free floating ''prostaspheres'' in liquid medium; and express over 40-fold higher matrix metalloproteinase-2 activity. These results indicate that WPE-stem cells express several features characteristic of stem/progenitor cells present in the UGS and in adult prostatic epithelium. In contrast, WPE-int cells have an intermediate, committed phenotype on the pathway to luminal cell differentiation. We propose that in normal prostatic epithelium, cells exist at many stages in a continuum of differentiation progressing from stem cells to definitive basal and luminal cells. Establishment and characterization of clones of human prostatic epithelial cells provide novel models for determining cell lineages, the origin of prostate cancer, and for developing new strategies for tumor prevention and treatment.
Epithelial Stem Cells of the Prostate and Their Role in Cancer Progression
Cold Spring Harbor Symposia on Quantitative Biology, 2008
Prostate cancer is a leading cause of cancer-related death in adult men. It can regress dramatically upon antihormonal therapy, but it often recurs in a more aggressive, androgen-independent form. Defining the prostate tissue stem cells (PrSCs) and their involvement in cancer initiation and maintenance may lead to better therapeutics. Using a tissue-regeneration model in which dissociated prostate epithelial cells mixed with inductive mesenchyme give rise to prostatic tubules, we have identified a small population of prostate cells that contains multiple stem cell characteristics. In this system, prostate cancer can be initiated by autocrine or paracrine growth factor signaling and intracellular overexpression of genes often found mutated in human prostate cancer. Using an in vitro prostate sphere assay, we further defined the PrSC population and demonstrated their selfrenewal and multilineage differentiation capabilities. Microarray analyses of the stem-and non-stem-cell populations have assisted us in finding and evaluating additional markers that can better define the PrSC population and further delineate the different cell types of the prostate, including those that serve as the target cell for tumor initiation.
Identification of a stem cell candidate in the normal human prostate gland
European journal of cell …, 2005
Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+ cells). The Ck6a+ cells are present within a specialized niche in the basal cell compartment in fetal, juvenile and adult prostate tissue, and within the stem cell-enriched urogenital sinus. In adult normal prostate tissue, the average abundance of Ck6a+ cells was 4.9%. With proliferative stimuli in the prostate organ culture model, in which the epithelial–stromal interaction was maintained, a remarkable increase of Ck 6a expression was noticed to up to 64.9%. The difference in cytokeratin 6a expression between the normal adult prostate and the prostate organ culture model was statistically significant (p<0.0001). Within the prostate organ culture model the increase of cytokeratin 6a-expressing cells significantly correlated with increased proliferation index (r = 0.7616; p = 0.0467) The Ck6a+ cells were capable of differentiation as indicated by their expression of luminal cell markers such as ZO-1 and prostate specific antigen (PSA). Our data indicate that Ck6a+ cells represent a prostatic epithelial stem cell candidate possessing high potential for proliferation and differentiation. Since the development of benign prostatic hyperplasia and prostate carcinogenesis are disorders of proliferation and differentiation, the Ck6a+ cells may represent a major element in the development of these diseases.
Prostate cancer stem/progenitor cells: Identification, characterization, and implications
Molecular Carcinogenesis, 2006
Several solid tumors have now been shown to contain stem cell-like cells called cancer stem cells (CSC). These cells, although generally rare, appear to be highly tumorigenic and may be the cells that drive tumor formation, maintain tumor homeostasis, and mediate tumor metastasis. In this Perspective, we first provide our insight on how a CSC should be defined. We then summarize our current knowledge of stem/progenitor cells in the normal human prostate (NHP), an organ highly susceptible to hyperproliferative diseases such as benign prostate hyperplasia (BPH) and prostate cancer (PCa). We further review the evidence that cultured PCa cells, xenograft prostate tumors, and patient tumors may contain stem/progenitor cells. Along with our discussion, we present several methodologies that can be potentially used to identify putative tumor-reinitiating CSC. Finally, we present a hypothetical model for the hierarchical organization of human PCa cells and discuss the implications of this model in helping understand prostate carcinogenesis and design novel diagnostic, prognostic, and therapeutic approaches.