Pilot and feasibility study of serum chemokines as markers to distinguish prostatic disease in men with low total serum PSA

Pro-inflammatory cytokines and CXC chemokines as game-changer in age-associated prostate cancer and ovarian cancer: Insights from preclinical and clinical studies' outcomes

Prostate cancer (PC) and Ovarian cancer (OC) are two of the most common types of cancer that affect the reproductive systems of older men and women. These cancers are associated with a poor quality of life among the aged population. Therefore, finding new and innovative ways to detect, treat, and prevent these cancers in older patients is essential. Finding biomarkers for these malignancies will increase the chance of early detection and effective treatment, subsequently improving the survival rate. Studies have shown that the prevalence and health of some illnesses are linked to an impaired immune system. However, the age-associated changes in the immune system during malignancies such as PC and OC are poorly understood. Recent research has suggested that the excessive production of inflammatory immune mediators, such as interleukin-6 (IL-6), interleukin-8 (IL-8), transforming growth factor (TGF), tumor necrosis factor (TNF), CXC motif chemokine ligand 1 (CXCL1), CXC motif chemokine ligand 12 (CXCL12), and CXC motif chemokine ligand 13 (CXCL13), etc., significantly impact the development of PC and OC in elderly patients. Our review focuses on the latest functional studies of pro-inflammatory cytokines (interleukins) and CXC chemokines, which serve as biomarkers in elderly patients with PC and OC. Thus, we aim to shed light on how these biomarkers affect the development of PC and OC in elderly patients. We also examine the current status and future perspective of cytokines (interleukins) and CXC chemokines-based therapeutic targets in OC and PC treatment for elderly patients.

Prognostic and therapeutic potential of senescent stromal fibroblasts in prostate cancer

The stromal component of the tumour microenvironment in primary and metastatic prostate cancer can influence and promote disease progression. Within the prostatic stroma, fibroblasts are one of the most prevalent cell types associated with precancerous and cancerous lesions; they have a vital role in the structural composition, organization and integrity of the extracellular matrix. Fibroblasts within the tumour microenvironment can undergo cellular senescence, which is a stable arrest of cell growth and a phenomenon that is emerging as a recognized hallmark of cancer. Supporting the idea that cellular senescence has a pro-tumorigenic role, a subset of senescent cells exhibits a senescence-associated secretory phenotype (SASP), which, along with increased inflammation, can promote prostate cancer cell growth and survival. These cellular characteristics make targeting senescent cells and/or modulating SASP attractive as a potential preventive or therapeutic option for prostate cancer.

The FGF/FGFR system in the physiopathology of the prostate gland

Fibroblast growth factors (FGFs) are a family of proteins possessing paracrine, autocrine, or endocrine functions in a variety of biological processes, including embryonic development, angiogenesis, tissue homeostasis, wound repair, and cancer. Canonical FGFs bind and activate tyrosine kinase FGF receptors (FGFRs), triggering intracellular signaling cascades that mediate their biological activity. Experimental evidence indicates that FGFs play a complex role in the physiopathology of the prostate gland that ranges from essential functions during embryonic development to modulation of neoplastic transformation. The use of ligand- and receptor-deleted mouse models has highlighted the requirement for FGF signaling in the normal development of the prostate gland. In adult prostate, the maintenance of a functional FGF/FGFR signaling axis is critical for organ homeostasis and function, as its disruption leads to prostate hyperplasia and may contribute to cancer progression and metastatic dissemination. Dissection of the molecular landscape modulated by the FGF family will facilitate ongoing translational efforts directed toward prostate cancer therapy.

Prostatic osteopontin expression is associated with symptomatic benign prostatic hyperplasia

BACKGROUND

Male lower urinary tract symptoms (LUTS) occur in more than half of men above 50 years of age. LUTS were traditionally attributed to benign prostatic hyperplasia (BPH) and therefore the clinical terminology often uses LUTS and BPH interchangeably. More recently, LUTS were also linked to fibrogenic and inflammatory processes. We tested whether osteopontin (OPN), a proinflammatory and profibrotic molecule, is increased in symptomatic BPH. We also tested whether prostate epithelial and stromal cells secrete OPN in response to proinflammatory stimuli and identified downstream targets of OPN in prostate stromal cells.

METHODS

Immunohistochemistry was performed on prostate sections obtained from the transition zone of patients who underwent surgery (Holmium laser enucleation of the prostate) to relieve LUTS (surgical BPH, S-BPH) or patients who underwent radical prostatectomy to remove low-grade prostate cancer (incidental BPH, I-BPH). Images of stained tissue sections were captured with a Nuance Multispectral Imaging System and histoscore, as a measure of OPN staining intensity, was determined with inForm software. OPN protein abundance was determined by Western blot analysis. The ability of prostate cells to secrete osteopontin in response to IL-1β and TGF-β1 was determined in stromal (BHPrS-1) and epithelial (NHPrE-1 and BHPrE-1) cells by enzyme-linked immunosorbent assay. Quantitative polymerase chain reaction was used to measure gene expression changes in these cells in response to OPN.

RESULTS

OPN immunostaining and protein levels were more abundant in S-BPH than I-BPH. Staining was distributed across all cell types with the highest levels in epithelial cells. Multiple OPN protein variants were identified in immortalized prostate stromal and epithelial cells. TGF-β1 stimulated OPN secretion by NHPrE-1 cells and both IL-1β and TGF-β1 stimulated OPN secretion by BHPrS-1 cells. Interestingly, recombinant OPN increased the mRNA expression of CXCL1, CXCL2, CXCL8, PTGS2, and IL6 in BHPrS-1, but not in epithelial cell lines.

CONCLUSIONS

OPN is more abundant in prostates of men with S-BPH compared to men with I-BPH. OPN secretion is stimulated by proinflammatory cytokines, and OPN acts directly on stromal cells to drive the synthesis of proinflammatory mRNAs. Pharmacological manipulation of prostatic OPN may have the potential to reduce LUTS by inhibiting both inflammatory and fibrotic pathways.

CXCL12 promoter methylation and PD-L1 expression as prognostic biomarkers in prostate cancer patients

Background

The CXCR4/CXCL12 axis plays a central role in systemic metastasis of prostate carcinoma (PCa), thereby representing a promising target for future therapies. Recent data suggest that the CXCR4/CXCL12 axis is functionally linked to the PD-1/PD-L1 immune checkpoint. We evaluated the prognostic value of aberrant CXCL12 DNA methylation with respect to PD-L1 expression in primary PCa.

Results

CXCL12 methylation showed a consistent significant correlation with Gleason grading groups in both cohorts (p < 0.001 for training and p = 0.034 for testing cohort). Short BCR-free survival was significantly associated with aberrant CXCL12 methylation in both cohorts and served as an independent prognostic factor in the testing cohort (hazard ratio = 1.92 [95%CI: 1.12–3.27], p = 0.049). Concomitant aberrant CXCL12 methylation and high PD-L1 expression was significantly associated with shorter BCR-free survival (p = 0.005). In comparative analysis, the CXCL12 methylation assay was able to provide approximately equivalent results in biopsy and prostatectomy specimens.

Materials and Methods

CXCL12 methylation was determined by means of a methylation specific quantitative PCR analysis in a radical prostatectomy patient cohort (n = 247, training cohort). Data published by The Cancer Genome Atlas served as a testing cohort (n = 498). CXCL12 methylation results were correlated to clinicopathological parameters including biochemical recurrence (BCR)-free survival.

Conclusions

CXCL12 methylation is a powerful prognostic biomarker for BCR in PCa patients after radical prostatectomy. Further studies need to ascertain if CXCL12 methylation may aid in planning active surveillance strategies.

MicroRNA-19a acts as a prognostic marker and promotes prostate cancer progression via inhibiting VPS37A expression

Prostate cancer (PCa) is a leading cause of cancer-related deaths among males worldwide. However, the molecular mechanisms underlying the progression of PCa remain unclear. Despite several reported miRNAs in prostate cancer, these reports lacked system-level identification of differentially expressed miRNAs in large sample size. Moreover, it's still largely unknown how miRNAs result in tumorigenesis and progression of PCa. Therefore, by analyzing three public databases, we identified 16 upregulated miRNAs and 13 downregulated miRNAs, and validated miR-19a was one of the most upregulated miRNAs using qRT-PCR. The dual-luciferase reporter assays indicated VPS37A was a potential target of miR-19a. Functional assays revealed miR-19a served as an oncogene by inhibiting VPS37A. Notably, a significant inverse correlation of miR-19a and VPS37A expression was observed in PCa specimens. Moreover, miR-19a-high and VPS37A-low phenotypes were associated with poor prognosis with biochemical recurrence-free probability. In this study, we confirmed the oncogenic role of miR-19a via targeting VPS37A in PCa, identifying miR-19a and VPS37A as diagnosis and therapeutic biomarkers for PCa.

Proliferation of Prostate Stromal Cell Induced by Benign Prostatic Hyperplasia Epithelial Cell Stimulated With Trichomonas vaginalis via Crosstalk With Mast Cell

BACKGROUND

Chronic inflammation has a role in the pathogenesis of benign prostatic hyperplasia (BPH) and prostate cancer. Mast cells have been detected in chronic inflammatory infiltrate of the prostate, and it is possible that the interaction between prostate epithelial cells and Trichomonas vaginalis influences the activity of mast cells in the prostate stroma. Activated mast cells might influence the biological functions of nearby tissues and cells. In this study, we investigated whether mast cells reacted with the culture supernatant of BPH epithelial cells infected with T. vaginalis may induce the proliferation of prostate stromal cells.

METHODS

To measure the proliferation of prostate stromal cells in response to chronic inflammation caused by the infection of BPH-1 cells with T. vaginalis, the CCK-8 assay and wound healing assay were used. ELISAs, quantitative real-time PCR, western blotting and immunofluorescence were used to measure the production and expression of inflammatory cytokine and cytokine receptor.

RESULTS

BPH-1 cells incubated with live trichomonads produced increased levels of CCL2, IL-1β, IL-6, and CXCL8, and induced the migration of mast cells and monocytes. When the culture supernatant of BPH-1 cells stimulated with trichomonads (TCM) was added to mast cells, they became activated, as confirmed by release of β-hexosaminidase and CXCL8. Prostate stromal cells incubated with the culture supernatant of mast cells activated with TCM (M-TCM) proliferated and expressed increased levels of CXCL8, CCL2, and the cytokine receptors CXCR1 and CCR2. Blocking the chemokine receptors reduced the proliferation of stromal cells and also decreased the production of CXCL8 and CCL2. Moreover, the expression of FGF2, cyclin D1, and Bcl-2 was increased in the proliferated stromal cells stimulated with M-TCM. Additionally, the M-TCM-treated stromal cells were more invasive than control cells.

CONCLUSIONS

The inflammatory mediators released by BPH epithelial cells in response to infection by trichomonads induce the migration and activation of mast cells. The activated mast cells induce the proliferation of prostate stromal cells via CXCL8-CXCR1 and CCL2-CCR2 signaling. Our results therefore show that the inflammatory response by BPH epithelial cells stimulated with T. vaginalis induce the proliferation of prostate stromal cells via crosstalk with mast cells. Prostate 76:1431-1444, 2016. © 2016 Wiley Periodicals, Inc.

Is Eotaxin-1 a serum and urinary biomarker for prostate cancer detection and recurrence?

INTRODUCTION AND OBJECTIVES

Eotaxin-1 (CCL11) is a protein expressed in various tissues influencing immunoregulatory processes by acting as selective eosinophil chemo-attractant. In prostate cancer (PCa), the expression and functional role of CCL11 have not been intensively investigated so far. Therefore, the aim of the present study was to investigate the diagnostic or prognostic potential of Eotaxin-1 in PCa patients.

MATERIALS AND METHODS

We analyzed serum from 140 patients who have undergone prostate biopsy due to elevated prostate-specific antigen (PSA) levels as well as serum of 20 individuals with PSA levels < 1ng/ml (healthy control group). Moreover, 40 urine samples were analyzed. A custom-made Q-Plex array ELISA (Quansys Biosciences) for the detection of Eotaxin-1 was performed and Q-View Software used for quantification. In addition, clinical courses of patients documented in our Prostate Biobank database were analyzed. ROC and survival analyses were used to determine the diagnostic and prognostic power of Eotaxin-1 levels.

RESULTS

Serum Eotaxin-1 levels were significantly decreased in PCa (P = 0.006) as well as in benign prostate hyperplasia (P = 0.0006) compared to the control group. ROC analysis revealed that Eotaxin-1 is a significant marker to distinguish PCa from disease-free prostate. Moreover, we found that Eotaxin-1 expression is significantly decreased in Gleason score (GS) 6 (P = 0.0135) and GS 8 (P = 0.0057) patients compared to samples of healthy men, respectively. However, PCa aggressiveness was not predictable by Eotaxin-1 levels. In line with serum analyses, urine Eotaxin-1 was significantly decreased in patients with PCa compared to cancer-free individuals (P = 0.0185) but was not different between cancers of different GS. Patientś follow-up analyses showed no significant correlation between serum Eotaxin-1 levels and time to biochemical recurrence. Survival analyses also revealed no significant changes in progression-free survival among low (≤ 112.2 pg/ml) and high (> 112.2 pg/ml) Eotaxin-1 serum levels.

CONCLUSION

Although this study has not established a prognostic role of Eotaxin-1 in PCa patients, this chemokine may serve as a diagnostic marker to distinguish between disease-free prostate and cancer.

Urine chemokines indicate pathogenic association of obesity with BPH/LUTS

OBJECTIVES

High prevalence of lower urinary tract symptoms (LUTS) consistent with benign prostate hyperplasia (BPH) is associated with obesity and prostatic inflammation. Here, we investigated whether chemokines associated with obesity and prostatic inflammation can be measured in normally voided urine of BPH/LUTS patients to demonstrate the mechanistic association between obesity and BPH/LUTS.

METHODS

Frozen urine specimens of BPH/LUTS patients enrolled in the Nashville Men's Health Study were sent for blinded analysis to University of Pittsburgh. Thirty patients were blocked by their AUA-SI (>7 or ≤7) and prostatic enlargement (<40, 40-60, >60 cc). Clinical parameters including age, prostate size, and medications were derived from chart review. CXC chemokines (CXCL-1, CXCL-8, and CXCL-10), CC chemokines (CCL2 and CCL3), and sIL-1ra were measured in thawed urine using Luminex™ xMAP(®) technology and ELISA for NGF.

RESULTS

Urinary CCL2 levels were several fold higher compared with the other six proteins, of which CCL3 was detectable in less than one-fourth of patients. Urine levels of sIL-1ra and CXCL-8 were significantly associated with increasing BMI and waist circumference in BPH patients. CXCL-8 showed a marginal association with overall AUA-SI scores, as well as obstructive (p = 0.08) symptom subscores. Prostate volume was inversely and marginally associated with urinary CXCL-10 (p = 0.09).

CONCLUSIONS

Urine levels of CXCL-8, CXCL-10, and sIL-1ra were associated with varying degrees with LUTS severity, prostate size, and obesity, respectively. These findings in urine are consistent with past studies of chemokine levels from expressed prostatic secretions and demonstrate the potential of noninvasively measured chemokine in urine to objectively classify BPH/LUTS patients.

CXCL12 Modulates Prostate Cancer Cell Adhesion by Altering the Levels or Activities of β1-Containing Integrins

The mechanisms by which prostate cancer (PCa) cell adhesion and migration are controlled during metastasis are not well understood. Here, we studied the effect of CXCL12 in PCa cell adhesion and spreading in DU145 and PC3 cell lines using as substrates collagen I, fibronectin (FN), and their recombinant fragments. CXCL12 treatment increased β1 integrin-dependent PC3 cell adhesion on FN which correlated with increased focal adhesion kinase activation. However neither α5β1 nor α4β1 subunits were involved in this adhesion. By contrast, CXCL12 decreased DU145 adhesion and spreading on FN by downregulating α5 and β1 integrin expression. To demonstrate the clinical relevance of CXCL12 in PCa, we measured CXCL12 levels in plasma by using ELISA and found that the chemokine is elevated in PCa patients when compared to controls. The high concentration of CXCL12 in patients suffering from PCa in comparison to those with benign disease or healthy individuals implicates CXCL12 as a potential biomarker for PCa. In addition these data show that CXCL12 may be crucial in controlling PCa cell adhesion on fibronectin and collagen I, possibly via crosstalk with integrin receptors and/or altering the expression levels of integrin subunits.

CCL2 Chemokine as a Potential Biomarker for Prostate Cancer: A Pilot Study

Purpose

Prostate specific antigen is not reliable in diagnosing prostate cancer (PCa), making the identification of novel, precise diagnostic biomarkers important. Since chemokines are associated with more aggressive disease and poor prognosis in diverse malignancies, we aimed to investigate the diagnostic relevance of chemokines in PCa.

Materials and Methods

Preoperative and early postoperative serum samples were obtained from 39 consecutive PCa patients undergoing radical prostatectomy. Serum from 15 healthy volunteers served as controls. Concentrations of CXCL12, CXCL13, CX3CL1, CCL2, CCL5, and CCL20 were measured in serum by Luminex. The expression activity of CXCR3, CXCR4, CXCR5, CXCR7, CXCL12, CXCL13, CX3CR1, CXCL1, CCR2, CCR5, CCR6, CCR7, CCL2, and CCL5 mRNA was assessed in tumor and adjacent normal tissue of prostatectomy specimens by quantitative real-time polymerase chain reaction. The associations of these chemokines with clinical and histological parameters were tested.

Results

The gene expression activity of CCL2 and CCR6 was significantly higher in tumor tissue compared to adjacent normal tissue. CCL2 was also significantly higher in the blood samples of PCa patients, compared to controls. CCL5, CCL20, and CX3CL1 were lower in patient serum, compared to controls. CCR2 tissue mRNA was negatively correlated with the Gleason score and grading.

Conclusion

Chemokines are significantly modified during tumorigenesis of PCa, and CCL2 is a promising diagnostic biomarker.

CCL11 (eotaxin-1): a new diagnostic serum marker for prostate cancer

BACKGROUND

The recent recommendation of the U.S. Preventive Services Task Force against PSA-based screening for prostate cancer was based, in part, on the lack of demonstrated diagnostic utility of serum PSA values in the low, but detectable range to successfully predict prostate cancer. Though controversial, this recommendation reinforced the critical need to develop, validate, and determine the utility of other serum and/or urine transcript and protein markers as diagnostic markers for PCa. The studies described here were intended to determine whether inflammatory cytokines might augment serum PSA as a diagnostic marker for prostate cancer.

METHODS

Multiplex ELISA assays were performed to quantify CCL1, CCL2, CCL5, CCL8, CCL11, CCL17, CXCL1, CXCL5, CXCL8, CXCL10, CXCL12, and IL-6 protein levels in the serum of 272 men demonstrating serum PSA values of <10 ng/ml and undergoing a 12 core diagnostic needle biopsy for detection of prostate cancer. Logistic regression was used to identify the associations between specific chemokines and prostate cancer status adjusted for prostate volume, and baseline PSA.

RESULTS

Serum levels for CCL1 (I-309) were significantly elevated among all men with enlarged prostates (P < 0.04). Serum levels for CCL11 (Eotaxin-1) were significantly elevated among men with prostate cancer regardless of prostate size (P < 0.01). The remaining 10 cytokines examined in this study did not exhibit significant correlations with either prostate volume or cancer status.

CONCLUSIONS

Serum CCL11 values may provide a useful diagnostic tool to help distinguish between prostatic enlargement and prostate cancer among men demonstrating low, but detectable, serum PSA values.

Increased infiltrated macrophages in benign prostatic hyperplasia (BPH): role of stromal androgen receptor in macrophage-induced prostate stromal cell proliferation

Infiltrated macrophages may play important roles in the development and progression of benign prostatic hyperplasia (BPH), but the underlying mechanisms remain largely unknown. We found increased macrophages infiltration in human and mouse BPH tissues. By establishing a co-culture transwell system, we found increased migration of macrophages and proliferation of prostate stromal cells during co-culture. Importantly, stromal androgen receptor (AR) could enhance the migration of macrophages and macrophage-mediated stromal cell proliferation. We identified CCL3 as an AR downstream player, and found CCL3 levels were notably increased in human and mouse BPH prostates. Ablation of prostate stromal AR in a mouse BPH model significantly reduced CCL3 expression levels in prostates. Consistently, targeting AR via an AR degradation enhancer, ASC-J9®, or neutralization of CCL3 with an antibody, resulted in suppression of macrophage migration and prostate stromal cell growth. Our study provides mechanistic insights on the regulation of prostate stromal cells by macrophages via stromal AR/CCL3 signaling pathways, which could potentially allow the development of therapeutic approaches for battling BPH with persistent inflammation.

Secreted proteins as a fundamental source for biomarker discovery

The proteins secreted by various cells (the secretomes) are a potential rich source of biomarkers as they reflect various states of the cells at real time and at given conditions. To have accessible, sufficient and reliable protein markers is desirable as they mark various stages of disease development and their presence/absence can be used for diagnosis, prognosis, risk stratification and therapeutic monitoring. As direct analysis of blood/plasma, a common and noninvasive patient screening method, can be difficult for candidate protein biomarker identification, the alternative/complementary approaches are required, one of them is the analysis of secretomes in cell conditioned media in vitro. As the proteins secreted by cells as a response to various stimuli are most likely secreted into blood/plasma, the identification and pre-selection of candidate protein biomarkers from cell secretomes with subsequent validation of their presence at higher levels in serum/plasma is a promising approach. In this review, we discuss the proteins secreted by three progenitor cell types (smooth muscle, endothelial and cardiac progenitor cells) and two adult cell types (neonatal rat ventrical myocytes and smooth muscle cells) which can be relevant to cardiovascular research and which have been recently published in the literature. We found, at least for secretome studies included in this review, that secretomes of progenitor and adult cells overlap by 48% but the secretomes are very distinct among progenitor cell themselves as well as between adult cells. In addition, we compared secreted proteins to protein identifications listed in the Human Plasma PeptideAtlas and in two reports with cardiovascular-related proteins and we performed the extensive literature search to find if any of these secreted proteins were identified in a biomarker study. As expected, many proteins have been identified as biomarkers in cancer but 18 proteins (out of 62) have been tested as biomarkers in cardiovascular diseases as well.

The functional role of reactive stroma in benign prostatic hyperplasia

The human prostate gland is one of the only internal organs that continue to enlarge throughout adulthood. The specific mechanisms that regulate this growth, as well as the pathological changes leading to the phenotype observed in the disease benign prostatic hyperplasia (BPH), are essentially unknown. Recent studies and their associated findings have made clear that many complex alterations occur, involving persistent and chronic inflammation, circulating hormonal level deregulation, and aberrant wound repair processes. BPH has been etiologically characterized as a progressive, albeit discontinuous, hyperplasia of both the glandular epithelial and the stromal cell compartments coordinately yielding an expansion of the prostate gland and clinical symptoms. Interestingly, the inflammatory and repair responses observed in BPH are also key components of general wound repair in post-natal tissues. These responses include altered expression of chemokines, cytokines, matrix remodeling factors, chronic inflammatory processes, altered immune surveillance and recognition, as well as the formation of a prototypical 'reactive' stroma, which is similar to that observed across various fibroplasias and malignancies of a variety of tissue sites. Stromal tissue, both embryonic mesenchyme and adult reactive stroma myofibroblasts, has been shown to exert potent and functional regulatory control over epithelial proliferation and differentiation as well as immunoresponsive modulation. Thus, the functional biology of a reactive stroma, within the context of an adult disease typified by epithelial and stromal aberrant hyperplasia, is critical to understand within the context of prostate disease and beyond. The mechanisms that regulate reactive stroma biology in BPH represent targets of opportunity for new therapeutic approaches that may extend to other tissue contexts. Accordingly, this review seeks to address the dissection of important factors, signaling pathways, genes, and other regulatory components that mediate the interplay between epithelium and stromal responses in BPH.

Androgen regulated genes in human prostate xenografts in mice: relation to BPH and prostate cancer

Benign prostatic hyperplasia (BPH) and prostate carcinoma (CaP) are linked to aging and the presence of androgens, suggesting that androgen regulated genes play a major role in these common diseases. Androgen regulation of prostate growth and development depends on the presence of intact epithelial-stromal interactions. Further, the prostatic stroma is implicated in BPH. This suggests that epithelial cell lines are inadequate to identify androgen regulated genes that could contribute to BPH and CaP and which could serve as potential clinical biomarkers. In this study, we used a human prostate xenograft model to define a profile of genes regulated in vivo by androgens, with an emphasis on identifying candidate biomarkers. Benign transition zone (TZ) human prostate tissue from radical prostatectomies was grafted to the sub-renal capsule site of intact or castrated male immunodeficient mice, followed by the removal or addition of androgens, respectively. Microarray analysis of RNA from these tissues was used to identify genes that were; 1) highly expressed in prostate, 2) had significant expression changes in response to androgens, and, 3) encode extracellular proteins. A total of 95 genes meeting these criteria were selected for analysis and validation of expression in patient prostate tissues using quantitative real-time PCR. Expression levels of these genes were measured in pooled RNAs from human prostate tissues with varying severity of BPH pathologic changes and CaP of varying Gleason score. A number of androgen regulated genes were identified. Additionally, a subset of these genes were over-expressed in RNA from clinical BPH tissues, and the levels of many were found to correlate with disease status. Our results demonstrate the feasibility, and some of the problems, of using a mouse xenograft model to characterize the androgen regulated expression profiles of intact human prostate tissues.