Reduced KLK2 expression is a strong and independent predictor of poor prognosis in ERG-negative prostate cancer.

BACKGROUND: Kallikrein-related peptidase 2 (KLK2)-like KLK3 (prostate-specific antigen [PSA])-belongs to the highly conserved serine proteases of the glandular kallikrein protein family (KLK family). Studies suggested that measurement of KLK2 serum levels advanced the predictive accuracy of PSA testing in prostate cancer. METHODS: To clarify the potential utility of KLK2 as a prognostic tissue biomarker, KLK2 expression was analyzed by immunohistochemistry in more than 12 000 prostate cancers. RESULTS: Normal epithelium cells usually showed weak to moderate KLK2 immunostaining, whereas KLK2 was negative in 23%, weak in 38%, moderate in 35%, and strong in 4% of 9576 analyzable cancers. Lost or reduced KLK2 immunostaining was associated with advanced tumor stage, high Gleason score, lymph node metastasis, increased cell proliferation, positive resection margin, and early PSA recurrence (P < .0001). Comparison with previously analyzed molecular alterations revealed a strong association of KLK2 loss and presence of TMPRSS2:ERG fusion (P < .0001), most of all analyzed common deletions (9 of 11; P ≤ .03), and decreased PSA immunostaining (P < .0001 each). Cancers with combined negative or weak immunostaining of KLK2 and PSA showed worse prognosis than cancers with at least moderate staining of one or both proteins (P < .0001). Multivariate analyses including established preoperative and postoperative prognostic parameters showed a strong independent prognostic impact of KLK2 loss alone or in combination of PSA, especially in erythroblast transformation-specific-negative cancers (P ≤ .006). CONCLUSIONS: Loss of KLK2 expression is a potentially useful prognostic marker in prostate cancer. Analysis of KLK2 alone or in combination with PSA may be useful for estimating cancer aggressiveness at the time of biopsy.

Androgen receptor signalling impairs docetaxel efficacy in castration-resistant prostate cancer.

Androgen receptor (AR) signalling drives neoplastic growth and therapy resistance in prostate cancer. Recent clinical data show that docetaxel combined with androgen deprivation therapy improves outcome in hormone-sensitive disease. We studied whether testosterone and AR signalling interferes with docetaxel treatment efficacy in castration-resistant prostate cancer (CRPC). We found that testosterone supplementation significantly impaired docetaxel tumour accumulation in a CRPC model, resulting in decreased tubulin stabilisation and antitumour activity. Furthermore, testosterone competed with docetaxel for uptake by the drug transporter OATP1B3. Irrespective of docetaxel-induced tubulin stabilisation, AR signalling by testosterone counteracted docetaxel efficacy. AR-pathway activation could also reverse long-term tumour regression by docetaxel treatment in vivo. These results indicate that to optimise docetaxel efficacy, androgen levels and AR signalling need to be suppressed. This study lends evidence for continued maximum suppression of AR signalling by combining targeted therapeutics with docetaxel in CRPC.

CCN3/Nephroblastoma Overexpressed Is a Functional Mediator of Prostate Cancer Bone Metastasis That Is Associated with Poor Patient Prognosis.

Prostate cancer (PC) commonly metastasizes to the bone, resulting in pathologic fractures and poor prognosis. CCN3/nephroblastoma overexpressed is a secreted protein with a known role in promoting breast cancer metastasis to bone. However, in PC, CCN3 has been ascribed conflicting roles; some studies suggest that CCN3 promotes PC metastasis, whereas others argue a tumor suppressor role for CCN3 in this disease. Indeed, in the latter context, CCN3 has been shown to sequester the androgen receptor (AR) and suppress AR signaling. In the present study, we demonstrate that CCN3 functions as a bone-metastatic mediator, which is dependent on its C-terminal domain for this function. Analysis of tissue microarrays comprising >1500 primary PC patient radical prostatectomy specimens reveals that CCN3 expression correlates with aggressive disease and is negatively correlated with the expression of prostate-specific antigen, a marker of AR signaling. Together, these findings point to CCN3 as a biomarker to predict PC aggressiveness while providing clarity on its role as a functional mediator of PC bone metastasis.

Tyrosine kinase inhibitor therapy prescribed for non-urologic diseases can modify PSA titers in urology patients.

BACKGROUND: The tyrosine kinase inhibitors (TKI), imatinib and nilotinib, are used to treat chronic myelogenous leukemia (CML). In three CML patients being monitored for urologic diseases, we observed that switching of TKI therapy affected prostate-specific antigen (PSA) titers. Urologists and other medical professionals need to be aware of the potential side-effects of drugs that patients may be receiving for other indications to modify this important prostate diseases indicator. TKIs may affect PSA titers independent of prostate growth or volume. MATERIALS AND METHODS: We followed PSA levels in urology patients who were also undergoing TKI treatment for CML. We determined the effects of nilotinib and imatinib on proliferation, AR and PSA expression in the LNCaP and 22Rv1 prostate cancer (PCa) cell lines using real-time PCR and Western blotting. RESULTS: Clinically, nilotinib and dasatinib reversibly reduced PSA titers compared to imatinib. At high doses nilotinib and imatinib both demonstrated antiproliferative effects in the PCa cells. At low doses expression of AR and PSA was decreased by both drugs, at mRNA and protein levels. Nilotinib exerted greater effects at lower doses than imatinib. CONCLUSIONS: Nilotinib down-regulates serum PSA in patients being treated for non-urological indications, potentially masking a clinical useful marker, we cannot exclude a similar but smaller effect of imatinib. Nilotinib and imatinib both decreased AR and PSA expression in PCa cell lines with the nilotinib effect evident at lower doses. Urologists must appreciate the effects of drugs provided for other diseases on PSA titers and be aware that sudden changes may not reflect underlying prostatic disease.

Prostate epithelial cell of origin determines cancer differentiation state in an organoid transformation assay.

The cell of origin for prostate cancer remains a subject of debate. Genetically engineered mouse models have demonstrated that both basal and luminal cells can serve as cells of origin for prostate cancer. Using a human prostate regeneration and transformation assay, our group previously demonstrated that basal cells can serve as efficient targets for transformation. Recently, a subpopulation of multipotent human luminal cells defined by CD26 expression that retains progenitor activity in a defined organoid culture was identified. We transduced primary human prostate basal and luminal cells with lentiviruses expressing c-Myc and activated AKT1 (myristoylated AKT1 or myrAKT1) to mimic theMYCamplification andPTENloss commonly detected in human prostate cancer. These cells were propagated in organoid culture before being transplanted into immunodeficient mice. We found that c-Myc/myrAKT1-transduced luminal xenografts exhibited histological features of well-differentiated acinar adenocarcinoma, with strong androgen receptor (AR) and prostate-specific antigen (PSA) expression. In contrast, c-Myc/myrAKT1-transduced basal xenografts were histologically more aggressive, with a loss of acinar structures and low/absent AR and PSA expression. Our findings imply that distinct subtypes of prostate cancer may arise from luminal and basal epithelial cell types subjected to the same oncogenic insults. This study provides a platform for the functional evaluation of oncogenes in basal and luminal epithelial populations of the human prostate. Tumors derived in this fashion with defined genetics can be used in the preclinical development of targeted therapeutics.

Comparison of the effect of the antiandrogen apalutamide (ARN-509) versus bicalutamide on the androgen receptor pathway in prostate cancer cell lines.

Apalutamide (ARN-509) is an antiandrogen that binds selectively to androgen receptors (AR) and does not show antagonist-to-agonist switch like bicalutamide. We compared the activity of ARN versus bicalutamide on prostate cancer cell lines. The 22Rv1, PC3, and DU145 cell lines were used to study the effect of ARN and bicalutamide on the expression cytoplasmic/nuclear kinetics of AR, AR-V7 variant, phosphorylated AR, as well as the levels of the AR downstream proteins prostate-specific antigen and TMPRSS2, under exposure to testosterone and/or hypoxia. The effects on autophagic flux (LC3A, p62, TFEB, LAMP2a, cathepsin D) and cell metabolism-related enzymes (hypoxia-inducible factor 1α/2α, BNIP3, carbonic anhydrase 9, LDHA, PDH, PDH-kinase) were also studied. The 22Rv1 cell line responded to testosterone by increasing the nuclear entry of AR, AR-V7, and phosphorylated AR and by increasing the levels of prostate-specific antigen and TMPRSS2. This effect was strongly abrogated by ARN and to a clearly lower extent by bicalutamide at 10 µmol/l, both in normoxia and in hypoxia. ARN had a stronger antiproliferative effect than bicalutamide, which was prominent in the 22Rv1 hormone-responsive cell line, and completely repressed cell proliferation at a concentration of 100 µmol/l. No effect of testosterone or of antiandrogens on autophagy flux, hypoxia-related proteins, or metabolism enzyme levels was noted. The PC3 and DU145 cell lines showed poor expression of the proteins and were not responsive to testosterone. On the basis of in-vitro studies, evidence has been reported that ARN is more potent than bicalutamide in blocking the AR pathway in normoxia and in hypoxia. This reflects a more robust, dose-dependent, repressive effect on cell proliferation.

Androgen Receptor Is Inactivated and Degraded in Bladder Cancer Cells by Phenyl Glucosamine via miR-449a Restoration.

BACKGROUND Bladder cancer caused by exposure to aniline dyes, chronic cystitis, and smoking is detected in approximately 70 000 new cases annually. In the USA alone, it leads to 15 000 deaths every year. In the present study, we investigated the role of 3-((4'-amino-[1,1'-biphenyl]-4-yl)amino)-4-bromo-5-oxo-2,5-dihydrofuran-2-yl acetate (ABDHFA) in the inhibition of bladder cancer cell viability. MATERIAL AND METHODS Viability of cells was examined using MTT assay and distribution of cell cycle was assessed by flow cytometry. Expression of cyclin D1, androgen, prostate-specific antigen (PSA), and miR-449a was analyzed using Western blot and quantitative real-time polymerase chain reaction assays. RESULTS The results demonstrated that ABDHFA treatment inhibited viability of UMUC3 and TCCSUP AR-positive bladder cancer cells. ABDHFA treatment led to break-down of AR in UMUC3 and TCCSUP cells after 48 h in a dose-dependent manner. Up-regulation of miR-449a by lentivirus transfection down-regulated the AR signalling pathway. In UMUC3 and TCCSUP cells, ABDHFA treatment led to inhibition of mRNA and protein expression corresponding to AR. CONCLUSIONS In summary, the present study demonstrates that proliferation of AR-positive bladder carcinoma cells is markedly reduced by ABDHFA treatment through arrest of cell cycle and degradation of AR protein. Thus, ABDHFA, a novel compound, can be used for the treatment of bladder cancer.

Potential of Moringa oleifera in the Treatment of Benign Prostate Hyperplasia: Role of Antioxidant Defence Systems.

OBJECTIVE: This study sought to evaluate the protective effect of ethanolic leaf extract of Moringa oleifera on testosterone-induced benign prostatic hyperplasia (BPH) in male Sprague-Dawley rats. MATERIALS AND METHODS: BPH was induced in rats by the administration of testosterone propionate (3 mg/kg, s.c., in olive oil) for 4 weeks. M. oleifera (50, 100, or 200 mg/kg), celecoxib (20 mg/kg), or M. oleifera (50 mg/kg) + celecoxib (20 mg/kg) were orally administered daily 15 min before testosterone. On day 29, blood was collected to measure the levels of serum testosterone and prostate-specific antigen before the animals were sacrificed. The prostates were weighed, assayed, and histologically examined. RESULTS: M. oleifera significantly reduced the testosterone-induced increase in prostate weight (20.16%), prostate index (65.85%), serum testosterone (72.86%), and prostate-specific antigen (48.49%). Testosterone caused a significant increase in malondialdehyde (73%) as well as a reduction in glutathione (62.5%), superoxide dismutase (50%), and catalase (64%) activities which were attenuated by M. oleifera with a peak effect obtained at 100 mg/kg. The disruption of prostate histoarchitecture by testosterone was also ameliorated by M. oleifera. CONCLUSION: M. oleifera prevented testosterone-induced BPH through enhancement of antioxidant defence mechanisms, and hence could be used as an adjunct in the treatment of BPH.

Establishment of a mammalian expression system for recombinant [-2]proPSA and a specific antibody against the truncated leader peptide.

A truncated precursor form of prostate-specific antigen (PSA), [-2]proPSA, is a well-known biomarker for prostate cancer. To develop a biomarker assay, highly purified [-2]proPSA is required as a standard reference and for generation of a specific antibody. In this study, we generated an efficient mammalian expression system for producing a recombinant [-2]proPSA-human kappa constant domain (Cκ ) fusion protein. N-terminal amino acid sequencing using Edman degradation demonstrated that over 95% of the recombinant protein produced is [-2]proPSA, thereby showing for the first time that recombinant [-2]proPSA can be produced as a major fraction. We also generated a recombinant chicken antibody specific to [-2]proPSA but not cross-reactive to recombinant [-7]proPSA-Cκ , [-5]proPSA-Cκ , and PSA purified from human seminal fluid in enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. Also, the recombinant chicken antibody reacted to recombinant [-2]proPSA protein bound to an anti-PSA antibody coated on the micrometer plate in a sandwich ELISA. All of these results suggest that the N-terminus of the [-2]proPSA-Cκ fusion protein resides on the exterior of the protein, thus allowing exposure to the antibody.

Carnosic acid promotes degradation of the androgen receptor and is regulated by the unfolded protein response pathway in vitro and in vivo.

Androgen deprivation therapy in prostate cancer is extremely effective; however, due to the continuous expression and/or mutagenesis of androgen receptor (AR), the resistance to antihormonal therapy is a natural progression. Consequently, targeting the AR for degradation offers an alternate approach to overcome this resistance in prostate cancer. In this study, we demonstrate that carnosic acid, a benzenediol diterpene, binds the ligand-binding domain of the AR and degrades the AR via endoplasmic reticulum (ER) stress-mediated proteasomal degradative pathway. In vitro, carnosic acid treatment induced degradation of AR and decreased expression of prostate-specific antigen in human prostate cancer cell lines LNCaP and 22Rv1. Carnosic acid also promoted the expression of ER proteins including BiP and CHOP in a dose-dependent manner. Downregulation of CHOP by small interfering RNA somewhat restored expression of AR suggesting that AR degradation is dependent on ER stress pathway. Future studies will need to evaluate other aspects of the unfolded protein response pathway to characterize the regulation of AR degradation. Furthermore, cotreating cells individually with carnosic acid and proteasome inhibitor (MG-132) and carnosic acid and an ER stress modulator (salubrinal) restored protein levels of AR, suggesting that AR degradation is mediated by ER stress-dependent proteasomal degradation pathway. Degradation of AR and induction of CHOP protein were also evident in vivo along with a 53% reduction in growth of xenograft prostate cancer tumors. In addition, carnosic acid-induced ER stress in prostate cancer cells but not in normal prostate epithelial cells procured from patient biopsies. In conclusion, these data suggest that molecules such as carnosic acid could be further evaluated and optimized as a potential therapeutic alternative to target AR in prostate cancer.

Neuronal Trans-Differentiation in Prostate Cancer Cells.

BACKGROUND: Neuroendocrine (NE) differentiation in prostate cancer (PCa) is an aggressive phenotype associated with therapy resistance. The complete phenotype of these cells is poorly understood. Clinical classification is based predominantly on the expression of standard NE markers. METHODS: We analyzed the phenotype of NE carcinoma of the prostate utilizing in vitro methods, in silico, and immunohistochemical analyses of human disease. RESULTS: LNCaP cells, subjected to a variety of stressors (0.1% [v/v] fetal bovine serum, cyclic AMP) induced a reproducible phenotype consistent with neuronal trans-differentiation. Cells developed long cytoplasmic processes resembling neurons. As expected, serum deprived cells had decreased expression in androgen receptor and prostate specific antigen. A significant increase in neuronal markers also was observed. Gene array analysis demonstrated that LNCaP cells subjected to low serum or cAMP showed statistically significant manifestation of a human brain gene expression signature. In an in silico experiment using human data, we identified that only hormone resistant metastatic prostate cancer showed enrichment of the "brain profile." Gene ontology analysis demonstrated categories involved in neuronal differentiation. Three neuronal markers were validated in a large human tissue cohort. CONCLUSION: This study proposes that the later stages of PCa evolution involves neuronal trans-differentiation, which would enable PCa cells to acquire independence from the neural axis, critical in primary tumors. Prostate 76:1312-1325, 2016. © 2016 Wiley Periodicals, Inc.

MD-miniRNA could be a more accurate biomarker for prostate cancer screening compared with serum prostate-specific antigen level.

Prostate cancer and prostatic hyperplasia detection remains a great challenge, lacking of effective non-invasive and specific diagnostic biomarkers. In the current study, we aimed to identify the relative expression of plasma MD-miniRNA and its diagnostic performance in differentiating prostate cancer and prostatic hyperplasia patients from healthy controls, compared with serum prostate-specific antigen (PSA) level. All of the clinical participants (63 prostate cancer patients, 32 prostatic hyperplasia patients, and 50 healthy controls) were obtained from the Third Affiliated Hospital of Suzhou University in China between January 2013 and April 2014. Clinical characteristics were well matched. Plasma samples were extracted to test the relative expression of MD-miniRNA using the method of qRT-PCR. SPSS 22.0 statistical software package was used to analyze the data and GraphPad Prism 6.0 was used to generate the graphs. Relativity expression of plasma MD-miniRNA was significantly upregulated in prostate cancer, compared with prostatic hyperplasia patients and healthy controls. Serum PSA level revealed similar differences among these groups. MD-miniRNA presented a relatively high diagnostic accuracy with AUC of 0.86 (95 % CI 0.80-0.93) in differentiating prostate cancer patients from healthy controls. Simultaneously, MD-miniRNA was able to discriminate prostate cancer patients from prostatic hyperplasia controls with AUC of 0.79 (95 % CI 0.70-0.88). In addition, MD-miniRNA displayed a better diagnostic performance than PSA level. However, the panel of these two biomarkers revealed the best diagnostic performance, compared with either single biomarker. Results of this study showed that plasma MD-miniRNA could serve as a promising and noninvasive biomarker for diagnosing prostate cancer. Further large-scale studies are needed to confirm its clinical diagnosis accuracy.

Prediction of Significant Prostate Cancer at Prostate Biopsy and Per Core Detection Rate of Targeted and Systematic Biopsies Using Real-Time Shear Wave Elastography.

INTRODUCTION: Prostate cancer (PCa) detection is accompanied by overdiagnosis and mischaracterization of PCa. Therefore, new imaging modalities like shear wave elastography (SWE) are required. AIM: The aim of this study was to evaluate per-core detection rates (DRs) of targeted biopsies and systematic biopsies and to test if SWE findings can predict presence of clinically significant PCa (csPCa) at biopsy. PATIENTS AND METHODS: Overall, 95 patients scheduled for prostate biopsy in our center underwent SWE. SWE findings were classified into suspicious or normal. Targeted biopsies were taken in up to 3 SWE-suspicious areas. csPCa was defined as the presence of Gleason pattern ≥4, level of prostate-specific antigen ≥10 ng/ml or >2 positive cores. RESULTS: Overall DR for csPCa in our study cohort was 40%. Per-core DR for exclusively SWE-targeted cores versus systematic samples cores was 10.5 vs. 8.6% (p = 0.3). In the logistic regression models, individuals with suspicious SWE findings are at 6.4-fold higher risk of harboring csPCa (p = 0.03). Gain in predictive accuracy was 2.3% (0.82 vs. 0.84, p = 0.01). CONCLUSIONS: Presence of suspicious SWE findings is an independent predictor of csPCa. Therefore, SWE may be helpful in selecting patients for biopsy. Nonetheless, per-core DR for SWE-targeted cores was not statistically significant higher than DR of systematic sampled cores. Therefore, additional systematic biopsy is mandatory.

Proteomic analysis of patient tissue reveals PSA protein in the stroma of benign prostatic hyperplasia.

BACKGROUND: Benign prostatic hyperplasia (BPH) is an age-related disease frequently associated with lower urinary tract symptoms (LUTS) that involves hyperplasia of both epithelial and stromal cells. Stromal fibrosis is a distinctive feature of BPH, but the exact mechanisms underlying this phenomenon are poorly understood. METHODS: In the current study, proteomics analyses were utilized to identify proteins altered in the BPH stromal compartment from patients with symptomatic BPH. Stromal cells were isolated from histological nodules of BPH by laser capture microdissection (LCM) and subjected to liquid chromatography/mass spectrometry. RESULTS: Proteins identified included several stromal-specific proteins involved in extracellular matrix (ECM) remodeling, focal adhesion, and cellular junctions. Additionally, the proteomics array identified the presence of luminal epithelial secretory protein PSA. Immunostaining, ELISA, and in situ hybridization analyses of BPH tissues verified the presence of PSA protein but absence of PSA mRNA in the stromal compartment. E-cadherin was down-regulated in BPH epithelial cells compared to normal adjacent tissues, suggesting that alteration of cellular junctions could contribute to the presence of luminal epithelial secreted proteins PSA and KLK2 in the stromal compartment. CONCLUSIONS: The above findings suggest that the presence of secreted proteins PSA and KLK2 from prostate luminal epithelial cells in BPH stroma is a hallmark of BPH nodules, which could in part be due to alterations in cellular junction proteins and/or increased epithelial barrier permeability. Elucidating the cause and consequence of these secreted proteins in the stromal compartment of BPH may lead to new understanding of BPH pathogenesis as well as approaches to prevent and/or treat this common disease.

KLK3, PCA3, and TMPRSS2-ERG expression in the peripheral blood mononuclear cell fraction from castration-resistant prostate cancer patients and response to docetaxel treatment.

BACKGROUND: To monitor systemic disease activity, the potential of circulating tumor cells (CTCs) bears great promise. As surrogate for CTCs we measured KLK3, PCA3, and TMPRSS2-ERG messenger RNA (mRNA) in the peripheral blood mononuclear cell (PBMC) fraction from a castration-resistant prostate cancer (CRPC) patient cohort and three control groups. Moreover, biomarker response to docetaxel treatment was evaluated in the patient group. METHODS: Blood samples from 20 CRPC patients were analyzed at four different time points (prior to docetaxel treatment, at 9 weeks, 27 weeks, and 2 months after treatment). Blood was drawn once from three control groups (10 age-matched men, 10 men under 35 years of age, 12 women). All samples were analyzed for KLK3, PCA3, and TMPRSS2-ERG mRNA by using a quantitative nucleic acid amplification assay with gene-specific primers in the complementary DNA synthesis. RESULTS: At baseline, mRNA for KLK3 was detected in 17 (89%, 95% CI 76-100%), PCA3 in 10 (53%, 95% CI 30-75%), and TMPRSS2-ERG in seven of 19 evaluable patients (37%, 95% CI 15-59%). In contrast, the blood samples from all 32 healthy volunteers were reproducible negative for all markers. In response to docetaxel treatment, KLK3 levels decreased in 80% (95% CI 60-100%), PCA3 in 89% (95% CI 68-100%), and TMPRSS2-ERG in 86% (95% CI 60-100%) of patients. CONCLUSIONS: The feasibility of a highly sensitive modified nucleic acid amplification assay to assess KLK3, PCA3, and TMPRSS2-ERG mRNA in the PBMC fraction from CRPC patients was demonstrated. Moreover, response of these markers to systemic treatment was shown.

High placenta-specific 1/low prostate-specific antigen expression pattern in high-grade prostate adenocarcinoma.

BACKGROUND: The scarcity of effective therapeutic approaches for prostate cancer (PCa) has encouraged steadily growing interest for the identification of novel antigenic targets. Placenta-specific 1 (PLAC1) is a novel cancer-testis antigen with reported ectopic expression in a variety of tumors and cancer cell lines. The purpose of the present study was to investigate for the first time the differential expression of PLAC1 in PCa tissues. METHODS: We investigated the differential expression of PLAC1 in PCa, high-grade prostatic intraepithelial neoplasia (HPIN), benign prostatic hyperplasia (BPH), and nonneoplastic/nonhyperplastic prostate tissues using microarray-based immunohistochemistry (n = 227). The correlation of PLAC1 expression with certain clinicopathological parameters and expression of prostate-specific antigen (PSA), as a prostate epithelial cell differentiation marker, were investigated. RESULTS: Placenta-specific 1 (PLAC1) expression was increased in a stepwise manner from BPH to PCa, which expressed highest levels of this molecule, while in a majority of normal tissues, PLAC1 expression was not detected. Moreover, PLAC1 expression was positively associated with Gleason score (p ≤ 0.001). Interestingly, there was a negative correlation between PLAC1 and PSA expression in patients with PCa and HPIN (p ≤ 0.01). Increment of PLAC1 expression increased the odds of PCa and HPIN diagnosis (OR 49.45, 95 % CI for OR 16.17-151.25). CONCLUSION: Our findings on differential expression of PLAC1 in PCa plus its positive association with Gleason score and negative correlation with PSA expression highlight the potential usefulness of PLAC1 for targeted PC therapy especially for patients with advanced disease.

Expressed prostatic secretion biomarkers improve stratification of NCCN active surveillance candidates: performance of secretion capacity and TMPRSS2:ERG models.

PURPOSE: Active surveillance is a viable patient option for prostate cancer provided that a clinical determination of low risk and presumably organ confined disease can be made. To standardize risk stratification schemes the NCCN (National Comprehensive Cancer Network®) provides guidelines for the active surveillance option. We determined the effectiveness of expressed prostatic secretion biomarkers for detecting occult risk factors in NCCN active surveillance candidates. MATERIALS AND METHODS: Expressed prostatic secretion specimens were obtained before robot-assisted radical prostatectomy. Secretion capacity biomarkers, including total RNA and expressed prostatic secretion specimen volume, were measured by standard techniques. RNA expression biomarkers, including TXNRD1 mRNA, prostate specific antigen mRNA, TMPRSS2:ERG fusion mRNA and PCA3 mRNA, were measured by quantitative reverse-transcription polymerase chain reaction. RESULTS: Of the 528 patients from whom expressed prostatic secretions were collected 216 were eligible for active surveillance under NCCN guidelines. Variable selection on logistic regression identified 2 models, including one featuring types III and VI TMPRSS2:ERG variants, and one featuring 2 secretion capacity biomarkers. Of the 2 high performing models the secretion capacity model was most effective for detecting cases in this group that were up-staged or up-staged plus upgraded. It decreased the risk of up-staging in patients with a negative test almost eightfold and decreased the risk of up-staging plus upgrading about fivefold while doubling the prevalence of up-staging in the positive test group. CONCLUSIONS: Noninvasive expressed prostatic secretion testing may improve patient acceptance of active surveillance by dramatically reducing the presence of occult risk factors among those eligible for active surveillance under NCCN guidelines.

Can delayed time to referral to a tertiary level urologist with an abnormal PSA level affect subsequent Gleason grade in the opportunistically screened population?

PURPOSE: There is growing conflict in the literature describing the effect of delayed treatment on outcomes following radical prostatectomy. There is also evidence to suggest progression of low-risk prostate cancer to develop higher grades and volumes of prostate cancer during active surveillance. It is unknown as to what affect a delay in referral of those men with abnormal screened-PSA levels have on subsequent Gleason grade. METHODS: We identified 350 men through our rapid access prostate clinic who underwent TRUS biopsy for abnormal age-related PSA and/or abnormal clinical examination. Clinicopathological findings were compared for those with positive versus negative TRUS biopsies, and for those with initial delays in referral (<12 months, 12-18 months, and >18 months). We used ANOVA and Student's t-tests amongst other statistical tools to examine significance of clinical findings. RESULTS: Of the 350 men who underwent TRUS biopsy, those with a delay in referral of 12 months or more were significantly associated with higher PSA titers, clinically palpable disease and likelihood of diagnosis with prostate cancer. A delay of 18 months or more led to a significantly higher risk of being diagnosed with a leading grade 4 prostate cancer, which was further supported using PSA velocity as a diagnostic tool (change >0.4 ng/ml/year). CONCLUSION: We recommend that repeated asymptomatic abnormal age-related PSA readings and/or abnormal clinical examination in the screened population be referred without delay to a urologist for further assessment, enrolment into an active surveillance program or definitive subsequent treatment.

Fenofibrate down-regulates the expressions of androgen receptor (AR) and AR target genes and induces oxidative stress in the prostate cancer cell line LNCaP.

Fenofibrate, a peroxisome proliferator-androgen receptor-alpha agonist, is widely used in treating different forms of hyperlipidemia and hypercholesterolemia. Recent reports have indicated that fenofibrate exerts anti-proliferative and pro-apoptotic properties. This study aims to investigate the effects of fenofibrate on the prostate cancer (PCa) cell line LNCaP. The effects of fenofibrate on LNCaP cells were evaluated by flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assays, Western blot analysis, and dual-luciferase reporter assay. Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells, reduces the expressions of androgen receptor (AR) and AR target genes (prostate-specific antigen and TMPRSS2), and inhibits Akt phosphorylation. Fenofibrate can induce the accumulation of intracellular reactive oxygen species and malondialdehyde, and decrease the activities of total anti-oxidant and superoxide dismutase in LNCaP cells. Fenofibrate exerts an anti-proliferative property by inhibiting the expression of AR and induces apoptosis by causing oxidative stress. Therefore, our data suggest fenofibrate may have beneficial effects in fenofibrate users by preventing prostate cancer growth through inhibition of androgen activation and expression.

Comparison of MRS and DWI in the diagnosis of prostate cancer based on sextant analysis.

PURPOSE: To evaluate apparent diffusion coefficient (ADC) value, metabolic ratio ((Cho + Cr)/Cit) and the combination of the two in identifying prostate malignant regions. MATERIALS AND METHODS: Fifty-six consecutive patients with prostate biopsy results were retrospectively recruited in this study. Transrectal ultrasound-guided (TRUS) systemic prostate biopsies were used as a standard of reference. Mean ADC value and mean metabolic ratio (MMR) were calculated within each benign sextant region or malignant region. The efficiency of these two indices in prostate cancer (PCa) diagnosis is estimated in Fisher linear discriminant analysis (FLDA). The area under the receiver operating characteristic (ROC) curve was used to evaluate the distinguishing capacity of mean ADC, MMR, and the combination of the two in differentiating between noncancerous and cancerous cases. RESULTS: There were significant differences for mean ADC value and MMR between malignant and benign regions. Weights of mean ADC value obtained by FLDA were much higher than those of MMR. In differentiating malignant regions, both ADC alone and combined ADC and metabolic ratio performed significantly better than MMR alone. However, accuracy improvements were not significant by using combined ADC and MMR than ADC alone. CONCLUSION: DWI is more efficient than MR spectroscopic (MRS) in the detection of PCa in this study. Combined ADC and MMR performed significantly better than MMR alone in distinguishing malignant from benign region in prostate peripheral zone.