Malignant Prostate Tissue Research Articles

Role of the androgen receptor in prostate cancer

AbstractInhibition of the androgen receptor leads to regression of normal and malignant prostate tissue. The authors discuss therapeutic strategies for directly targeting the androgen receptor to help address the problem of castrate‐resistant prostate cancer. Copyright © 2013 John Wiley & Sons

Why prostate tumour delineation based on apparent diffusion coefficient is challenging: An exploration of the tissue microanatomy

Background. Focal boosting of prostate tumours to improve outcome, requires accurate tumour delineation. For this, the apparent diffusion coefficient (ADC) derived from diffusion-weighted MR imaging (DWI) seems a useful tool. On voxel level, the relationship between ADC and histological presence of tumour is, however, ambiguous. Therefore, in this study the relationship between ADC and histological variables was investigated on voxel level to understand the strengths and limitations of DWI for prostate tumour delineation. Material and methods. Twelve radical prostatectomy patients underwent a pre-operative 3.0T DWI exam and the ADC was calculated. From whole-mount histological sections cell density and glandular area were retrieved for every voxel. The distribution of all variables was described for tumour, peripheral zone (PZ) and central gland (CG) on regional and voxel level. Correlations between variables and differences between regions were calculated. Results. Large heterogeneity of ADC on voxel level was observed within tumours, between tumours and between patients. This heterogeneity was reflected by the distribution of cell density and glandular area. On regional level, tumour was different from PZ having higher cell density (p = 0.007), less glandular area (p = 0.017) and lower ADCs (p = 0.017). ADC was correlated with glandular area (r = 0.402) and tumour volume (r = −0.608), but not with Gleason score. ADC tended to decrease with increasing cell density (r = −0.327, p = 0.073). On voxel level, correlations between ADC and histological variables varied among patients, for cell density ranging from r = −0.439 to r = 0.261 and for glandular area from r = 0.593 to r = 0.207. Conclusions. The variation in ADC can to a certain extent be explained by the variation in cell density and glandular area. The ADC is highly heterogeneous, which reflects the heterogeneity of malignant and benign prostate tissue. This heterogeneity might however obscure small tumours or parts of tumours. Therefore, DWI has to be used in the context of multiparametric MRI.

Impaired expression of protein phosphatase 2A subunits enhances metastatic potential of human prostate cancer cells through activation of AKT pathway

Background:Protein phosphatase 2A (PP2A) is a dephosphorylating enzyme, loss of which can contribute to prostate cancer (PCa) pathogenesis. The aim of this study was to analyse the transcriptional and translational expression patterns of individual subunits of the PP2A holoenzyme during PCa progression.Methods:Immunohistochemistry (IHC), western blot, and real-time PCR was performed on androgen-dependent (AD) and androgen-independent (AI) PCa cells, and benign and malignant prostate tissues for all the three PP2A (scaffold, regulatory, and catalytic) subunits. Mechanistic and functional studies were performed using various biochemical and cellular techniques.Results:Through immunohistochemical analysis we observed significantly reduced levels of PP2A-A and -B′γ subunits (P<0.001 and P=0.0002) in PCa specimens compared with benign prostate. Contemporarily, there was no significant difference in PP2A-C subunit expression between benign and malignant tissues. Similar to the expression pattern observed in tissues, the endogenous levels of PP2A-A and B′γ subunits were abrogated from the low metastatic to high metastatic and AD to AI cell line models, without any change in the catalytic subunit expression. Furthermore, using in vitro studies we demonstrated that PP2A-Aα scaffold subunit has a role in dampening AKT, β-catenin, and FAK (focal adhesion kinase) signalling.Conclusion:We conclude that loss of expression of scaffold and regulatory subunits of PP2A is responsible for its altered function during PCa pathogenesis.

Abstract 3040: Cavin-1 alters oncogenic effects of caveolin-1 microdomains in prostate cancer.

Abstract Caveolin-1 is associated with prostate cancer progression and has been suggested to be a biomarker and therapeutic target. Mature caveolin-1 resides in lipid raft domains at the plasma membrane, where it forms caveolae upon co-expression of cavin-1 (also known as PTRF; polymerase I and transcript release factor). In the absence of cavin-1, caveolin-1 does not form caveolae but are found on flat membrane. To determine if oncogenic caveolin-1 in prostate cancer is present in caveolae, we examined the relative expression of caveolin-1 and cavin-1 in normal, non-malignant and malignant prostate tissues. We found that caveolin-1 is induced in prostate cancer without cavin-1, an expression pattern mirror in the PC3 cell line. Previously we showed that expression of cavin-1 in PC3 cells recruits flat membrane caveolin-1 to caveolae and reduced transmigration. Here we report that cavin-1 expression reduces tumour size and metastasis of PC3 cells in vivo, using an orthotopic prostate cancer xenograft mouse model. To determine if cavin-1 acts by neutralizing oncogenic caveolin-1, we expressed cavin-1 in caveolin-1 negative LNCaP and 22Rv1 cells. While caveolin-1 over-expression increased anchorage-independent growth of LNCaP and 22Rv1 cells, cavin-1 over-expression had no effect. Furthermore, co-expression of cavin-1 in LNCaP+caveolin-1 cells reversed caveolin-1 effect. Taken together, these results suggest that caveolin-1 in prostate cancer is present outside of caveolae, and caveola formation by cavin-1 co-expression alters the oncogenic effect of non-caveolar caveolin-1 microdomains. Citation Format: Hyeongsun Moon, C Soon Lee, Sowmya Sharma, Kerry Inder, Debra Black, Kim-Anh Lê Cao, Clay Winterford, Patrick Ling, the Australian Prostate Cancer BioResource, David Craik, Robert Parton, Pamela Russell, Michelle Hill. Cavin-1 alters oncogenic effects of caveolin-1 microdomains in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3040. doi:10.1158/1538-7445.AM2013-3040

Abstract 5205: Galectin-3 and AP-1 mediate transcriptional effect of Arylsulfatase B (N-acetylgalactosamine-4-sulfatase) on versican in prostatic cells.

Abstract N-acetylgalactosamine-4-sulfatase (Arylsulfatase B; ARSB) modifies the glycosaminoglycans (GAGs) chondroitin-4-sulfate (C4S) and dermatan sulfate by removing 4-sulfate groups from the non-reducing end and thereby regulating GAG degradation. Previous studies demonstrated that ARSB was reduced in malignant human colonic, mammary, and prostatic tissue and suggested that ARSB acts as a tumor suppressor. In this report, ARSB was silenced by siRNA in the WPMY-1 human prostate stromal myofibroblast cell line (ATCC), and effects on C4S, total sulfated glycosaminoglycans (GAGs), ErbB2, total EGFR, phospho-ERK, versican, and AP-1 were determined. Total sulfated GAGs were measured by Blyscan assay (Biocolor), and C4S was determined by Blyscan assay following immunoprecipitation by C4S antibody. Phospho(T202/Y204 for ERK1 or T185/Y187 for ERK2)-ERK, ErbB2, and total EGFR were measured by ELISA. Versican, an extracellular matrix chondroitin sulfate proteoglycan with EGF-like repeats at its C-terminus, was measured by ELISA and QPCR. ARSB and galectin-3 were silenced by siRNA (Qiagen). ARSB activity declined from 140.4 ± 8.4 to 21.4 ± 0.9 nmol/mg protein/hr following silencing. Total sulfated GAGs increased from 17.9 ± 0.7 μg/mg protein in control cells to 28.6 ± 1.4 μg/mg protein following ARSB silencing, and C4S increased from 7.4 ± 0.6 μg/mg protein to 15.5 ± 0.8 μg/mg protein following ARSB silencing. Total EGFR increased to 2.65 times baseline, and ErbB2 increased to over six-fold times baseline. Phospho-ERK increased to more than three times baseline, from 5.0 ± 0.5 ng/mg protein to 15.2 ± 0.8 ng/mg protein following silencing. Versican protein increased from 122.1 ± 5.3 ng/mg protein in control to 295.2 ± 11.2 ng/mg protein and mRNA increased more than two-fold. ARSB-silencing induced increases in versican mRNA and in activation of c-Jun and c-Fos, and these increases were inhibited when galectin-3 was also silenced. [All findings are highly significant (p&amp;lt;0.001, one-way ANOVA with Tukey-Kramer post-test)]. Previously, we have shown reduced binding of galectin-3 to C4S following ARSB silencing. Since there is an AP-1 binding site in the versican promoter, study data demonstrate that transcriptional effects of ARSB silencing on versican are mediated by galectin-3 and AP-1. The profound effects of ARSB silencing on versican and phospho-ERK in the prostatic myofibroblasts provide further evidence that ARSB acts as a tumor suppressor. Citation Format: Sumit Bhattacharyya, Leonid Feferman, Joanne Kramer Tobacman. Galectin-3 and AP-1 mediate transcriptional effect of Arylsulfatase B (N-acetylgalactosamine-4-sulfatase) on versican in prostatic cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5205. doi:10.1158/1538-7445.AM2013-5205

Abstract 4683: Correlation of transcript levels of members of the urokinase-type plasminogen activator system with clinico-pathological parameters in prostate cancer .

Abstract Background: Members of the urokinase-type plasminogen activator (uPA) system play an important role in tumor progression and angiogenesis in different human malignancies including breast, kidney, colon, stomach and prostate cancer (PCa). Aim of the study was to characterize mRNA expression levels of members of the uPA system in tissue specimens from primary PCa and their potential association with clinico-pathological parameters. Methods: Transcript levels of members of the uPA system, i.e., uPA, uPA receptor (uPAR) and plasminogen activator inhibitor type 1 (PAI-1) were analyzed in a cohort of 132 corresponding pairs of malignant and adjacent non-malignant prostate tissue samples. Relative gene expression levels were determined by quantitative PCR (qPCR) and normalized to the reference gene TATA-box-binding protein (TBP). Potential correlations between the three markers themselves and the clinico-pathological parameters were assessed by Spearman's Rho test and by Fisher's exact test. Results: There were no significant differences in expression levels of uPA system genes between the corresponding malignant and non-malignant tissue specimens. Transcript levels of all members of the uPA system displayed a significant correlation with each other in the tumor tissues. At stratifying uPA, uPAR and PAI-1 expression levels by the median a significant correlation between an elevated expression of uPA and PAI-1 was correlated with higher Gleason score (P = 0.001 and P = 0.007). In addition, a significant positive correlation between uPAR transcript levels and tumor stage was detected (P = 0.025). Conclusion: Our results demonstrate that mRNA expression levels of members of the uPA system correlated with each other and with clinico-pathological parameters. We suggest that transcript levels of uPA system members can be helpful markers for the study of tumor behavior of prostate cancer. Citation Format: Omar Al-Janabi, Helge Taubert, Sven Wach, Robert Stöhr, Maximilian Burger, Wolf Ferdinand Wieland, Andrea Lohse-Fischer, Michael Fröhner, Manfred P. Wirth, Bernd Wullich, Viktor Magdolen, Matthias Kotzsch, Susanne Fuessel. Correlation of transcript levels of members of the urokinase-type plasminogen activator system with clinico-pathological parameters in prostate cancer . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4683. doi:10.1158/1538-7445.AM2013-4683

Role of choline PET/CT in guiding target volume delineation for irradiation of prostate cancer

Choline PET/CT has shown limitations for the detection of primary prostate cancer and nodal metastatic disease, mainly due to limited sensitivity and specificity. Conversely in the restaging of prostate cancer recurrence, choline PET/CT is a promising imaging modality for the detection of local regional and nodal recurrence with an impact on therapy management. This review highlights current literature on choline PET/CT for radiation treatment planning in primary and recurrent prostate cancer. Due to limited sensitivity and specificity in differentiating between benign and malignant prostatic tissues in primary prostate cancer, there is little enthusiasm for target volume delineation based on choline PET/CT. Irradiation planning for the treatment of single lymph node metastases on the basis of choline PET/CT is controversial due to its limited lesion-based sensitivity in primary nodal staging. In high-risk prostate cancer, choline PET/CT might diagnose lymph node metastases, which potentially can be included in the conventional irradiation field. Prior to radiation treatment of recurrent prostate cancer, choline PET/CT may prove useful for patient stratification by excluding distant disease which would require systemic therapy. In patients with local recurrence, choline PET/CT can be used to delineate local sites of recurrence within the prostatic resection bed allowing a boost to PET-positive sites. In patients with lymph node metastases outside the prostatic fossa and regional metastatic lymph nodes, choline PET/CT might influence radiation treatment planning by enabling extension of the target volume to lymphatic drainage sites with or without a boost to PET-positive lymph nodes. Further clinical randomized trials are required to assess treatment outcomes following choline-based biological radiation treatment planning in comparison with conventional radiation treatment planning.

Role of androgen and vitamin D receptors in endothelial cells from benign and malignant human prostate

Forty years ago, Judah Folkman (Folkman. N Engl J Med 285: 1182-1186, 1971) proposed that tumor growth might be controlled by limiting formation of new blood vessels (angiogenesis) needed to supply a growing tumor with oxygen and nutrients. To this end, numerous "antiangiogenic" agents have been developed and tested for therapeutic efficacy in cancer patients, including prostate cancer (CaP) patients, with limited success. Despite the lack of clinical efficacy of lead anti-angiogenic therapeutics in CaP patients, recent published evidence continues to support the idea that prostate tumor vasculature provides a reasonable target for development of new therapeutics. Particularly relevant to antiangiogenic therapies targeted to the prostate is the observation that specific hormones can affect the survival and vascular function of prostate endothelial cells within normal and malignant prostate tissues. Here, we review the evidence demonstrating that both androgen(s) and vitamin D significantly impact the growth and survival of endothelial cells residing within prostate cancer and that systemic changes in circulating androgen or vitamin D drastically affect blood flow and vascularity of prostate tissue. Furthermore, recent evidence will be discussed about the expression of the receptors for both androgen and vitamin D in prostate endothelial cells that argues for direct effects of these hormone-activated receptors on the biology of endothelial cells. Based on this literature, we propose that prostate tumor vasculature represents an unexplored target for modulation of tumor growth. A better understanding of androgen and vitamin D effects on prostate endothelial cells will support development of more effective angiogenesis-targeting therapeutics for CaP patients.

Treatment Effects in Prostate Cancer following Traditional and Emerging Therapies

Treatment options for prostate cancer consist of radical prostatectomy, hormonal therapy and radiation therapy. Hormonal and radiation therapy have well-known, often profound, effects on the histological appearance of benign and malignant prostate tissue. Novel therapies including focal ablative treatments, chemotherapies and targeted molecular therapies are beginning to emerge and pathologists will play a central role in documenting the effects of these treatments at the tissue level. As such, knowledge of treatment-related changes and access to clinical information are essential to ensure accurate interpretation and reporting of post-treatment prostate specimens by pathologists.

Orphan Nuclear Receptor Nurr1 as a Potential Novel Marker for Progression in Human Prostate Cancer

A number of studies have indicated that Nurr1, which belongs to a novel class of orphan nuclear receptors (the NR4A family), is important for carcinogenesis. Here we investigated expression of Nurr1 protein in benign and malignant human prostate tissues and association with clinicopathologic features using immunohistochemical techniques. Moreover, we also investigated the ability of Nurr1 to influence proliferation, migration, invasion and apoptosis of human prostate cancer cells using small interfering RNA silencing. Immunohistochemical analysis revealed that the expression of Nurr1 protein was higher in prostate cancer tissues than in benign prostate tissue (P < 0.001), levels being positively correlated with tumor T classification (P = 0.003), N classification (P = 0.017), M classification (P = 0.011) and the Gleason score (P = 0.020) of prostate cancer patients. In vitro, silencing of endogenous Nurr1 attenuated cell proliferation, migration and invasion, and induced apoptosis of prostate cancer cells. These results suggest that Nurr1 may be used as an indicator for prostate cancer progression and be useful for novel potential therapeutic strategies.

801 REVERSAL OF CHEMOSENSITIVITY AND INDUCTION OF CELL MALIGNANCY OF A NON-MALIGNANT PROSTATE CANCER CELL LINE UPON MICROVESICLE EXPOSURE

You have accessJournal of UrologyProstate Cancer: Basic Research (IV)1 Apr 2013801 REVERSAL OF CHEMOSENSITIVITY AND INDUCTION OF CELL MALIGNANCY OF A NON-MALIGNANT PROSTATE CANCER CELL LINE UPON MICROVESICLE EXPOSURE Sam Cross-Knorr, Joseph Renzulli, Dionysios Pantazatos, Kiki Panagopoulos, Michael Del Tatto, Lisa Goldstein, Peter Quesenberry, and Devasis Chatterjee Sam Cross-KnorrSam Cross-Knorr Providence, RI More articles by this author , Joseph RenzulliJoseph Renzulli Providence, RI More articles by this author , Dionysios PantazatosDionysios Pantazatos Providence, RI More articles by this author , Kiki PanagopoulosKiki Panagopoulos Providence, RI More articles by this author , Michael Del TattoMichael Del Tatto Providence, RI More articles by this author , Lisa GoldsteinLisa Goldstein Providence, RI More articles by this author , Peter QuesenberryPeter Quesenberry Providence, RI More articles by this author , and Devasis ChatterjeeDevasis Chatterjee Providence, RI More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.365AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Microvesicle trafficking is a fundamental cellular process that occurs in cells and is required for multifarious aspects of pathophysiology. A wide variety of microvesicle trafficking genes have been shown to display altered expression in diverse cancers. Moreover, microvesicle trafficking leads to other changes in cellular function, including apoptosis, angiogenesis and proliferation required for increased tumor formation. It has been suggested that the clinical behavior and response of prostate cancer is linked to differences in gene expression. We report several phenotypic changes mediated by microvesicles (MVs) isolated from non- and malignant prostate cells as well as patient biopsied prostate tumor samples. METHODS Human prostate cancer tissue was harvested from fresh specimens and prostate cancer microvesicles were isolated. The microvesicles were then co-cultured with non-malignant cells from a prostate cell line for 21 days. The cells were then harvested and western blot analysis was carried out. RESULTS Microvesicles can reverse the resistance of prostate cancer cells to camptothecin(CPT)chemotherapy. Prostate cells resistant to camptothecin(RC1) undergo apoptosis when co-cultured with MVs isolated from DU145 cells. In addition, we observe the reciprocal effect whereby DU145 cells become resistant to CPT when co-cultured with MVs from RC1 cells. MVs isolated from non-malignant PrEC cells can reverse soft agar colony formation of malignant DU145 cells, with the reciprocal effect also observed. Significantly, we identified an increase in SOCS2 and decrease in STAT3, 2 proteins intimately involved with Jak/STAT signaling, via antibody analysis that may be responsible for the phenotypic changes. Isolation of MVs from 2 Gleason grade 8 prostate cancer patients significantly induced soft agar colony formation of non-malignant PrEC cells. Mass spectrometry analysis of lysates revealed several protein candidates that may be responsible for this phenotypic change. Western blot analysis confirmed the phosphorylation of RKIP, a protein known to lead to enhanced Raf-mediated cell survival signaling and 14-3-3 zeta, a tumor promoting protein. CONCLUSIONS Our study provides a rational basis to investigate proteins and other genetic factors that may be responsible for phenotypic changes that are associated with normal and malignant prostate tissue microvesicles. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e330 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sam Cross-Knorr Providence, RI More articles by this author Joseph Renzulli Providence, RI More articles by this author Dionysios Pantazatos Providence, RI More articles by this author Kiki Panagopoulos Providence, RI More articles by this author Michael Del Tatto Providence, RI More articles by this author Lisa Goldstein Providence, RI More articles by this author Peter Quesenberry Providence, RI More articles by this author Devasis Chatterjee Providence, RI More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Bcl-2 associated athanogene 5 (Bag5) is overexpressed in prostate cancer and inhibits ER-stress induced apoptosis

BackgroundThe Bag (Bcl-2 associated athanogene) family of proteins consists of 6 members sharing a common, single-copied Bag domain through which they interact with the molecular chaperone Hsp70. Bag5 represents an exception in the Bag family since it consists of 5 Bag domains covering the whole protein. Bag proteins like Bag1 and Bag3 have been implicated in tumor growth and survival but it is not known whether Bag5 also exhibits this function.MethodsBag5 mRNA and protein expression levels were investigated in prostate cancer patient samples using real-time PCR and immunoblot analyses. In addition immunohistological studies were carried out to determine the expression of Bag5 in tissue arrays. Analysis of Bag5 gene expression was carried out using one-way ANOVA and Bonferroni’s Multiple Comparison test. The mean values of the Bag5 stained cells in the tissue array was analyzed by Mann-Whitney test. Functional studies of the role of Bag5 in prostate cancer cell lines was performed using overexpression and RNA interference analyses.ResultsOur results show that Bag5 is overexpressed in malignant prostate tissue compared to benign samples. In addition we could show that Bag5 levels are increased following endoplasmic reticulum (ER)-stress induction, and Bag5 relocates from the cytoplasm to the ER during this process. We also demonstrate that Bag5 interacts with the ER-resident chaperone GRP78/BiP and enhances its ATPase activity. Bag5 overexpression in 22Rv.1 prostate cancer cells inhibited ER-stress induced apoptosis in the unfolded protein response by suppressing PERK-eIF2-ATF4 activity while enhancing the IRE1-Xbp1 axis of this pathway. Cells expressing high levels of Bag5 showed reduced sensitivity to apoptosis induced by different agents while Bag5 downregulation resulted in increased stress-induced cell death.ConclusionsWe have therefore shown that Bag5 is overexpressed in prostate cancer and plays a role in ER-stress induced apoptosis. Furthermore we have identified GRP78/BiP as a novel interaction partner of Bag5.

A parallelism between spectral grading and Gleason grading of malignant prostate tissues

Gleason score is the most common method of grading the virulence of prostate malignancy and is based on the pathological assessment of morphology of cellular matrix. Since this involves the excision of the tissue, we are working on a new, minimally invasive, non-contact, procedure of spectral diagnosis of prostate malignancy. In this preliminary in vitro study reported here, we have analyzed 27 tissue samples (normal control=7: benign=8: malignant=12) by Stokes' shift spectra (SSS) to establish a one-to-one correspondence between spectral grading and Gleason grading.

Glutamate, a metabolic biomarker of aggressiveness and a potential therapeutic target for prostate cancer

Glutamate, a metabolic biomarker of aggressiveness and a potential therapeutic target for prostate cancer

The Long and Winding Road to FDA Approval of a Novel Prostate Cancer Test: Our Story

Only a very small fraction of the many tumor biomarkers discovered are successfully translated from the academic research laboratory into clinical practice. The pathway has not always been linear and has involved people with expertise in a wide range of specialties, including basic research, assay development, clinical affairs, regulatory affairs, marketing, business, oncology, and executive-management leadership. The experience with a tumor biomarker, the PCA3 [prostate cancer gene 3 (non-protein coding)] gene, illustrates the long and winding road that must be navigated. Here we reflect, from a historical point of view, on how the interface between academic science, industry, urologists, and clinical laboratories has been essential to advance biomarkers from solid basic science to a validated clinical laboratory test. PCA3 was first described as DD3 in 1999 by Bussemakers and colleagues (1). Researchers in the Isaacs laboratory at Johns Hopkins University used differential-display analysis to compare patterns of mRNA production in benign and malignant prostate tissue, with the goal of identifying unknown genes involved in prostate tumorigenesis. PCA3 expression was further characterized in the Schalken laboratory at Radboud University, Nijmegen (2), and this research confirmed 2 important properties of PCA3 as a prostate cancer (PCa)6 marker: PCA3 expression is prostate tissue specific, and PCA3 is highly overexpressed in PCa compared with benign tissue. This PCa-specific overexpression led the Nijmegen researchers to assess the feasibility of a PCA3 -based urine test for PCa detection. In 2001, a license for PCA3 was obtained by DiagnoCure, a company in Quebec City, Canada, to develop the assay and provide a clinical application. Transfer of a cancer biomarker to industry requires both the appropriate technology and a proper cancer strategy. The Nijmegen methodology was converted from PCR to nucleic acid sequence–based amplification (NASBA), a …

New Players for Advanced Prostate Cancer and the Rationalisation of Insulin-Sensitising Medication

Obesity and type 2 diabetes are recognised risk factors for the development of some cancers and, increasingly, predict more aggressive disease, treatment failure, and cancer-specific mortality. Many factors may contribute to this clinical observation. Hyperinsulinaemia, dyslipidaemia, hypoxia, ER stress, and inflammation associated with expanded adipose tissue are thought to be among the main culprits driving malignant growth and cancer advancement. This observation has led to the proposal of the potential utility of “old players” for the treatment of type 2 diabetes and metabolic syndrome as new cancer adjuvant therapeutics. Androgen-regulated pathways drive proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen deprivation therapy (ADT) exploits this dependence to systemically treat advanced prostate cancer resulting in anticancer response and improvement of cancer symptoms. However, the initial therapeutic response from ADT eventually progresses to castrate resistant prostate cancer (CRPC) which is currently incurable. ADT rapidly induces hyperinsulinaemia which is associated with more rapid treatment failure. We discuss current observations of cancer in the context of obesity, diabetes, and insulin-lowering medication. We provide an update on current treatments for advanced prostate cancer and discuss whether metabolic dysfunction, developed during ADT, provides a unique therapeutic window for rapid translation of insulin-sensitising medication as combination therapy with antiandrogen targeting agents for the management of advanced prostate cancer.

Distribution and Possible Function of Cannabinoid Receptor Subtype 1 in the Human Prostate

Background: Cannabinoid receptor subtype 1 (CB1) has a relationship to the proliferation of various cells including malignant tumoral cells. We investigated and compared the expression of CB1 in benign and malignant human prostate tissues and in benign and malignant human prostate cell lines, as well as its function for the proliferation of human prostate cancer cells. Methods: Real-time quantitative PCR was performed to compare its expressions in human prostate tissues (normal, benign hyperplasia, and cancer) and prostate cell lines (3 normal and 3 malignant). For localization of CB1, immunofluorescent staining with rabbit anti-CB1 polyclonal antibodies and tetramethyl isothiocyanate (TRITC)-labeled swine anti-rabbit immunoglobulin (DAKO) were used under fluorescence microscope. To further analyze whether cell death was induced by anandamide (non-selective agonist for CB1/CB2) via a receptor dependent mechanism, the viability of DU145 cells, which is known as androgen-insensitive prostate cancer cell, was measured using MTT assay. Results: CB1mRNA was found to be expressed in the all 3 human prostate tissues, however, CB1 protein was expressed in BPH and low grade malignant PC tissues, but not in high grade malignant PC tissues. CB1 as for cell lines, the expression of CB1 was low in malignant cell lines except for DU145. Anandamide elicited cell death, which was significantly inhibited by AM251 (selective antagonist for CB1), indicating that cell death induced by anandamide in DU145 cells was mediated by CB1. Anandamide time-dependently elicits up-regulation of CB1 in DU145 cells. Conclusions: CB1 may be an inhibitory regulator of androgen-insensitive human prostate cancer epithelial cell growth.

Epithelial-to-Mesenchymal Transition Leads to Docetaxel Resistance in Prostate Cancer and Is Mediated by Reduced Expression of miR-200c and miR-205

Docetaxel is a standard chemotherapy for patients with metastatic prostate cancer. However, the response is rather limited and not all of the patients benefit from this treatment. To uncover key mechanisms of docetaxel insensitivity in prostate cancer, we have established docetaxel-resistant sublines. In this study, we report that docetaxel-resistant cells underwent an epithelial-to-mesenchymal transition during the selection process, leading to diminished E-cadherin levels and up-regulation of mesenchymal markers. Screening for key regulators of an epithelial phenotype revealed a significantly reduced expression of microRNA (miR)-200c and miR-205 in docetaxel-resistant cells. Transfection of either microRNA (miRNA) resulted in re-expression of E-cadherin. Functional assays confirmed reduced adhesive and increased invasive and migratory abilities. Furthermore, we detected an increased subpopulation with stem cell-like properties in resistant cells. Tissue microarray analysis revealed a reduced E-cadherin expression in tumors after neoadjuvant chemotherapy. Low E-cadherin levels could be linked to tumor relapse. The present study uncovers epithelial-to-mesenchymal transition as a hallmark of docetaxel resistance. Therefore, we suggest that this mechanism is at least in part responsible for chemotherapy failure, with implications for the development of novel therapeutics.

Cathepsin D acts as an essential mediator to promote malignancy of benign prostatic epithelium.

Stromal-epithelial interactions are important in both development and prostate cancer. Stromal changes have been shown to be powerful prognostic indicators of prostate cancer progression and of patient death helping to define lethal versus indolent phenotypes. The specific molecular underpinnings of these interactions are incompletely understood. We investigated whether stromal cathepsin D (CathD) overexpression affects prostate tumorigenesis through a paracrine mechanism. Normal prostate fibroblasts (NPF) were retrovirally transduced to overexpress cyclin D1 (CD1) and were designated NPF(CD1) . Cathepsin D expression was knocked down using shRNA in cancer associated fibroblasts (CAF) and NPF(CD1) . We analyzed these stromal cell lines using immunohistochemistry, Western blot, and tissue recombination. An examination of human prostate tissue revealed significantly increased stromal staining of CathD in malignant prostate tissue. Overexpression of CD1 in normal prostate fibroblasts (NPF(CD1) ) produced a phenotype similar to, but more moderate than, CAF in a tissue recombination model. Knockdown studies revealed that CathD is required for NPF(CD1) motility and invasive growth in vitro. BPH-1 cell proliferation was found to be induced when cultured with NPF(CD1) conditioned medium, this effect was inhibited when CathD was knocked down in NPF(CD1) cells. Overexpression of CathD in prostate stromal cells induced malignancy in adjacent epithelium, and this transformation was inhibited when stromal CathD expression was knocked down in CAF. The study presented here demonstrates increased CathD expression is seen in human CAF. The upregulation of CD1 results in concomitant increases in CathD expression. Elevated CathD expression in the stroma contributes to tumor promotion.

Human papillomavirus and Epstein Barr virus in prostate cancer: Koilocytes indicate potential oncogenic influences of human papillomavirus in prostate cancer

The purpose of this study is to determine if high risk human papillomaviruses (HPV) and Epstein Barr virus (EBV) are both present in the same prostate cancer specimens. We used a range of analytical techniques including in situ polymerase chain reaction (IS-PCR) and standard liquid PCR followed by sequencing of the product to seek to identify HPV and EBV in normal, benign, and malignant prostate tissues. Both HPV type 18 and EBV gene sequences were identified in a high and approximately equal proportion of normal, benign, and prostate cancer specimens. These sequences were located in the nuclei of prostate epithelial cells. HPV associated koilocytes were identified in 24% of prostate cancer specimens. The presence of both HPV and EBV gene sequences in most of the same normal, benign, and malignant prostate specimens is particularly noteworthy because of recent experimental evidence demonstrating that EBV and HPV can collaborate to increase proliferation of cultured cervical cells. Because the presence of EBV and HPV in normal, benign, and malignant prostate tissues appears to be ubiquitous, it is possible that they are harmless. On the other hand HPV type 18 in particular, has high oncogenic potential and may be associated with some prostate cancers. The identification of HPV associated koilocytes in prostate cancer specimens is an indication of HPV infection and potential oncogenic influences of human papillomavirus in prostate cancer.