Malignant Prostate Tissue Research Articles

Identification and characterization of membrane androgen receptors in the ZIP9 zinc transporter subfamily: II. Role of human ZIP9 in testosterone-induced prostate and breast cancer cell apoptosis.

Recently, we discovered a cDNA in teleost ovarian follicle cells belonging to the zinc transporter ZIP9 subfamily (SLC39A9) encoding a protein with characteristics of a membrane androgen receptor (mAR). Here, we demonstrate that human ZIP9 expressed in MDA-MB-468 breast cancer cells and stably overexpressed in human prostate cancer PC-3 cells (PC-3-ZIP9) also displays the ligand binding and signaling characteristics of a specific, high-affinity mAR. Testosterone treatment of MDA-MB-468 and PC-3-ZIP9 cells caused activation of G proteins and second messenger pathways as well as increases in intracellular free zinc concentrations that were accompanied by induction of apoptosis. [1,2,6,7-(3)H]-testosterone binding and these responses were abrogated in MDA-MB-468 cells after ZIP9 small interfering RNA (siRNA) treatment and absent in PC-3 cells transfected with empty vector, confirming that ZIP9 functions as an mAR. Testosterone treatment caused up-regulation of proapoptotic genes Bax (Bcl-2-associated X protein), p53 (tumor protein p53), and JNK (c-Jun N-terminal kinases) in both cell lines and increased expression of Bax, Caspase 3, and cytochrome C proteins. Treatment with a zinc chelator or a MAPK inhibitor blocked testosterone-induced increases in Bax, p53, and JNK mRNA expression. The results suggest that both androgen signaling and zinc transporter functions of ZIP9 mediate testosterone promotion of apoptosis. ZIP9 is widely expressed in human tissues and up-regulated in malignant breast and prostate tissues, suggesting that it is a potential therapeutic target for treating breast and prostate cancers. These results provide the first evidence for a mechanism mediated by a single protein through which steroid and zinc signaling pathways interact to regulate physiological functions in mammalian cells.

Toward microendoscopic electrical impedance tomography for intraoperative surgical margin assessment.

No clinical protocols are routinely used to intraoperatively assess surgical margin status during prostate surgery. Instead, margins are evaluated through pathological assessment of the prostate following radical prostatectomy, when it is too late to provide additional surgical intervention. An intraoperative device potentially capable of assessing surgical margin status based on the electrical property contrast between benign and malignant prostate tissue has been developed. Specifically, a microendoscopic electrical impedance tomography (EIT) probe has been constructed to sense and image, at near millimeter resolution, the conductivity contrast within heterogeneous biological tissues with the goal of providing surgeons with real-time assessment of margin pathologies. This device consists of a ring of eight 0.6-mm diameter electrodes embedded in a 5-mm diameter probe tip to enable access through a 12-mm laparoscopic port. Experiments were performed to evaluate the volume of tissue sensed by the probe. The probe was also tested with inclusions in gelatin, as well as on a sample of porcine tissue with clearly defined regions of adipose and muscle. The probe's area of sensitivity consists of a circular area of 9.1 mm(2) and the maximum depth of sensitivity is approximately 1.5 mm. The probe is able to distinguish between high contrast muscle and adipose tissue on a sub-mm scale (∼500 μm). These preliminary results suggest that EIT is possible in a probe designed to fit within a 12-mm laparoscopic access port.

Gene expression of androgen metabolising enzymes in benign and malignant prostatic tissues.

Benign prostatic hyperplasia (BPH) as well as prostate cancer (CaP) are prevalent in the aging male population, and both the diseases display androgen-dependence when the circulating testosterone from the gonads decreases. This suggests that the local or intracrine production of androgens may drive these diseases. Both diseases are dependent on the conversion of androgen by the epithelial compartment to the ligand with higher affinity and can be treated by blocking synthesis of this androgen metabolite. For this approach to be effective, a detailed knowledge of androgen biosynthesis in both disease states is required. The aim of the present study was to investigate the gene expression levels of androgen metabolising enzymes in BPH compared to normal adjacent prostate tissues and CaP. Expression of the genes HSD3B1, HSD17B3, and SRD5A2 was significantly increased in BPH tissues compared to normal adjacent prostate tissues. In contrast to BPH, CaP demonstrated significant decrease in the expression of HSD17B3, AKR1C2, and SRD5A2 compared to normal adjacent prostate tissues. HSD17B2 expression was significantly decreased in all samples. Moreover, HSD3B1 and SRD5A2 mRNA levels were upregulated in BPH compared with CaP. These results suggest that a change in androgen metabolism may be an important step in the pathogenesis of BPH, leading to increased cell proliferation due to in situ androgen synthesis. These features can be used to develop differential treatment strategies for BPH. HSD3B1 and SRD5A2 could be used as therapeutic target for BPH.

Deep optical imaging of tissue using the second and third near-infrared spectral windows.

Light at wavelengths in the near-infrared (NIR) region allows for deep penetration and minimal absorption through high scattering tissue media. NIR light has been conventionally used through the first NIR optical tissue window with wavelengths from 650 to 950 nm. Longer NIR wavelengths had been overlooked due to major water absorption peaks and a lack of NIR-CCD detectors. The second NIR spectral window from 1100 to 1350 nm and a new spectral window from 1600 to 1870 nm, known as the third NIR optical window, were investigated. Optical attenuation measurements from thin tissue slices of normal and malignant breast and prostate tissues, pig brain, and chicken tissue were obtained in the spectral range from 400 to 2500 nm. Optical images of chicken tissue overlying three black wires were also obtained using the second and third spectral windows. Due to a reduction in scattering and minimal absorption, longer attenuation lengths and clearer optical images could be seen in the second and third NIR optical windows compared to the conventional first NIR optical window. A possible fourth optical window centered at 2200 nm was noted.

«Fokal statt total» – Umdenken in der Therapie des Prostatakarzinoms

Treatment options for prostate cancer are currently widely discussed in the media and by urologic associations. International studies showed that current treatment options may significantly affect the quality of life (including incontinence and erectile dysfunction) while only offering marginal survival benefits. Low to medium risk patients in particular don't seem to be ideal candidates for radical treatment by surgery of radio therapy. For this large group of patients focal therapy offers additional valuable treatment option. Malignant prostate tissue can be specifically ablated by High-Intensity Focused Ultrasound (HIFU). Thus, the cancer can be controlled without removing the whole prostate and with minimal side effects. Multimodal magnetic resonance tomography, specific biopsies and monitoring contribute to the safety of this new treatment strategy.

Programmed Cell Death Protein 4 -Expression in Urologic Tumors

Introduction: To investigate the role of the tumor suppressor gene Pdcd4 (programmed cell death 4) in benign and malignant prostate tissue specimen. Materials and Methodology: Pdcd4 immunohistochemical expression was investigated in 73 prostate cancer and 14 normal tissues. The expression levels were correlated with clinicopathological parameters. Results: Both, cytoplasmic and nuclear Pdcd4 staining was significantly decreased in malignant prostate tissue. Furthermore, Pdcd4 expression decreased with histopathological progression of the tumor. Receiver operating characteristic analyses showed in core staining results high sensitivity (83.3%) and specificity (93.8%) for the discrimination of prostate cancer from non-malignant tissue. Conclusion: Our data support a role for Pdcd4 in prostate carcinogenesis. Pdcd4 immunohistochemical staining turns out to be a possible diagnostic marker for differentiation of prostate carcinoma and benign prostate tissue.

An automated, sensitive, high-throughput biomarker protocol for tissue microarrays containing archival prostate specimens: The prognostic potential of an ERG EMT panel.

181 Background: Tissue microarrays (TMAs), linked to clinical databases containing clinical outcome data, offer a great potential for defining and validating new biomarkers in urological oncology. The long term follow up required for true clinical outcome prostate cancer results in the use of archival material for TMA construction. The use of such material has inherent problems which must be overcome to unlock the full potential of prostate TMAs. Methods: A prostate 2,450 core TMA containing normal, prostatic intraepithelial neoplasia and malignant prostate tissue from 524 archival patient specimens was constructed and analysed. Each core was independently verified histologically. An automated, high throughput fluorescent staining (Leica BOND-MAX), image capture (Carl Zeiss Microimaging Mirax scanner) and scoring (Definiens Tissue Studio) protocol was compared with standardised conventional staining and manual scoring techniques. Results: Image analysis showed excellent correlation (r=0.785) and absolute agreement between the automated and manual scoring protocols (ICC=0.769, 95% CI [0.629-0.877]). Replicate analysis demonstrated that the automated, high throughput protocol was more reliable and consistent than the standardised manual staining and scoring protocols. The increased sensitivity of fluorescent staining in the automated protocol highlighted significant (p>0.0001) antigen degradation (pan-cytokeratin), hence poorly persevered regions, in 50.7% of the archival TMA cores. Using well preserved cores the potential of combining Erg expression with EMT markers as a prognostic marker will be presented. Conclusions: This study shows that archival TMAs can be utilised for biomarker characterisation and validation. However there are caveats to their use, namely antigen preservation. The use of multicolour automated protocols, which utilise a house keeping antigen, circumvents these caveats and releases the full potential of TMAs in biomarker research.

Value of perfusion CT parameters, microvessl density and VEGF expression in differentiation of benign and malignant prostate tumours.

The purpose of this study was to assess the correlation between parameters evaluated using computed tomography perfusion (CTP) and microvessel density (MVD), the vascular endothelial growth factor labelling index (VEGFLI), as well as known clinicopathological indicators of tumour malignancy, in non-advanced prostatic cancer. We included 110 patients with early stage prostate cancer who were subjected to CT examinations followed by radical prostatectomy between 2007 and 2011 (in this analysis we included only patients diagnosed with CT). Both in affected and in healthy tissue the following perfusion parameters were assessed: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface area product (PS). After surgery in the resected prostate tumour tissue the MVD and VEGFLI were assessed. The mean BF and PS values were significantly higher in carcinomas with high histological grade (p = 0.02). The sensitivity, specificity and accuracy of the threshold BF value, for the distinction between malignant and healthy prostate tissue, were: 67%, 54% and 59% respectively. For BV sensitivity was 71%, specificity was 52%, and accuracy was 48%. Microvessel density significantly correlated with BV, MTT and PS (p < 0.05), while VEGFLI did not correlate with any of the perfusion parameters. Our results suggest that BF and PS might be helpful in discrimination between benign and malignant prostate tissue, while the positive correlation between BV, MTT, PS and MVD might suggest their potential utility in assessment of cancer angiogenesis.

Differential expression of 5-alpha reductase isozymes in the prostate and its clinical implications

The development of human benign or malignant prostatic diseases is closely associated with androgens, primarily testosterone (T) and dihydrotestosterone (DHT). T is converted to DHT by 5-alpha reductase (5-AR) isozymes. Differential expression of 5-AR isozymes is observed in both human benign and malignant prostatic tissues. 5-AR inhibitors (5-ARI) are commonly used for the treatment of benign prostatic hyperplasia (BPH) and were once promoted as chemopreventive agents for prostate cancer (PCa). This review discusses the role of the differential expression of 5-AR in the normal development of the human prostate and in the pathogenesis and progression of BPH and PCa.

The Prevalence of Persistent Prostate Cancer after Radiotherapy Detected at Radical Cystoprostatectomy for Bladder Cancer

More than half of the men who receive treatment for prostate cancer elect radiotherapy. After radiotherapy recurrence is determined by an increase in prostate specific antigen and not usually by pathological confirmation. We describe the prevalence of persistent gradable prostate cancer in men treated with radiotherapy for prostate cancer at radical cystoprostatectomy for bladder cancer. A total of 78 patients underwent radiotherapy (brachytherapy and/or external beam radiation) before the development of bladder cancer requiring radical cystectomy at our institution. All tissues were evaluated by a specialized genitourinary pathologist. Median time from radiotherapy to radical cystoprostatectomy was 77 months. Gradable prostate cancer was identified in 45% of patients. Of the tumors 69% were Gleason score 7 or greater, 17% were pT3 or greater and 5% showed positive lymph nodes. Men treated more recently were less likely to have gradable prostate cancer, including 100% before 1980, 49% between 1980 and 2000 and 10% from 2000 to the present (p=0.002) as were those who received external beam radiation alone compared to brachytherapy and combined brachytherapy/external beam radiation (58% vs 27% and 14%, respectively, p=0.005). After radiotherapy 45% of men had persistent prostate cancer (37% of men with no evidence of disease). A decreased prostate cancer rate was associated with later treatment year and combined brachytherapy/external beam radiation regimens. Similar to men treated with radical cystoprostatectomy for muscle invasive bladder cancer, meticulous attention should be paid during prostate removal in men treated with radiotherapy because many may have persistent prostate cancer. In addition, markers other than prostate specific antigen should be studied in men treated with radiotherapy to better identify those with biochemical recurrence.

STEAP1 is overexpressed in prostate cancer and prostatic intraepithelial neoplasia lesions, and it is positively associated with Gleason score

BackgroundSix transmembrane epithelial antigen of the prostate 1 (STEAP1) is a transmembrane protein of epithelial cells, mostly located at cell-cell junctions, and is overexpressed in several types of tumors, particularly prostate cancer. Several studies have pointed STEAP1 as a biomarker, but the clinical significance of its overexpression is not fully understood. Therefore, we aimed to establish the association of STEAP1 immunoreactivity with histologic diagnosis and clinical data of patients. Materials and methodsHuman tissue microarrays were constructed from tissue biopsies of prostate adenocarcinoma (n = 63), including nonneoplastic adjacent tissue (n = 41), prostatic intraepithelial neoplasia (PIN) lesions (n = 7), and 41 prostate samples from patients diagnosed with benign prostatic hyperplasia (BPH). The histologic features of tumor specimens were classified and clinical and pathologic data were retrieved. STEAP1 expression was evaluated by immunohistochemical analysis, and a semiquantitative quantification was performed using a grade score system based on the intensity and percentage of stained cells. ResultsOverexpression of STEAP1 protein was found in both plasma membrane and cytoplasm of prostate cancer and PIN lesions when compared with nonneoplastic adjacent tissue and BPH samples. Furthermore, its expression associates positively with higher Gleason scores, but not with other clinical data, such as age, prostate-specific antigen levels, pathologic stage, and metastasis. Regarding its role as a biomarker, STEAP1 is highly liable for distinguishing malignant prostate stages from BPH. On the contrary, it lacks specificity in distinguishing PIN lesions from prostate cancer. ConclusionsSTEAP1 is consistently overexpressed in malignant prostate tissue, namely adenocarcinoma and PIN lesions. Its overexpression in PIN lesions and positive association with higher Gleason scores suggest that STEAP1 could be involved in tumor initiation and progression. The high sensitivity and specificity for detection of malignant lesions suggests that STEAP1 may be of clinical usefulness in early disease diagnosis.

Characterization of Prostate Cancer Bone Metastases According to Expression Levels of Steroidogenic Enzymes and Androgen Receptor Splice Variants

BackgroundIntra-tumoral steroidogenesis and constitutive androgen receptor (AR) activity have been associated with castration-resistant prostate cancer (CRPC). This study aimed to examine if CRPC bone metastases expressed higher levels of steroid-converting enzymes than untreated bone metastases. Steroidogenic enzyme levels were also analyzed in relation to expression of constitutively active AR variants (AR-Vs) and to clinical and pathological variables.Methodology/Principal FindingsUntreated, hormone-naïve (HN, n = 9) and CRPC bone metastases samples (n = 45) were obtained from 54 patients at metastasis surgery. Non-malignant and malignant prostate samples were acquired from 13 prostatectomy specimens. Transcript and protein levels were analyzed by real-time RT-PCR, immunohistochemistry and immunoblotting. No differences in steroidogenic enzyme levels were detected between CRPC and HN bone metastases. Significantly higher levels of SRD5A1, AKR1C2, AKR1C3, and HSD17B10 mRNA were however found in bone metastases than in non-malignant and/or malignant prostate tissue, while the CYP11A1, CYP17A1, HSD3B2, SRD5A2, and HSD17B6 mRNA levels in metastases were significantly lower. A sub-group of metastases expressed very high levels of AKR1C3, which was not due to gene amplification as examined by copy number variation assay. No association was found between AKR1C3 expression and nuclear AR staining, tumor cell proliferation or patient outcome after metastases surgery. With only one exception, high AR-V protein levels were found in bone metastases with low AKR1C3 levels, while metastases with high AKR1C3 levels primarily contained low AR-V levels, indicating distinct mechanisms behind castration-resistance in individual bone metastases.Conclusions/SignificanceInduced capacity of converting adrenal-gland derived steroids into more potent androgens was indicated in a sub-group of PC bone metastases. This was not associated with CRPC but merely with the advanced stage of metastasis. Sub-groups of bone metastases could be identified according to their expression levels of AKR1C3 and AR-Vs, which might be of relevance for patient response to 2nd line androgen-deprivation therapy.

Multispectral Photoacoustic Imaging of Prostate Cancer: Preliminary Ex-vivo Results

Objective:The objective of this study is to validate if ex-vivo multispectral photoacoustic (PA) imaging can differentiate between malignant prostate tissue, benign prostatic hyperplasia (BPH), and normal human prostate tissue.Materials and Methods:Institutional Review Board's approval was obtained for this study. A total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer were included in this study with informed consent. Multispectral PA imaging was performed on surgically excised prostate tissue and chromophore images that represent optical absorption of deoxyhemoglobin (dHb), oxyhemoglobin (HbO2), lipid, and water were reconstructed. After the imaging procedure is completed, malignant prostate, BPH and normal prostate regions were marked by the genitourinary pathologist on histopathology slides and digital images of marked histopathology slides were obtained. The histopathology images were co-registered with chromophore images. Region of interest (ROI) corresponding to malignant prostate, BPH and normal prostate were defined on the chromophore images. Pixel values within each ROI were then averaged to determine mean intensities of dHb, HbO2, lipid, and water.Results:Our preliminary results show that there is statistically significant difference in mean intensity of dHb (P < 0.0001) and lipid (P = 0.0251) between malignant prostate and normal prostate tissue. There was difference in mean intensity of dHb (P < 0.0001) between malignant prostate and BPH. Sensitivity, specificity, positive predictive value, and negative predictive value of our imaging system were found to be 81.3%, 96.2%, 92.9% and 89.3% respectively.Conclusion:Our preliminary results of ex-vivo human prostate study suggest that multispectral PA imaging can differentiate between malignant prostate, BPH and normal prostate tissue.

Increased expression of CYP24A1 correlates with advanced stages of prostate cancer and can cause resistance to vitamin D3‐based therapies

A major limitation of exogenous vitamin D3 administration for the treatment of prostate cancer is the marginal, if any, clinical efficacy. We dissected the basis for the resistance to the vitamin D3 antitumor properties and specifically examined the effect of its major catabolic enzyme, CYP24A1, in prostate cancer. Local CYP24A1 expression levels and the effect of selective modulation were analyzed using tissue microarrays from needle core biopsy specimens and xenograft-bearing mouse models. CYP24A1 mRNA was elevated in malignant human prostate tissues compared to benign lesions. High CYP24A1 protein levels were seen in poorly differentiated and highly advanced stages of prostate cancer and correlated with parallel increase in the tumor proliferation rate. The use of CYP24A1 RNAi enhanced the cytostatic effects of vitamin D3 in human prostate cancer cells. Remarkably, subcutaneous and orthotopic xenografts of prostate cancer cells harboring CYP24A1 shRNA resulted in a drastic reduction in tumor volume when mice were subjected to vitamin D3 supplementation. CYP24A1 may be a predictive marker of vitamin D3 clinical efficacy in patients with advanced prostate cancer. For those with up-regulated CYP24A1, combination therapy with RNAi targeting CYP24A1 could be considered to improve clinical responsiveness to vitamin D3.

Isolation and genome-wide expression and methylation characterization of CD31+ cells from normal and malignant human prostate tissue

Endothelial cells (ECs) are an important component involved in the angiogenesis. Little is known about the global gene expression and epigenetic regulation in tumor endothelial cells. The identification of gene expression and epigenetic difference between human prostate tumor-derived endothelial cells (TdECs) and those in normal tissues may uncover unique biological features of TdEC and facilitate the discovery of new anti-angiogenic targets. We established a method for isolation of CD31+ endothelial cells from malignant and normal prostate tissue obtained at prostatectomy. TdECs and normal-derived ECs (NdECs) showed >90% enrichment in primary culture and demonstrated microvascular endothelial cell characteristics such as cobblestone morphology in monolayer culture, diI-acetyl-LDL uptake and capillary-tube like formation in Matrigel®. In vitro primary cultures of ECs maintained expression of endothelial markers such as CD31, von Willebrand factor, intercellular adhesion molecule, vascular endothelial growth factor receptor 1, and vascular endothelial growth factor receptor 2. We then conducted a pilot study of transcriptome and methylome analysis of TdECs and matched NdECs from patients with prostate cancer. We observed a wide spectrum of differences in gene expression and methylation patterns in endothelial cells, between malignant and normal prostate tissues. Array-based expression and methylation data were validated by qRT-PCR and bisulfite DNA pyrosequencing. Further analysis of transcriptome and methylome data revealed a number of differentially expressed genes with loci whose methylation change is accompanied by an inverse change in gene expression. Our study demonstrates the feasibility of isolation of ECs from histologically normal prostate and prostate cancer via CD31+ selection. The data, although preliminary, indicates that there exist widespread differences in methylation and transcription between TdECs and NdECs. Interestingly, only a small proportion of perturbed gene was overlapped between American (AA) and Caucasian American (CA) patients with prostate cancer. Our study indicates that identifying gene expression and/or epigenetic differences between TdECs and NdECs may provide us with new anti-angiogenic targets. Future studies will be required to further characterize the isolated ECs and determine the biological features that can be exploited in the prognosis and therapy of prostate cancer.

PTRF/cavin-1 neutralizes non-caveolar caveolin-1 microdomains in prostate cancer.

Caveolin-1 has a complex role in prostate cancer and has been suggested to be a potential biomarker and therapeutic target. As mature caveolin-1 resides in caveolae, invaginated lipid raft domains at the plasma membrane, caveolae have been suggested as a tumor-promoting signaling platform in prostate cancer. However, caveola formation requires both caveolin-1 and cavin-1 (also known as PTRF; polymerase I and transcript release factor). Here, we examined the expression of cavin-1 in prostate epithelia and stroma using tissue microarray including normal, non-malignant and malignant prostate tissues. We found that caveolin-1 was induced without the presence of cavin-1 in advanced prostate carcinoma, an expression pattern mirrored in the PC-3 cell line. In contrast, normal prostate epithelia expressed neither caveolin-1 nor cavin-1, while prostate stroma highly expressed both caveolin-1 and cavin-1. Utilizing PC-3 cells as a suitable model for caveolin-1-positive advanced prostate cancer, we found that cavin-1 expression in PC-3 cells inhibits anchorage-independent growth, and reduces in vivo tumor growth and metastasis in an orthotopic prostate cancer xenograft mouse model. The expression of α-smooth muscle actin in stroma along with interleukin-6 (IL-6) in cancer cells was also decreased in tumors of mice bearing PC-3-cavin-1 tumor cells. To determine whether cavin-1 acts by neutralizing caveolin-1, we expressed cavin-1 in caveolin-1-negative prostate cancer LNCaP and 22Rv1 cells. Caveolin-1 but not cavin-1 expression increased anchorage-independent growth in LNCaP and 22Rv1 cells. Cavin-1 co-expression reversed caveolin-1 effects in caveolin-1-positive LNCaP cells. Taken together, these results suggest that caveolin-1 in advanced prostate cancer is present outside of caveolae, because of the lack of cavin-1 expression. Cavin-1 expression attenuates the effects of non-caveolar caveolin-1 microdomains partly via reduced IL-6 microenvironmental function. With circulating caveolin-1 as a potential biomarker for advanced prostate cancer, identification of the molecular pathways affected by cavin-1 could provide novel therapeutic targets.

18F-MK-9470 PET imaging of the type 1 cannabinoid receptor in prostate carcinoma: a pilot study

BackgroundPreclinical and histological data show overexpression of the type 1 cannabinoid receptor (CB1R) in prostate carcinoma (PCa). In a prospective study, the feasibility of 18F-MK-9470 positron emission tomography (PET) imaging in patients with primary and metastatic PCa was evaluated.MethodsEight patients were included and underwent 18F-MK-9470 PET/CT imaging. For five patients with primary PCa, dynamic PET/CT imaging was performed over three acquisition intervals (0 to 30, 60 to 90 and 120 to 150 min post-injection). In malignant and benign prostate tissue regions, time activity curves of the mean standardized uptake value (SUVmean) were determined as well as the corresponding area under the curve to compare 18F-MK-9470 uptake over time. Muscle uptake of 18F-MK-9470 was used as reference for non-specific binding. Magnetic resonance imaging (MRI) was used as anatomical reference and for delineating intraprostatic tumours. Histological and immunohistochemical (IHC) examination was performed on the whole-mount histopathology sections of four patients who underwent radical prostatectomy to assess the MRI-based tumour versus benign tissue classification. For three patients with proven advanced metastatic disease, two static PET/CTs were performed 1 and 3 h post-injection. 18F-MK-9470 uptake was evaluated in bone lesions of metastatic PCa by comparing SUVmean values of metastases with these of the contralateral bone tissue.Results18F-MK-9470 uptake was significantly higher in benign and malignant prostate tissue compared to muscle, but it did not differ between both prostate tissue compartments. IHC findings of corresponding prostatic histopathological sections indicated weak CB1R expression in locally confined PCa, which was not visualized with 18F-MK-9470 PET. Metastases in the axial skeleton could not be detected while some metastases in the appendicular skeleton showed higher 18F-MK-9470 uptake as compared to the uptake in contralateral normal bone.Conclusions18F-MK-9470 PET could not detect local PCa or bone metastases in the axial skeleton but was able to visualize metastases in the appendicular skeleton. Based on these pilot observations, it seems unlikely that CB1R PET will play a significant role in the evaluation of PCa.

Arylsulfatase B (N-acetylgalactosamine-4-sulfatase): potential role as a biomarker in prostate cancer

BACKGROUNDThe enzyme Arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase) degrades chondroitin-4-sulfate (C4S) and is reduced in malignant colonic and mammary tissues, but has not previously been evaluated in prostate cancer.METHODSARSB immunostaining was performed on two tissue microarrays (TMA) and analyzed by digital image analysis, generating ARSB H-scores for prevalence and intensity of epithelial, stromal, and combined epithelial and stromal immunostaining. Also, paired malignant and normal prostate tissues were analyzed for ARSB activity, C4S, total sulfated glycosaminoglycans, and versican content. The quantities of C4S and of the epidermal growth factor receptor that co-immunoprecipitated with versican were determined in the normal and malignant paired prostate tissues.RESULTS44 cases of prostate cancer were paired by age (± 5y), race, Gleason score (in order), and pathologic TNM score. The pairs differed by recurrence vs. non-recurrence of elevated PSA at 4 or more years. When TMA cores were analyzed for ARSB H-score, 18 of the 22 pairs had lower ARSB H-scores in the recurrent member of the pair, whereas higher initial PSA values were associated with recurrence in only 65% of the paired cases. In a second TMA, Gleason scores 6 and 7 were associated with higher ARSB H-scores than Gleason scores 8 and 9 for stroma, epithelium, and stroma and epithelium combined (p=0.052, p=0.015, p<0.0001, respectively) and were inversely correlated (r = −0.98, −0.97, and −0.99, respectively). In other paired normal and malignant prostate tissues, ARSB activity was significantly higher in the normal tissues, and C4S and versican values were lower (p<0.0001). C4S that co-immunoprecipitated with versican was greater in the malignant than in the normal tissue, whereas total EGFR that co-immunoprecipitated with versican was reduced.DISCUSSIONStudy findings suggest that ARSB may be useful as a prognostic biomarker in prostate cancer, and that the biological action of ARSB on chondroitin sulfate may impact upon versican’s effects in the tumor microenvironment.

Electrical property sensing biopsy needle for prostate cancer detection

Significant electrical property differences have been demonstrated to exist between malignant and benign prostate tissues. We evaluated how well a custom designed clinically deployable electrical property sensing biopsy needle is able to discriminate between these tissue types in an ex vivo prostate model. An electrical impedance spectroscopy (EIS) sensing biopsy (Bx) needle was developed to record resistive (ρR) and reactive (ρX) components of electrical impedance from 100 Hz to 1 MHz. Standard twelve-core biopsy protocols were followed, in which the EIS-Bx device was used to gauge electrical properties prior to extracting tissue cores through biopsy needle firing from 36 ex vivo human prostates. Histopathological assessment of the cores was statistically compared to the impedance spectrum gauged from each core. The magnitudes of the mean resistive and reactive components were significantly higher in cancer tissues (P < 0.05). ROC curves showed that ρR at 63.09 kHz was optimal for discriminating cancer from benign tissues; this parameter had 75.4% specificity, 76.1% sensitivity, and ROC AUC of 0.779. Similarly, 251.1 kHz was optimal when using ρX to discriminate cancer from benign tissues; this parameter had a 77.9% specificity, 71.4% sensitivity, and ROC AUC of 0.79. Significant electrical property differences noted between benign and malignant prostate tissues suggest the potential efficacy an EIS-Bx device would provide for cancer detection in a clinical setting. By sensing a greater fraction of the prostate's volume in real-time, the EIS-Bx device has the potential to improve the accuracy of cancer grading and volume estimation made with current biopsy procedures.

Comparison of p40 (ΔNp63) and p63 expression in prostate tissues – which one is the superior diagnostic marker for basal cells?

p63 is one of the standard markers for basal cells of the prostate gland. Recently, it has been suggested that the p63 isoform p40 might be more specific as a basal cell marker. In this study we compare the staining characteristics of p63 and p40 in normal and malignant prostate tissues. A prostatectomy cohort (n=640) in tissue microarray format was evaluated for p63 (clone 4A4) and for p40 (rabbit polyclonal) immunoreactivity in malignant and normal tissues. Immunoreactivity of basal and secretory cells was evaluated in a semiquantitative manner and compared case-wise. In normal tissues, p40 showed highly similar immunoreactivity compared to p63. The staining patterns were absolutely identical in 88% of cases. Additional cytoplasmic p40 staining in tumour cells occurred in 59.6% of cancer cases. Differences were seen in nuclear staining of carcinomas: 1.4% of carcinomas were p63-positive, whereas 0.6% were p40-positive. In most cases, p40 stains prostatic basal cells as reliably as p63, with only minor differences. Aberrant staining of tumour cells is seen more rarely than with p63 (clone 4A4), establishing its higher specificity. However, additional cytoplasmic immunoreactivity narrows its eligibility for antibody cocktails (e.g. with alpha-methylacyl-CoA racemase).