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Background: Gleason grading is the strongest prognostic parameter in prostate cancer. Gleason grading is categorized as Gleason ≤ 6, 3 + 4, 4 + 3, 8, and 9-10, but there is variability within these subgroups. For example, Gleason 4 components may range from 5-45% in a Gleason 3 + 4 = 7 cancer., Objective: To assess the clinical relevance of the fractions of Gleason patterns., Design, Setting, and Participants: Prostatectomy specimens from 12823 consecutive patients and of 2971 matched preoperative biopsies for which clinical data with an annual follow-up between 2005 and 2014 were available from the Martini-Klinik database., Outcome Measurements and Statistical Analysis: To evaluate the utility of quantitative grading, the fraction of Gleason 3, 4, and 5 patterns seen in biopsies and prostatectomies were recorded. Gleason grade fractions were compared with prostatectomy findings and prostate-specific antigen recurrence., Results and Limitations: Our data suggest a striking utility of quantitative Gleason grading. In prostatectomy specimens, there was a continuous increase of the risk of prostate-specific antigen recurrence with increasing percentage of Gleason 4 fractions with remarkably small differences in outcome at clinically important thresholds (0% vs 5%; 40% vs 60% Gleason 4), distinguishing traditionally established prognostic groups. Also, in biopsies, the quantitative Gleason scoring identified various intermediate risk groups with respect to Gleason findings in corresponding prostatectomies. Quantitative grading may also reduce the clinical impact of interobserver variability because borderline findings such as tumors with 5%, 40%, or 60% Gleason 4 fractions and very small Gleason 5 fractions (with pivotal impact on the Gleason score) are disclaimed., Conclusions: Quantitative Gleason pattern data should routinely be provided in addition to Gleason score categories, both in biopsies and in prostatectomy specimens., Patient Summary: Gleason score is the most important prognostic parameter in prostate cancer, but prone to interobserver variation. The results of our study show that morphological aspects that define the Gleason grade in prostate cancer represent a continuum. Quantitation of Gleason patterns provides clinically relevant information beyond the traditional Gleason grading categories ≤ 3 + 3, 3 + 4, 4 + 3, 8, 9 -1 0. Quantitative Gleason scoring can help to minimize variations between different pathologists and substantially aid in optimized therapy decision-making., (Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Zinc-alpha 2-glycoprotein (AZGP1) is involved in lipid metabolism and was suggested as a candidate prognostic biomarker in prostate cancer. To evaluate the clinical impact and relationship with key genomic alterations in prostate cancer, AZGP1 expression was analyzed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancers. Data on ERG status and PTEN, 3p13, 5q21 and 6q15 deletions were available from earlier studies. AZGP1 expression was strong in benign prostatic glands but absent in 38.0% of 8,510 interpretable prostate cancers. Reduced AZGP1 expression was associated with TPMRSS2:ERG fusions, both by FISH and immunohistochemical analysis (p < 0.0001 each). For example, AZGP1 was absent in 54.6% of 2,029 ERG IHC positive but in only 28.1% of 2,398 ERG negative cancers. Irrespective of the ERG status, reduced AZGP1 expression was tightly linked to high Gleason score, advanced pathological tumor stage, positive nodal status and early PSA recurrence (p < 0.0001 each). Reduced AZGP1 expression was also strongly associated with PTEN deletions. AZGP1 immunostaining was lacking in 62.7% of 842 PTEN deleted but in only 37.3% of PTEN non-deleted cancers but retained strong prognostic influence in both subgroups (p < 0.0001 each). The prognostic role of AZGP1 expression was also independent of Gleason score, pT stage, pN stage, surgical margin status and preoperative PSA, irrespective of whether preoperative or postoperative variables were used for modeling. In conclusion, the results of our study demonstrate that reduced AZGP1 expression is strongly related to adverse prostate cancer prognosis, independently of established clinic-pathological variables and PTEN deletions., (© 2015 UICC.)

Background: ELAVL1 is an RNA binding protein involved in translation control, which might have a regulatory role in prostate cancer progress., Methods: To evaluate its impact and relationship with key genomic alterations, ELAVL1 expression was analyzed by immunohistochemistry on a tissue microarray containing 12,427 prostate cancers., Results: The analysis revealed a mild to moderate predominantly nuclear immunostaining in normal prostate epithelium and an often higher both cytoplasmic and nuclear expression in cancer cells. Weak, moderate, and strong cytoplasmic ELAVL1 staining was found in 43%, 18%, and 3% of 10,478 interpretable tumors. Strong ELAVL1 staining was linked to high Gleason grade, advanced pathological tumor stage, positive nodal status, and PSA recurrence (P < 0.0001 each). A combined analysis of the effect of nuclear and cytoplasmic ELAVL1 expression on PSA recurrence revealed that the association with patient outcome was entirely driven by cytoplasmic staining. ELAVL1 positivity was more frequent in cancers harboring TMPRSS2:ERG fusions found by FISH (78%) or showing immunohistochemical ERG expression (74%) than in cancers without ERG rearrangement (63%) or ERG expression (58%, P < 0.0001 each). Strong cytoplasmic ELAVL1 staining was further linked to presence of PTEN, 5q21, 6q15, and 3p13 deletions (P < 0.0001 each), an observation consistent with cytoplasmic ELAVL1 accumulation in case of genomic instability. The prognostic role of ELAVL1 expression was independent of Gleason grade, T stage, N stage, surgical margin status, and preoperative PSA, irrespective of whether preoperative or postoperative variables were used for modeling., Conclusion: Our study identifies cytoplasmic accumulation of ELAVL1 as a predictor of adverse clinical behavior of prostate cancer independent of established clinico-pathological parameters., (© 2015 Wiley Periodicals, Inc.)

Aquaporin 5 (AQP5) is an androgen-regulated member of a family of small hydrophobic integral transmembrane water channel proteins regulating cellular water homeostasis and growth signaling. To evaluate its clinical impact and relationship with key genomic alterations in prostate cancer, AQP5 expression was analyzed by immunohistochemistry on a tissue microarray containing 12427 prostate cancers. The analysis revealed weak to moderate immunostaining in normal prostate epithelium. In prostate cancers AQP5 staining levels were more variable and also included completely negative and highly overexpressing cases. Negative, weak, moderate, and strong AQP5 staining was found in 25.0%, 32.5%, 32.5%, and 10.0% of 10239 interpretable tumors. Comparison of AQP5 expression levels with tumor characteristics showed a dichotomous pattern with both high and low staining levels being linked to unfavorable tumor phenotype. AQP5 was negative in 28%, 23%, 24%, and 35% of tumors with Gleason score ≤3 + 3, 3 + 4, 4 + 3 and ≥4 + 4, while the rate of strongly positive cases continuously increased from 7.0% over 10.0% and 12.0% to 13.0% in cancers with Gleason score ≤3 + 3, 3 + 4, 4 + 3 and ≥4 + 4. AQP5 expression was also related to ERG positivity and phosphatase and tensin homolog (PTEN) deletion (P < .0001 each). Strong AQP5 positivity was seen in 15.5% of ERG-positive and 5.8% of ERG-negative cancers (P < .0001) as well as in 14.7% of cancers with PTEN deletion and 9.4% of cancers without PTEN deletion. Remarkably, both negativity and strong positivity of AQP5 were linked to unfavorable disease outcome. This was however only seen in subgroups defined by TMPRSS2-ERG fusion and/or PTEN deletion. In summary, AQP5 can be both overexpressed and lost in subgroups of prostate cancers. Both alterations are linked to unfavorable outcome in molecularly defined cancer subgroups. It is hypothesized that this dichotomous role of AQP5 is due to two highly different mechanisms as to how the protein can influence cancer cells, that is, hydraulic motility regulation and Ras/MAPK pathway activation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Enhancer of zeste homolog 2 (EZH2) plays an important role in tumor development and progression by interacting with histone and nonhistone proteins. In the current study, we analyzed prevalence and prognostic impact of EZH2 in prostate cancer. EZH2 expression was analyzed by immunohistochemistry on a tissue microarray containing more than 12400 prostate cancer specimens. Results were compared to tumor phenotype, biochemical recurrence and molecular subtypes defined by ERG status as well as genomic deletions of 3p, 5q, 6q and PTEN. EZH2 immunostaining was detectable in 56.6% of 10168 interpretable cancers and considered strong in 1.1%, moderate in 12.2% and weak in 43.3% of cases. High EZH2 expression was strongly associated with high Gleason grade (P < 0.0001), advanced pathological tumor stage (P < 0.0001), positive nodal status (P < 0.0001), elevated preoperative PSA level (P = 0.0066), early PSA recurrence (P < 0.0001) and increased cell proliferation P < 0.0001). High-level EZH2 staining was also associated with TMPRSS2:ERG rearrangement and ERG expression in prostate cancers (P < 0.0001) and was linked to deletions of PTEN, 6q15, 5q21 and 3p13 (P < 0.0001 each) particularly in ERG-negative cancers. The prognostic impact of EZH2 was independent of established pre- and postoperatively assessed clinicopathological parameters. EZH2 has strong prognostic impact in prostate cancer and might contribute to the development of a fraction of genetically instable and particularly aggressive prostate cancers. EZH2 analysis might therefore be of clinical value for risk stratification of prostate cancer., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Deletion of 12p is a recurrent alteration in prostate cancer, but the prevalence and clinical consequences of this alteration have not been studied in detail. Dual labeling fluorescence in situ hybridization using probes for 12p13 (CDKN1B; p27) and centromere 12 as a reference was used to successfully analyze more than 3700 prostate cancers with clinical follow-up data assembled in a tissue microarray format. CDKN1B was selected as a probe because it is located in the center of the deletion, which spans > 10 Mb and includes > 50 genes in 80% of cancers with 12p deletion. Deletion of 12p was found in 13.7% of cancers and included 13.5% heterozygous and 0.2% homozygous deletions. 12p deletion were linked to advanced tumor stage (p < 0.0001), high Gleason grade (p < 0.0001), rapid tumor cell proliferation (p < 0.0001), lymph node metastasis (p = 0.0004), and biochemical recurrence (p = 0.0027). Multivariate analysis including pT stage (p < 0.0001), Gleason grade (p < 0.0001), pN status (p = 0.0001), preoperative PSA levels (p = 0.0001), and resection margin status (p = 0.0001) revealed an independent prognostic value of 12p deletion (p = 0.0014). Deletion of 12p was unrelated to the ERG fusion status. Deletion of 12p was only marginally linked to reduced p27 expression, which by itself was unrelated to clinical outcome. This argues against p27 as the key target gene of 12p deletions. In summary, the results of our study demonstrate that 12p deletion is frequent in prostate cancer and provides independent prognostic information. 12p deletion analysis alone, or in combination with other prognostic parameters may thus have clinical utility.

DNA ligases are essential for the maintenance of genome integrity as they are indispensable for DNA replication, recombination and repair. The present study was undertaken to gain insights into the prevalence and clinical significance of ligase IV (LIG4) expression in prostate cancer. A total of 11,152 prostate cancer specimens were analyzed by immunohistochemistry for LIG4 expression. Results were compared to follow-up data, ERG status and deletions at PTEN, 3p13, 5q21 and 6q15. LIG4 expression was predominantly localized in the nucleus of the cells with increased intensities in malignant as compared to benign prostate epithelium. In prostate cancer, LIG4 expression was found in 91% of interpretable tumors, including 12% cancers with weak, 23% with moderate and 56% with strong LIG4 positivity. Strong LIG4 expression was tightly linked to advanced Gleason score (P<0.0001) and positive nodal involvement (P=0.03). There was a remarkable accumulation of strong LIG4 expression in tumors harboring TMPRSS2:ERG fusion and PTEN deletions (P<0.0001 each). High LIG4 expression was also tightly related to early biochemical recurrence when all tumors (P<0.0001) or the subsets of ERG-negative (P=0.0004) or ERG-positive prostate cancers (P=0.006) were analyzed. Multivariate analysis including parameters that are available before surgery demonstrated independent association with biochemical recurrence for advanced Gleason grade on biopsy, high preoperative PSA level, high clinical stage (P<0.0001 each) and for LIG4 immunostaining (P=0.03). Our study identifies LIG4 as a predictor of an increased risk for early PSA recurrence in prostate cancer. Moreover, the strong association with TMPRSS2:ERG fusion and PTEN deletions suggest important interactions between these pathways in prostate cancers.

Purpose: Sequestosome 1 (p62) is a multifunctional adapter protein accumulating in autophagy-defective cells., Experimental Design: To evaluate the clinical impact and relationship with key genomic alterations in prostate cancer, p62 protein levels were analyzed by immunohistochemistry on a tissue microarray containing 12,427 prostate cancers. Data on ERG status and deletions of PTEN, 3p13, 5q21, and 6q15 were available from earlier studies., Results: p62 immunostaining was absent in benign prostatic glands but present in 73% of 7,822 interpretable prostate cancers. Strong cytoplasmic p62 staining was tightly linked to high Gleason grade, advanced pathologic tumor (pT) stage, positive nodal status, positive resection margin, and early PSA recurrence (P < 0.0001 each). Increased levels of p62 were significantly linked to TMPRSS2-ERG fusions, both by FISH and immunohistochemical analysis (P < 0.0001 each). For example, moderate or strong p62 immunostaining was seen in 28.5% of cancers with TMPRSS2-ERG fusion detected by FISH and in 23.1% of cancers without such rearrangements (P < 0.0001). Strong p62 staining was significantly linked to the presence of all tested deletions, including PTEN (P < 0.0001), 6q15 (P < 0.0001), 5q21 (P = 0.0002), 3p13 (P = 0.0088), and 6q15 (P < 0.0001), suggesting a link between p62 accumulation and loss of genomic stability. The prognostic role of p62 protein accumulation was striking and independent of Gleason grade, pT stage, pN stage, surgical margin status, and preoperative PSA, regardless of whether preoperative or postoperative parameters were used for modeling., Conclusions: Our study identifies cytoplasmic accumulation of p62 as a strong predictor of an adverse prognostic behavior of prostate cancer independently from established clinicopathologic findings., (©2015 American Association for Cancer Research.)

Hook microtubule-tethering protein 3 (HOOK3) is an adaptor protein for microtubule-dependent intracellular vesicle and protein trafficking. In order to assess the role of HOOK3 in prostate cancer we analyzed HOOK3 expression by immunohistochemistry on a TMA containing more than 12,400 prostate cancers. Results were compared to tumor phenotype and PSA recurrence as well as aberrations possibly defining relevant molecular subtypes such as ERG status and deletions of 3p13, 5q21, 6q15 and PTEN. HOOK3 immunostaining was negative in normal luminal cells of prostate epithelium, whereas 53.3% of 10,572 interpretable cancers showed HOOK3 expression, which was considered low in 36.4% and high in 16.9% of cases. High-level HOOK3 expression was linked to advanced tumor stage, high Gleason score, high proliferation index, positive lymph node stage, and PSA recurrence (p<0.0001 each). The prognostic role of HOOK3 expression was independent of established clinico-pathological parameters both in preoperative and postoperative settings. Comparisons with molecular features were performed to draw conclusions on the potential function of HOOK3 in the prostate. A strong association with all examined deletions is consistent with a role of HOOK3 for maintaining genomic integrity by contributing to proper centrosome assembly. Finding HOOK3 expression in 74% of ERG positive but in only 38% of ERG negative cancers (p<0.0001) further suggests functional interactions between these genes. In conclusion, the results of our study identify HOOK3 as a strong candidate prognostic marker with a possible role in maintaining genomic integrity in prostate cancer, which may have potential for inclusion into clinical routine assays.

Background: Posttranscriptional protein modification by SUMOylation plays an important role in tumor development and progression. In the current study we analyzed prevalence and prognostic impact of the de-SUMOylation enzyme SENP1 in prostate cancer., Methods: SENP1 expression was analyzed by immunohistochemistry on a tissue microarray containing more than 12,400 prostate cancer specimens. Results were compared to tumor phenotype, ERG status, genomic deletions of 3p, 5q, 6q and PTEN, and biochemical recurrence., Results: SENP1 immunostaining was detectable in 34.5 % of 9,516 interpretable cancers and considered strong in 7.3 %, moderate in 14.9 % and weak in 12.3 % of cases. Strong SENP1 expression was linked to advanced pT stage (p < 0.0001), high Gleason grade (p < 0.0001), positive lymph node status (p = 0.0019), high pre-operative PSA levels (p = 0.0037), and PSA recurrence (p < 0.0001). SENP1 expression was strongly associated with positive ERG fusion status as determined by both in situ hybridization (FISH) and immunohistochemistry as well as with PTEN deletions. Detectable SENP1 immunostaining was found in 41 % of ERG positive and in 47 % of PTEN deleted cancers but in only 30 % of ERG negative and 30 % of PTEN non-deleted cancers (p < 0.0001 each). Deletions of 3p, 5q, and 6q were unrelated to SENP1 expression. Subset analyses revealed that the prognostic impact of SENP1 expression was solely driven by the subgroup of ERG positive, PTEN undeleted cancers. In this subgroup, the prognostic role of SENP1 expression was independent of the preoperative PSA level, tumor stage, Gleason grade, and the status of the resection margin., Conclusions: SENP1 expression has strong prognostic impact in a molecularly defined subset of cancers. This is per se not surprising as the biologic impact of each individual molecular event is likely to be dependent on its cellular environment. However, such findings challenge the concept of finding clinically relevant molecular signatures that are equally applicable to all prostate cancers.

Background: To date, no study has examined clinical, pathological, and surgical characteristics of D׳Amico low-risk patients according to active surveillance (AS) eligibility., Material and Methods: We relied on patients with low-risk prostate cancer, who were classified based on the D׳Amico classification, treated with radical prostatectomy (RP) between 2008 and 2013 at the Martini-Clinic Prostate Cancer Center. We assessed differences in clinical, pathological, and surgical characteristics in D׳Amico low-risk patients according to AS eligibility (prostate-specific antigen [PSA]≤ 10 ng/ml, Gleason score ≤ 3 + 3, ≤ 2 positive cores,≤5 0% tumor content per core, and ≤ cT1-2a). Multivariable logistic regression analyses targeted 2 end points: (1) presence of either intermediate- or high-risk characteristics (Gleason score ≥ 3+4 or ≥ pT3 or pN1) or (2) exclusive presence of high-risk characteristics (Gleason score ≥ 4+4 or ≥ pT3 or pN1) at RP., Results: Of 1,331 patients low-risk prostate cancer classified based on the D׳Amico classification, 825 (62%) men were eligible for AS. AS candidates were less frequently either upgraded (55% vs. 78%, P<0.001) or upstaged (8% vs. 15%, P<0.001). Similarly, at final pathology, AS candidates less frequently harbored either intermediate- or high-risk (56% vs. 78%, P<0.001), or exclusive high-risk characteristics (9% vs. 16%, P<0.001). Tumor involvement per core (>50%) (most powerful), number of positive cores, PSA values, and age were independent predictors for either intermediate- or high-risk characteristics at RP. Tumor involvement per core and PSA values were independent predictors for exclusive high-risk characteristics at RP., Conclusions: D׳Amico low-risk patients did not have a homogeneous histology at RP. Especially, non-AS candidates were at a higher risk of either upgrading or upstaging at final pathology. Tumor involvement greater than 50% per core was the most powerful indicator of adverse pathology. Therefore, D'Amico low-risk criteria are not safe enough to identify AS candidates., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Histone deacetylases (HDACs) play an important role in tumor development and progression by modifying histone and non-histone proteins. In the current study we analyzed prevalence and prognostic impact of HDAC1 in prostate cancer. HDAC1 expression was analyzed by immunohistochemistry on a tissue microarray containing more than 12,400 prostate cancer specimens. Results were compared to tumor phenotype, biochemical recurrence, and molecular subtypes defined by ERG status as well as genomic deletions of 3p, 5q, 6q and PTEN. HDAC1 immunostaining was detectable in 75.4% of 9744 interpretable cancers and considered strong in 15.4%, moderate in 39.4% and weak in 20.7% of cases. High HDAC1 expression was associated with high Gleason grade (p<0.0001), advanced pathological tumor stage (p<0.0001), positive nodal status (p=0.0010), elevated preoperative PSA-level (p=0.0127), early PSA recurrence (p<0.0001) and increased cell proliferation (p<0.0001). Moreover, high-level HDAC1 staining was associated with TMPRSS2:ERG rearrangement and ERG expression in prostate cancers (p<0.0001) and was linked to deletions of PTEN (p<0.0001), 6q (p<0.0001) and 5q (p=0.0028) in ERG-negative cancers. The prognostic impact of HDAC1 was independent of established clinicopathological parameters and was mostly driven by ERG-negative cancers as revealed by subgroup analyses. HDAC1 has strong prognostic impact in prostate cancer and might contribute to the development of a fraction of genetically instable and particularly aggressive prostate cancers. HDAC1 measurement might therefore be of clinical value for risk stratification of prostate cancer and should be further evaluated in this regard., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The transcription factor SOX9 plays a crucial role in normal prostate development and has been suggested to drive prostate carcinogenesis in concert with PTEN inactivation. To evaluate the clinical impact of SOX9 and its relationship with key genomic alterations in prostate cancer, SOX9 expression was analyzed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancers. Data on ERG status and deletions of PTEN, 3p13, 5q21 and 6q15 were available from earlier studies. SOX9 expression levels were comparable in luminal cells of normal prostate glands (50% SOX9 positive) and 3,671 cancers lacking TMPRSS2:ERG fusion (55% SOX9 positive), but was markedly increased in 3,116 ERG-fusion positive cancers (81% SOX9 positive, p<0.0001). While no unequivocal changes in the SOX9 expression levels were found in different stages of ERG-negative cancers, a gradual decrease of SOX9 paralleled progression to advanced stage, high Gleason grade, metastatic growth, and presence of PTEN deletions in ERG-positive cancers (p<0.0001 each). SOX9 levels were unrelated to deletions of 3p, 5q, and 6q. Down-regulation of SOX9 expression was particularly strongly associated with PSA recurrence in ERG-positive tumors harboring PTEN deletions (p=0.001), but had no significant effect in ERG-negative cancers or in tumors with normal PTEN copy numbers. In summary, the results of our study argue against a tumor-promoting role of SOX9 in prostate cancer, but demonstrate that loss of SOX9 expression characterizes a particularly aggressive subset of ERG positive cancers harboring PTEN deletions.

HOXB13 is a prostate cancer susceptibility gene which shows a cancer predisposing (G84E) mutation in 0.1-0.6% of males. We analyzed the prognostic impact of HOXB13 expression by immunohistochemistry on a tissue microarray containing more than 12,400 prostate cancers. Results were compared to tumor phenotype, biochemical recurrence, androgen receptor (AR) and prostate specific antigen (PSA) as well as molecular subtypes defined by ERG status and genomic deletions of 3p, 5q, 6q, and PTEN. HOXB13 immunostaining was detectable in 51.7% of 10,216 interpretable cancers and considered strong in 9.6%, moderate in 19.7% and weak in 22.3% of cases. HOXB13 expression was linked to advanced pT stage, high Gleason grade, positive lymph node status (p < 0.0001 each), high pre-operative PSA levels (p = 0.01), TMPRSS2:ERG fusion, PTEN deletions, AR expression, cell proliferation, reduced PSA expression and early PSA recurrence (p < 0.0001 each). The prognostic value of HOXB13 was independent from established parameters including Gleason, stage, nodal stage and PSA. Co-expression analysis identified a subset of tumors with high HOXB13 and AR but low PSA expression that had a particularly poor prognosis. HOXB13 appears to be a promising candidate for clinical routine tests either alone or in combination with other markers, including AR and PSA.

The VEGFR-1 is suggested to promote tumor progression. In the current study we analyzed prevalence and prognostic impact of the VEGFR-1 by immunohistochemistry on a tissue microarray containing more than 3000 prostate cancer specimens. Results were compared to tumor phenotype, ETS-related gene (ERG) status, and biochemical recurrence. Membranous VEGFR-1 expression was detectable in 32.6% of 2669 interpretable cancers and considered strong in 1.7%, moderate in 6.7% and weak in 24.2% of cases. Strong VEGFR-1 expression was associated with TMPRSS2:ERG fusion status as determined by fluorescence in situ hybridization (FISH) and immunohistochemistry (p < 0.0001 each). Elevated VEGFR-1 expression was linked to high Gleason grade and advanced pT stage in TMPRSS2:ERG negative cancers (p = 0.0008 and p = 0.001), while these associations were absent in TMPRSS2:ERG positive cancers. VEGFR-1 expression was also linked to phosphatase and tensin homolog (PTEN) deletions. A comparison with prostate specific antigen (PSA) recurrence revealed that the 1.7% of prostate cancers with the highest VEGFR-1 levels had a strikingly unfavorable prognosis. This could be seen in all cancers, in the subsets of TMPRSS2:ERG positive or negative, PTEN deleted or undeleted carcinomas (p < 0.0001 each). High level VEGFR-1 expression is infrequent in prostate cancer, but identifies a subgroup of aggressive cancers, which may be candidates for anti-VEGFR-1 targeted therapy.

Thymidylate synthase (TYMS) plays a role in DNA synthesis and is a target for 5-fluorouracil. In this study TYMS was analyzed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancers. TYMS expression was higher in neoplastic than in normal prostate epithelium and was detectable in 72.9% of 10,223 interpretable cancers. It was considered strong in 21.9%, moderate in 33.4% and weak in 17.6% of tumors. TYMS overexpression was associated with deletions at 5q21 (p < 0.0001), 6q15 (p < 0.0001) and 3p13 (p = 0.0083) and gradually increased with the total number of these deletions present in the respective cancer sample (p < 0.0001). TYMS expression was unrelated to PTEN deletions (p = 0.9535) but tightly linked to high Gleason grade, advanced pathological tumor stage and early PSA recurrence (p < 0.0001). The prognostic value of TYMS was independent from the ERG status and deletions at 3p13, 5q21, and 6q15. In multivariate analyses the prognostic role of TYMS expression was independent of Gleason grade, pT stage, preoperative PSA, pN stage, or resection margins. TYMS expression analysis might result in clinically useful information in prostate cancer. The striking link to some but not all chromosomal aberrations might suggest a mechanistical link with specific types of DNA damage.

The cytosolic factor Saccharomyces cerevisiae-like 1 (SEC14L1) is a regulator of lipid metabolism and signaling pathways that has been suggested to play a role in cancer. To learn more about its relevance for prostate cancer, SEC14L1 expression was analyzed on a tissue microarray containing samples from 11152 prostate cancer patients. In benign prostate glands, SEC14L1 immunostaining was absent or weak. In prostate cancer, SEC14L1 positivity was found in 80% of 9876 interpretable tumors including 9% with strong, 38% with moderate, and 32% with weak immunostaining. SEC14L1 expression was more frequent in Transmembrane Protease, Serine 2 (TMPRSS2):Ets-related gene (ERG) fusion-positive (89%) than in TMPSSR2:ERG-negative cancers (73%, P < .0001). Comparative analysis of SEC14L1 expression in TMPSSR2:ERG-positive and -negative cancers suggested a different role of SEC14L1 in the 2 subsets: in TMPSSR2:ERG-negative cancers, strong SEC14L1 expression was associated with early prostate-specific antigen recurrence (P = .0270), advanced tumor stage (P = .0042), high Gleason score (P < .0001), and high preoperative prostate-specific antigen levels (P = .0035). In TMPSSR2:ERG-positive cancers, strong SEC14L1 staining was linked to a prolonged recurrence-free interval (P = .0023) and absence of lymph node metastases (P = .0002). Strong associations of high SEC14L1 levels with chromosomal deletions (5q, 6q, phosphatase and tensin homolog gene, 3p13; P < .0001) and a high Ki-67 labeling index (P < .0001) were seen in TMPSSR2:ERG-negative but not TMPSSR2:ERG-positive cancers. A direct or indirect role of SEC14L1 in maintenance of genomic integrity and regulating cell proliferation may thus exclusively exist in TMPSSR2:ERG-negative cancers. In conclusion, our data suggest a markedly different role of SEC14L1 in TMPSSR2:ERG-negative and TMPSSR2:ERG-positive prostate cancers., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The benefit of intraoperative neurovascular structure-adjacent frozen section examination (NeuroSAFE) of the prostate was demonstrated in open radical prostatectomy. In da Vinci robot-assisted prostatectomy (DVP), this approach is often avoided due to suspected difficulties in harvesting the prostate, loss in pneumoperitoneum, increased blood loss, and prolonged operating room (OR) time., Objective: To provide a detailed description of the technique, feasibility, and impact of the NeuroSAFE technique on OR time, blood loss, frequency of nerve sparing (NS), and positive surgical margins (PSMs) in DVP., Design, Setting, and Participants: We analyzed 1570 consecutive patients undergoing DVP from 2004 to 2012. NeuroSAFE was performed in 1178 patients., Surgical Procedure: The prostate was intraoperatively harvested via an extension of the camera trocar incision without undocking the robotic arms. Blood spillage from the dorsal vein complex due to the loss of pneumoperitoneum was avoided by upward traction on the transurethral catheter. After prostate removal, pneumoperitoneum was reestablished by closing the extended incision with running sutures and repositioning the optical trocar. The NeuroSAFE procedure consisted of intraoperative bilateral frozen sections covering the entire neurovascular bundles adjacent prostate surface., Outcome Measurements and Statistical Analysis: We compared OR time, blood loss, NS frequency, and PSMs in non-NeuroSAFE versus NeuroSAFE DVP., Results and Limitations: There was no significant difference in blood loss (253.5 ± 204.4 ml vs 265.8 ± 246.7 ml; p=0.49) and OR time (220 min ± 51 vs 224 min ± 64; p=0.22). No complications associated with specimen harvesting occurred. NS rate increased significantly with versus without NeuroSAFE (overall 97% vs 81%; pT2 99% vs 90%, pT3a 94% vs 74%, pT3b 91% vs 30). PSM rate dropped significantly with NeuroSAFE (overall 16% vs 24%; pT2 8% vs 15%, pT3a 22% vs 39%, pT3b 49% vs 67%; all p<0.05)., Conclusions: We demonstrate a time-efficient and safe adaption of the NeuroSAFE technique to DVP., Patient Summary: We describe a feasible and secure adaption of the neurovascular structure-adjacent frozen section examination (NeuroSAFE) procedure for da Vinci robot-assisted prostatectomy. We showed that there was no increased blood loss and operating room time. We maximized the nerve-sparing frequency and could reduce positive surgical margins even in non-organ-confined tumors., (Copyright © 2013 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Purpose: The prognostic significance of a tertiary Gleason pattern in the radical prostatectomy specimen is controversial. We tested the impact of a tertiary Gleason pattern on adverse histopathological features and biochemical recurrence rates after radical prostatectomy., Materials and Methods: We assessed data on 11,226 consecutive patients treated with radical prostatectomy at our institution between June 2007 and February 2013. We compared 2,396 patients with (22.4%) and 8,260 without (77.5%) a tertiary Gleason pattern for adverse histopathological features (extraprostatic extension, seminal vesicle invasion, positive surgical margins and lymph node invasion) using the chi-square test. The effect of a tertiary Gleason pattern on biochemical recurrence was tested in univariable and multivariable models. Subanalyses were then done for different radical prostatectomy Gleason groups (6 or less, 3 + 4 and 4 + 3)., Results: A tertiary Gleason pattern was statistically significantly associated with all evaluated histopathological parameters (each p <0.001). It was an independent predictor of biochemical recurrence (HR 1.43, p <0.001). On subanalysis only a tertiary Gleason pattern independently predicted biochemical recurrence in the patient cohort with a radical prostatectomy Gleason score of 3 + 4 and 4 + 3. However, it failed to attain independent predictor status in patients with a radical prostatectomy Gleason score of 6 or less., Conclusions: A tertiary Gleason pattern is a significant and independent predictor of biochemical recurrence after radical prostatectomy with the strongest prognostic effect in cases with Gleason scores 3 + 4 and 4 + 3. Therefore, a tertiary Gleason pattern should be recorded in the pathological report., (Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Molecular prognostic markers are urgently needed in order to improve therapy decisions in prostate cancer. To better understand the requirements for biomarker studies, we re-analyzed prostate cancer tissue microarray immunohistochemistry (IHC) data from 39 prognosis markers in subsets of 50 - >10,000 tumors. We found a strong association between the "prognostic power" of individual markers and the number of tissues that should be minimally included in such studies. The prognostic relevance of more than 90% of the 39 IHC markers could be detected if ≥6400 tissue samples were analyzed. Studying markers of tissue quality, including immunohistochemistry of ets-related gene (ERG) and vimentin, and fluorescence in-situ hybridization analysis of human epidermal growth factor receptor 2 (HER2), we found that 18% of tissues in our tissue microarray (TMA) showed signs of reduced tissue preservation and limited immunoreactivity. Comparing the results of Kaplan-Meier survival analyses or associations to ERG immunohistochemistry in subsets of tumors with and without exclusion of these defective tissues did not reveal statistically relevant differences. In summary, our study demonstrates that TMA-based marker validation studies using biochemical recurrence as an endpoint require at least 6400 individual tissue samples for establishing statistically relevant associations between the expression of molecular markers and patient outcome if weak to moderate prognosticators should also be reliably identified.

Background and Aims: A major impediment to establishing new treatments for non-alcoholic steatohepatitis is the lack of suitable animal models that accurately mimic the biochemical and metabolic characteristics of the disease. The aim of this study was to explore a unique polygenic animal model of metabolic disease as a model of non-alcoholic steatohepatitis by determining the effects of 2% dietary cholesterol supplementation on metabolic and liver endpoints in Psammomys obesus (Israeli sand rat)., Methods: P. obesus were provided ad libitum access to either a standard rodent diet (20% kcal/fat) or a standard rodent diet supplemented with 2% cholesterol (w/w) for 4 weeks. Histological sections of liver from animals on both diets were examined for key features of non-alcoholic steatohepatitis. The expression levels of key genes involved in hepatic lipid metabolism were measured by real-time PCR., Results: P. obesus fed a cholesterol-supplemented diet exhibited profound hepatomegaly and steatosis, and higher plasma transaminase levels. Histological analysis identified extensive steatosis, inflammation, hepatocyte injury and fibrosis. Hepatic gene expression profiling revealed decreased expression of genes involved in delivery and uptake of lipids, and fatty acid and triglyceride synthesis, and increased expression of genes involved in very low density lipoprotein cholesterol synthesis, triglyceride and cholesterol export., Conclusions: P. obesus rapidly develop non-alcoholic steatohepatitis when fed a cholesterol-supplemented diet that appears to be histologically and mechanistically similar to patients.

Combination therapy is being increasingly used as a treatment paradigm for metabolic diseases such as diabetes and obesity. In the peptide therapeutics realm, recent work has highlighted the therapeutic potential of chimeric peptides that act on two distinct receptors, thereby harnessing parallel complementary mechanisms to induce additive or synergistic benefit compared to monotherapy. Here, we extend this hypothesis by linking a known anti-diabetic peptide with an anti-obesity peptide into a novel peptide hybrid, which we termed a phybrid. We report on the synthesis and biological activity of two such phybrids (AC164204 and AC164209), comprised of a glucagon-like peptide-1 receptor (GLP1-R) agonist, and exenatide analog, AC3082, covalently linked to a second generation amylin analog, davalintide. Both molecules acted as full agonists at their cognate receptors in vitro, albeit with reduced potency at the calcitonin receptor indicating slightly perturbed amylin agonism. In obese diabetic Lep(ob)/Lep (ob) mice sustained infusion of AC164204 and AC164209 reduced glucose and glycated haemoglobin (HbA1c) equivalently but induced greater weight loss relative to exenatide administration alone. Weight loss was similar to that induced by combined administration of exenatide and davalintide. In diet-induced obese rats, both phybrids dose-dependently reduced food intake and body weight to a greater extent than exenatide or davalintide alone, and equal to co-infusion of exenatide and davalintide. Phybrid-mediated and exenatide + davalintide-mediated weight loss was associated with reduced adiposity and preservation of lean mass. These data are the first to provide in vivo proof-of-concept for multi-pathway targeting in metabolic disease via a peptide hybrid, demonstrating that this approach is as effective as co-administration of individual peptides.

Shortcomings of previously reported preclinical models of nonalcoholic steatohepatitis (NASH) include inadequate methods used to induce disease and assess liver pathology. We have developed a dietary model of NASH displaying features observed clinically and methods for objectively assessing disease progression. Mice fed a diet containing 40% fat (of which ∼18% was trans fat), 22% fructose, and 2% cholesterol developed three stages of nonalcoholic fatty liver disease (steatosis, steatohepatitis with fibrosis, and cirrhosis) as assessed by histological and biochemical methods. Using digital pathology to reconstruct the left lateral and right medial lobes of the liver, we made comparisons between and within lobes to determine the uniformity of collagen deposition, which in turn informed experimental sampling methods for histological, biochemical, and gene expression analyses. Gene expression analyses conducted with animals stratified by disease severity led to the identification of several genes for which expression highly correlated with the histological assessment of fibrosis. Importantly, we have established a biopsy method allowing assessment of disease progression. Mice subjected to liver biopsy recovered well from the procedure compared with sham-operated controls with no apparent effect on liver function. Tissue obtained by biopsy was sufficient for gene and protein expression analyses, providing the opportunity to establish an objective method of assessing liver pathology before subjecting animals to treatment. The improved assessment techniques and the observation that mice fed the high-fat diet exhibit many clinically relevant characteristics of NASH establish a preclinical model for identifying pharmacological interventions with greater likelihood of translating to the clinic.

Antagonism of opioid systems (e.g., with naltrexone) has been explored as an anti-obesity strategy, and is particularly effective when co-administered with dual inhibitors of dopamine and norepinephrine reuptake (e.g., bupropion). Previously, we demonstrated that amylin enhances the food intake lowering and weight loss effects of neurohormonal (e.g., leptin, cholecystokinin, melanocortins) and small molecule (e.g., phentermine, sibutramine) agents. Here, we sought to characterize the interaction of amylin with naltrexone/bupropion on energy balance. Wild-type and amylin knockout mice were similarly responsive to the food intake lowering effects of either naltrexone (1mg/kg, subcutaneous) or bupropion (50mg/kg, subcutaneous) suggesting that they act independently of amylinergic systems and could interact additively when given in combination with amylin. To test this, diet-induced obese rats were treated (for 11 days) with vehicle, rat amylin (50 μg/kg/d, infused subcutaneously), naltrexone/bupropion (1 and 20mg/kg, respectively by twice daily subcutaneous injection) or their combination. We found that amylin+naltrexone/bupropion combination therapy exerted additive effects to reduce cumulative food intake, body weight and fat mass. In a separate study, the effects of amylin and naltrexone/bupropion administered at the same doses (for 14 days) were compared to a pair-fed group. Although the combination and pair-fed groups lost a similar amount of body weight, rats treated with the combination lost 68% more fat and better maintained their lean mass. These findings support the strategy of combined amylin agonism with opioid and catecholaminergic signaling systems for the treatment of obesity., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Intraoperative frozen-section analysis allows real-time histologic assessment of surgical margins (SMs) and identification of candidates for nerve-sparing (NS) procedures., Objective: To examine the efficacy and oncologic safety of a systematic neurovascular structure-adjacent frozen-section examination (NeuroSAFE) during NS radical prostatectomy (RP)., Design, Setting, and Participants: From January 2002 to June 2011, 11 069 consecutive RPs were performed at the University Medical Center Hamburg-Eppendorf. Of these, 5392 (49%) were conducted with NeuroSAFE., Surgical Procedure: Our NeuroSAFE approach included the whole laterorectal circumference of the prostate to determine the SM status of the complete neurovascular tissue-corresponding prostatic surface., Outcome Measurements and Statistical Analysis: The impact of NeuroSAFE on NS frequency, SM status, and biochemical recurrence (BCR) was analyzed by chi-square test, and by Kaplan-Meier analyses in propensity score-based matched cohorts., Results and Limitations: Positive SMs (PSMs) were detected in 1368 (25%) NeuroSAFE RPs, leading to a secondary resection of the ipsilateral neurovascular tissue. Secondary wide resection resulted in conversion to a definitive negative SM (NSM) status in 1180 (86%) patients. In NeuroSAFE RPs, frequency of NS was significantly higher (all stages: 97% vs 81%; pT2: 99% vs 92%; pT3a: 94% vs 72%; pT3b: 88% vs 40%; p<0.0001) and PSM rates were significantly lower (all stages: 15% vs 22%; pT2: 7% vs 12%; pT3a: 21% vs 32%; p<0.0001) than in the matched non-NeuroSAFE RPs. In propensity score-based comparisons, NeuroSAFE had no negative impact on BCR (pT2, p=0.06; pT3a, p=0.17, pT3b, p=0.99), and BCR-free survival of patients with conversion to NSM did not differ significantly from patients with primarily NSM (pT2, p=0.16; pT3, p=0.26). The accuracy of our NeuroSAFE approach was 97% with a false-negative rate of 2.5%. The major limitations of this study are its retrospective nature and relatively short follow-up., Conclusions: NeuroSAFE enables real-time histologic monitoring of the oncologic safety of a NS procedure. Systematic NeuroSAFE significantly increases NS frequencies and reduces PSMs. Patients with a NeuroSAFE-detected PSM could be converted to a prognostically more favorable NSM status by secondary wide resection., (Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

These preclinical studies aimed to 1) increase our understanding the dietary induction of nonalcoholic steatohepatitis (NASH), and, 2) further explore the utility and mechanisms of glucagon-like peptide-1 receptor (GLP-1R) agonism in NASH. We compared the effects of a high trans-fat (HTF) or high lard fat (HLF) diet on key facets of nonalcoholic fatty liver disease (NAFLD)/NASH in Lep(ob)/Lep(ob) and C57BL6J (B6) mice. Although HLF-fed mice experienced overall greater gains in weight and adiposity, the addition of trans-fat better mirrored pathophysiological features of NASH (e.g., hepatomegaly, hepatic lipid, and fibrosis). Administration of AC3174, an exenatide analog, and GLP-1R agonist to Lep(ob)/Lep(ob) and B6 ameliorated hepatic endpoints in both dietary models. Next, we assessed whether AC3174-mediated improvements in diet-induced NASH were solely due to weight loss in HTF-fed mice. AC3174-treatment significantly reduced body weight (8.3%), liver mass (14.2%), liver lipid (12.9%), plasma alanine aminotransferase, and triglycerides, whereas a calorie-restricted, weight-matched group demonstrated only modest nonsignificant reductions in liver mass (9%) and liver lipid (5.1%) relative to controls. Treatment of GLP-1R-deficient (GLP-1RKO) mice with AC3174 had no effect on body weight, adiposity, liver or plasma indices pointing to the GLP-1R-dependence of AC3174's effects. Interestingly, the role of endogenous GLP-1Rs in NASH merits further exploration as the GLP-1RKO model was protected from the deleterious hepatic effects of HTF. Our pharmacological data further support the clinical evaluation of the utility of GLP-1R agonists for treatment of NASH.

Background: Prostate specific membrane antigen (PSMA) is a suggested target for antibody-based therapy of prostate cancer potentially involved in the regulation of cell migration. This study was undertaken, to gain more insight on the role of PSMA in early prostate cancer and its distribution in various normal tissues., Methods: A total of 1,700 different prostate cancers treated by radical prostatectomy and 612 samples from 76 different normal tissue types were successfully analyzed by immunohistochemistry (IHC) in a tissue microarray (TMA) format. PSMA immunostaining in cancers was also compared with clinical follow-up, preexisting HER2 expression and Ki67 labeling index data., Results: PSMA staining was only found in prostate epithelium and expression was higher in cancer cells than in benign tissue. PSMA staining was found in 94.1% of cancers and was significantly associated with tumor stage, high Gleason grade, preoperative PSA, and HER2 expression (P < 0.0001 each). Tumors with strong PSMA expression had a higher risk of biochemical recurrence than cancers with only weak PSMA staining intensity (P = 0.0483). There was no significant association between PSMA expression and Ki67 labeling index (P = 0.442)., Conclusions: Based on the high frequency of PSMA overexpression in all stages and grades of prostate cancer and the high prevalence of PSMA overexpression, it can be speculated that increased PSMA expression may be related with prostate cancer development rather than progression. The known function of PSMA activating cell migration would be in line with the suggested role in cancer progression and the missing association between PSMA overexpression and tumor cell proliferation., (Copyright © 2010 Wiley-Liss, Inc.)

In rodents, ovariectomy (OVX) elicits weight gain and diminished responsiveness to homeostatic signals. Here we characterized the response of obese OVX rats to peripheral amylin. Rats received sham surgery (SHAM), OVX, or OVX with hormonal replacement (17β-estradiol, 2 μg per 4 d; OVX+E) and were infused with vehicle or amylin (50 μg/kg · d) for 28 d. Amylin reduced body weight (5.1 ± 1.1%) and food intake (10.9 ± 3.4%) in SHAM rats but was twice as efficacious in OVX rats in reducing weight (11.2 ± 1.9%) and food intake (23.0 ± 2.0%). There were no differences between amylin-treated SHAM and OVX+E rats. OVX decreased metabolic rate (∼24%) and increased respiratory exchange ratio relative to SHAM. Amylin partially normalized metabolic rate (13% increase) in OVX rats and decreased respiratory exchange ratio in OVX and SHAM rats. Regarding central mechanisms, amylin infusion corrected the OVX-induced decrease in hippocampal neurogenesis and increased immobility in the forced swim test. Additionally, amylin increased neurogenesis (∼2-fold) within the area postrema of OVX rats. To assess the contribution of endogenous leptin to amylin-mediated weight loss in OVX rats, amylin was administered to SHAM or OVX Zucker diabetic fatty rats. In SHAM rats, amylin infusion reduced food intake but not body weight, whereas in OVX Zucker diabetic fatty rats, food intake, body weight, and insulin were reduced. Overall, amylin induced greater body weight loss in the absence of estradiol via central and peripheral actions that did not require leptin. These findings support the clinical investigation of amylin in low estradiol (e.g. postmenopausal) states.

Cholecystokinin (CCK) acutely synergizes with amylin to suppress food intake in lean mice. To extend on these findings, the present studies sought to identify neural correlates for the interaction of amylin and CCK, as well as further understand the therapeutic potential of CCK-based combinations in obesity. First, c-Fos activation was assessed in various brain nuclei after a single intraperitoneal injection of amylin (5microg/kg) and/or CCK (5microg/kg). Amylin and CCK additively increased c-Fos within the area postrema (AP), predominantly in noradrenergic (e.g., dopamine-beta-hydroxylase-containing) cells. Next, amylin (100 or 300microg/kg/d) and/or CCK (100 or 300microg/kg/d) were subcutaneously infused for 7days in diet-induced obese (DIO) rats. Amylin treatment of DIO rats for 7days induced significant body weight loss. CCK, while ineffective alone, significantly enhanced body weight loss when co-administered with the higher dose of amylin. Finally, the addition of CCK (300microg/kg/d) to leptin (125microg/kg/d), and to the combination of amylin (50microg/kg/d) and leptin (125microg/kg/d), was also explored in DIO rats via sustained subcutaneous infusion for 14days. Infusion of amylin/leptin/CCK for 14days exerted significantly greater body weight loss, inhibition of food intake, and reduction in adiposity compared to amylin/leptin treatment alone in DIO rats. However, co-infusion of CCK and leptin was an ineffective weight loss regimen in this model. Whereas CCK agonism alone is ineffective at eliciting or maintaining weight loss, it durably augmented the food intake and body weight-lowering effects of amylin and amylin/leptin in a relevant disease model, and when combined with amylin, cooperatively activated neurons within the caudal brainstem., (Copyright 2010 Elsevier Inc. All rights reserved.)

The present studies aimed to identify mechanisms contributing to amylin/leptin synergy in reducing body weight and adiposity. We reasoned that if amylin/leptin harnessed complementary neuronal pathways, then in the leptin-sensitive state, amylin should augment leptin signaling/binding and that in the absence of endogenous amylin, leptin signaling should be diminished. Amylin (50 microg/kg, ip) amplified low-dose leptin-stimulated (15 microg/kg, ip) phosphorylated signal transducer and activator of transcription-3 signaling within the arcuate nucleus (ARC) in lean rats. Amylin (50 microg/kg x d) or leptin (125 microg/kg x d) infusion to lean rats decreased 28-d food intake (14 and 10%, respectively), body weight (amylin by 4.3%, leptin by 4.9%), and epididymal fat (amylin by 19%, leptin by 37%). Amylin/leptin co-infusion additively decreased food intake (by 26%) and reduced body weight (by 15%) and epididymal fat (by 78%; all P < 0.05 vs. all groups) in a greater than mathematically additive manner, consistent with synergy. Amylin increased leptin binding within the ventromedial hypothalamus (VMN) by 35% and dorsomedial hypothalamus by 47% (both P < 0.05 vs. vehicle). Amylin/leptin similarly increased leptin binding in the VMN by 40% and ARC by 70% (P < 0.05 vs. vehicle). In amylin-deficient mice, hypothalamic leptin receptor mRNA expression was reduced by 50%, leptin-stimulated phosphorylated signal transducer and activator of transcription-3 within ARC and VMN was reduced by 40%, and responsiveness to leptin's (1 mg/kg x d for 28 d) weight-reducing effects was attenuated (all P < 0.05 vs. wild-type controls). We suggest that amylin/leptin's marked weight- and fat-reducing effects are due to activation of intrinsic synergistic neuronal signaling pathways and further point to the integrated neurohormonal therapeutic potential of amylin/leptin agonism in obesity.

Previously, we reported that combination treatment with rat amylin (100 microg/kg.d) and murine leptin (500 microg/kg.d) elicited greater inhibition of food intake and greater body weight loss in diet-induced obese rats than predicted by the sum of the monotherapy conditions, a finding consistent with amylin-induced restoration of leptin responsiveness. In the present study, a 3 x 4 factorial design was used to formally test for a synergistic interaction, using lower dose ranges of amylin (0, 10, and 50 microg/kg.d) and leptin (0, 5, 25, and 125 microg/kg.d), on food intake and body weight after 4 wk continuous infusion. Response surface methodology analysis revealed significant synergistic anorexigenic (P < 0.05) and body weight-lowering (P < 0.05) effects of amylin/leptin combination treatment, with up to 15% weight loss at doses considerably lower than previously reported. Pair-feeding (PF) experiments demonstrated that reduction of food intake was the predominant mechanism for amylin/leptin-mediated weight loss. However, fat loss was 2-fold greater in amylin/leptin-treated rats than PF controls. Furthermore, amylin/leptin-mediated weight loss was not accompanied by the counterregulatory decrease in energy expenditure and chronic shift toward carbohydrate (rather than fat) utilization observed with PF. Hepatic gene expression analyses revealed that 28 d treatment with amylin/leptin (but not PF) was associated with reduced expression of genes involved in hepatic lipogenesis (Scd1 and Fasn mRNA) and increased expression of genes involved in lipid utilization (Pck1 mRNA). We conclude that amylin/leptin interact synergistically to reduce body weight and adiposity in diet-induced obese rodents through a number of anorexigenic and metabolic effects.

Genetic mechanisms leading to androgen-independent growth in advanced prostatic carcinomas (PC) are still poorly understood. Analysis of genes potentially involved in the regulation of tumor cell proliferation and apoptosis might confer better insight into this process and might lead to improved therapeutic strategies. Fluorescence in situ hybridization (FISH) analysis of dissociated nuclei with DNA probes for MYC (8q24)/#8, cyclin D1 gene (CCND1; 11q13)/#11, ERBB2 (17q13)/#17, the androgen receptor gene (AR; Xq12)/#X, and the retinoblastoma gene (RB; 13q14) was applied to formalin-fixed tissue from 63 patients with advanced PC after androgen deprivation therapy (ADT); matched tumor tissue before ADT was also available in 22 of these cases. The cut-points used were: "increased copy number," > or = 30% of all nuclei with increased FISH signals (centromere and/or gene); "amplification," > or = 15% of nuclei with "increased gene copy number." CCND1 and MYC gene "amplifications" were present before ADT in 25% and 33% of the cases, respectively; the frequency of these "amplifications" increased to 37% and 57% after ADT. Loss of the RB gene was nearly four times more frequent after ADT than before therapy (22% versus 6%). AR and ERBB2 gene "amplifications" occurred only after ADT in 36% and 30% of cases, respectively. With the exception of the AR gene, the copy number increase was low. After treatment, MYC and AR gene "amplifications" correlated with the proliferation rate (Ki-67/MIB1 index; p = 0.01 and p = 0.04), whereas ERBB2 "amplifications" were associated with increased apoptotic index (PCD/TUNEL; p = 0.016). However, no correlation between FISH results and clinical follow-up could be established. FISH analysis of genes putatively involved in PC progression revealed characteristic patterns of aberrations in advanced PC before and after ADT. Distinct changes in gene copy number before and after therapy suggests possible involvement of these genes in the escape from androgen control.