[EXPRESSION OF PLAKIN FAMILY IN UROTHELIAL CARCINOMA OF THE UPPER URINARY TRACT].

(Objective) To determine whether the plakin family proteins periplakin, desmoplakin, plectin, and envoplakin could be markers of urothelial carcinoma of the upper urinary tract. (Materials and methods) Fifty-seven surgical specimens were obtained from patients with urothelial carcinoma of the upper urinary tract, who were admitted to the Jikei University Hospital between April 2000 and December 2005. The expression of plakin family proteins in cancerous and normal tissues was investigated using immunohistochemistry, and its association with clinicopathological parameters was analyzed. (Results) The expression of periplakin, envoplakin, and desmoplakin was significantly lower in cancerous tissue than in normal urothelium (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). Strong desmoplakin expression in cancerous tissue was significantly associated with poor cancer-specific survival and overall survival (P = 0.023 and P = 0.034, respectively, compared with cancerous tissue with slight or less desmoplakin expression). Furthermore, strong plectin expression was significantly associated with poor metastasis-free survival (P = 0.034, compared with cancerous tissue with slight or less plectin expression). (Conclusion) Plakin family, particularly desmoplakin was suggested to be a prognostic marker of urothelial carcinoma of the upper urinary tract.

Time Trends in Histological Features of Latent Prostate Cancer in Japan.

PURPOSE: The incidence of prostate cancer is reported to be increasing in Asia, including Japan. Although this trend has been attributed partly to a more Western diet, this assumption may involve variable confounders. Thus, we examined the histological features of contemporary vs historical latent prostate cancer. MATERIALS AND METHODS: Prostate specimens from a consecutive autopsy series (127, present study, 2008 to 2013) were examined. Each prostate gland was fixed and sliced in step sections. The findings were compared to those from another autopsy series (501 subjects, 1983 to 1987) at our institution. RESULTS: The mean age of subjects in the present study was 68.9 years while the mean age was not available from the earlier study. However, the mean age of the 566 entrants in the expanded database (1983 to 1989) was 63.5 years (p=0.0001). Prostate weight was significantly greater in the present study (p <0.0001). Latent prostate cancer was found more frequently in the present study than in the previous study (43.3% and 20.8%, respectively, p <0.0001). No distinct difference was seen in the proportion of tumor grade between the groups. An increasing trend of moderately to poorly differentiated tumors with advancing age was more evident in the present study. Index cancer volume was greater in the present study with 25.5% measuring 500 mm(3) or greater vs only 9.6% of cancers in the previous study (p=0.008). CONCLUSIONS: Chronological changes in the histological characteristics of Japanese latent prostate cancer were noted as it is more prevalent in the contemporary series. Our data may reflect a worldwide trend in increasingly aging societies.

Salvage partial brachytherapy for prostate cancer recurrence after primary brachytherapy.

OBJECTIVES: To characterize local recurrence of prostate cancer and to assess the effect of salvage partial brachytherapy after primary 125-iodine low-dose rate brachytherapy with or without external beam radiotherapy in Japanese men. METHODS: Between 2003 and 2010, a total of 616 consecutive patients underwent low-dose rate brachytherapy-based therapy for clinically localized prostate cancer at Jikei University Hospital in Tokyo, Japan. Biochemical recurrence occurred in 45 (7.3%) patients at a median of 30 months (range 11-93 months). A total of 20 patients subsequently underwent transperineal template prostatic biopsy; of those, eight had positive cores at the base of the prostate or at the seminal vesicles. These eight patients had underdosed areas identified at initial low-dose rate brachytherapy corresponding to the positive biopsy sites. All were confirmed to have only localized recurrence, and seven underwent salvage partial low-dose rate brachytherapy. RESULTS: Median prostate-specific antigen nadir level in the eight patients with biopsy-proven local recurrence after initial low-dose rate brachytherapy was 0.75 ng/mL (range 0.39-2.06). The seven retreated patients tolerated the salvage partial low-dose rate brachytherapy well, and showed a decrease in prostate-specific antigen level at follow up. Two patients later developed biochemical and clinical progression at 11 and 13 months, respectively. Prostate-specific antigen level continued to be low in the remaining five patients. No significant genitourinary or gastrointestinal toxicity was encountered. CONCLUSIONS: Salvage partial low-dose rate brachytherapy for biopsy-proven localized prostate cancer recurrence appears rational, technically feasible and safe. Optimal patient selection is of utmost importance for long-term success. Larger studies with longer follow up are warranted.

Mid-term outcome of permanent prostate iodine-125 brachytherapy in Japanese patients.

OBJECTIVES: To analyze mid-term oncological outcomes of low-dose rate brachytherapy in Japanese patients. METHODS: Between 2003 and 2010, 604 consecutive patients with clinically localized prostate cancer were treated with low-dose rate brachytherapy at Jikei University Hospital in Tokyo, Japan. Median follow up was 48 months. Of these patients, 260 (43%) were treated with neoadjuvant therapy, 45 (7.5%) with adjuvant hormonal therapy and 75 (12.4%) with supplemental external beam radiation therapy. Biochemical recurrence was defined as the prostate-specific antigen nadir plus 2 ng/mL. RESULTS: Of the 604 patients, 219 (36.2%) were low risk, 361 (59.8%) were intermediate risk and 24 (4.0%) had high-risk disease. The median biologically effective dose was 174.4 Gy2. At 8 years, biochemical recurrence-free survival, cancer-specific survival, and overall survival were 82.2%, 100% and 95.6%, respectively. Biochemical recurrence-free survival at 8 years was 89.9%, 79.4% and 52.5%, for the low-, intermediate-, and high-risk groups, respectively. Biochemical recurrence-free survival for the high-risk group was significantly lower than the low- and intermediate-risk groups (P < 0.001). Biochemical recurrence-free survival did not differ significantly by biologically effective dose stratification. In multivariate analysis, younger age (P = 0.045), higher prostate-specific antigen (P = 0.004), higher Gleason score (P = 0.006) and higher clinical T stage (P = 0.008) were significant covariates associated with biochemical recurrence. The addition of hormonal therapy or external beam radiation therapy was associated with significantly better outcomes than low-dose rate brachytherapy monotherapy (P = 0.0021 and 0.010). Just four patients experienced G3 genitourinary or gastrointestinal toxicity. CONCLUSIONS: Low-dose rate brachytherapy results in excellent mid-term oncological outcomes and acceptable toxicity in Japanese patients. In our experience, biologically effective dose does not represent a significant predictor for biochemical recurrence.

[Solitary adrenal metastasis of bladder carcinoma : a case report].

A 64-year-old man underwent chemotherapy after radical cystectomy for bladder cancer (UC, G3, pT3aN1M0). Three years later, computed tomography showed a left adrenal mass, and we performed left adrenalectomy. Histological findings showed that the adrenal mass was a metastasis of the bladder cancer. Over 6 years after salvage chemotherapy, the patient had no evidence of metastasis to other parts of the body. In the case of a solitary metastasis of bladder cancer, surgical resection should be positively considered.

[New biomarkers for the prostate cancer].

Prostate-specific antigen (PSA) has been widely used as a biomarker for prostate cancer detection and progression. However, PSA has limitations in terms of predicting the prognosis in specific cases of prostate cancer because it does not reflect cancer biology. Due to the development of new techniques in the fields of genomics and proteomics, many new biomarkers have been discovered in the last several years. In this review, we described some of these new and promising biomarkers including gene and protein markers, cytokines and circulating tumor cells. Moreover, we introduced our proteomic-based findings in our search for new prostate cancer biomarkers.

Staphylococcal nuclease domain-containing protein 1 as a potential tissue marker for prostate cancer.

Using high molecular-weight proteomic analysis, we previously showed that Staphylococcal nuclease domain-containing protein 1 (SND1) is highly expressed in recurrent androgen-insensitive prostate cancer tissues. SND1 is a component of the RNA-induced splicing complex that mediates RNA interference, leading to degradation of specific mRNAs. The objective of this study was to further characterize SND1 expression and to investigate its biological potential in prostate cancer. Radical prostatectomy specimens were obtained from 62 prostate cancer patients. SND1 immunohistochemical staining patterns were evaluated using an in-house polyclonal antibody. We confirmed SND1 mRNA expression in prostate cancer cells using an in situ hybridization technique. To determine the importance of SND1 mRNA, we knocked down SND1 in vitro with small interfering RNA and observed a significant decrease in cell growth. SND1 was expressed in 60 of 62 prostate cancers (97%), appearing in the cytoplasm as small, granular structures; it was also present at high levels in prostate cancer specimens, while in hyperplasia specimens and normal epithelium, it was weakly or negatively expressed. SND1 expression intensity increased with increasing grade and aggressiveness of the cancer. As SND1 mRNA was overexpressed in cancer cells, the growth of these cells was suppressed following SND1 knockdown in vitro, thus representing a promising prostate cancer biomarker and therapeutic target.

Dietary administration of mushroom mycelium extracts in patients with early stage prostate cancers managed expectantly: a phase II study.

OBJECTIVE: To assess the efficacy and safety of dietary supplements in patients with early stage prostate cancers who are managed expectantly. METHODS: Seventy-four patients with early prostate cancer, who were treated with expectant management, enrolled in the study. A mushroom mycelium extract was given at a dose of 4.5 g/day for 6 months. The primary endpoint was the proportion of patients in which the prostate specific antigen level decreased by 50% or more following treatment. The adverse events, change of prostate specific antigen value and quality of life were also evaluated. RESULTS: In only one of 74 patients (1.4%), the prostate specific antigen value decreased more than 50%. Grade 2 diarrhea and grade 1 itching were observed in one patient, and patient ingestion compliance was maintained near 100%. The alternation of prostate specific antigen values was stable before and after treatment. In subjects with strong anxiety prior to supplement ingestion, these feelings were significantly alleviated (state anxiety, P = 0.0018; trait anxiety, P = 0.0099). CONCLUSIONS: In this phase II study of early prostate cancer patients who were managed expectantly, a mushroom mycelium extract was an ineffective treatment for reducing 50% or more the patient prostate specific antigen values.

The maximum tumour length in biopsy cores as a predictor of outcome after radical prostatectomy.

OBJECTIVES: To evaluate maximum tumour length (MTL) in biopsy cores as a predictor of prostate-specific antigen (PSA)-failure, systemic failure, and death from prostate cancer after radical prostatectomy (RP). PATIENTS AND METHODS: We assessed 209 men with clinically localized prostate cancer treated with RP; preoperative variables were correlated with unfavourable pathological characteristics in the RP specimens and with outcome after surgery, using univariate and multivariate analysis. RESULTS: The median (range) MTL was 4 (0.2-19) mm and correlated with adverse pathological findings, including specimen Gleason score (P = 0.003), pT3 (P < 0.001), seminal vesicle invasion (P < 0.001) and lymph node involvement (P = 0.019) in multivariate analysis. Preoperative PSA (P < 0.001), biopsy Gleason score (P = 0.002), and MTL (P = 0.045) were independent predictors of PSA failure, whereas only MTL remained a predictor of systemic-failure (P < 0.001) and death from prostate cancer (P = 0.004). The median (range) follow-up after surgery was 90 (17-152) months, during which 83 patients had PSA failure, 20 developed systemic failure and 15 died from prostate cancer. CONCLUSIONS: The MTL correlates well with adverse pathological findings and appears to be an independent predictor of outcome after RP. Patients with a greater MTL might have cancer with an aggressive phenotype and therefore be candidates for more aggressive therapies.

SEMA3C drives cancer growth by transactivating multiple receptor tyrosine kinases via Plexin B1.

Growth factor receptor tyrosine kinase (RTK) pathway activation is a key mechanism for mediating cancer growth, survival, and treatment resistance. Cognate ligands play crucial roles in autocrine or paracrine stimulation of these RTK pathways. Here, we show SEMA3C drives activation of multiple RTKs including EGFR, ErbB2, and MET in a cognate ligand-independent manner via Plexin B1. SEMA3C expression levels increase in castration-resistant prostate cancer (CRPC), where it functions to promote cancer cell growth and resistance to androgen receptor pathway inhibition. SEMA3C inhibition delays CRPC and enzalutamide-resistant progression. Plexin B1 sema domain-containing:Fc fusion proteins suppress RTK signaling and cell growth and inhibit CRPC progression of LNCaP xenografts post-castration in vivo SEMA3C inhibition represents a novel therapeutic strategy for treatment of advanced prostate cancer.

Prospective comparison of the efficacy of caudal versus periprostatic nerve block, both with intrarectal local anesthesia, during transrectal ultrasonography-guided prostatic needle biopsy.

OBJECTIVE: The aim of this study was to compare the effectiveness of caudal block (CB) versus periprostatic nerve block (PPNB), both with intrarectal local anesthesia (IRLA), in reducing pain during transrectal ultrasonography (TRUS)-guided prostatic biopsy. MATERIALS AND METHODS: This study included 532 patients: 266 patients received CB with IRLA and 266 patients PPNB with IRLA. A visual analogue scale (VAS) was applied to prospectively evaluate pain (1) at induction of anesthesia, (2) at insertion of the TRUS probe, (3) at needle penetration to the prostate, and (4) throughout the biopsy procedure. Pain scores were compared to evaluate differences between groups. The secondary endpoint of serious complication rate was also evaluated. As a subanalysis, the pain scores were compared in patients with high body mass index (BMI ≥25 kg/m²). RESULTS: Overall, the pain score in the PPNB group was significantly lower than in the CB group at induction of anesthesia (mean ± SD: 2.0 ± 1.9 vs 2.9 ± 2.1, p = .0001) but higher at insertion of the TRUS probe (2.7 ± 2.5 vs 1.9 ± 1.7, p = .009). The pain score did not differ significantly between groups at needle penetration or throughout the biopsy. Univariate analyses indicated no significant association between VAS scores and patient demographics. Overall rates of serious complications did not differ between the two groups (5.6% vs 5.3%, p = .85). In patients with high BMI, the pain score was significantly lower in the PPNB group than in the CB group throughout the procedure (2.5 ± 2.0 vs 3.5 ± 2.5, p = .03). CONCLUSIONS: Both procedures were equally effective in reducing pain, and the incidence of serious complications was similar. PPNB with IRLA may be more applicable than CB with IRLA in obese patients.

The Master Neural Transcription Factor BRN2 Is an Androgen Receptor-Suppressed Driver of Neuroendocrine Differentiation in Prostate Cancer.

Mechanisms controlling the emergence of lethal neuroendocrine prostate cancer (NEPC), especially those that are consequences of treatment-induced suppression of the androgen receptor (AR), remain elusive. Using a unique model of AR pathway inhibitor-resistant prostate cancer, we identified AR-dependent control of the neural transcription factor BRN2 (encoded by POU3F2) as a major driver of NEPC and aggressive tumor growth, both in vitro and in vivo Mechanistic studies showed that AR directly suppresses BRN2 transcription, which is required for NEPC, and BRN2-dependent regulation of the NEPC marker SOX2. Underscoring its inverse correlation with classic AR activity in clinical samples, BRN2 expression was highest in NEPC tumors and was significantly increased in castration-resistant prostate cancer compared with adenocarcinoma, especially in patients with low serum PSA. These data reveal a novel mechanism of AR-dependent control of NEPC and suggest that targeting BRN2 is a strategy to treat or prevent neuroendocrine differentiation in prostate tumors. SIGNIFICANCE: Understanding the contribution of the AR to the emergence of highly lethal, drug-resistant NEPC is critical for better implementation of current standard-of-care therapies and novel drug design. Our first-in-field data underscore the consequences of potent AR inhibition in prostate tumors, revealing a novel mechanism of AR-dependent control of neuroendocrine differentiation, and uncover BRN2 as a potential therapeutic target to prevent emergence of NEPC. Cancer Discov; 7(1); 54-71. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1.

Potential Role for YB-1 in Castration-Resistant Prostate Cancer and Resistance to Enzalutamide Through the Androgen Receptor V7.

BACKGROUND: Although androgen deprivation therapy for advanced prostate cancer initially exerts excellent anticancer effects, most prostate cancer treated with androgen deprivation therapy eventually recurs as castration-resistant prostate cancer (CRPC). Although aberrant kinase activation has been proposed as a mechanism of castration resistance, comprehensive kinase profiles in CRPC remain unknown. Therefore, we aimed to elucidate the kinome in CRPC as well as the role of key molecules. METHODS: We utilized a kinome array in androgen-dependent LNCaP and castration-resistant CxR cells. The effect of Y-box binding protein-1 (YB-1) on androgen receptor (AR) expression was examined by quantitative polymerase chain reaction and western blot analysis. The association between polymorphisms in the YB-1 gene determined by genotyping and YB-1 expression evaluated by immunohistochemistry in prostate cancer tissues, as well as outcome in metastatic prostate cancer, were investigated by the Cochran-Armitage test and the Cox proportional hazards model, respectively. All statistical tests were two-sided. RESULTS: One hundred fifty-six of 180 kinase phosphorylation sites, including ERK and RSK, were activated in CRPC cells, leading to increased phosphorylation of YB-1, which is a key molecule in the progression to CRPC. YB-1 signaling regulated AR V7 expression, and YB-1 inhibition augmented the anticancer effect of enzalutamide. Moreover, polymorphism (rs12030724) in the YB-1 gene affected YB-1 expression in 93 prostate cancer tissues (YB-1 positive rate; 14.3% in TT, 40.0% in AT, and 52.9% in AA, P = .04) and associated with probability of progression in 104 metastatic prostate cancer case patients (AT/TT vs AA, hazard ratio = 0.49, 95% confidence interval = 0.32 to 0.77, P = .001). CONCLUSIONS: YB-1 appears to be a promising target to inhibit the development of castration resistance, even at the AR variant-expressing stage. Polymorphism in the YB-1 gene may be a promising predictive biomarker in hormonal therapy.

Do androgen deprivation and the biologically equivalent dose matter in low-dose-rate brachytherapy for intermediate-risk prostate cancer?

The objective of this study was to investigate the impact of the biologically equivalent dose (BED) on treatment outcomes after iodine-125 low-dose-rate brachytherapy (LDR-BT) with or without supplemental external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT) for intermediate-risk prostate cancer (PCa). We retrospectively evaluated 292 Japanese patients. The impact of the BED and ADT on treatment outcomes was investigated. Cox proportional hazard models were used for univariate and multivariate analysis with biological progression-free survival (bPFS) and clinical progression-free survival (cPFS) as the primary outcome measures. The median follow-up was 66 months. The bPFS and cPFS rates at 5-/7-years were 91.6/87.7% and 95.9/94.0%, respectively. When stratified by BED levels, the bPFS rates at 5-/7-years were 92.1/89.3% for <178.0 Gy2, and 91.2/86.0% for ≥178.0 Gy2 , respectively (P > 0.05). Based on ADT duration, the bPFS rates at 5-/7-years were 89.8/83.5%, 89.7/89.7%, and 97.5/97.5% for none, 1-3 months, and 4-12 months, respectively (P = 0.03). For the univariate analysis, the use of ADT and its duration were significant predictors for bPFS, whereas BED was not significant. A multivariate analysis did not indicate the use of ADT itself was significant, however, when covariates were accounted for by the duration of ADT, the longer use of ADT was found to significantly improve bPFS. Although cPFS was associated neither with the BED levels nor ADT duration (P > 0.05), ADT duration had a trend of improving cPFS (P = 0.053). The higher levels of BED did not significantly impact bPFS for intermediate-risk PCa after LDR-BT with or without supplemental EBRT and ADT. The longer duration of ADT could provide an additional benefit in the context of high-dose irradiation generated by LDR-BT.

Crosstalk between epithelial-mesenchymal transition and castration resistance mediated by Twist1/AR signaling in prostate cancer.

Although invasive and metastatic progression via the epithelial-mesenchymal transition (EMT) and acquisition of resistance to castration are both critical steps in prostate cancer, the molecular mechanism of this interaction remains unclear. In this study, we aimed to elucidate the interaction of signaling between castration resistance and EMT, and to apply this information to the development of a novel therapeutic concept using transforming growth factor-ß (TGF-ß) inhibitor SB525334 combined with androgen-deprivation therapy against prostate cancer using an in vivo model. This study revealed that an EMT inducer (TGF-ß) induced full-length androgen receptor (AR) and AR variant expression. In addition, a highly invasive clone showed augmented full-length AR and AR variant expression as well as acquisition of castration resistance. Conversely, full-length AR and AR as well as Twist1 and mesenchymal molecules variant expression were up-regulated in castration-resistant LNCaP xenograft. Finally, TGF-ß inhibitor suppressed Twist1 and AR expression as well as prostate cancer growth combined with castration. Taken together, these results demonstrate that Twist1/AR signaling was augmented in castration resistant as well as mesenchymal-phenotype prostate cancer, indicating the molecular mechanism of mutual and functional crosstalk between EMT and castration resistance, which may play a crucial role in prostate carcinogenesis and progression.

Inhibition of the HER2-YB1-AR axis with Lapatinib synergistically enhances Enzalutamide anti-tumor efficacy in castration resistant prostate cancer.

Incurable castration-resistant prostate cancer (CRPC) is driven by androgen receptor (AR) activation. Potent therapies that prevent AR signaling, such as Enzalutamide (ENZ), are mainstay treatments for CRPC; however patients eventually progress with ENZ resistant (ENZR) disease. In this study, we investigated one mechanism of ENZ resistance, and tried to improve therapeutic efficiency of ENZ. We found HER2 expression is increased in ENZR tumors and cell lines, and is induced by ENZ treatment of LNCaP cells. ENZ-induced HER2 overexpression was dependent on AKT-YB1 activation and modulated AR activity. HER2 dependent AR activation in LNCaP and ENZR cells was effectively blocked by treatment with the EGFR/HER2 inhibitor Lapatinib, which reduced cell viability and increased apoptosis. Despite efficacy in vitro, in vivo monotherapy with Lapatinib did not prevent ENZR tumor growth. However, combination treatment of Lapatinib with ENZ most effectively induced cell death in LNCaP cells in vitro and was more effective than ENZ alone in preventing tumor growth in an in vivo model of CRPC. These results suggest that while HER2 overexpression and subsequent AR activation is a targetable mechanism of resistance to ENZ, therapy using Lapatinib is only a rational therapeutic approach when used in combination with ENZ in CRPC.

[Subsequent upper urothelial cancer following bladder tumor].

A total of 110 patients were treated with primary transitional cell carcinoma (TCC) of the urinary bladder from 1990 to 2000. During the follow-up period, which was for at least two years, four patients (3.6 percent) had subsequent upper urothelial cancer at an average of 61.5 months after initial treatment of the bladder tumor. Two of the four patients received transurethral resection several times, and the remaining two patients underwent radical cystectomy for the initial bladder tumor. The histopathological findings of subsequent upper urothelial cancer were almost the same as those for the initial bladder tumor. One patient had accompanying carcinoma in situ (CIS) and the other had adenocarcinoma with TCC. Since 1) high grade, 2) multiple, 3) recurrent and 4) occupational bladder tumors, 5) concomitant CIS, 6) vesicoureteral reflux and 7) tumor invasion of the intravesical ureters have been reported to be risk factors for developing subsequent upper urothelial cancer, patients with bladder tumors who have these risk factors should be followed-up closely.

[Prostate-specific antigen and its related parameters in detecting prostate cancer].

Prostate-specific antigen (PSA) is the most useful tumor marker available today. However, its inability to clearly distinguish between prostate cancer and benign prostatic hyperplasia may result in serial and unnecessary prostate biopsies. Various attempts have been made to improve its specificity. PSA-related parameters including PSA density, PSA density for the transition zone, age- or race-specific PSA reference range, PSA velocity, and percent free PSA are the most promising approaches available at present.

Loss of periplakin expression is associated with pathological stage and cancer-specific survival in patients with urothelial carcinoma of the urinary bladder.

The objective of this study was to determine periplakin expression in normal urothelium and bladder cancer tissues and the relationship to clinicopathological findings. Immunohistochemical staining for periplakin was carried out in 92 archival radical cystectomy specimens, with immunoreactivity being stratified on a 0-6 scale. Immunohistochemical staining for periplakin was shown to be significantly lower in bladder cancer tissues compared to non-cancerous tissues including inflammation,hyperplasia and normal urothelium. Loss of periplakin expression was associated with pathological stage (P=0.04). In multivariate Cox regression analysis, loss of periplakin expression and positive lymph node status were independent prognostic factors for cancer-specific survival (P=0.03 and 0.015; odds ratio=2.29 and 2.66; 95% confidence interval=1.085-4.814 and 1.214-5.845, respectively). This new molecular marker may aid in identifying and selecting bladder cancer patients undergoing radical cystectomy who may potentially benefit from neoadjuvant or adjuvant therapy.