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We aimed to develop a sandwich ELISA to detect prostate-specific membrane antigen (PSMA) on small extracellular vesicles (EVs) using T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) as a capture molecule for EVs and to evaluate its diagnostic potential in urologic malignancies. First, we optimized the conditions for sandwich ELISA measuring the PSMA level on EVs captured from serum by Tim4 and found that the use of highly-purified EVs released from Tim4 that had captured EVs in serum reduced the background. Second, we confirmed its validity by studying mouse xenograft model for prostate cancer (PC). Lastly, we measured PSMA-EVs in serum of patients with urologic malignancies. The PSMA-EV levels were significantly higher in metastatic PC and castration-resistant PC (CRPC) patients than in therapy-naïve PC patients. In renal cell carcinoma (RCC) patients, PSMA-EVs were elevated in those with metastasis compared with those without metastasis, which may reflect the development of the neovasculature positive for PSMA in tumors. In conclusion, we developed a sandwich ELISA for detection of PSMA-EVs using highly-purified EVs isolated from serum by Tim4. Our results suggest that PSMA-EVs may be useful to diagnose and monitor not only PC but also RCC and possibly other hypervascular solid tumors.

Background/aim To identify novel biomarkers for prostate cancer (PC), we evaluated changes of miRNAs contained in serum small extracellular vesicles (EVs) in patients who received low dose rate prostate brachytherapy (BT). Materials and methods EVs were isolated from the pooled serum of 10 PC patients prior to and 1 month after BT. miRNA profiling and quantitation in EVs was performed by microarray analysis and RT-digital PCR, respectively. Expression of miRNA-93 in prostate tissue was evaluated using the TCGA database and its level in EVs was determined in 25 patients before and 1, 3, 6 and 12 months after BT. Results Profiling and quantitation identified miRNA-93 as significantly down-regulated in EVs after BT. TCGA database analysis showed that miRNA-93 was increased in PC tissue. miRNA-93 in EVs significantly decreased in 3, 6 and 12 months after BT. Conclusion miRNA-93 contained in serum EVs may be a novel diagnostic and monitoring biomarker for PC.

BACKGROUND: Although the patients with muscle-invasive bladder cancer (MIBC) generally have poor prognosis, the utility of these biomarkers for the prediction of oncological outcomes in MIBC has not been completely explored. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, and angiogenesis. Thus, we aimed to evaluate the impact of serum ghrelin levels on survival in MIBC. METHODS: In this study, we reviewed the clinical and pathological records of 56 patients who were diagnosed with MIBC between November 2015 and November 2019 at Gifu and Hirosaki University Hospitals. We focused on 27 patients who had received chemotherapy and collected blood samples before and after chemotherapy. Blood samples were collected before chemotherapy and after completing two cycles of chemotherapy. Serum acyl (AG) and desacyl ghrelin (DG) were measured using AG and DG enzyme-linked immunosorbent assay kits (SCETI, Tokyo, Japan), respectively. RESULTS: The 3-year overall and progression-free survival (PFS) rates were 82.9% and 68.3%, respectively. According to the AG level after chemotherapy, the 3-year PFS rates were 77.5% and 53.0% in patients with AG levels ≥1.34 and

Aim To identify novel diagnostic markers for renal cell carcinoma (RCC), we analyzed miRNAs in serum extracellular vesicles (EVs). Materials and methods EVs were purified from serum of healthy controls and patients with localized and advanced RCC using T-cell immunoglobulin domain and mucin domain-containing protein 4 conjugated to magnetic beads. miRNA profiling of EVs was conducted by microarray analysis. miRNA expression was examined by quantitative reverse transcription-polymerase chain reaction. Lastly, proteomic analysis of RCC cells transfected with a miRNA inhibitor was performed to identify its potential targets. Results Microarray analysis revealed that nine miRNAs were increased by more than 1.5-fold in EVs from patients with RCC. Among them, miRNA-4525 was significantly elevated; miRNA-4525 expression was higher in RCC tissue than in the adjacent normal tissue. Proteomic analysis identified alpha fetoprotein and albumin as its potential targets. Conclusion These findings suggest the potential of miRNA-4525 in serum EVs as a novel biomarker for advanced RCC.

The aim of the present study was to evaluate the prognosis of Japanese patients with metastatic renal cell carcinoma (mRCC) receiving nivolumab and to identify factors predicting the overall survival (OS) in this cohort of patients. This study retrospectively assessed the outcomes of 77 consecutive Japanese patients with mRCC who were treated using either 1 or 2 molecular-targeted agents followed by nivolumab in routine clinical practice. The best responses to nivolumab observed were as follows: Complete response in 3 patients, partial response in 27, stable disease in 33 and progressive disease in 14; therefore, the objective response rate in the 77 patients was 39.0%. During the median follow-up period of 11 months after the introduction of nivolumab, the median progression-free survival and OS were 7 months and not reached, respectively. On multivariate analysis of several parameters, age, Karnofsky Performance Status (KPS) and neutrophil counts were demonstrated to be independently associated with OS in the 77 patients. By dividing these patients into 3 groups according to 3 risk factors, it was possible to stratify the OS; however, the International Metastatic Renal Cell Carcinoma Database Consortium model was unable to classify the OS. These results suggested that age, KPS and neutrophil counts were useful predictors of OS in previously treated patients with mRCC who received nivolumab.

INTRODUCTION Li Fraumeni Syndrome (LFS) is a rare autosomal dominant tumor predisposition syndrome caused by germline alterations of the TP53. Brain tumors are included in LFS core cancers. Choroid plexus carcinomas and medulloblastomas tend to occur in pediatric LFS patients, while gliomas tend to occur in adult LFS patients. There are few previous reports about gliomas arising in the setting of LFS. Here, we report clinical and molecular features of three cases of glioblastoma, IDH-wildtype arising in the setting of LFS. RESULTS Mean age at diagnosis was 40 years (range: 32-45). Two patients were male. Two patients had medical history of multiple tumors and family history of brain tumors. Magnetic resonance imaging of each patients revealed a left cerebellar peduncle lesion with faint contrast-enhancement, a right parietal lobe lesion with nodular contrast-enhancement and two lesions in the pons (no enhancement) and right parietal lobe (ring enhancement), respectively. All patients underwent chemotherapy including temozolomide and/or bevacizumab combined with radiation therapy (60Gy) after surgery. Mean progression free survival was 10.4 months (range: 5.1-17.0). All patients were admitted to palliative care mean 17.3 months (range: 14.4-21.4) after diagnosis. All patients harbored heterozygous germline mutations of TP53. Whole exome sequencing and copy number analysis of tumor tissues revealed TP53 mutation and PDGFRA amplification in all patients. However, EGFR amplification, the combination of gain of chromosome 7 and loss of chromosome 10 (7+/10-) and mutations of IDH, H3F3A, BRAF and TERT promoter were not detected in all tissues. CONCLUSION We experienced three cases of glioblastoma, IDH-wildtype arising in the setting of LFS. Although tumor locations and radiographic features were varied, all clinical courses were poor. Notably, all tumor tissues harbored TP53 mutation and PDGFRA amplification, while no tumor tissues harbored TERT promoter mutation, EGFR amplification and 7+/10-.

Background/aim De-differentiation is a key step for the progression of cancer cells. This study investigated the anti-tumor effect of kartogenin (KGN), which has the ability to differentiate cells, on prostate cancer (PC) cells. Materials and methods The effects of KGN on androgen receptor (AR) nuclear localization, prostate-specific antigen (PSA) expression, and Smad2 activation as well as the growth of PC cell lines (LNCaP, 22Rv1 and PC-3) were analyzed. Results KGN significantly inhibited growth of AR-expressing LNCaP and 22Rv1 cells but not of AR-lacking PC-3 cells. KGN decreased AR nuclear localization and PSA expression, but did not enhance the anti-tumor effect of bicalutamide in LNCaP cells. KGN activated Smad2 both in the absence and presence of TGF-β1. KGN also inhibited growth of docetaxel-resistant PC cells, 22Rv1DR, and re-sensitized them to the agent. Conclusion KGN has a potential as a novel therapeutic for PC patients after treatment failure.

Perforin secreted from cytotoxic T cells and natural killer cells play important roles in anti-tumor immunoreaction leading to cancer cell apoptosis. The aim of this study is to investigate whether perforin-rich tumor microenvironment could inhibit tumor growth. Advanced prostate cancer (PC) expresses high amount of prostate-specific antigen (PSA) that is a possible therapeutic target, therefore, we constructed a PSA promoter-driven perforin expression vector for its predominant expression in tumor microenvironment of PC. Prostate membrane-specific antigen (PSMA) expressed on PC cell surface is also an attractive therapeutic target. To deliver perforin expression vector to PC, it was encapsulated in liposomes conjugated with anti-PSMA antibody (PSMA-pLipo), then the anti-tumor effect of PSMA-pLipo was evaluated using docetaxel-resistant PC cell line, 22Rv1DR, expressing both PSA and PSMA. The conjugated anti-PSMA antibody on PSMA-pLipo recognized recombinant PSMA protein, and incubation with PSMA-pLipo induced perforin expression in 22Rv1DR cells but not in PC-3 cells not expressing both PSA and PSMA. Growth of 22Rv1DR and PC-3 cells was barely inhibited by PSMA-pLipo alone. Perforin functions in concert with cytotoxic lymphocytes, therefore anti-tumor effect of PSMA-pLipo was analyzed in the presence of human peripheral blood mononuclear cells (PBMCs). Low concentration of PSMA-pLipo with human PBMCs significantly inhibited growth of 22Rv1DR cells but not PC-3 cells. High concentration of PSMA-pLipo with human PBMCs showed nearly complete inhibition of 22Rv1DR cell growth. In a mouse xenograft model implanted with 22Rv1DR cells, PSMA-pLipo was intravenously administrated via tale vein and tumor volume was monitored. PSMA-pLipo inhibited growth of 22Rv1DR cells compared to injection of anti-PSMA antibody alone. The data presented here suggest that gene therapy expressing perforin specifically in PC cells could be a novel therapy for advanced PC. Citation Format: Kosuke Mizutani, Kyojiro Kawakami, Yasunori Fujita, Taku Kato, Manabu Takai, Daiki Kato, Koji Iinuma, Takuya Koie, Masafumi Ito. Prostate cancer targeting therapy using PSA promoter-driven perforin expression vector encapsulated in liposomes conjugated with anti-PSMA antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5332.

Aim: To identify novel diagnostic markers for renal cell carcinoma (RCC), we analyzed miRNAs in serum extracellular vesicles (EVs). Materials and Methods: EVs were purified from serum of healthy controls and patients with localized and advanced RCC using T-cell immunoglobulin domain and mucin domain-containing protein 4 conjugated to magnetic beads. miRNA profiling of EVs was conducted by microarray analysis. miRNA expression was examined by quantitative reverse transcription-polymerase chain reaction. Lastly, proteomic analysis of RCC cells transfected with a miRNA inhibitor was performed to identify its potential targets. Results: Microarray analysis revealed that nine miRNAs were increased by more than 1.5-fold in EVs from patients with RCC. Among them, miRNA-4525 was significantly elevated; miRNA-4525 expression was higher in RCC tissue than in the adjacent normal tissue. Proteomic analysis identified alpha fetoprotein and albumin as its potential targets. Conclusion: These findings suggest the potential of miRNA-4525 in serum EVs as a novel biomarker for advanced RCC.

Background Although few studies evaluated the significance of random biopsies under white light cystoscopy (WLC) in patients with non‐muscle‐invasive bladder cancer (NMIBC), the findings are controversial. Aim This aim of this study was to evaluate what kind of preoperative covariates were useful as predictive factors in detecting carcinoma in situ (CIS) from normal‐appearing mucosa using random bladder biopsies under WLC. Methods and Results A total of 229 patients with NMIBC underwent initial TUR followed by random biopsies under WLC at Red Cross Takayama Hospital between 2007 and 2016. These patients underwent TUR with complete resection of intravesical visible tumors followed by random biopsies of normal‐appearing mucosa. In this study, random bladder biopsies of normal‐appearing urothelial mucosa, excluding abnormal mucosa, were carried out with a cold punch in the selected intravesical sites. The covariates included age, gender, the urine cytology result, presence of an abnormal mucosa, number of tumors, size of the largest tumors, configuration of the tumor, and tumor type. Abnormal mucosa was defined as reddish or mossy areas at the time of TUR under WLC. The primary endpoint was to determine what kind of preoperative covariates were useful as predictive factors in detecting CIS from normal‐appearing mucosa using random bladder biopsies under WLC. Finally, 212 patients were evaluated, and 67 patients (31.6%) were diagnosed with CIS from normal‐appearing mucosa. In univariate analysis, positive urine cytology, abnormal mucosa, and the number of tumors were significantly associated with concomitant CIS. On multivariate analysis, positive urine cytology and abnormal mucosa were significantly associated with CIS. Conclusion The patients who were diagnosed with positive urine cytology or abnormal mucosa by WLC are ideal candidates for TUR followed by random biopsy of normal‐appearing mucosa.

Radiation therapy with permanent iodine-125 implant brachytherapy is well established for curable prostate cancer. To maximize the therapeutic potential of brachytherapy, delivered radiation doses have been increased accompanied by refined intraoperative procedures of radioactive seeds placement. However, dose escalation is a double-edged sword in prostate brachytherapy; it could induce rectal toxicity, yet is successful in curable treatment in prostate cancer. To reduce irradiation of the rectum, the SpaceOAR® system has been used to inject synthetic polyethylene glycol hydrogel between the prostate and the rectum. The present report describes a case of spontaneous healing of rectal penetration associated with SpaceOAR® hydrogel.

Nivolumab has shown good prognosis in renal cell carcinoma (RCC) patients previously treated with targeted therapy. We aimed to study irAE (immune-related adverse event) due to nivolumab and numbers of previous treatment lines in RCC patients. Between October 2016 and November 2019, 114 patients were treated with nivolumab as second- and later-line therapy. Among them, 110 patients with complete data were evaluated in this retrospective observational study. The primary endpoint was the relation between irAE and numbers of previous targeted therapies. Secondary endpoints were the relation of irAE with the duration of nivolumab treatment and with best overall response. For the primary analysis, proportional odds logistic regression was used to assess the effect of the number of prior therapies on the grade of any irAE as the ordinal variable. For the secondary analysis, binomial logistic regression models adjusted for the covariates were prepared to confirm the association between the incidence of irAE and the number of courses, number of nivolumab treatments and best overall response. Overall, 69, 66, 33, 13, 9 and 9 patients were treated with sunitinib, axitinib, pazopanib, sorafenib, temsirolimus and everolimus, respectively, prior to nivolumab. In total, 60 adverse events (Grade 1, 21; Grade 2, 21; Grade 3, 14; Grade 4, 2; not evaluated, 2) were identified in the patients treated with nivolumab. Ordered logistic regression analysis showed that the adjusted odds ratios of numbers of prior treatment for grade of irAE were 1.12 (numbers of prior treatment: 2 to 1) and 1.31 (3 to 1). Odds ratios of the numbers of nivolumab treatments and best overall response for the incidence of irAE were not significant. No statistically significant relations were found between grade of irAE and numbers of treatments prior to nivolumab. Patients treated with nivolumab should be closely monitored for irAE regardless number of previous therapies.

There have been few comprehensive studies on Haemophilus influenza-positive urethritis.In this retrospective study, we enrolled 68 men with H. influenzae-positive urethritis, including coinfections with Neisseria gonorrhoeae, Chlamydia trachomatis, and/or genital mycoplasmas: 2, 3, 20, and 43 treated with ceftriaxone, levofloxacin, sitafloxacin, and extended-release azithromycin (azithromycin-SR), respectively. We assessed microbiological outcomes in 54 men and clinical outcomes in 46 with H. influenzae-positive monomicrobial nongonococcal urethritis. We determined minimum inhibitory concentrations (MICs) of 6 antimicrobial agents for 59 pretreatment isolates.H. influenzae was eradicated from the men treated with ceftriaxone, levofloxacin, or sitafloxacin. The eradication rate with azithromycin-SR was 85.3%. The disappearance or alleviation of urethritis symptoms and the decreases in leukocyte counts in first-voided urine were significantly associated with the eradication of H. influenzae after treatment. For the isolates, ceftriaxone, levofloxacin, sitafloxacin, azithromycin, tetracycline, and doxycycline MICs were ≤0.008-0.25, 0.008-0.5, 0.001-0.008, 0.12-1, 0.25-16, and 0.25-2 μg/mL, respectively. The azithromycin MICs for 3 of 4 strains persisting after azithromycin-SR administration were 1 μg/mL. H. influenzae with an azithromycin MIC of 1 μg/mL increased chronologically.H. influenzae showed good responses to the chemotherapies for urethritis. The significant associations of the clinical outcomes of the chemotherapies with their microbiological outcomes suggested that H. influenzae could play pathogenic roles in urethritis. All isolates, except for one with decreased susceptibility to tetracyclines, were susceptible to the examined agents. However, the increase in H. influenzae with an azithromycin MIC of 1 μg/mL might threaten efficacies of azithromycin regimens on H. influenzae-positive urethritis.

Unlike urinary tract infection (UTI), asymptomatic bacteriuria (ABU) should not be treated, with some exceptions such as pregnant women and patients who will undergo traumatic urologic interventions. However, there has been no clinically available marker for their differential diagnosis. Exosomes or small extracellular vesicles carry proteins contained in cells from which they are derived, thus having the potential as a biomarker of several diseases. On the basis of the hypothesis that the molecular signature of exosomes in urine may differ between UTI and ABU patients, we examined if urinary exosomes could serve as a marker for their differential diagnosis. Exosomes were isolated by ultracentrifugation or affinity-based method from cell culture medium of monocytic THP-1 and uroepithelial SV-HUC-1 cells and human urine. Protein expression was examined by Western blot analysis, ELISA, and CLEIA. The results showed that the levels of intracellular signalling molecules Akt and ERK and transcription factor NF-κB increased in exosomes isolated from THP-1 and SV-HUC-1 cells cocultured with Escherichia coli and/or treated with lipopolysaccharide. In urinary exosomes of UTI patients, Akt significantly diminished, and an exosomal marker CD9 showed a trend to decrease after treatment with antimicrobial agents. More importantly, Akt and CD9 levels in urinary exosomes were higher in UTI patients than in ABU patients, which was also observed after correction by urine creatinine. Collectively, these results suggest that Akt and CD9 in urinary exosomes could be useful markers for differential diagnosis of UTI and ABU.

Radical cystectomy remains the gold standard for treatment of muscle-invasive bladder cancer. Robot-assisted radical cystectomy has technical advantages over laparoscopic radical cystectomy and has emerged as an alternative to open radical cystectomy. Despite the advancements in robotic surgery, experience with total intracorporeal reconstruction of urinary diversion remains limited. Most surgeons have carried out the hybrid approach of robot-assisted radical cystectomy and extracorporeal reconstruction of urinary diversion, as intracorporeal reconstruction of urinary diversion remains technically challenging. However, intracorporeal reconstruction of urinary diversion might potentially proffer additional benefits, such as decreased fluid loss, reduction in estimated blood loss and a quicker return of bowel function. The adoption of intracorporeal ileal neobladder reconstruction has hitherto been limited to high-volume academic institutions. In the present review, we compare the totally intracorporeal robot-assisted radical cystectomy approach with open radical cystectomy and robot-assisted radical cystectomy + extracorporeal reconstruction of urinary diversion in muscle-invasive bladder cancer patients.

OBJECTIVES We treated men with gonococcal urethritis with a single-dose regimen of 1 g of ceftriaxone, which is recommended as the first-line treatment for gonorrhoea in Japan, to determine its microbiological outcomes and tolerability. METHODS We enrolled 255 men with gonococcal urethritis and treated them with a single-dose regimen of 1 g of ceftriaxone. We evaluated its microbiological outcomes and tolerability. We also determined ceftriaxone MICs for pretreatment isolates of Neisseria gonorrhoeae collected from the patients. RESULTS The microbiological efficacy of the ceftriaxone regimen, which was determined between 5 and 9 days after treatment in 111 men based on the Japanese guideline for clinical research on antimicrobial agents in urogenital infections, was 100%. In the 194 men who returned to the clinic between 2 and 41 days after treatment, 191 (98.5%; 95% CI 96.8%-100%) were negative for N. gonorrhoeae after treatment. Ceftriaxone MICs determined for 136 pretreatment isolates obtained from these 194 men ranged from 0.001 to 0.25 mg/L. One isolate persisting after treatment exhibited a ceftriaxone MIC of 0.008 mg/L. For two isolates persisting after treatment, ceftriaxone MICs were not determined. Seven adverse events were observed in 7 (3.2%) of the 220 men treated with the ceftriaxone regimen. Four men had diarrhoea classified as grade 1. Three had urticaria during ceftriaxone administration, with one event classified as grade 1 and two events classified as grade 3. CONCLUSIONS A single-dose regimen of 1 g of ceftriaxone was microbiologically effective against gonococcal urethritis and was safe and tolerable.

Background Docetaxel is first-line chemotherapy for castration-resistant prostate cancer (CRPC), but most patients acquire docetaxel resistance. CD44 has been shown to be involved in drug resistance of cancers including prostate cancer. We hypothesized that CD44 in serum exosomes could be a diagnostic marker for docetaxel resistance in CRPC patients. In this study, we examined CD44 protein and mRNA expression in cell lysates and exosomes isolated from prostate cancer cells, evaluated the effect of CD44v8-10 knockdown on docetaxel sensitivity and measured CD44 mRNA copy numbers contained in serum exosomes in prostate cancer patients. Materials and methods Docetaxel-sensitive PC-3 prostate cancer cells and docetaxel-resistant PC-3R cells established previously from parental PC-3 cells were used. CD44v8-10 knockdown was performed by siRNA transfection. Blood was collected from 50 docetaxel-naïve and 10 docetaxel-resistant patients and 15 control males. CD44 protein expression was evaluated by Western blotting. CD44 mRNA expression was measured by RT-digital PCR. Results The levels of CD44v8-10 protein and mRNA in cell lysates and exosomes were higher in PC-3R cells than in PC-3 cells. CD44v8-10 knockdown significantly increased docetaxel sensitivity of PC-3R cells. The CD44v8-10 mRNA copy numbers in serum exosomes were higher in docetaxel-resistant patients than in docetaxel-naïve patients and control males (median 46, 12 and 17 copies/mL serum, respectively, P = 0.032). In contrast, the serum exosomal mRNA copy numbers of CD44 standard isoform (CD44s) were not different among 3 groups (median 25, 14 and 13 copies/mL serum, respectively, P = 0.150). Conclusions CD44v8-10 may be involved in docetaxel resistance in prostate cancer and serum exosomal CD44v8-10 mRNA could be a diagnostic marker for docetaxel-resistant CRPC., Cell biology; Molecular biology; Cancer research; Chemotherapy; Urology; Castration-resistant prostate cancer, CD44, Docetaxel resistance, Exosomes, Diagnostic marker

A 26-year-old woman with gross hematuria was seen in a previous hospital. Magnetic resonance imaging (MRI) showed a tumor at the dome of the urinary bladder with invasion outside of the bladder wall. The patient underwent transurethral resection of the bladder tumor (TUR-BT). From the result of the pathological examination, the tumor was suggested to be carcinosarcoma of the bladder. The patient was then referred to our hospital for treatment. We performed radical cystectomy and ileal conduit diversion. Pathological examination of the excised specimen revealed an inflammatory myofibroblastic tumor as the basis for immunostaining of anaplastic lymphoma kinase (ALK).

The authors present a case report of collecting duct carcinoma (CDC) that responded to nivolumab, a programmed death 1 (PD-1) immune-checkpoint-inhibitor antibody, following the failure of systemic treatment with chemotherapy and targeted therapy. The patient underwent right radical nephrectomy and segmentectomy of the lung following chemotherapy. Fifteen months following the first surgery, segmentectomy and subsequent second-line chemotherapy were performed for recurrence in the lung. Targeted therapy with temsirolimus for recurrence of the lung and lymph node metastases was ultimately used for 30 months. However, the temsirolimus treatment failed to suppress the growth of metastatic lesions. Nivolumab resulted in complete response of the lung metastasis, and it stabilized the lymph node metastasis. PD-L1 was highly expressed in both primary tumor and the metastatic regions. Therapy with nivolumab is ongoing. These findings suggest that treatment with nivolumab may be considered for metastatic and treatment-failure CDC.

Background Exosomes or extracellular vesicles have the potential as a diagnostic marker for various diseases including cancer. In order to identify novel exosomal markers for prostate cancer (PC), we performed proteomic analysis of exosomes isolated from PC cell lines and examined the usefulness of the marker in patients. Methods Exosomes isolated by differential centrifugation from the culture medium of androgen-dependent LNCaP prostate cancer cell line and its sublines of partially androgen-independent C4, androgen-independent C4–2 and bone metastatic C4–2B were subjected to iTRAQ-based proteomic analysis. Exosomes were also isolated by immunocapture and separated by size exclusion chromatography and density gradient centrifugation. Protein expression was determined by Western blot analysis. GGT activity was measured using a fluorescent probe, γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG). Immunohistochemical analysis of tissues was performed using anti-GGT1 antibody. Results Among proteins upregulated in C4–2 and C4–2B cells than in LNCaP cells, we focused on gamma-glutamyltransferase 1 (GGT1), a cell-surface enzyme that regulates the catabolism of extracellular glutathione. The levels of both GGT1 large and small subunits were elevated in exosomes isolated from C4–2 and C4–2B cells by differential centrifugation and by immunocapture with anti-CD9 or -prostate-specific membrane antigen (PSMA) antibody. In cell lysates and exosomes, GGT1 expression correlated with GGT activity. Size exclusion chromatography of human serum demonstrated the presence of GGT activity and GGT1 subunits in fractions positive for CD9. Density gradient centrifugation revealed the co-presence of GGT1 subunits with CD9 in exosomes isolated by differential centrifugation from human serum. Since GGT activity correlated with GGT1 expression in serum exosomes isolated by differential centrifugation, we measured serum exosomal GGT activity in patients. Unexpectedly, we found that serum exosomal GGT activity was significantly higher in PC patients than in benign prostatic hyperplasia (BPH) patients. In support of this finding, immunohistochemical analysis showed increased GGT1 expression in PC tissues compared with BPH tissues. Conclusions Our results suggest that serum exosomal GGT activity could be a useful biomarker for PC. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3301-x) contains supplementary material, which is available to authorized users.

Introduction: Antibody therapy has been successfully used for several caners, but the efficacy is still limited. To select patients that respond well to the therapy, development of companion diagnostics is essential. Although PD-L1 expression determined by immunohistochemistry has been shown to be a marker to select patients with non-small-cell lung cancer who will benefit from antibody therapy, its potential for Nivolumab treatment in renal cell carcinoma (RCC) patients is unclear. Detection of the soluble form of PD-1 in serum has been reported, but there are few studies demonstrating its clinical role in RCC. Antibody-based assays may rely on characteristics and quality of antibody used. We hypothesized that the use of Nivolumab as a capture antibody in ELISA would give more clinically relevant results to evaluate the serum PD-1 levels in RCC patients. Materials and Methods: After approval of the study by the Medical Review Board of Gifu University, a total of 71 participants were recruited (22; healthy volunteers, 29; localized RCC and 20; RCC patients with metastasis or recurrence). Serum PD-1 levels were determined using PD-1 Human ELISA Kit (Thermo Fisher Scientific Inc., MA, USA). For Nivolumab-based ELISA, a capture antibody included in the kit was changed to Nivolumab. Nivolumab was coated to 96-well microplates using a commercially available kit. Results: Medians of the serum PD-1 levels measured by conventional ELISA were 31.8, 29.8 and 34.3 pg/ml in healthy volunteers, localized RCC patients and those with metastasis or recurrence, respectively, which showed no statistically significant difference. When the same set of patients were analyzed by Nivolumab-based ELISA, medians were 24.6, 23.7 and 46.4 pg/ml and the serum PD-1 levels were significantly elevated in patients with metastasis or recurrence (P = 0.013) compared to controls and localized patients. Of the 29 localized patients, 3 patients with relatively higher serum PD-1 levels at initial diagnosis relapsed later. Among 6 patients with metastasis who were treated with Nivolumab, well responders showed relatively lower serum PD-1 levels before treatment. Conclusion: The serum PD-1 levels determined using Nivolumab were increased in advanced RCC patients. Our results suggest that the detection of target molecules using a therapeutic antibody may yield more clinically relevant information, thus providing a novel approach to develop companion diagnostics. Citation Format: Kosuke Mizutani, Kengo Horie, Taku Kato, Keita Nakane, Kyojiro Kawakami, Yasunori Fujita, Masafumi Ito. Nivolumab-based ELISA revealed increased serum PD-1 levels in advanced RCC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3973.

Castration-refractory prostate cancer (CRPC) is treated with taxane-based chemotherapy, but eventually becomes drug resistant. It is thus essential to identify novel therapeutic targets for taxane resistance in CRPC patients. We investigated the role of the chemokine (C-C motif) receptor 1 (CCR1) and its ligand, chemokine (C-C motif) ligand 5 (CCL5), in taxane-resistant CRPC using paclitaxel-resistant prostate cancer cells (PC3PR) established from PC3 cells. We found that the expression levels of CCR1 mRNA and protein were up-regulated in PC3PR cells compared to PC3 cells. In order to investigate the role of increased CCR1 in PC3PR cells, we stimulated cells with CCL5, one of the chemokine ligands of CCR1. In CCL5-stimulated PC3PR cells, siRNA-mediated knockdown of CCR1 expression reduced phosphorylation of ERK1/2 and Rac1/cdc42. Furthermore, CCR1 knockdown and MEK1/2 inhibition decreased CCL5-stimulated secretion of MMPs 2 and 9, which play important roles in cancer cell invasion and metastasis. In the Matrigel invasion assay, knockdown of CCR1 and inhibition of the ERK and Rac signaling pathways significantly decreased the number of invading cells. Finally, the serum CCL5 protein level as measured by ELISA was not different among the three groups of patients: those with negative prostate biopsy, those at initial diagnosis of prostate cancer, and those with taxane-resistant prostate cancer. These results demonstrated for the first time that the interaction of CCR1 with CCL5 caused by increased expression of CCR1 promotes invasion of PC3PR cells by increasing secretion of MMPs 2 and 9 and by activating ERK and Rac signaling. Our findings suggest that CCR1 could be a novel therapeutic target for taxane-resistant CRPC.

Advanced bladder cancer is treated mainly with gemcitabine and cisplatin, but most patients eventually become resistance. Androgen receptor (AR) signaling has been implicated in bladder cancer as well as other types of cancer including prostate cancer. In this study, we investigated the expression and role of AR in gemcitabine-resistant bladder cancer cells and also the potential of enzalutamide, an AR inhibitor, as a therapeutic for the chemoresistance. First of all, we established gemcitabine-resistant T24 cells (T24GR) from T24 bladder cancer cells and performed gene expression profiling. Microarray analysis revealed upregulation of AR expression in T24GR cells compared with T24 cells. AR mRNA and protein expression was confirmed to be increased in T24GR cells, respectively, by quantitative RT-PCR and western blot analysis, which was associated with more potent AR transcriptional activity as measured by luciferase reporter assay. The copy number of AR gene in T24GR cells determined by PCR was twice as many as that of T24 cells. AR silencing by siRNA transfection resulted in inhibition of proliferation of T24GR cells. Cell culture in charcoal-stripped serum and treatment with enzalutamide inhibited growth of T24GR cells, which was accompanied by cell cycle arrest. AR transcriptional activity was found to be reduced in T24GR cells by enzalutamide treatment. Lastly, enzalutamide also inhibited cell proliferation of HTB5 bladder cancer cells that express AR and possess intrinsic resistance to gemcitabine. Our results suggest that enzalutamide may have the potential to treat patients with advanced gemcitabine-resistant bladder cancer with increased AR expression.

Objectives We examined four clinical strains of Neisseria gonorrhoeae (GU030113, GU110095, GU110332 and GU110362) isolated between 2000 and 2014 in Japan, exhibiting ceftriaxone MICs of 0.5 mg/L, for mutations of the genes associated with penicillin resistance. Methods The penA, mtrR, porB1b (penB), ponA and pilQ genes of the strains were sequenced. PBP2s of the strains were aligned to the PBP2s associated with decreased susceptibility to oral cephalosporins, and PBP2s of previously reported strains with decreased susceptibility to ceftriaxone. Results GU030113 had PBP2 pattern X with an additional substitution of A502T. GU110095 had PBP2 pattern XXVII. GU110332 had PBP2 pattern XXXIV with an additional substitution of P552S. GU110362 had PBP2 composed of pattern X (amino acid positions 1-291) and pattern V (amino acid positions 292-576). GU030113, GU110095 and GU110332 had deletion of A in the mtrR promoter, G120K and A121D or A121N in PorB1b and L421P in PBP1. GU110362 had A40D in the repressor of MtrR and L421P in PBP1. The strains did not have mutations of pilQ1 and pilQ2. Conclusions Addition of A502T to PBP2 pattern X in GU030113 and of P552S to PBP2 pattern XXXIV in GU110332 would possibly contribute to decreased susceptibility to ceftriaxone. In GU110095 and GU110362, it was suggested that, in addition to their altered PBP2s, the enhanced efflux pump, reduced permeability in the outer membrane, another altered target of β-lactams and/or other mechanisms not identified in the present study might contribute to decreased susceptibility.

Advanced renal cell carcinoma is treated with mammalian target of rapamycin (mTOR) inhibitors or tyrosine kinase inhibitors (TKIs). The effects of these drugs are, however, limited and novel treatment strategies are required. Clear-cell type renal cell carcinoma (ccRCC) is chemo-resistant, in part, due to expression of multidrug resistance proteins such as p-glycoprotein. Cabazitaxel, a tubulin-binding taxane drug used for castration-resistant prostate cancer, has less affinity for p-glycoprotein compared to docetaxel. In the current study, the effects of docetaxel and cabazitaxel on ccRCC cells were investigated.The expression of p-glycoprotein was evaluated in the ccRCC cell lines, Caki-1, KMRC-1 and OS-RC-2 by western blotting. Cells were treated with cabazitaxel or docetaxel, and growth kinetics and tubulin polymerization were determined by the WST-1 assay and cell-based tubulin polymerization assay, respectively. Intracellular drug concentrations were measured by chromatography. AKT activation after treatment was examined by western blotting.All ccRCC cell lines expressed p-glycoprotein. Cabazitaxel inhibited cell growth and induced tubulin polymerization more potently than docetaxel. The intracellular concentration of cabazitaxel was much higher than docetaxel in all cell lines. Both docetaxel and cabazitaxel inhibit AKT phosphorylation at 5 min among three cells.Cabazitaxel inhibits growth of ccRCC cells expressing p-glycoprotein and could thus be possibly used for advanced ccRCC patients in combination with targeted-therapy enhancing their effects.

Macrophages within the tumor microenvironment promote angiogenesis, extracellular matrix breakdown, and tumor cell migration, invasion, and metastasis. Activation of the urokinase plasminogen activator (uPA) and its receptor (uPAR) axis promotes prostate cancer tumorigenicity, invasion, metastasis, and survival within the tumor microenvironment. The link between macrophage infiltration and the uPA/uPAR axis in prostate cancer development has not been established, although it has been reported that uPA plays a critical role inmonocyte and macrophage chemotaxis. In this study, murine prostate cancer RM-1 cells were subcutaneously inoculated into wild-type (WT), uPA(-/-), and uPAR(-/-) mice. Tumor volume was significantly diminished in both uPA(-/-) and uPAR(-/-) mice compared with WT controls. Greater inhibition of tumor volume was also observed in uPA(-/-) mice compared with uPAR(-/-) mice, suggesting the important contribution of stromal-derived uPA to sustain the tumor growth. Immunohistochemical staining revealed that tumors in uPA(-/-) and uPAR(-/-) mice displayed significantly lower proliferative indices, higher apoptotic indices, and less neovascularity compared with the tumors in WT mice. Tumors in uPA(-/-) and uPAR(-/-) mice displayed significantly less macrophage infiltration as demonstrated by F4/80 staining and MAC3(+) cell numbers by flow cytometry compared with the tumors from WT mice. These findings suggest that the uPA/uPAR axis acts in both autocrine and paracrine manners in the tumor microenvironment, and activation of uPA/uPAR axis is essential for macrophage infiltration into prostate tumors.

Purposes of the study: Clear renal cell carcinoma (ccRCC) is one of the most lethal malignant tumors. Molecular targeted therapies have been used to improve outcomes for metastatic or advanced ccRCC. However, currently approved therapies have limited success and a cure remains elusive. Since ccRCC could be curable if diagnosed at the early stage, novel diagnostic approach is needed to identify circulating markers that may help diagnose early and evaluate prognosis. Exosomes are membrane vesicles with a diameter of 40-150 nm that are secreted by various types of cells including cancer cells. Exosomes contain a variety of molecular constituents of their origin such as proteins and nucleic acids. Over the years, exosome has been suggested to be a novel diagnostic marker. The purpose of this study is to find candidates of ccRCC markers in exosomes. Experimental procedures: Exosomes were collected from cell culture supernatant of RPTEC human renal proximal tubule epithelial cells and ccRCC cell lines (Caki-1, KMRC-1, and OS-RC-2) by ultracentrifugation. Isolation of exosome was confirmed by western blot analysis for CD9. Exosome fraction was analyzed by iTRAQ-based quantitative proteomics. Results: A total of 52 proteins were detected and 3 proteins were found to be upregulated by more than 1.2 fold in exosomes isolated from ccRCC cells compared with those from RPTEC cells. Twelve proteins were found to be downregulated by less than 0.8 fold in exosomes from ccRCC cells compared with those from RPTEC cells. The expression profiles of several proteins were verified by western blot analysis. Conclusions: While major challenges still remain, exosome studies in ccRCC could provide a wealth of information to find novel diagnostic and prognostic markers. Citation Format: Kosuke Mizutani, Kyojiro Kawakami, Yasunori Fujita, Kengo Horie, Masafumi Ito, Takashi Deguchi. Proteomic analysis of exosomes isolated from ccRCC cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5663.

Septins, a conserved family of GTP/GDP-binding proteins, are present in organisms as diverse as yeast and mammals. We analyzed the distribution of five septins, Sept6, Sept7, Sept8, Sept9 and Sept11, in various rat tissues by western blot analyses and found all septins to be expressed in brain. We also examined the developmental changes of expression of these septins in the rat brain and found that the level of Sept8 increased during post-natal development. Morphological analyses revealed that Sept8 is enriched at pre-synapses. Using yeast two-hybrid screening, we identified vesicle-associated membrane protein 2 (VAMP2), a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE), as an interacting protein for Sept8. Synaptophysin is reported to associate with and recruit VAMP2 to synaptic vesicles and dissociate prior to forming the SNARE complex consisting of VAMP2, syntaxin and synaptosome-associated protein of 25 kDa. We showed that Sept8 suppresses the interaction between VAMP2 and synaptophysin through binding to VAMP2. In addition, we found that Sept8 forms a complex with syntaxin1A, and the Sept8-VAMP2 interaction is disrupted by synaptosome-associated protein of 25 kDa. These results suggest that Sept8 may participate in the process of the SNARE complex formation and subsequent neurotransmitter release.

Vinexinbeta is an adaptor protein supposed to play pivotal roles in cell adhesion, cytoskeletal organization and signaling. Vinexinbeta is reported to be phosphorylated by extracelluler signal-regulated kinase (ERK) and the phosphorylation has been shown to be involved in cell adhesion, migration and growth. However, physiological function as well as pathophysiological relevance of vinexinbeta in cancer cells is almost unknown.By use of biochemical and cell biological techniques, we analyzed the effects of overexpression or RNAi-mediated silencing of vinexinbeta on the growth and paclitaxel sensitivity in a prostate cancer cell line PC-3.Vinexinbeta was highly expressed in androgen-independent prostate cancer cell lines, PC-3 and DU145, but not in androgen-dependent LNCaP cells. We established two PC-3 cell lines, PC-3/Vinbeta#1 and #2, overexpressing GFP-tagged vinexinbeta and found that growth rate of these lines was significantly increased compared to a mock-transfected cell line. In addition, we found that PC-3/Vinbeta#1 and #2 became resistant to the treatment with 100 nM paclitaxel for 48 h. On the other hand, when siRNA-mediated vinexinbeta gene silencing was performed, PC-3 cell growth was suppressed. In addition, by vinexinbeta silencing, PC-3 cells became significantly sensitized to 10 nM paclitaxel treatment for 48 h.Vinexinbeta plays an important role in PC-3 cell growth, and abrogation of vinexinbeta may be effective for therapeutic cell death and enhanced chemotherapy sensitization in androgen-independent prostate cancer cells.

Vinexin is an adaptor protein that is supposed to play pivotal roles in cell adhesion, cytoskeletal organization and signaling. At least three splice variants, vinexinalpha, beta and gamma, have so far been reported. In spite of the possible importance of vinexin, the properties and functions of vinexin in neuronal cells are almost unknown. Here we show that vinexin isoforms are expressed in rat brain in a developmental stage-dependent manner, and that vinexinalpha is relatively abundant in the telencephalon regions of the adult rat brain. An immunohistochemical study showed the localization of vinexinalpha in neurons and glia in the rat brain. In primary cultured rat hippocampal neurons, vinexin was found to be present at synapses and filopodia in growth cones by immunofluorescent analyses. Biochemical fractionation revealed the distribution of vinexin in synaptosomes. Nerve terminal localization of vinexin was confirmed by electron microscopy. Vinexinbeta is reported to be phosphorylated by extracellular signal-regulated kinase (ERK) at Ser189, which is equivalent to Ser593 of vinexinalpha. We thus constructed a site- and phosphorylation state-specific antibody to monitor the ERK-mediated phosphorylation of vinexin. In immunofluorescent analyses, the phosphorylation was observed at synapses formed among cultured rat hippocampal neurons and it was reduced by treatment of the cells with PD98059. In an immunoelectron microscopic examination, the phosphorylation signal was mainly detected on the postsynaptic side of synapses in the rat hippocampal neurons. As active ERK was co-localized with vinexin in synapses, the ERK signal is likely to be involved in the regulation of vinexin-dependent cellular processes in synapses. On the other hand, the phosphorylation was hardly detected in neurons cultured for 3 days, suggesting the presence of a yet unidentified regulatory mechanism of vinexin at the growth cone.

Treatment with taxanes for castration-resistant prostate cancer often leads to the development of resistance. It has been recently demonstrated that exosomes present in the body fluids contain proteins and RNAs in the cells from which they are derived and could serve as a diagnostic marker for various diseases. In the present study, we aimed to identify proteins contained in exosomes that could be markers for progression and taxane-resistance of prostate cancer. Exosomes were isolated by differential centrifugation from the culture medium of taxane-resistant human prostate cancer PC-3 cells (PC-3R) and their parental PC-3 cells. Isolated exosomes were subjected to iTRAQ-based quantitative proteomic analysis. Exosomes were also isolated from the culture medium by using anti-CD9 antibody-conjugated magnetic beads. Protein expression was knocked down by siRNA transfection followed by analysis of the silencing effects. Proteomic analysis showed that integrin β4 (ITGB4) and vinculin (VCL) were upregulated in exosomes derived from PC-3R cells compared to PC-3 cells. The elevation of ITGB4 and VCL was confirmed in exosomes captured by anti-CD9 antibody from the culture medium of PC-3R cells. Silencing of ITGB4 and VCL expression did not affect proliferation and taxane-resistance of PC-3R cells, but ITGB4 knockdown attenuated both cell migration and invasion and VCL knockdown reduced invasion. Our results suggest that ITGB4 and VCL in exosomes could be useful markers for progression of prostate cancer associated with taxane-resistance, providing the basis for development of an exosome-based diagnostic system.

Purposes of the study: Exosome has been demonstrated to be a useful non-invasive biomarker for several cancers including prostate cancer. For better understanding cancer-derived exosome, their proteomic analysis is necessary. The aim of this study is to establish the method for isolation and analysis of prostate cancer-related exosomes. Experimental procedures: Total exosomes were isolated from the conditioned media of LNCaP cells by ultracentrifugation. Then, exosomes positive for CD9 or prostate specific membrane antigen (PSMA) were isolated by magnetic beads conjugated with anti-CD9 or -PSMA antibody, respectively. Isolated exosomes were subjected to proteomic analysis. The PSMA positive fraction was also collected by anti-PSMA beads from diluted serum of 3 prostate cancer patients and analyzed by proteomics. Results: A total of 126, 139 and 13 proteins were detected in the LNCaP exosome fractions that were isolated by ultracentrifugation, anti-CD9 beads and anti-PSMA beads, respectively. Out of 126 proteins identified in ultracentrifuge isolated exosome, 56 and 6 protein were found in exosomes that were isolated by anti-CD9 beads and anti-PSMA beads, respectively. Seven proteins were commonly detected in exosomes that were isolated by both beads. Fifty, 54 and 48 proteins were identified in the PSMA positive fraction from serum of 3 prostate cancer patients (P1: localized prostate cancer, P2: advanced prostate cancer and P3: castration resistant prostate cancer). Thirty-three proteins were detected in one patient, 22 in two patients and 25 in three patients. Most proteins detected in all patients were serum- or immunoglobulin-related proteins. The numbers of proteins that were detected only in P2 and P3 were 16 and 8, respectively. Six proteins were found in both P2 and P3 patients. Conclusion: In the present study, we analyzed prostate cancer-related exosomes that were isolated by immunoaffinity-based method. Although most proteins were serum- or immunoglobulin-related proteins, proteins that had been reported as a cancer marker were also detected, which could be candidates for exosomal marker of prostate cancer. Citation Format: Kosuke Mizutani, Kyojiro Kawakami, Yasunori Fujita, Kengo Horie, Koji Kameyama, Masafumi Ito, Takashi Deguchi. Proteomic analysis of prostate cancer-related exosomes isolated by anti-PSMA antibody beads [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5697. doi:10.1158/1538-7445.AM2017-5697

Exosomes have been demonstrated to be useful non-invasive biomarkers for several cancers including prostate cancer. Since normal cells also secrete exosomes, isolation of cancer-derived exosomes from blood is a prerequisite for their better understanding. The aim of this study is to establish the method for isolation of prostate cancer-related exosomes from blood.Exosomes were collected from prostate cancer LNCaP and PC-3 cell lines by ultracentrifugation and by using magnetic beads conjugated with anti-CD9 antibody and anti-prostate-specific membrane antigen (PSMA) antibody. Prostate cancer-related exosomes were also isolated from the plasma of prostate cancer patients by anti-PSMA beads. Isolated exosomes were analyzed by western blotting.Exosomes were isolated from LNCaP cells by ultracentrifugation, contained PSMA and androgen receptor (AR). AR was also detected in exosomes isolated from LNCaP cells by anti-PSMA and anti-CD9 beads, showing that AR is present in prostate cancer-related exosomes. The amount of CD9 in isolated exosomes was much higher in advanced and chemo-resistant prostate cancer patients than in prostate cancer patients without metastasis and healthy volunteers, indicating that patients with aggressive prostate cancer exhibit higher levels of prostate cancer-related exosomes in blood.The immunoaffinity-based method we developed is capable of isolating prostate cancer-related exosomes from blood, the use of which will enhance investigation processes on exosomes in prostate cancer.

Recent data strongly support the idea that the orchestrated interaction between cancer and other cells in the tumor microenvironment is a vital component in the neoplastic process. Thus, tumor cells take advantage of the signaling molecules of the immune system to proliferate, survive, and invade other tissues. CCL2 (Chemokine (C-C motif) ligand 2, Monocyte chemoattractant protein-1 (MCP-1) has been demonstrated to play a significant role in prostate cancer neoplasia and invasion, and is highly expressed in the tumor microenvironment. We recently reported that CCL2 elicits a strong survival advantage in prostate cancer PC3 cells through PI3K/Akt-dependent regulation of autophagy via the mammalian target of rapamycin (mTOR) pathway and importantly, survivin upregulation is essential in this survival mechanism. Autophagy protects cells from nutrient depletion stress, but, paradoxically, excessive autophagy will result in cell death. How these life or death decisions are regulated remains unclear. Here we discuss the function of survivin in the control of autophagy and the interaction between CCL2, survivin and autophagy in the complex program of tumor progression.