Kengo Horie

Renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: radiological findings mimicking papillary subtype.

The authors describe the computed tomography (CT) and magnetic resonance imaging (MRI) findings of an 18‐year‐old man with renal cell carcinoma (RCC) associated with the Xp11.2 translocation/transcription factor E3 (TFE3) gene fusion (Xp11 translocation carcinoma). The lesion was hyperdense on unenhanced CT, hypovascular on contrast‐enhanced studies, hypointense on T2‐weighted MR images, and hemosiderin deposition was suspected on phase‐shift gradient‐echo MR images. Histopathological specimens revealed pathological findings resembling papillary RCC predominantly and exhibited immunoreactivity for TFE3. Because there is often considerable morphological overlap between this carcinoma and papillary RCC, the imaging findings of Xp11 translocation carcinoma may be similar to those of the papillary subtype. Therefore, Xp11 translocation carcinoma should be considered, particularly in young patients when radiologic images demonstrate a renal tumor mimicking the papillary subtype. J. Magn. Reson. Imaging 2011;33:217–220.

Drug Resistance-Associated Mutations in Mycoplasma genitalium in Female Sex Workers, Japan

Mycoplasma genitalium was detected in 21 (14.1%) of 149 vaginal swab samples and in 1 (0.7%) of 149 throat washing samples from female sex workers during 2013–2014 in Japan. Prevalences of M. genitalium with macrolide resistance–associated 23S rRNA mutations and fluoroquinolone resistance–associated parC alterations were 47.1% and 36.8%, respectively.

Gamma-glutamyltransferase activity in exosomes as a potential marker for prostate cancer

BackgroundExosomes 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.MethodsExosomes 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.ResultsAmong 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.ConclusionsOur results suggest that serum exosomal GGT activity could be a useful biomarker for PC.

Bacterial loads of Ureaplasma parvum contribute to the development of inflammatory responses in the male urethra

Ureaplasma parvum, which has been recognised as a coloniser in the male urethra, is detected in some men with non-gonococcal urethritis. In this study, we quantified the 16 S rRNA genes of U. parvum by a real-time polymerase chain reaction-based assay in first-voided urine from 15 symptomatic and 38 asymptomatic men who were positive only for U. parvum. We also determined the leukocyte counts by automated quantitative urine particle analysis in their first-voided urine. Positive correlations were observed between copies of the 16 S rRNA genes of U. parvum/ml and the leukocyte counts/µl in first-voided urine (p = 0.0019). The loads of ≥104 copies of the 16 S rRNA gene/ml, corresponding to ≥5 × 103 cells of U. parvum/ml, were significantly associated with the presence of ≥12.5 leukocytes/µl in first-voided urine that might document the presence of inflammatory responses in the urethra. However, a large portion of the subjects (83.0%) had bacterial loads of <5 × 103 cells of U. parvum/ml, and 79.5% of them showed <12.5 leukocytes/µl. The ambiguity of the pathogenic role of U. parvum in non-gonococcal urethritis could, in part, be due to its low bacterial loads, which might not give rise to inflammatory responses in the male urethra.

ALK Gene Translocation in Inflammatory Myofibroblastic Tumor of the Urinary Bladder: A Case Report.

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).

Response to nivolumab in metastatic collecting duct carcinoma expressing PD‑L1: A case report

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.

Abstract 5697: Proteomic analysis of prostate cancer-related exosomes isolated by anti-PSMA antibody beads

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

Usefulness of quantifying leukocytes in first-voided urine to predict positivity for Chlamydia trachomatis in asymptomatic men at high risk for chlamydial infection

Chlamydia trachomatis causes acute non-gonococcal urethritis, but some infected men are asymptomatic. We examined leukocytes in uncentrifuged first-voided urine (FVU) from asymptomatic men at high risk for chlamydial infection by automated urine particle analyzers to assess whether the quantification of urinary leukocytes could predict chlamydial infection in these men. We enrolled 209 asymptomatic men, whose female sexual partners had been diagnosed as having a genital chlamydial infection. Their FVU specimens were examined for quantification of leukocytes with automated urine particle analyzers and tested for Neisseria gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum by nucleotide acid amplification tests. Eleven men positive for N. gonorrhoeae or M. genitalium were excluded from further analysis. In the remaining 198 men, 84 positive for C. trachomatis (42.4%) had 1.8-1666.9 white blood cells (WBCs)/μl (median, 43.3 WBCs/μl) in their FVU, whereas 114 negative for C. trachomatis had 0.1-1378 WBCs/μl (median, 4.8 WBCs/μl). A receiver operating characteristic (ROC) curve was constructed to examine the sensitivity and specificity of leukocytes counts for predicting chlamydial infection. A cut-off point of leukocyte counts of 12.5 WBCs/μl was determined from the ROC curve, resulting in a sensitivity of 86.9% and specificity of 88.6% for predicting chlamydial infection. Leukocyte quantification in FVU by automated urine particle analyzers showed good performance in predicting the positivity and negativity for chlamydial infection in asymptomatic men. This test could potentially develop into a relevant tool for preselecting asymptomatic men prior to C. trachomatis screening.