市川 智彦

Testosterone plays a significant role in maintaining the tumor microenvironment. The role of the target serum testosterone (TST) level in enzalutamide- (Enza) and abiraterone (Abi)-treated castration-resistant prostate cancer (CRPC) patients was studied. In total, 107 patients treated with Enza and/or Abi at Chiba University Hospital and affiliated hospitals were studied. The relationships between progression-free survival (PFS), overall survival (OS), and clinical factors were studied by Cox proportional hazard and Kaplan-Meier models. In the Abi and Enza groups overall, TST ≥ 13 ng/dL (median) (Hazard Ratio (HR) 0.43, p = 0.0032) remained an independent prognostic factor for PFS. In the Enza group, TST ≥ 13 ng/dL (median) was found to be a significant prognostic factor (HR 0.28, p = 0.0044), while, in the Abi group, TST ≥ 12 ng/dL (median) was not significant (HR 0.40, p = 0.0891). TST showed significant correlation with PFS periods (r = 0. 32, p = 0.0067), whereas, for OS, TST ≥ 13 ng/dL (median) showed no significant difference in the Abi and Enza groups overall. According to Kaplan-Meier analysis, a longer PFS at first-line therapy showed a favorable prognosis in the Enza group (p = 0.0429), while no difference was observed in the Abi group (p = 0.6051). The TST level and PFS of first-line therapy may be considered when determining the treatment strategy for CRPC patients.

OBJECTIVES: To identify oncogenes regulated by micro-ribonucleic acid, miR-199a/b-3p, in metastatic castration-resistant prostate cancer. METHODS: Advanced ribonucleic acid sequencing technologies were applied to construct a micro-ribonucleic acid expression signature using metastatic castration-resistant prostate cancer autopsy specimens. Ectopic expression of mature micro-ribonucleic acids or small-interfering ribonucleic acids were applied to functional assays for cancer cell lines. Genome-wide gene expression and in silico database analyses were carried out to predict micro-ribonucleic acid targets. RESULTS: Ectopic expression of miR-199a/b inhibited cancer cell aggressiveness. The gene coding for non-structural maintenance of chromosomes condensin I complex subunit H was directly regulated by miR-199a/b-3p. High expression of condensin I complex subunit H was significantly associated with poor disease-free survival by The Cancer Genome Atlas database analysis (P < 0.0001). Overexpression of condensin I complex subunit H was detected in hormone-sensitive prostate cancer and castration-resistant prostate cancer specimens, and knockdown assays showed that its expression enhanced cancer cell migration and invasive abilities. CONCLUSIONS: Small ribonucleic acid sequencing of metastatic castration-resistant prostate cancer specimens showed the presence of several antitumor micro-ribonucleic acids whose targets are involved in hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer pathogenesis. Condensin I complex subunit H seems to be a promising diagnostic marker and therapeutic target for this disease. Our approach, based on the roles of anti-tumor micro-ribonucleic acids and their targets, will contribute to an improved understanding of the molecular pathogenesis of hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer.

1. The metabolism of the prostacyclin receptor agonist selexipag (NS-304; ACT-293987) and its active metabolite MRE-269 (ACT-333679) has been investigated in liver microsomes and hepatocytes of rats, dogs, and monkeys. MRE-269 formation is the main pathway of selexipag metabolism, irrespective of species. Some interspecies differences were evident for both compounds in terms of both metabolic turnover and metabolic profiles. The metabolism of MRE-269 was slower than that of selexipag in all three species. 2. The metabolism of selexipag was also studied in bile-duct-cannulated rats and dogs after a single oral and intravenous dose of [14C]selexipag. MRE-269 acyl glucuronide was found in both rat and dog bile. Internal acyl migration reactions of MRE-269 glucuronide were identified in an experiment with the synthetic standard MRE-6001. 3. MRE-269 was the major component in the faeces of rats and dogs. In ex vivo study using rat and dog faeces, selexipag hydrolysis to MRE-269 by the intestinal microflora is considered to be a contributory factor in rats and dogs. 4. A taurine conjugate of MRE-269 was identified in rat bile sample. Overall, selexipag was eliminated via multiple routes in animals, including hydrolysis, oxidative metabolism, conjugation, intestinal deconjugation, and gut flora metabolism.

Androgen deprivation therapy is frequently used to treat prostate cancer (PCa), but resistance can occur, a condition known as castration-resistant prostate cancer (CRPC). Thus, novel approaches for identification of CRPC are important for designing effective PCa treatments. Analysis of microRNA (miRNA) expression signatures by RNA sequencing showed that both passenger and guide strands of the miR-455-duplex (miR-455-5p and miR-455-3p, respectively) acted as antitumor miRNAs in PCa cells. The involvement of miRNA passenger strands in cancer pathogenesis is a novel concept for miRNA functionality. Based on a large patient cohort in The Cancer Genome Atlas, expression of eight miR-455-5p/-3p target genes (PIR: P = 0.0137, LRP8: P = 0.0495, IGFBP3: P = 0.0172, DMBX1: P = 0.0175, CCDC64: P = 0.0446, TUBB1: P = 0.0149, KIF21B: P = 0.0336, and NFAM1: P = 0.0013) was significantly associated with poor prognosis of PCa patients. Here, we focused on PIR (pirin), a highly conserved member of the cupin superfamily. PIR expression was directly regulated by miR-455-5p, and PIR overexpression was detected in hormone-sensitive prostate cancer (HSPC) surgical specimens and CRPC autopsy specimens. Loss-of-function assays using siRNA or an inhibitor (bisamide) showed that downregulation of PIR expression blocked cancer cell migration and invasion. Moreover, the miR-455-5p/PIR axis contributed to cancer cell aggressiveness. These results suggest that PIR might be a promising diagnostic marker for HSPC and CRPC. Furthermore, CRPC treatment strategies targeting PIR may be possible in the future. Identification of antitumor miRNAs, including miRNA passenger strands, may contribute to the development of new diagnostic markers and therapeutic strategies for CRPC.

In liver microsomes, selexipag (NS-304; ACT-293987) mainly undergoes hydrolytic removal of the sulfonamide moiety by carboxylesterase 1 (CES1) to yield the pharmacologically active metabolite MRE-269 (ACT-333679). However, it is not known how much CES in the liver and intestine contributes to the hydrolysis of selexipag or how selexipag is metabolized in the intestine, including by hydrolysis. To obtain a better understanding of selexipag metabolism in humans, we determined the percentage contribution of CES1 and carboxylesterase 2 (CES2) to the hydrolysis of selexipag and 7 of its analogs with different sulfonamide moieties and evaluated its nonhydrolytic metabolism in human liver microsomes and human intestinal microsomes (HIMS). For selexipag, the percentage contributions of CES1 and CES2 in human liver microsomes were 77.0% and 9.99%, respectively, while the percentage contribution of CES2 in HIMS was 100%. In HIMS, the rate of hydrolysis of selexipag was the lowest among the compounds tested, and no difference between the presence and absence of nicotinamide adenine dinucleotide phosphate was noted. We infer from these results that selexipag is likely to be hydrolyzed by CES2 as well as CES1, and only selexipag itself and the MRE-269 produced by hydrolysis in the intestine would be absorbed after oral administration.

OBJECTIVES: To determine changes and trends in the annual incidence and epidemiological aspects of lower urinary tract stones in Japan. METHODS: Data about patients who had been diagnosed by urologists in 2015 with first and recurrent lower urinary tract stones were collected from 301 hospitals approved by the Japanese Board of Urology. The estimated annual incidence according to sex, age and stone composition was compared with previous nationwide surveys between 1965 and 2005. RESULTS: The incidence of lower urinary tract stones in Japan has steadily increased from 4.7 per 100 000 in 1965 to 12.0 per 100 000 in 2015. However, the age standardized annual incidence of lower urinary tract stones has remained relatively stable over the same period at 5.5 per 100 000 and 6.0 per 100 000 in 1965 and 2015, respectively. The increase in incidence was most evident among individuals aged ≥80 years. The incidence of calcium oxalate stones has steadily increased among males and females, whereas that of infection-related stones has significantly decreased from 26.2% to 14.3% among men over the past 50 years. CONCLUSIONS: Nationwide surveys suggest a steady increase in the incidence of lower urinary tract stones over a 50-year period in Japan. This trend might reflect changes in the aging population and improved Japanese medical standards.

The aims of this study were to clarify the safety and efficacy of 12-fraction carbon-ion radiotherapy (CIRT) for primary renal cell carcinoma (RCC) and to confirm the recommended dose in a prospective clinical trial. This clinical trial was planned as a non-randomized, open-label, single-center phase I/II study of CIRT monotherapy. The incidence of acute adverse events was the primary endpoint. Dose-limiting toxicities (DLTs) were defined as grade ≥3 skin, gastrointestinal tract, or urologic adverse events. Based on the eligibility criteria, 8 patients with primary RCC, including 3 medically inoperable patients and 5 patients with tumors >4 cm, were enrolled. Of the 8 patients, 5 were treated with 66 Gy (relative biological effectiveness [RBE]), and subsequently, the dose was escalated to 72 Gy (RBE) for the remaining 3 patients. The median follow-up time was 43.1 months. No DLTs were observed at any dose level though the end of follow-up. Although 1 patient died of pneumonia 3 months after CIRT, which was determined to be unrelated to CIRT, no grade 3 or higher adverse events were observed, and both local control and cancer-specific survival rates were 100%. In conclusion, the safety and efficacy of CIRT hypofractionation using 12-fractions for the treatment of eligible RCC patients, including those with inoperable or tumor size >4 cm, were confirmed in this prospective trial, and a recommended dose of 72 Gy (RBE) was established.

Analyses of our previously determined microRNA (miRNA) expression signature of renal cell carcinoma (RCC) and The Cancer Genome Atlas (TCGA) database revealed that both strands of the pre-miR-532-duplex-miR-532-5p (the guide strand) and miR-532-3p (the passenger strand)- are closely associated with poor prognosis of RCC patients (P = 0.0411 and P = 0.022, respectively). In this study we investigated the functional significance of these miRNAs and identified gene targets involved in RCC pathogenesis. Ectopic expression of these miRNAs significantly attenuated the malignant phenotypes including proliferation, migration and invasion of two RCC cell lines, 786-O and A498. A combination of genome-wide gene expression and in silico database analyses revealed 36 and 34 genes as putative target oncogenes regulated by miR-532-5p and miR-532-3p, respectively, in RCC cells. Among these targets, expression of aquaporin9 (AQP9), a water channel protein, was directly regulated by both miR-532-5p and miR-532-3p, and high expression levels of AQP9 were significantly associated with poor prognosis of RCC patients (P = 2.03e-05). Multivariate analysis indicated that AQP9 expression is an independent prognostic factor for RCC patients. Aberrant AQP9 expression at both the gene and protein level was detected in RCC clinical specimens. siRNA-mediated knockdown of AQP9 by si-AQP9 inhibited the malignant phenotypes of RCC cells. Rescue assays of AQP9 overexpression showed that the miR-532/AQP9 axis was closely involved in RCC oncogenesis. The identification of antitumor miRNAs and their targets will contribute to an increased understanding of the molecular pathogenesis of RCC.

1. The purpose of this study is to investigate the heteroactivation mechanism of CYP3A4 by efavirenz, which enhances metabolism of midazolam in vivo, in terms of its binding to CYP3A4 with in vitro spectroscopic methods. 2. Efavirenz exhibited a type II spectral change with binding to CYP3A4 indicating a possible inhibitor. Although dissociation constant (K d) was approximated as 520 μM, efavirenz enhanced binding affinity of midazolam as a co-existing drug with an estimated iK d value of 5.6 µM which is comparable to a clinical concentration. 3. Efavirenz stimulated the formation of 1'-hydroxymidazolam, and the product formation rate (V max) concentration-dependently increased without changing the K m. Besides, an efavirenz analogue, [6-chloro-1,4-dihydro-4-(1-pentynyl)-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one] (efavirenz impurity) slightly facilitated the binding affinity of midazolam in a concentration-dependent manner. These results propose that efavirenz affects midazolam-binding via binding to the peripheral site which is apart from the active site of CYP3A4. 4. A molecular dynamics simulation also suggested the bound-efavirenz was repositioned to effector-binding site. As a consequence, our spectroscopic studies clarified the heteroactivation of CYP3A4 caused by efavirenz with a proper affinity to the peripheral site, and we concluded the method can be a useful tool for characterising the potential for drug-drug interactions.

OBJECTIVES: To identify key oncogenes and proteins that are controlled by the microRNA miR-29 family (miR-29a, miR-29b and miR-29c) in renal cell carcinoma pathogenesis. METHODS: Genome-wide gene expression and in silico database analyses were carried out. The Cancer Genome Atlas database was used to investigate the clinical significance of gene expression data in renal cell carcinoma patients. Loss-of-function assays were applied to investigate the function of target genes. RESULTS: We identified 47 possible target genes that might be regulated by the miR-29 family in renal cell carcinoma cells. Among the targets of the miR-29 family, high expression of 10 genes (ADAMTS14, TRIB13, SERPINH1, FCGR1B, COL1A1, LAIR2, WISP2, TREM1, TNKS1BP1 and GBP2) significantly predicted poor patient prognosis (P < 0.001). SERPINH1 was directly regulated by the miR-29 family, and its overexpression was detected in renal cell carcinoma surgical specimens and tyrosine kinase inhibitor failure autopsy specimens. High expression of SERPINH1 was significantly associated with tumor stage, pathological grade and poor prognosis (P < 0.0001). Knockdown assays showed that its expression enhanced cancer cell migration and invasive abilities. CONCLUSIONS: Genes regulated by the anti-tumor miR-29 family are closely involved in the molecular pathogenesis of renal cell carcinoma. Our approach based on anti-tumor microRNAs might contribute to the development of new diagnostic markers and therapeutic strategies.

Background: In the era of improving assisted reproductive technology (ART), patients with obstructive azoospermia (OA) have 2 options: vasal repair or testicular sperm extraction with intracytoplasmic sperm injection. Vasal repair, including vasovasostomy (VV) and vasoepididymostomy (VE), is the only option that leads to natural conception. Methods: This article reviews the surgical techniques, outcomes, and predictors of postoperative patency and pregnancy, with a focus on articles that have reported over the last 10 years, using PubMed database searches. Main findings: The reported mean patency rate was 87% and the mean pregnancy rate was 49% for a patient following microscopic VV and/or VE for vasectomy reversal. Recently, robot-assisted techniques were introduced and have achieved a high rate of success. The predictors and predictive models of postoperative patency and pregnancy also have been reported. The obstructive interval, presence of a granuloma, and intraoperative sperm findings predict postoperative patency. These factors also predict postoperative fertility. In addition, the female partner's age and the same female partner correlate with pregnancy after surgery. Conclusion: In the era of ART, the physician should present and discuss with both the patient with OA and his partner the most appropriate procedure to conceive by using these predictors.

There is significant debate within the diagnostics community regarding the accuracy of variant identification by next-generation sequencing and the necessity of confirmatory testing of detected variants. Because the quality threshold to discriminate false positives depends on the workflow, no regulatory standard regarding this matter has yet been published. The goal of this study was to empirically determine the threshold to perform additional Sanger sequencing and to reduce the experimental cost to a practical level. Using 278 model genes, a hybridization capture-based protocol was examined to meet the clinical requirements of low cost, high efficiency, and high-quality data. To reduce excessive false-positive detection, filtering processes were introduced to remove mismapped reads and strand-biased detection to a published best-practices pipeline. With seven samples from the 1000 Genomes Project, 2750 single-nucleotide polymorphisms and 142 insertions/deletions were identified by our designed workflow. Compared with variants registered in the single nucleotide polymorphism database (dbSNP), a zero false-positive threshold value was determined (quality score > 1000). The variants satisfying these criteria accounted for 95.6% of single-nucleotide polymorphisms and 50.7% of insertions/deletions. Except for deletions located within the highly repeated sequences, the workflow achieved 100% sensitivity. The established threshold allowed us to discriminate between convincing variants and those requiring validation, a design that reconciles the competing objectives of cost minimization and quality maximization of clinical gene panel testing.

In the human genome, miR-451a, miR-144-5p (passenger strand), and miR-144-3p (guide strand) reside in clustered microRNA (miRNA) sequences located within the 17q11.2 region. Low expression of these miRNAs is significantly associated with poor prognosis of patients with renal cell carcinoma (RCC) (miR-451a: P = .00305; miR-144-5p: P = .00128; miR-144-3p: P = 9.45 × 10-5 ). We previously reported that miR-451a acted as an antitumor miRNA in RCC cells. Involvement of the passenger strand of the miR-144 duplex in the pathogenesis of RCC is not well understood. Functional assays showed that miR-144-5p and miR-144-3p significantly reduced cancer cell migration and invasive abilities, suggesting these miRNAs acted as antitumor miRNAs in RCC cells. Analyses of miR-144-5p targets identified a total of 65 putative oncogenic targets in RCC cells. Among them, high expression levels of 9 genes (FAM64A, F2, TRIP13, ANKRD36, CENPF, NCAPG, CLEC2D, SDC3, and SEMA4B) were significantly associated with poor prognosis (P < .001). Among these targets, expression of SDC3 was directly controlled by miR-144-5p, and its expression enhanced cancer cell aggressiveness. We identified genes downstream by SDC3 regulation. Data showed that expression of 10 of the downstream genes (IL18RAP, SDC3, SH2D1A, GZMH, KIF21B, TMC8, GAB3, HLA-DPB2, PLEK, and C1QB) significantly predicted poor prognosis of the patients (P = .0064). These data indicated that the antitumor miR-144-5p/oncogenic SDC3 axis was deeply involved in RCC pathogenesis. Clustered miRNAs (miR-451a, miR-144-5p, and miR-144-3p) acted as antitumor miRNAs, and their targets were intimately involved in RCC pathogenesis.

Long-term oncological outcomes for primary renal cell carcinoma (RCC) treated with carbon-ion radiotherapy (CIRT) are poorly understood. Patients with primary RCC were treated with 12 or 16-fraction CIRT at The Hospital of the National Institute of Radiological Sciences outside of clinical trials. Outcome data were pooled and retrospectively analyzed for toxicity, local control, and disease-free, cancer-specific, and overall survival. From 1997 to 2014, 19 RCC patients (11 with T1aN0M0, 4 with T1bN0M0, and 4 with inoperable advanced stage [T4N0M0, T3aN1M0, and T1aN0M1]) were treated with CIRT and followed up for a median of 6.6 (range, 0.7-16.5) years; 9 of these patients were inoperable because of comorbidities or advanced-stage disease. Diagnoses were confirmed by imaging in 11 patients and by biopsy in the remaining 8. In 4 of 5 patients with definitive renal comorbidities, including diabetic nephropathy, sclerotic kidney or solitary kidney pre-CIRT progressed to grade 4 chronic kidney disease (CKD). In contrast, the remaining 14 patients without definitive renal comorbidities did not progress to grade 3 or higher CKD. Furthermore, although 1 case of grade 4 dermatitis was observed, there were no other grade 3 or higher non-renal adverse events. Local control rate, and disease-free, cancer-specific, and overall survival rates at 5 years of all 19 patients were 94.1%, 68.9%, 100%, and 89.2%, respectively. This updated retrospective analysis based on long-term follow-up data suggests that CIRT is a safe treatment for primary RCC patients without definitive renal comorbidities pre-CIRT, and yield favorable treatment outcomes, even in inoperable cases.