市川 智彦

Our recent studies of microRNA (miRNA) expression signatures of prostate cancer (PCa) showed that six miRNAs (specifically, miR-26a, miR-26b, miR-29a, miR-29b, miR-29c and miR-218) were markedly reduced in cancer tissues. Moreover, ectopic expression of these miRNAs suppressed PCa cell aggressiveness, indicating that these miRNAs acted in concert to regulate genes that promoted metastasis. Genome-wide gene expression analysis and in silico database analysis identified a total of 35 candidate genes that promoted metastasis and were targeted by these 6 miRNAs. Using luciferase reporter assays, we showed that the lysyl oxidase-like 2 (LOXL2) gene was directly controlled by these tumor-suppressive miRNAs in PCa cells. Overexpression of LOXL2 was confirmed in PCa tissues and knockdown of the LOXL2 gene markedly inhibited the migration and invasion of PCa cells. Aberrant expression of LOXL2 enhanced migration and invasion of PCa cells. Downregulation of antitumor miRNAs might disrupt the tightly controlled RNA networks found in normal cells. New insights into the novel molecular mechanisms of PCa pathogenesis was revealed by antitumor miRNA-regulated RNA networks.

Bladder cancer (BC) and renal cell carcinoma (RCC) are frequently diagnosed urinary tract cancers. Recently developed molecular-targeted therapies for RCC have shown remarkable therapeutic efficacy; however, no targeted therapeutics are currently approved for the treatment of BC, and few effective treatment options exist. Current studies have shown that small noncoding RNA molecules have major roles in cancer cells. MicroRNAs (miRNAs) are endogenous small noncoding RNA molecules that regulate protein-/nonprotein-coding RNAs in human cells. A large body of evidence suggests that aberrantly expressed miRNAs are deeply involved in the pathogenesis of human cancers. In this paper, we review recently published miRNA expression signatures of BC and RCC. We focus on downregulated or upregulated miRNAs in multiple signatures and discuss putative target genes of miRNAs. Comparisons of RCC and BC expression signatures revealed that the two types of cancer showed opposite expression patterns for miR-200 family miRNAs (i.e., miR-141/200c and miR-200a/200b/429). We discuss in silico analysis of genes targeted by miR-200 family miRNAs and the molecular mechanisms underlying BC and RCC.

(Purpose) Targeted therapy has been standard therapeutic approach for advanced renal cell carcinoma (RCC). General fatigue is frequently observed in patients who receive targeted therapies for advanced RCC. General fatigue makes it difficult to continue a standard schedule of treatment in many cases. In this preliminary report, we explored the effect of Koujin powder (red ginseng powder) with Ninjin-youeito for general fatigue induced by targeted therapies for advanced RCC. (Material and method) The patients who complained of general fatigue during the treatment of Tyrosine Kinase Inhibitors (TKIs) as targeted therapies for advanced RCC were included in this retrospective analysis. Thirty patients with advanced RCC were enrolled from January 2016 to December 2016 at Chiba University Hospital. Twelve patients were given 3 g of Koujin powder with 9 g of Ninjin-youeito orally for two to four weeks (ginseng combination group). Eighteen patients who were not orally administered were compared as a control group (ginseng non-combination group). General fatigue was assessed with the Cancer Fatigue Scale (CFS), which divides quality of fatigue into three subgroups by using a "physical subscale", an "affective subscale", and a "cognitive subscale". We compared CFS scores at baseline and 2-8 weeks after administration. (Results) There was no statistical difference in the clinical variables between the two groups. The total CFS score was significantly decreased after treatment in the ginseng combination group (average score, 21.8 points at baseline vs 18.5 points after treatment; p=0.041). On subgroup analyses, the physical subscale score was significantly reduced after treatment in the ginseng combination group (average score, 9.7 points at baseline vs 7 points after treatment; p=0.0042). In the ginseng non-combination group, the total CFS score was significantly increased during the course (average score, 16.2 points at baseline vs 20.6 points during the course; p=0.047). On subgroup analyses, the physical subscale score was significantly increased during the course (average score, 4.4 points at baseline vs 7.3 points during the course; p=0.0042). (Conclusions) Koujin powder with Ninjin-youeito can be a therapeutic approach for general fatigue induced by targeted therapies. The precise management for general fatigue can keep patients on therapy, consequently provides a survival benefit.

Purpose: The incidence of incisional hernia after laparoscopic surgery is reportedly 0–5.2 % there are only a few reports of that following retroperitoneal laparoscopic nephrectomy. We evaluated the incidence of and risk factors for incisional hernia after retroperitoneal laparoscopic nephrectomy, and the efficacy of our novel prophylaxis technique. Methods: A total of 207 renal cell carcinoma patients who underwent laparoscopic nephrectomy at Chiba University Hospital were retrospectively enrolled in this study. We compared the incidences of incisional hernia following the transperitoneal vs. retroperitoneal approaches, and, among the latter group, the incidences with vs. without use of our prophylaxis method. Also among the retroperitoneal-approach group, we evaluated selected patient characteristics as potential hernia risk factors. Results: The rate of incisional hernias was 14 (8.7 %) after 161 retroperitoneal laparoscopic nephrectomies and one (2.2 %) after 46 transperitoneal laparoscopic nephrectomies (P = 0.132). For those undergoing the retroperitoneal approach, 14 (11.3 %) hernias were identified in 124 non-prophylaxed patients and none in 37 prophylaxed patients. Transversus abdominis fascia closure was a statistically significant factor for reducing the incidence of incisional hernia after retroperitoneal laparoscopic nephrectomy (P = 0.0324): rectus abdominis muscle thickness ≤7 mm and perioperative blood loss &gt 100 ml were statistically significant independent risk factors, by multivariate analysis. Conclusions: To prevent incisional hernia after retroperitoneal laparoscopic nephrectomy in the patients with risk factors, it is useful to close the transversus abdominis fascia at the port sites from inside the surgical cavity, through the open specimen-removal trocar port site, under direct observation.

Molecular targeted therapy is a standard treatment for patients with advanced renal cell carcinoma (RCC). Sunitinib is one of the most common molecular-targeted drugs for metastatic RCC. Molecular mechanisms of sunitinib resistance in RCC cells is still ambiguous. The microRNA (miRNA) expression signature of patients with sunitinib failure in RCC was constructed using a polymerase chain reaction (PCR)-based array. Several miRNAs that were aberrantly expressed in RCC tissues from patients treated with sunitinib were identified in this analysis. MicroRNA-101 (miR- 101) was markedly suppressed in sunitinib treated RCC tissues. Restoration of miR-101 significantly inhibited cell migration and invasion in Caki-1 and 786-O cells. Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) was directly suppressed by miR-101 in RCC cells, and overexpression of UHRF1 was confirmed in sunitinib-treated RCC tissues. The pathways of nucleotide excision repair and mismatch repair were significantly suppressed by knockdown of UHRF1. Our findings showed that antitumor miR-101- mediated UHRF1 pathways may be suppressed by sunitinib treatment.

Purpose: The aim of our study was to identify the clinical predictors of spermatogenesis recovery in testicular cancer (TC) patients after chemotherapy and to determine the recuperation period for spermatogenesis. Methods: Patients treated for TC from January 1982 to November 2001 at Chiba University Hospital were retrospectively assessed. Thirty-five patients who met the following criteria were examined-(i) underwent both high orchiectomy and cisplatin-based chemotherapy; (ii) had semen analyses and hormonal measurements; and (iii) were alive with no evidence of disease. Clinical variables associated with normalization of spermatogenesis after chemotherapy were examined. Time to recover normospermia was also evaluated using Kaplan-Meier analysis. Results: The observation period was 13.3 ± 5.6 years. Reappearance of sperm was confirmed in 85.7 % of patients, and 54.3 % of patients recovered normospermia. Age at diagnosis <25 years (p = 0.0057), number of chemotherapy cycles <4 cycles (p = 0.0042), and follicle-stimulating hormone at the end of chemotherapy <18 mIU/ml (p = 0.0220) were independent factors related to post-chemotherapy normalization of semen findings. The median (95 % CI) time to recover normospermia was 40 (range 22-96) months. Conclusions: These findings help to predict whether spermatogenesis will recover and its timing. They may also help clinicians identify and manage TC patients at a higher risk of prolonged azoospermia after chemotherapy.

Advanced prostate cancer (PCa) metastasizes to bone and lymph nodes, and currently available treatments cannot prevent the progression and metastasis of the disease. Therefore, an improved understanding of the molecular mechanisms of the progression and metastasis of advanced PCa using current genomic approaches is needed. Our miRNA expression signature in castration-resistant prostate cancer (CRPC) revealed that microRNA-320a (miR‑320a) was significantly reduced in cancer tissues, suggesting that miR‑320a may be a promising anticancer miRNA. The aim of this study was to investigate the functional roles of miR‑320a in naïve PCa and CRPC cells and to identify miR‑320a-regulated genes involved in PCa metastasis. The expression levels of miR‑320a were significantly reduced in naïve PCa, CRPC specimens, and PCa cell lines. Restoration of mature miR‑320a in PCa cell lines showed that miR‑320a significantly inhibited cancer cell migration and invasion. Moreover, we found that lysosomal-associated membrane protein 1 (LAMP1) was a direct target of miR‑320a in PCa cells. Silencing of LAMP1 using siRNA significantly inhibited cell proliferation, migration, and invasion in PCa cells. Overexpression of LAMP1 was observed in PCa and CRPC clinical specimens. Moreover, downstream pathways were identified using si-LAMP1-transfected cells. The discovery of tumor-suppressive miR‑320a-mediated pathways may provide important insights into the potential mechanisms of PCa metastasis.

Adrenal tumors with more than one cellular component are uncommon. Furthermore, an adrenal tumor composed of a pheochromocytoma and a malignant peripheral nerve sheath tumor is extremely rare. A composite pheochromocytoma with malignant peripheral nerve sheath tumor in a 42-year-old man is reported here. After adequate preoperative control, left adrenalectomy was performed simultaneously with resection of the ipsilateral kidney for spontaneous rupture of the left adrenal tumor. Pathological findings demonstrated pheochromocytoma and malignant peripheral nerve sheath tumor in a ruptured adrenal tumor. To date, there have been only four reported cases of composite pheochromocytoma with malignant peripheral nerve sheath tumor, so the present case is only the fifth case in the world. Despite the very poor prognosis of patients with pheochromocytoma and malignant peripheral nerve sheath tumors reported in the literature, the patient remains well without evidence of recurrence or new metastatic lesions at 36 months postoperatively.

BACKGROUND: MicroRNA-224 (miR-224) and microRNA-452 (miR-452) are closely located on the human chromosome Xq28 region. miR-224 functions as a tumour suppressor by targeting tumour protein D52 (TPD52) in prostate cancer (PCa). Here, we aimed to investigate the functional significance of miR-452 in PCa cells. METHODS: Functional studies of PCa cells were performed using transfection with mature miRNAs or siRNAs. Genome-wide gene expression analysis, in silico analysis, and dual-luciferase reporter assays were applied to identify miRNA targets. The association between miR-452 levels and overall patient survival was estimated by the Kaplan-Meier method. RESULTS: Expression of miR-452 was significantly downregulated in PCa tissues. Transfection with mature miR-452 inhibited the migration and invasion of PCa cells. Kaplan-Meier survival curves showed that low expression of miR-452 predicted a short duration of progression to castration-resistant PCa. WW domain-containing E3 ubiquitin protein ligase-1 (WWP1) was a direct target of miR-452, and knockdown of WWP1 inhibited the migration and invasion of PCa cells. WWP1 was upregulated in PCa clinical specimens. CONCLUSIONS: Regulation of the miR-452-WWP1 axis contributed to PCa cell migration and invasion, and elucidation of downstream signalling of this axis will provide new insights into the mechanisms of PCa oncogenesis and metastasis.

PURPOSE: Cancer cells require massive amounts of amino acids for survival. LAT1 (L-type amino acid transporter 1) transports essential amino acids, including leucine, which trigger the downstream mTOR (mammalian target of rapamycin) pathway. We examined the association between androgen receptor and LAT1, and the association between LAT1 expression and the acquisition of castration resistance. MATERIALS AND METHODS: Western blot and real-time polymerase chain reaction were performed to study protein and mRNA expression. siRNA was used to knock down target genes. A total of 92 prostate biopsy specimens of patients who underwent androgen deprivation therapy were used for immunohistochemical analyses. Cox hazard proportional models and the Kaplan-Meier method were used for statistical analyses. RESULTS: LAT1 was highly expressed in hormone resistant prostate cancer cell lines. Knockdown of LAT1 in LNCaP and C4-2 cells significantly suppressed cell proliferation, migration and invasion. Androgen receptor siRNA or androgen receptor blocking through bicalutamide (10 μM) or MDV3100 (10 μM) significantly increased LAT1 expression (p <0.01). Treatment with dihydrotestosterone (0.1 to 10 nM) reduced LAT1 expression in a dose dependent manner (p <0.01). Bicalutamide/MDV3100 plus siLAT1 synergistically suppressed prostate cancer cell proliferation compared to single inhibition by androgen receptor or LAT1 (p <0.01). High LAT1 expression correlated with significantly shorter prostate specific antigen recurrence-free survival in patients receiving androgen deprivation therapy (p <0.0001). LAT1 expression was an independent predictor of castration resistance on multivariate analysis (HR 3.56, p = 0.0133). CONCLUSIONS: The current data may indicate a novel mechanism to acquire castration resistance through activation of the amino acid transporter LAT1.

Our recent studies of microRNA (miRNA) expression signatures in human cancers revealed that microRNA-26a (miRNA-26a) and microRNA-26b (miRNA-26b) were significantly reduced in cancer tissues. To date, few reports have provided functional analyses of miR-26a or miR-26b in renal cell carcinoma (RCC). The aim of the present study was to investigate the functional significance of miR-26a and miR-26b in RCC and to identify novel miR-26a/b-mediated cancer pathways and target genes involved in RCC oncogenesis and metastasis. Downregulation of miR-26a or miR-26b was confirmed in RCC clinical specimens. Restoration of miR-26a or miR-26b in RCC cell lines (786-O and A498) revealed that these miRNAs significantly inhibited cancer cell migration and invasion. Our in silico analysis and luciferase reporter assays showed that lysyl oxidase-like 2 (LOXL2) and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were directly regulated by these miRNAs. Moreover, downregulating the PLOD2 gene significantly inhibited cell migration and invasion in RCC cells. Thus, our data showed that two genes promoting metastasis, LOXL2 and PLOD2, were epigenetically regulated by tumor-suppressive microRNAs, miR-26a and miR-26b, providing important insights into the molecular mechanisms of RCC metastasis.

BACKGROUND: Although the perioperative management of patients with pheochromocytoma has been improving recently, severe hypotensive episodes can occur that require postoperative catecholamine support and are challenging to manage. Our aim was to identify the clinical factors that predict prolonged postresection hypotension in patients after laparoscopic adrenalectomy for pheochromocytoma. METHODS: The records of 73 Japanese patients who underwent unilateral laparoscopic adrenalectomy for pheochromocytoma were surveyed retrospectively. Patients were divided into 2 groups according to whether catecholamine support was needed after postoperatively. Clinical and biochemical data were evaluated at baseline and after operation. RESULTS: Thirty-four of 73 patients (47%) required continuous infusion of catecholamine to maintain systolic blood pressure >90 mm Hg at the end of the operation. The median duration of postoperative catecholamine support was 17 hours (range, 3-130) in these 34 patients. On multivariate analysis, tumor size >60 mm, urinary epinephrine levels >200 μg/day, and urinary norepinephrine levels >600 μg/day were independent predictors of prolonged hypotension requiring postoperative catecholamine support. Tumor size and urinary norepinephrine levels were significantly correlated with the duration of postoperative catecholamine support. CONCLUSION: Larger tumor size and greater values of urinary epinephrine and norepinephrine levels were significant predictors of prolonged hypotension requiring postoperative catecholamine support. Moreover, tumor size and urinary norepinephrine levels were positively correlated with the duration of postoperative catecholamine support. Clinicians can identify and manage patients more effectively with a greater risk of prolonged hypotension after tumor resection using these preoperative clinical variables.

クッシング症候群／サブクリニカルクッシング症候群（CS／SCS）は，副腎皮質からコルチゾールの慢性的な過剰分泌により引き起こされる病態であり，長期間に渡る高コルチゾール血症の影響で，高血圧や低カリウム血症，耐糖能異常・糖尿病，肥満，心血管系疾患，筋力低下，横隔膜拳上による呼吸機能の低下，骨粗鬆症・病的骨折，易感染性，精神神経症状など周術期管理の上で様々な問題を抱えていることが多い。また，視床下部CRH-下垂体ACTH系が抑制され，非病変部の副腎皮質も萎縮しコルチゾール産生が強く抑制されているために，副腎摘除術後は副腎不全の状態にある。CRH-ACTH系が回復し内因性コルチゾール産生が正常化するまで，術後はステロイド補充が必須となる。本稿では，われわれ外科医が担当するCS／SCSの周術期管理および術後ステロイド補充に関して詳述する。

OBJECTIVES: To validate the ability of contemporary active surveillance protocols to predict pathologically insignificant prostate cancer among Asian men undergoing radical prostatectomy. METHODS: We retrospectively reviewed data on 132 patients eligible for any active surveillance criteria out of 450 patients that underwent radical prostatectomy at several institutions between 2006 and 2013. We validated the ability of seven contemporary active surveillance protocols to predict pathologically insignificant prostate cancer. Traditional and updated criteria to define pathologically insignificant prostate cancer were used. Predictive factors for pathologically insignificant prostate cancer were determined by logistic regression analysis. RESULTS: The predictive rate for updated pathologically insignificant prostate cancer of respective active surveillance criteria was 51% for Johns Hopkins Medical Institution, 41% for Prostate Cancer Research International: Active Surveillance Study, 39% for University of Miami, 32% for University of California, San Francisco, 32% for Memorial Sloan-Kettering Cancer Center, 31% for Kakehi and 27% for University of Toronto. Predictive rates for pathologically insignificant prostate cancer in Asian men were far lower than in USA men. On multivariate analysis, predictive factors of updated pathologically insignificant cancer was prostate volume (odds ratio 1.07, P = 0.004). By adding prostate volume to Prostate Cancer Research International: Active Surveillance Study criteria, the predictive rate for updated insignificant prostate cancer was improved up to 66.7%. CONCLUSIONS: Active surveillance can be carried out considering the clinical characteristics of prostate cancers depending on ethnicity, as current active surveillance criteria seem to have a lower predictive ability value of insignificant prostate cancer in Asian men compared with men in Western countries.

Analysis of microRNA (miRNA) expression signatures in prostate cancer (PCa) and castration-resistant PCa has revealed that miRNA-223 is significantly downregulated in cancer tissues, suggesting that miR-223 acts as a tumor-suppressive miRNA by targeting oncogenes. The aim of this study was to investigate the functional roles of miR-223 and identify downstream oncogenic targets regulated by miR-223 in PCa cells. Functional studies of miR-223 were carried out to investigate cell proliferation, migration, and invasion using PC3 and PC3M PCa cell lines. Restoration of miR-223 significantly inhibited cancer cell migration and invasion in PCa cells. In silico database and genome-wide gene expression analyses revealed that ITGA3 and ITGB1 were direct targets of miR-223 regulation. Knockdown of ITGA3 and ITGB1 significantly inhibited cancer cell migration and invasion in PCa cells by regulating downstream signaling. Moreover, overexpression of ITGA3 and ITGB1 was observed in PCa clinical specimens. Thus, our data indicated that downregulation of miR-223 enhanced ITGA3/ITGB1 signaling and contributed to cancer cell migration and invasion in PCa cells. Elucidation of the molecular pathways modulated by tumor-suppressive miRNAs provides insights into the mechanisms of PCa progression and metastasis.

Androgen receptor(AR) has a critical role in prostate cancer(PCa) progression and targeting AR axis signaling by androgen deprivation therapy is a standard treatment for advanced PCa. Recently, the role of AR even in castration-resistant PCa(CRPC) is well recognized and emerging evidence suggests survival advantages of treatment by targeting AR in CRPC. This review outlines AR functions that contribute to PCa progression, AR structural alterations and AR activation via intracrine, co-factors, and kinase pathways in CRPC. Finally, we describe about recently reported bipolar androgen therapy as a novel treatment for CRPC targeting AR.

OBJECTIVE: To evaluate a role of apparent diffusion coefficient (ADC) values measured from diffusion-weighted imaging we investigated its association with clinicopathological tumor characteristics of bladder cancer. MATERIALS AND METHODS: Diffusion-weighted MRI at 1.5 Tesla using b-values of 0, 1000 s/mm(2) was taken before transurethral resection by 114 bladder urothelial tumor patients. ADC value was measured and its relationship with pathological factors including T stage, tumor grade, infiltration style (INF) and lymphatic invasion (ly) was analyzed. RESULTS: Median ADC value was significantly lower in Grade 3 than in Grade 1 (P < 0.001) or in Grade 2 (P = 0.002), in INFb than in INFa (P = 0.004), in INFc than in INFa (P < 0.001), in ly1 than in ly0 (P < 0.001) and lower in T2≦ than in T1≧ (P < 0.001), respectively. Receiver operating curve demonstrated the accuracy of detecting muscle invasive bladder cancer or ly+ by using area under curve (AUC), showing 0.758 and 0.748. CONCLUSION: ADC value is likely to serve as a useful biomarker showing clinicopathological characterictics of bladder cancer.

BACKGROUND: Although transperineal (TP) prostate biopsy is growing in popularity, its safety has not been evaluated based on extensive studies. We prospectively assessed the adverse events associated with transrectal ultrasound (TRUS)-guided TP 16-core prostate biopsy at a single institution. PATIENTS AND METHODS: We enrolled 2,086 males who underwent first-time TRUS-guided TP prostate biopsy under lumbar spinal anesthesia at Chiba Cancer Center between 2009 and 2013. Eight adverse events were assessed prospectively using a purpose-designed questionnaire. The prevalence and duration of all adverse events were evaluated. We performed subgroup analyses for hematuria and urinary retention in relation to clinical factors. RESULTS: Questionnaires were collected from 1,663 cases (79.7 %). The cancer detection rate was 53.5 % in all patients. The prevalence and duration of complications were as follows: hematuria, 73.4 % and 4.51 ± 2.88 days; perineal bleeding, 7.1 % and 2.20 ± 2.24 days; hematospermia 14.4 %; dysuria, 15.7 % and 3.12 ± 2.71 days; urinary tract pain, 49.5 % and 2.43 ± 2.08 days; perineal pain, 35.5 % and 3.53 ± 2.59 days; fever ≥37 °C, 1.7 % and 1.79 ± 1.72 days; and headache, 22.1 % and 3.40 ± 2.10 days. Seventeen patients (1.1 %) required indwelling urethral catheterization for grade 2 urinary retention. Pre-biopsy International Prostate Symptom Score (p = 0.014) was an independent related factor for hematuria. Prostate volume (p = 0.001) was an independent related factor for grade 2 urinary retention. CONCLUSIONS: TRUS-guided TP prostate biopsy under lumbar spinal anesthesia can be performed safely with only minor adverse events.

BACKGROUND: Many patients with primary aldosteronism (PA) show a significant decline in kidney function after adrenalectomy. Thus, PA patients who undergo surgery are at greater risk of both postoperative renal damage and new-onset metabolic events associated with renal insufficiency. The aim of this study was to explore postoperative changes in serum lipid levels and to identify risk factors associated with postoperative new-onset dyslipidemia in PA patients. METHODS: The records of 57 Japanese patients who underwent unilateral laparoscopic adrenalectomy for PA were retrospectively surveyed. Clinical and biochemical data were evaluated at baseline and 12 months after surgery. Preoperative and postoperative estimated glomerular filtration (eGFR) and serum lipid profile, including triglycerides, high-density lipoprotein (HDL)-cholesterol and low-density lipoprotein (LDL)-cholesterol levels, were compared. Furthermore, uni- and multivariate analyses were performed to determine the predictors for postoperative new-onset dyslipidemia. RESULTS: A significant decrease in eGFR and deterioration of serum lipid levels was identified postoperatively in most patients. Of the 39 patients without pre-existing dyslipidemia, 18 developed new-onset dyslipidemia postoperatively. Multivariate analysis identified preoperative lower eGFR and higher body mass index as independent predictors for new-onset dyslipidemia after surgery. On univariate analyses, additional factors associated with new-onset dyslipidemia included older age, male sex, higher LDL-cholesterol, and higher LDL/HDL ratio. CONCLUSIONS: PA patients had a higher risk of postoperative new-onset or progressive dyslipidemia. Clinicians should pay attention to not only follow-up of renal impairment but also total management of new-onset metabolic events associated with renal insufficiency in PA patients.