Toru Shimazui

Nrf2 is essential for the chemopreventive efficacy of oltipraz against urinary bladder carcinogenesis

The induction of phase 2 detoxifying enzymes, such as UDP-glucuronosyltransferases (UGTs), in response to an array of naturally occurring and synthetic agents, such as oltipraz (4-methyl-5-[2-pyrazinyl]-1,2-dithiole-3-thione), provides an effective means of protection against a variety of carcinogens. Transcription factor Nrf2 is an essential regulator of the inducible expression of detoxifying enzyme genes by chemopreventive agents. In this study, we investigated in Nrf2-deficient mice the susceptibility to the urinary bladder-specific carcinogen N-nitrosobutyl(4-hydroxybutyl)amine (BBN) and the chemopreventive efficacy of oltipraz. The incidence of urinary bladder carcinoma by BBN was significantly higher in Nrf2−/− mice than in wild-type mice; invasive carcinoma was found in 24.0 and 38.5% of wild-type and Nrf2−/− mice, respectively. Oltipraz induced the phase 2 enzymes responsible for BBN detoxification in the liver and urinary bladder in an Nrf2-dependent manner. As expected, therefore, oltipraz decreased the incidence of urinary bladder carcinoma by BBN in wild-type mice but had little effect in Nrf2−/− mice. In wild-type mouse liver, oltipraz significantly induced BBN glucuronidation and decreased the urinary concentration of N-nitrosobutyl(3-carboxypropyl)amine, a proximate carcinogen of BBN. Importantly, BBN was found to suppress the expression of UGT1A specifically in the urinary bladder. This suppression was counteracted by oltipraz in wild-type mice but not in Nrf2−/− mice. These results show that Nrf2 and its downstream target genes are responsible for BBN detoxification. Furthermore, oltipraz prevents carcinogenesis by BBN by enhancing detoxification of this carcinogen in the liver and urinary bladder.

Molecular Features of Hormone-Refractory Prostate Cancer Cells by Genome-Wide Gene Expression Profiles

One of the most critical issues in prostate cancer clinic is emerging hormone-refractory prostate cancers (HRPCs) and their management. Prostate cancer is usually androgen dependent and responds well to androgen ablation therapy. However, at a certain stage, they eventually acquire androgen-independent and more aggressive phenotype and show poor response to any anticancer therapies. To characterize the molecular features of clinical HRPCs, we analyzed gene expression profiles of 25 clinical HRPCs and 10 hormone-sensitive prostate cancers (HSPCs) by genome-wide cDNA microarrays combining with laser microbeam microdissection. An unsupervised hierarchical clustering analysis clearly distinguished expression patterns of HRPC cells from those of HSPC cells. In addition, primary and metastatic HRPCs from three patients were closely clustered regardless of metastatic organs. A supervised analysis and permutation test identified 36 up-regulated genes and 70 down-regulated genes in HRPCs compared with HSPCs (average fold difference > 1.5; P < 0.0001). We observed overexpression of AR, ANLN, and SNRPE and down-regulation of NR4A1, CYP27A1, and HLA-A antigen in HRPC progression. AR overexpression is likely to play a central role of hormone-refractory phenotype, and other genes we identified were considered to be related to more aggressive phenotype of clinical HRPCs, and in fact, knockdown of these overexpressing genes by small interfering RNA resulted in drastic attenuation of prostate cancer cell viability. Our microarray analysis of HRPC cells should provide useful information to understand the molecular mechanism of HRPC progression and to identify molecular targets for development of HRPC treatment.

Antineoplastic activity of honey in an experimental bladder cancer implantation model: In vivo and in vitro studies

Objectives: The antitumor effect of bee honey against bladder cancer was examined in vitro and in vivo. Methods: Three human bladder cancer cell lines (T24, 253J and RT4) and one murine bladder cancer cell line (MBT‐2) were used in these experiments. In an in vitro study, the antitumor activity was assessed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay, TdT‐mediated dUTP‐biotin nick end labeling (TUNEL) assay, 5‐Bromodeoxyuridine (BrdU) labeling index and flowcytometry (FCM). In the in vivo study, cancer cells were implanted subcutaneously in the abdomens of mice, and the effects were assessed by the tumor growth.

Tissue elasticity imaging for diagnosis of prostate cancer: A preliminary report

Background: Elastography is a diagnostic imaging technique that evaluates the hardness of a lesion. It is expected to become a new diagnostic modality for prostate cancer. The aim of this study was to examine the usefulness of elastography in the diagnosis of prostate cancer.

Decreased expression of CXXC4 promotes a malignant phenotype in renal cell carcinoma by activating Wnt signaling

The Wnt signaling pathway is involved in normal embryonic development and controls the homeostatic self-renewal of stem cells in adult tissues. Constitutive activation of Wnt signaling contributes to cancer development and progression. We identified a CXXC4 homozygous deletion at 4q24 in an aggressive renal cell carcinoma (RCC) using single-nucleotide polymorphism (SNP) arrays. CXXC4 encodes Idax, which negatively regulates Wnt signaling by binding to the PDZ domain of Dishevelled. CXXC4 mRNA levels in tumor samples were significantly lower in patients with metastases compared with those without (P=0.0016). Patients whose tumors had lower CXXC4 expression than normal kidney showed a poorer cause-specific survival outcome than those with higher expression (P=0.0095). Decreased expression of CXXC4 also correlated with cytoplasmic staining of β-catenin. Knockdown of CXXC4 induced the nuclear translocation of β-catenin and altered expression of a set of genes involved in cell proliferation, invasion and survival. Furthermore, reduced expression of CXXC4 by small interfering RNAs promoted cell proliferation and inhibited apoptosis after 5-FU and doxorubicin treatment in RCC cells. These data suggest that CXXC4 plays a critical role in tumor progression of RCC through Wnt signaling. Wnt signaling could thus be a potential molecular target in RCC indicating decreased CXXC4 expression.

Clinical Practice Manual for Late-onset Hypogonadism Syndrome

With the aging of the population, the quality of life (QOL) of middleaged and elderly men has come into question and it has been taken up from an interdisciplinary standpoint in recent years. Partial androgen deficiency of the aging male (PADAM) or lateonset hypogonadism (LOH) is a syndrome consisting of symptoms caused by partial deficiency of androgens, but the time of onset varies and the epidemiological status is unclear. Therefore, in Japan to date, this syndrome has been considered as a general phenomenon associated with aging, the medical authorities have not reacted and patients are not being treated. In Western countries however, this phenomenon has attracted attention in relation to geriatrics and reproductive endocrinology since the 1980s. In 1998, the International Society for the Study of the Aging Male (ISSAM) was founded to conduct basic and clinical research, to provide postgraduate education and to engage in publicity activities for the enlightenment of the public. The social background is characterized by the appearance of a very rapidly aging society with longer average life spans. The importance of improving the health of the elderly and preventive medicine as government policy has increased. Improving the health of the elderly not only promotes self-reliance of the elderly but also increases the work force. A high QOL is also possible. The main topic for healthcare in the 21st century is how to maintain the QOL of the elderly. In women, hormone replacement therapy (HRT) is widely applied internationally, but specific healthcare for elderly men appears to be limited to the widespread use of phosphodiesterase type 5 (PDE5) inhibitors to treat erectile dysfunction (ED). Although the delay in healthcare policies for elderly men is not a direct reason, a large gap has appeared between the average life spans of men and women in recent years and in Japan, men have a shorter life span than women by about seven years. In response to this sense of crisis, the World Health Organization (WHO) issued the Geneva Manifesto in 1997 and ‘healthy aging for men’ became an international movement. ISSAM was established in 1998 with the goal of ‘aging male research on gender specific issues in male health’. The first meeting of the society in Asia was held in Malaysia in 2001 and this topic was adopted on an international level from an early stage. The reason appeared to be strong economic and social concern that Asian countries with a current pyramid-type population distribution will become aging societies with a lower birth rate than in developing countries. Japan has already become an aging society with a low birth rate. In the national census (summary) in 2005, the elderly population of 65 years and older accounted for about 21% of the total population, the highest in the developed world. In Japan, scientific research on the aging male started at about the same time as in the rest of Asia, and the Japanese Society for the Study of the Aging Male (JSSAM) was founded in November 2001 with Yoshiaki Kumamoto, professor emeritus of Sapporo Medical University, and Hajime Nawata, professor of Kyushu University as representative facilitators. The goal of this society is ‘undertaking basic, clinical and social research and surveys on policies for the diagnosis, treatment and prevention of male-specific medical problems, and contributing widely to men’s health by development, promotion and spread of proper healthcare’. As mentioned above, the concept of research on the aging male is being promoted as ‘healthy aging for men’ but almost no actual treatment for such patients has been performed. When the JSSAM was established , so-called ‘male climacteric symptoms’ or ‘male menopause’ was popular in the media, and when such treatment was started , many patients mainly with a chief complaint of climacteric symptoms appeared in medical practice. These patients included many with psychiatric problems such as depression and considerable confusion arose in clinics and hospitals. Based on this background , the Subcommittee on Endocrinology, Reproductive Function and Sexual Function of the Japanese Urological Association asked the Scientific Committee to prepare a clinical practice guideline, and a working group was organized to prepare the guideline by a collaborative team from the Japanese Urological Association and JSSAM after a review by the Board of Directors. In this clinical practice manual, the term ‘late–onset hypogonadism (abbreviation: LOH)’ syndrome was adopted as the term that best expresses this condition medically. In order to recommend standard procedures for diagnosis, treatment, prevention and monitoring of adverse reactions due to androgen replacement therapy (ART) and post-treatment assessments, a literature survey of clinical papers was performed , but since treatment of LOH Syndrome has just started , almost all papers had a low recommendation rank. Therefore, the name was changed to ‘Clinical Practice Manual for Treatment of Late-onset Hypogonadism (LOH) Syndrome’ (‘Manual’ hereinafter) instead of the initially planned ‘clinical practice guideline’. Care of LOH Syndrome is in its initial stages and such treatment requires careful consideration. Since many men visiting medical institutions at present complain of ‘climacteric symptoms’, measures must be taken to have this disease recognized in the mental health field. In the future, it will be necessary to establish evidence for treatment of LOH Syndrome from the broad perspective of promotion of ‘healthy aging for men.’ This ‘Manual’ is the first edition aimed at gathering evidence through future diagnosis and treatment of LOH and it is hoped that it will serve as a reference for routine medical practice. Correspondence: Eitetsu Koh MD, Department of Urology, Kanazawa University School of Medicine, 13-1 Takaramachi, Kanazawa 920-8641, Japan. Email: kohei@med.kanazawa-u.ac.jp This is an English translation of text originally published in Japanese in (LOH ) , 2007, Jihou

Decreased expression of α-catenin is associated with poor prognosis of patients with localized renal cell carcinoma

During the progression of many cancers, cell–cell adhesion molecules, e.g., E‐cadherin (EC), may be down‐regulated. In a number of carcinomas, EC has been described as an independent prognostic variable. We have studied the expression of adhesion molecules participating in cadherin–catenin complexes in renal cell carcinoma (RCC) specimens. Expression of EC, catenins and p120cas protein was examined in frozen tissue of 90 RCC specimens by immunohistochemistry, and these molecules were evaluated for their significance as prognostic markers. Staining was scored as normal (homogeneously positive at cell–cell borders) or abnormal (heterogeneous or absent). A significant correlation between poor survival and decreased expression of α‐, β‐ or γ‐catenin was observed, whereas no association between survival and EC or p120cas expression was seen. Coxs proportional hazard regression analysis showed that in patients with pT1‐3N0M0 disease, reduced α‐catenin expression correlated with poor survival, suggesting that α‐catenin expression might be an independent prognostic indicator for patients of this group. Int. J. Cancer 74:523–528, 1997.

Efficacy and safety of enoxaparin in Japanese patients undergoing curative abdominal or pelvic cancer surgery: results from a multicenter, randomized, open-label study.

BACKGROUND Enoxaparin sodium (enoxaparin) is used worldwide for the prevention of venous thromboembolism (VTE). Registration trials of enoxaparin have been conducted primarily in Caucasian populations, and its preventive use in Japanese patients has yet to be established. To address this, we evaluated the efficacy and safety of postoperative enoxaparin in Japanese patients undergoing surgery for abdominal cancer. METHODS This multicenter, open-label study randomized 151 Japanese patients undergoing curative surgery for abdominal cancer to enoxaparin 20mg twice daily for 14 days, started 24-36 hours after surgery (n=113) or intermittent pneumatic compression (IPC) as a reference (n=38). IPC was performed at least once in both groups between randomization and surgery. The primary efficacy endpoint was the incidence of VTE in the modified intention-to-treat (mITT) population. The primary safety outcome was the incidence of any bleeding during treatment and follow-up. RESULTS Incidence of VTE was 1.2% (95% CI, 0.03-6.53%) (1/83 patients) in the enoxaparin group and 19.4% (95% CI, 7.45-37.47%) (6/31 patients) in the IPC group. In the safety population, 10/109 patients in the enoxaparin group (9.2%; 95% CI, 4.49-16.23%) and 3/38 patients in the IPC group (7.9%; 95% CI, 1.66-21.38%) experienced a bleeding event. There were no cases of fatal bleeding or bleeding into any critical organ. CONCLUSIONS These favorable efficacy and safety data support the use of enoxaparin (20mg twice daily for 14 days started 24-36 hours after surgery) in Japanese patients undergoing abdominal or pelvic cancer surgery.

Immunocytochemical Demonstration of S Phase Cells by Antlbromobeoxyuribine Monoclonal Antibody in Human Prostate Adenocarcinoma

Using a monoclonal antibody to bromodeoxyuridine and immunohistochemistry, we measured the incorporation of this thymidine analogue into the deoxyribonucleic acid of human prostate adenocarcinoma cells exposed in situ. Fifteen patients with prostate cancer were given an intravenous infusion of 500 mg. bromodeoxyuridine at needle biopsy to label tumor cells in the deoxyribonucleic acid synthesis phase (S phase). The tumor specimens were fixed with 70 per cent ethanol, embedded in paraffin, sectioned and stained by an indirect immunoperoxidase method using anti-bromodeoxyuridine monoclonal antibody as the first antibody. The results showed that this method demonstrated bromodeoxyuridine-labeled nuclei satisfactorily in tissue section. The bromodeoxyuridine labeling index, S phase fraction, was determined by counting the number of bromodeoxyuridine-labeled cells in the tissue sections. Grade 3 tumors averaged 4.37 +/- 0.48 per cent labeling versus 2.41 +/- 0.49 per cent in grade 2 tumors, and grade 1 tumor in the series had an S phase fraction of 1.36 +/- 0.39 per cent. The average S phase fractions for single gland, cribriform, fused and medullary were 1.16, 2.30, 3.74 and 4.95 per cent, respectively. The results obtained with S phase fraction measured with bromodeoxyuridine labeling proved to be comparable to the results of histological grade and growth pattern. Thus, the higher S phase fraction may indicate biological malignancy. Moreover, the degree of heterogeneity concerning S phase fraction distribution within prostate cancer tissue could be compared to the morphological appearance. Our preliminary results suggest that the measurement of bromodeoxyuridine labeling index in prostate cancer may prove to be a new objective and quantitative assay of biological potential of individual tumor.

S Phase Fraction of Human Bladder Tumor Measured in Situ with Bromodeoxyuridine Labeling

A total of 18 patients with transitional cell bladder cancer was given a 0.5-hour intravenous infusion of bromodeoxyuridine at the time of endoscopic biopsy or transurethral resection to label tumor cells in the deoxyribonucleic acid synthesis phase (S phase). The tumor specimens were fixed with 70 per cent ethanol, embedded in paraffin, sectioned and stained by an indirect immunoperoxidase method with anti-bromodeoxyuridine monoclonal antibody as the first antibody. The bromodeoxyuridine labeling index, S phase fraction, was determined by counting the number of bromodeoxyuridine-labeled cells in the tissue sections. All grade 1 tumors had an S phase fraction of lower than 10 per cent. The average S phase fractions for noninvasive (11 cases) and invasive (7) tumors were 9.8 and 20.0 per cent, respectively. Two distant metastatic bladder tumors showed an average S phase fraction of 25.3 and 30.0 per cent. Thus, transitional cell bladder cancers with an S phase fraction of greater than 10 per cent appears to grow faster and be more invasive more often than those with an S phase fraction of less than 10 per cent. The higher S phase fraction may indicate greater biological malignancy. Our preliminary results suggest that measurement of the bromodeoxyuridine labeling index in bladder tumors may be a new objective and quantitative assay of biological potential of individual tumors.