Three-dimensional ultrastructural and anatomical analysis of prostatic neuroendocrine cells in mice.

BACKGROUND: A few studies have examined the ultrastructure of prostatic neuroendocrine cells (NECs), and no study has focused on their ultrastructure in three dimensions. In this study, three-dimensional ultrastructural analysis of mouse prostatic NECs was performed to clarify their anatomical characteristics. METHODS: Three 13-week-old male C57BL/6 mice were deeply anesthetized, perfused with physiological saline and 2% paraformaldehyde, and then placed in 2.5% glutaraldehyde in 0.1 M cacodylate (pH 7.3) buffer for electron microscopy. After perfusion, the lower urinary tract, which included the bladder, prostate, coagulation gland, seminal vesicle, upper vas deferens, and urethra, was removed, and the specimen was cut into small cubes and subjected to postfixation and en bloc staining. Three-dimensional ultrastructural analysis was performed on NECs, the surrounding cells, tissues, and nerves using focused ion beam/scanning electron microscope tomography. RESULTS: Twenty-seven serial sections were used in the present study, and 32 mouse prostatic NECs were analyzed. Morphologically, the NECs could be classified into three types: flask, flat, and closed. Closed-shaped NECs were always adjacent to flask-shaped cells. The flask-shaped and flat NECs were in direct contact with the ductal lumen and always had microvilli at their contact points. Many of the NECs had accompanying nerves, some of which terminated on the surface in contact with the NEC. CONCLUSIONS: Three-dimensional ultrastructural analysis of mouse prostatic NECs was performed. These cells can be classified into three types based on shape. Novel findings include the presence of microvilli at their points of contact with the ductal lumen and the presence of accompanying nerves.

Incidence and molecular characteristics of deficient mismatch repair conditions across nine different tumors and identification of germline variants involved in Lynch-like syndrome.

BACKGROUND: Based on molecular characteristics, deficient DNA mismatch repair (dMMR) solid tumors are largely divided into three categories: somatically MLH1-hypermethylated tumors, Lynch syndrome (LS)-associated tumors, and Lynch-like syndrome (LLS)-associated tumors. The incidence of each of these conditions and the corresponding pathogenic genes related to LLS remain elusive. METHODS: We identified dMMR tumors in 3609 tumors from 9 different solid organs, including colorectal cancer, gastric cancer, small-bowel cancer, endometrial cancer, ovarian cancer, upper urinary tract cancer, urinary bladder cancer, prostate cancer, and sebaceous tumor, and comprehensively summarized the characterization of dMMR tumors. Characterization of dMMR tumors were performed as loss of at least one of MMR proteins (MLH1, MSH2, MSH6, and PMS2), by immunohistochemistry, followed by MLH1 promotor methylation analysis and genetic testing for MMR genes where appropriate. Somatic variant analysis of MMR genes and whole exome sequencing (WES) were performed in patients with LLS. RESULTS: In total, the incidence of dMMR tumors was 5.9% (24/3609). The incidence of dMMR tumors and the proportion of the three categorized dMMR tumors varied considerably with different tumor types. One to three likely pathogenic/pathogenic somatic MMR gene variants were detected in 15 out of the 16 available LLS tumors. One patient each from 12 patients who gave consent to WES demonstrated non-MMR germline variants affect function (POLQ or BRCA1). CONCLUSIONS: Our data regarding the LS to LLS ratio would be useful for genetic counseling in patients who are suspected to have LS, though the genetic backgrounds for the pathogenesis of LLS need further investigation.

Clinicopathological characteristics of adrenocortical carcinoma in the Kyushu-Okinawa area of Japan.

OBJECTIVE: Adrenocortical carcinoma is a rare condition, with limited comprehensive reports from Japan. This study aimed to review Japan's data on adrenocortical carcinoma by assessing information from 46 patients-with adrenocortical carcinoma across 10 Japanese university hospitals. METHODS: We conducted a retrospective multi-institutional analysis of the clinical characteristics of adrenocortical carcinoma in Japan. We evaluated data from 46 patients across 10 university hospitals over 10 years and analyzed the relationship between clinicopathological characteristics and overall survival. RESULTS: Five- and 10-year overall survival rates were 59% and 53%, respectively. Overall survival was significantly different among the tumor-node-metastasis system for adrenocortical carcinoma of the American Joint Committee on Cancer/International Union Against Cancer, with the worst prognosis in stage IV (p = 0.0044). In our cohort, neither the Weiss score nor the Ki-67 proliferation index correlated with overall survival. Adjuvant treatment did not yield improved overall survival, whereas resection of the primary tumor in stage IV disease was significantly associated with improved overall survival (p = 0.0262). Out of the cases evaluated for plasma hormones, plasma cortisol, aldosterone, testosterone, and DHEA-S levels were measured at 23%, 42%, 29%, and 62%, respectively, demonstrating higher levels than the upper normal limits. CONCLUSION: Patients with stage IV adrenocortical carcinoma had a poor prognosis; however, resection of the primary tumor in stage IV disease was associated with prolonged survival. The results of this study are expected to contribute to future treatment of adrenocortical carcinoma in Japan.

GnRH antagonist monotherapy versus a GnRH agonist plus bicalutamide for advanced hormone-sensitive prostate cancer; KYUCOG-1401.

OBJECTIVES: To compare the effectiveness and safety of gonadotropin-releasing hormone (GnRH) antagonist monotherapy to combined androgen blockade (CAB) with a GnRH agonist and bicalutamide in patients with advanced hormone-sensitive prostate cancer (HSPC). METHODS: The study was conducted as KYUCOG-1401 trial (UMIN000014243) and enrolled 200 patients who were randomly assigned to either group A (GnRH antagonist monotherapy followed by the addition of bicalutamide) or group B (CAB by a GnRH agonist and bicalutamide). The primary endpoint was PSA progression-free survival. The secondary endpoints were the time to CAB treatment failure, radiographic progression-free survival, overall survival, changes in serum parameters, including PSA, hormones, and bone and lipid metabolic markers, and adverse events. RESULTS: PSA progression-free survival was significantly longer in group B (hazard ratio [HR], 95% confidence interval [CI]; 1.40, 1.01-1.95, p = 0.041). The time to CAB treatment failure was slightly longer in group A (HR, 95% CI; 0.80, 0.59-1.08, p = 0.146). No significant differences were observed in radiographic progression-free survival or overall survival. The percentage of patients with serum testosterone that did not reach the castration level was higher at 60 weeks (p = 0.046) in group A. No significant differences were noted in the serum levels of bone metabolic or lipid markers between the two groups. An injection site reaction was more frequent in group A. CONCLUSIONS: The present results support the potential of CAB using a GnRH agonist and bicalutamide as a more effective treatment for advanced HSPC than GnRH antagonist monotherapy.

Insights on Platelet-Derived Growth Factor Receptor α-Positive Interstitial Cells in the Male Reproductive Tract.

Male infertility is a significant factor in approximately half of all infertility cases and is marked by a decreased sperm count and motility. A decreased sperm count is caused by not only a decreased production of sperm but also decreased numbers successfully passing through the male reproductive tract. Smooth muscle movement may play an important role in sperm transport in the male reproductive tract; thus, understanding the mechanism of this movement is necessary to elucidate the cause of sperm transport disorder. Recent studies have highlighted the presence of platelet-derived growth factor receptor α (PDGFRα)-positive interstitial cells (PICs) in various smooth muscle organs. Although research is ongoing, PICs in the male reproductive tract may be involved in the regulation of smooth muscle movement, as they are in other smooth muscle organs. This review summarizes the findings to date on PICs in male reproductive organs. Further exploration of the structural, functional, and molecular characteristics of PICs could provide valuable insights into the pathogenesis of male infertility and potentially lead to new therapeutic approaches.

Real-world treatment outcomes of patients with penile cancer in the Kyushu-Okinawa area of Japan in the pre-guideline era.

OBJECTIVES: To understand the real-world outcomes for patients with penile cancer in the Kyushu-Okinawa area before the introduction of practice guidelines in Japan. METHODS: We retrospectively collected medical information on patients with penile squamous cell carcinoma and penile intraepithelial neoplasia at 12 university hospitals and their affiliated hospitals in the Kyushu-Okinawa area from January 2009 to December 2020. Patients with unknown clinical stage were excluded. Patient background characteristics and survival, as well as pretreatment factors involved in survival, were investigated. RESULTS: A total of 196 patients were included. Patients with clinical stage 0, I, IIA, IIB, IIIA, IIIB and IV comprised 9.7, 26.0, 22.4, 2.6, 10.7, 14.3 and 14.3%, respectively. The median follow-up was 26 months, and the mean 5-year overall survival and cancer-specific survival rates were 74.3 and 79.8%, respectively. On univariate analysis, tumor diameter ≥ 30 mm, penile shaft tumor, Eastern Cooperative Oncology Group performance status ≥ 1, cT ≥ 3, cN ≥ 2 and cM1 were associated with significantly poorer cancer-specific survival. On multivariate analysis, pretreatment factors of cN ≥ 2 (hazard ratio, 32.5; 95% confidence interval, 5.08-208; P = 0.0002), Eastern Cooperative Oncology Group performance status ≥ 1 (4.42; 1.79-10.9; P = 0.0012) and cT ≥ 3 (3.34; 1.11-10.1; P = 0.0319) were identified as independent prognostic factors. CONCLUSIONS: The study revealed basic data for future penile cancer treatment and research, including survival rates according to clinical stages, and identified cN ≥ 2, Eastern Cooperative Oncology Group performance status ≥ 1 and cT ≥ 3 at initial diagnosis as independent prognostic factors. Evidence for penile cancer in Japan is particularly scarce, and future large-scale prospective studies are warranted.

Three-Dimensional Ultrastructural Analysis of the Head-Most Mitochondrial Roots of Mice Spermatozoa Using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) Tomography.

This study aimed to clarify the three-dimensional ultrastructure of head-side mice spermatozoa mitochondria. Six 13-week-old male C57BL/6 mice were deeply anesthetized, perfused with 2% paraformaldehyde, and placed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3) for electron microscopy. After perfusion, the vas deferens was removed, and the specimens were cut into small cubes and subjected to postfixation and en bloc staining. Three-dimensional ultrastructural analysis was performed on five mitochondria on the spermatozoa head using conventional transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy (FIB/SEM) tomography. Conventional TEM analysis showed that head-side mitochondria were not spiral in morphology but clearly horizontal to the sperm axis. However, this was difficult to evaluate further using conventional TEM. In the FIB/SEM analysis, the first and second head-most mitochondria were flat and straight, with no helix, and shaped as an attachment plug with two electrodes, and their tail side contacted the third mitochondrion. The third mitochondrion was shorter than the fourth and fifth and had a semicircular arching structure. The fourth and fifth mitochondria were spiral-shaped and intertwined. The redundant nuclear envelope encircled the head-most mitochondria. This ultrastructural analysis clarified that the head-most mitochondria have a unique morphology.

Three-Dimensional Ultrastructural and Volume Analysis of the Redundant Nuclear Envelope of Developing and Matured Sperm in Mice.

The ultrastructure of the nuclear envelope (NE) and redundant NE (RNE) of the spermatozoon cannot be observed in detail using conventional electron microscopy. Thus, this study aimed to employ transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy (FIB/SEM) tomography to fill this research gap. Male mice aged 13 weeks were deeply anesthetized, and the testes and vas deferens were extracted and processed for electron microscopy. In round spermatids, the acrosomal vesicle compressed the nucleus, and the acrosomal center was depressed. The nucleoli concentrated on the contralateral side of the acrosome formation site. In mature spermatozoa, the RNE accumulated in the neck with the residual bodies. The NE pores exhibited a hexagonal pattern. The body surface area and volume of the nuclei of spermatids and spermatozoa in each maturation phase were analyzed using FIB/SEM tomography. The body surface area and volume of the nuclei decreased during spermatid maturation into spermatozoa. The RNE converged at the sperm neck and possessed a honeycomb structure. The method used revealed that the nuclei of spermatids gradually condense as they mature into spermatozoa. This method may be used to analyze small tissues, such as RNE, and detect morphological abnormalities in microtissues, such as spermatozoa.

Sarcopenia and excess visceral fat accumulation negatively affect early urinary function after I-125 low-dose-rate brachytherapy for localized prostate cancer.

OBJECTIVES: To evaluate the effects of sarcopenia and excess visceral fat accumulation on early urinary function after I-125 low-dose-rate brachytherapy for prostate cancer. METHODS: We retrospectively reviewed consecutive patients who underwent brachytherapy for prostate cancer. Pre-treatment computed tomography was used to measure skeletal muscle index at the L3 level to assess sarcopenia and visceral fat area at the umbilical level. The International Prostate Symptom Score and the University of California Los Angeles Prostate Cancer Index were used to assess quality of life during the 24 months after brachytherapy. Logistic regression analysis was used to examine whether sarcopenia and excess visceral fat accumulation had clinically significant effects on post-treatment quality of life. RESULTS: Among 246 patients, 92 (37.4%) were stratified into the sarcopenia group and 141 (57.3%) into the excess visceral fat accumulation group. The sarcopenia group had significantly lower University of California Los Angeles Prostate Cancer Index urinary function than the non-sarcopenia group 24 months post-brachytherapy. The excess visceral fat accumulation group had significantly poorer International Prostate Symptom Score total, storage, and voiding scores than the non-excess accumulation group 12 months post-brachytherapy. In the multivariate analysis, sarcopenia had a clinically significant adverse effect on the University of California Los Angeles Prostate Cancer Index urinary function at 12 months. Excess visceral fat accumulation had a clinically significant adverse effect on the International Prostate Symptom Score voiding and storage scores at 12 months. CONCLUSIONS: Sarcopenia and excess visceral fat accumulation negatively affect urinary function early after I-125 low-dose-rate brachytherapy for prostate cancer.

Absolute lymphocyte count is an independent predictor of survival in patients with metastatic renal cell carcinoma treated with nivolumab.

OBJECTIVE: Programmed cell death-1 antibody therapy has demonstrated improved progression-free survival and overall survival in patients with metastatic renal cell carcinoma. However, there are limited studies on biomarkers that can predict the efficacy of immune checkpoint inhibitors. We examined the influence of peripheral inflammatory biomarkers on the clinical outcomes of patients with metastatic renal cell carcinoma treated with nivolumab. METHODS: Data of 38 patients with metastatic renal cell carcinoma, who were treated with nivolumab monotherapy after receiving at least one molecular targeted therapy from November 2016 to February 2021, were retrospectively reviewed and analyzed. RESULTS: Median progression-free survival and overall survival were significantly shorter in patients with low absolute lymphocyte count (<1300/µl) versus those with high absolute lymphocyte count (progression-free survival: P = 0.0102; overall survival: P = 0.0026). Median overall survival was shorter in patients with high neutrophil-lymphocyte ratio (≥3.0) versus those with low neutrophil-lymphocyte ratio (P = 0.0344). Multivariate analysis showed that absolute lymphocyte count was an independent factor for progression-free survival (hazard ratio = 2.332, 95% confidence interval = 1.012-5.375, P = 0.0468) and overall survival (hazard ratio = 4.153, 95% confidence interval = 1.108-15.570, P = 0.0347). Increased absolute lymphocyte count, 1 month after nivolumab initiation, was a positive predictive factor for progression-free survival (hazard ratio = 0.419, 95% confidence interval = 0.189-0.926, P = 0.0317) and overall survival (hazard ratio = 0.285, 95% confidence interval = 0.091-0.890, P = 0.0308). CONCLUSION: Our study indicates that peripheral absolute lymphocyte count, before nivolumab initiation, is a predictor of poor response in metastatic renal cell carcinoma. Additionally, increased absolute lymphocyte count, 1 month post-nivolumab initiation, can be a predictor of the effects of nivolumab.

Immune-related adverse events are clinical biomarkers to predict favorable outcomes in advanced renal cell carcinoma treated with nivolumab plus ipilimumab.

BACKGROUND: Immune checkpoint inhibitors cause various immune-related adverse events. The present study examined the association between the incidence of immune-related adverse events and survival outcomes in patients treated with nivolumab plus ipilimumab for patients with advanced renal cell carcinoma. In addition, we compared the effect of adverse event profiles on survival for patients receiving nivolumab plus ipilimumab. METHODS: A total of 35 patients with advanced renal cell carcinoma who were treated with nivolumab plus ipilimumab from August 2018 to August 2021 were retrospectively reviewed and analyzed. Cox proportional hazards models were used for univariate and multivariate analyses, and hazard ratio and 95% confidence intervals were calculated. RESULTS: Of the 35 patients, 22 (62.9%) experienced immune-related adverse events. The median progression-free survival (P = 0.0012) and overall survival (P = 0.0147) were significantly longer in patients with immune-related adverse events than in those without immune-related adverse events. Multivariate analysis showed that the incidence of immune-related adverse events was an independent factor for progression-free survival (hazard ratio = 4.940, 95% confidence interval: 1.558-15.664, P = 0.0067). Skin reaction was a positive predictive immune-related adverse events for progression-free survival (hazard ratio = 9.322, 95% confidence interval: 1.954-44.475, P = 0.0051). CONCLUSION: Patients with advanced renal cell carcinoma with immune-related adverse events had superior clinical outcomes of nivolumab plus ipilimumab treatment than those without immune-related adverse events. Skin immune-related adverse events may be effective biomarkers in patients with advanced renal cell carcinoma treated with nivolumab plus ipilimumab.

Three-Dimensional Analysis of Interstitial Cells in the Smooth Muscle Layer of Murine Vas Deferens Using Confocal Laser Scanning Microscopy and FIB/SEM.

The smooth muscle contraction of the vas deferens has the important function of transporting sperm. Interstitial cells (ICs) play a critical role in the pacing and modulation of various smooth muscle organs by interactions with nerves and smooth muscle. Elucidating the three-dimensional (3D) architecture of ICs is important for understanding their spatial relationship on the mesoscale between ICs, smooth muscle cells (SMCs), and nerves. In this study, the 3D ultrastructure of ICs in the smooth muscle layer of murine vas deferens and the spatial relationships between ICs, nerves, and smooth muscles were observed using confocal laser scanning microscopy and focused ion beam/scanning electron microscopy. ICs have sheet-like structures as demonstrated by 3D observation using modern analytical techniques. Sheet-like ICs have two types of 3D structures, one flattened and the other curled. Multiple extracellular vesicle (EV)-like structures were frequently observed in ICs. Various spatial relations were observed in areas between ICs, nerves, and SMCs, which formed a complex 3D network with each other. These results suggest that ICs in the smooth muscle layer of murine vas deferens may have two subtypes with different sheet-like structures and may be involved in neuromuscular signal transmission via physical interaction and EVs.

Surveillance of urachal abscess in the Kyushu-Okinawa area of Japan.

OBJECTIVE: To report a multicenter experience with the management of urachal abscess treatment in Japan. METHODS: This was a retrospective study of 263 cases of urachal abscess managed at 12 university hospitals in the Kyushu-Okinawa region over a 10-year period. Age, sex, abscess size, clinical symptoms, type of urachal remnants, and treatment were collected and analyzed. RESULTS: The average age was 29.8 ± 18.1 years, with males accounting for approximately two-thirds of the study population. The average abscess size was 1.7 cm (range 0-11 cm). The most common presenting symptom was umbilical secretion (66%), followed by abdominal pain (46%). A total of 127 patients (48.3%) were treated with antibiotics alone, whereas 136 patients (51.7%) received surgical treatment. The surgical approach was laparotomy in 75 patients (61.0%) and laparoscopic surgery in 48 patients (39.0%). Regarding the type of urachal remnant, the urachus sinus (180 patients) accounted for 68.4% of the total. CONCLUSIONS: To our knowledge, this study represents the first report on urachal abscess treatment in Japan. Our data show that the clinical symptoms might vary depending on the type of urachus remnant. It should be noted that gross hematuria, a characteristic symptom of urachal cancer, is rare in patients with urachal abscess.

High sulfite oxidase expression could predict postoperative biochemical recurrence in patients with prostate cancer.

Sulfite oxidase (SUOX) is a metalloenzyme that plays a role in ATP synthesis via oxidative phosphorylation in mitochondria and has been reported to also be involved in the invasion and differentiation capacities of tumor cells. Here, we performed a clinicopathological investigation of SUOX expression in prostate cancer and discussed the usefulness of SUOX expression as a predictor of biochemical recurrence following surgical treatment in prostate cancer. This study was conducted using Tissue Micro Array specimens obtained from 97 patients who underwent radical prostatectomy at our hospital between 2007 and 2011. SUOX staining was used to evaluate cytoplasmic SUOX expression. In the high-expression group, the early biochemical recurrence was significantly more frequent than in the low-expression group (p = 0.0008). In multivariate analysis, high SUOX expression was found to serve as an independent prognostic factor of biochemical recurrence (hazard ratio = 2.33, 95% confidence interval = 1.32-4.15, p = 0.0037). In addition, Ki-67-labeling indices were significantly higher in the high-expression group than in the low-expression group (p = 0.0058). Therefore, SUOX expression may be a powerful prognostic biomarker for decision-making in postoperative follow-up after total prostatectomy and with regard to the need for relief treatment.

Personalized peptide vaccination as second-line treatment for metastatic upper tract urothelial carcinoma.

This study investigated the applicability of personalized peptide vaccination (PPV) for patients with metastatic upper tract urothelial cancer (mUTUC) after failure of platinum-based chemotherapy. In this single arm, open-label, phase II clinical trial, patients with mUTUC received PPV at a single institution. Personalized peptide vaccination treatment used a maximum of four peptides chosen from 27 candidate peptides according to human leukocyte antigen types and peptide-reactive IgG titers, for six s.c. injections weekly as one cycle. The safety of PPV, as well as its influence on host immunity and effect on overall survival were assessed. Forty-eight patients were enrolled in this study. Personalized peptide vaccinations were well tolerated without severe adverse events. Median survival time was 7.3 months (95% confidence interval [CI], 5.3-13.1) with 13.0 months for patients receiving combined salvage chemotherapy (95% CI, 5.7-17.5) and 4.5 months for patients receiving PPV alone (95% CI, 1.7-10.1) (P = 0.080). Patients with positive CTL responses showed a significantly longer survival than patients with negative CTL responses (hazard ratio, 0.37; 95% CI, 0.16-0.85; P = 0.019). Multivariate Cox regression analysis showed that lower numbers of Bellmunt risk factors and lower levels of B-cell activating factor were significantly associated with favorable overall survival for patients under PPV treatment. This study indicated that PPV for patients with mUTUC after failure of platinum-based chemotherapy induced substantial peptide-specific CTL responses without severe adverse events and has the potential to prolong survival when combined with salvage chemotherapy. UMIN Clinical Trials Registry ID: 000001854.

Role of protein phosphatases in genitourinary cancers.

The prevalence of genitourinary cancers has been increasing rapidly worldwide over the past 10 years. Advances in diagnosis and treatment have improved the oncological outcomes of patients with genitourinary cancer. However, the precise mechanisms of cancer development are largely unknown. Among various biological mechanisms, reversible phosphorylation is crucial for regulating the activities of many proteins in cancer cells. In contrast to protein kinases, the roles of cellular protein phosphatases have not been fully elucidated. However, emerging evidence suggests that various protein phosphatases are involved in genitourinary cancer development and have potential for cancer treatment. In the present review, we focus on recent progress in protein phosphatases regarding genitourinary cancers. We also explore the development of new strategies for cancer therapy using protein phosphatase and related molecules.

Clinical development of immunotherapy for prostate cancer.

Prostate cancer is the most common cancer in men, and the second leading cause of cancer-related death in Western countries. Prostate cancer-related death occurs in patients with metastatic castration-resistant prostate cancer. Although several new drugs for castration-resistant prostate cancer have been approved, each of these has prolonged survival by just a few months. Consequently, new therapies are sorely needed. Recently, it has been recognized that immunotherapy is an effective treatment for prostate cancer patients. Several strategies, such as cancer vaccines and immune checkpoint inhibitors, have been investigated in clinical studies for prostate cancer patients. In the present review, the results of the most recent clinical studies investigating immunotherapy in prostate cancer patients are reported, and the future clinical development of immunotherapy for prostate cancer is discussed.

METANEPHRIC ADENOMA DIAGNOSED PREOPERATIVELY AS RENAL CELL CARCINOMA: A REPORT OF TWO CASES.

Metanephric adenoma is an extremely rare benign tumor. We report two cases of metanephric adenoma that were diagnosed preoperatively as renal cell carcinoma (RCC).Case 1 was a right renal tumor found by ultrasonography in a 57-year old woman who presented for a medical examination. Abdominal CT revealed a 26-mm mass that was enhanced weakly in the early phase and enhanced strongly in the late phase, in the right kidney. Based on a clinical diagnosis of RCC (cT1aN0M0), laparoscopic partial nephrectomy was performed. Case 2 was a left renal tumor incidentally found during an annual examination of a 79-year old woman with a past history of breast cancer. Abdominal CT revealed a 24-mm mass that was enhanced heterogeneously in the left kidney. Based on a clinical diagnosis of RCC (cT1aN0M0), laparoscopic radical nephrectomy was performed. The pathological diagnosis of both cases was metanephric adenoma.It is often difficult to distinguish metanephric adenoma from other malignant neoplasms preoperatively. When it is difficult to distinguish between renal cell carcinoma and metanephric adenoma, renal tumor biopsy and minimal surgery is required.

[A case of extramammary Paget's disease with urethral invasion treated by construction of continent urinary diversion based on the Monti principle using the sigmoid colon].

Extramammary Paget's disease occurring in the female vulva is occasionally associated with invasive disease to urethra and bladder mucosa. For such cases, ensuring adequate surgical margin is essential. Not only adequate removal of tumor, but also urinary diversion is important for patient's quality of life. A 77- year-old woman was treated with excision of vulvar tumor, urethra, vagina, rectum and anus. The determination of excision area was decided according to the result of mapping biopsy including urethra and bladder. Then she received reconstruction of vulva using the gracilis muscle skin flap. We applied a technique of channel formation for intermittent catheterization using the retubularized sigmoid colon based on the Monti principle. The tube was implanted submucosally into the bladder to prevent the reflux of urine. Fifteen days after operation, self-intermittent catheterization was started successfully. Surgical margins were negative in urethra, skin, vagina and rectum. There are no obvious recurrence or metastasis 1 year after surgery.

Androgen-independent proliferation of LNCaP prostate cancer cells infected by xenotropic murine leukemia virus-related virus.

Xenotropic murine leukemia virus-related virus (XMRV) is a novel gammaretrovirus that was originally isolated from human prostate cancer. It is now believed that XMRV is not the etiologic agent of prostate cancer. An analysis of murine leukemia virus (MLV) infection in various human cell lines revealed that prostate cancer cell lines are preferentially infected by XMRV, and this suggested that XMRV infection may confer some sort of growth advantage to prostate cancer cell lines. To examine this hypothesis, androgen-dependent LNCaP cells were infected with XMRV and tested for changes in certain cell growth properties. We found that XMRV-infected LNCaP cells can proliferate in the absence of the androgen dihydrotestosterone. Moreover, androgen receptor expression is significantly reduced in XMRV-infected LNCaP cells. Such alterations were not observed in uninfected and amphotropic MLV-infected LNCaP cells. This finding explains why prostate cancer cell lines are preferentially infected with XMRV.