Yasushi Yamada

ALTERED METHYLATION OF MULTIPLE GENES IN CARCINOGENESIS OF THE PROSTATE

The methylation status of 7 genes was examined in four cell lines, 36 samples of benign prostatic hyperplasia (BPH), 20 samples of prostatic intraepithelial neoplasia (PIN) and 109 samples of prostate cancer (PCa), using methylation‐specific PCR (MSP): the pi‐class glutathione S‐transferase (GSTP1), retinoic acid receptor beta 2(RARβ2), androgen receptor (AR), death‐associated protein kinase (DAPK), tissue inhibitor of metalloproteinase‐3 (TIMP‐3), O6‐methylguanine DNA methyltransferase (MGMT), and hypermethylated in cancer‐1 (HIC‐1). The frequencies of methylation in PCa were 88% for GSTP1, 78% for RARβ2, 36% for DAPK, 15% for AR, 6% for TIMP‐3, and 2% for MGMT, whereas the values were 11% for AR and DAPK, 6% for TIMP‐3, 3% for GSTP1, and 0 for RARβ2 and MGMT in BPH. Aberrant methylation of the GSTP1 and RARβ2 genes was detected in 30% and 20% of PIN, respectively. Most samples of BPH and PCa were positive for HIC‐1 methylation. Regarding accumulation of methylated cancer‐related genes, there were significant correlations between PCa and BPH as well as PIN and BPH. In the present study, a high frequency of aberrant promoter methylation of the GSTP1 and RARβ2 genes was noted in PCa. Our findings suggest that methylation of cancer‐related genes may be involved in carcinogenesis of the prostate.

Impact of genetic polymorphisms of 17-hydroxylase cytochrome P-450 (CYP17) and steroid 5α-reductase type II (SRD5A2) genes on prostate-cancer risk among the Japanese population

Steroid hormones, especially testosterone, play important roles in the carcinogenesis of prostate cancer, and several studies have reported changes in risk with polymorphisms of genes involved in steroid metabolism. One example is the CYP17 gene, which has a polymorphic T‐to‐C substitution in the 5′‐untranslated region giving rise to A1 (T) and A2 (C) alleles. Steroid 5α‐reductase type II (SRD5A2), which converts testosterone to the metabolically more active dihydrotestosterone, exhibits 2 polymorphisms: V89L, which substitutes leucine for valine at codon 89, and A49T, which substitutes threonine for alanine at codon 49. We therefore designed a case‐control study of 105 prostate‐cancer patients and 210 controls with benign prostatic hyperplasia for the purpose of investigating the association between prostate‐cancer risk and polymorphisms in the SRD5A2 and CYP17 genes among the Japanese. The frequency of the CYP17 A2/A2 genotype in cases (18.8%) was higher than in controls (14.5%). Compared with the A1/A1 genotype, the odds ratio for the A2/A2 genotype was 2.39 (95% confidence interval 1.04–5.46, p = 0.04). The frequency of the SRD5A2 LL genotype in cases (29.3%) was also slightly higher than in controls (24.6%), but this was not significant. Regarding the A49T polymorphism of SRD5A2, we could not detect the T allele in any of the examined samples. These data suggest a significant association between the CYP17 polymorphism and prostate‐cancer risk among the Japanese.

Malignant phyllodes tumor of the prostate: retrospective review of specimens obtained by sequential transurethral resection.

A case of malignant phyllodes tumor of the prostate in a 67‐year‐old man is reported. The patient was referred to a hospital for urinary retention. From material taken at three transurethral resections of the prostate (TURP), a histological diagnosis of benign prostatic hyperplasia was made. However, at the fourth TURP, phyllodes tumor was diagnosed due to the presence of elongated epithelial ducts and proliferating cellular stroma with mitosis and nuclear atypia. Two months later, total cystoprostatectomy was performed. Histologically, the tumor was composed of dysplastic stromal cells and irregularly elongated epithelial ducts. Five months later the patient developed multiple lung and pelvic lymph node metastases and died. This report documents progression to a higher histological grade of prostatic phyllodes tumor documented with sequential pathological findings obtained from four TURP and surgical specimens over about 3 years.

Aberrant methylation of the vascular endothelial growth factor receptor-1 gene in prostate cancer

Transcriptional silencing of cancer‐related genes by DNA methylation is observed in various cancers. To identify genes controlled by methylation in prostate cancer, we used cDNA microarray analysis to investigate gene expression in prostate cancer cell lines LNCaP and DU145 treated with a methyltransferase inhibitor alone or together with a histone deacetylase inhibitor. We detected significant changes (3.4–5.7%) in gene expression in prostate cancer cell lines with the drug treatments. Among the affected genes, that for the vascular endothelial growth factor receptor 1 (VEGFR‐1) was re‐expressed in LNCaP and DU145 after the drug treatments. Bisulfite sequencing revealed the promoter and exon 1 of the VEGFR‐1 to be hypermethylated in the cell lines. These results support the idea that methylation is associated with loss of VEGFR‐1 mRNA expression in prostate cancer cell lines. Combined bisulfite restriction analysis (COBRA) showed the gene to be methylated in 24 (38.1%) of 63 primary local prostate cancer samples, while in all 13 benign prostate samples it was not. These findings indicate that methylation of VEGFR‐1 is related with prostatic carcinogenesis.

Intermittent docetaxel therapy with estramustine for hormone-refractory prostate cancer in Japanese patients.

BackgroundWe evaluated the efficacy and toxicity of intermittent docetaxel (DCT) with estramustine (EM) for hormone-refractory prostate cancer (HRPC).MethodsFifteen patients were enrolled. They received injected DCT (70 mg/m2 body surface) on day 1 in association with oral EM 560 mg/day (days 1–5). Treatments were repeated every 3 weeks. Serum prostate-specific antigen (PSA) levels were categorized based on the first three courses. Patients exhibiting either a response or stable disease (SD) could have a holiday from treatment (intermittent schedule). The holiday continued until elevation of the PSA level from the nadir baseline level occurred three times. All patients were evaluated for toxicity and quality of life (QOL). Survival curves were established using Kaplan-Meier graphs.ResultsThe median number of courses of DCT/EM therapy was five (range, 3–12 courses). The response rate of the first cycle was 53%: 3 patients with complete response (CR), 5 patients with partial response (PR), 4 patients with SD, and 3 patients with disease progression. Eight patients were able to begin the second re-entry cycle. No patients showed a CR, 2 patients exhibited PR, 4 patients had SD, and the overall response rate was 25%. The survival rates were 93% at 1 year, and 26.1% at 2 years Grade 3–4 anemia was observed in 2 patients (13.3%), neutropenia in 11 (73.3%), and thrombocytopenia in 2 (13.3%). The QOL scale showed good QOL after 6 months, with improvement in the score for nausea and vomiting.ConclusionIntermittent DCT/EM therapy was well tolerated, and has the potential to prolong survival, with a high QOL, in patients with HRPC.

Coexistence of renal replacement lipomatosis with xanthogranulomatous pyelonephritis

Abstract We report on a case of coexistence of replacement lipomatosis with xanthogranulomatous pyelonephritis (XGP) in the same kidney associated with staghorn calculi. A 63‐year‐old man was admitted to hospital complaining of a right abdominal mass. Computed tomography (CT) showed renal parenchymal atrophy with extremely increased perirenal fat. Right nephrectomy was performed. Postoperative diagnosis was renal replacement lipomatosis with XGP. Renal replacement lipomatosis and XGP have several similarities in terms of clinical background and CT findings. Sometimes it is difficult to differentiate them from malignant diseases. It is extremely rare that both conditions coexist in the same kidney. To our knowledge, only one such case has been reported.

An anterior urethral stitch improves urinary incontinence following radical prostatectomy

Objective: To determine the effects of an anterior urethral stitch, referred to as an endopelvic anterior urethral stitch (EAUS), in reducing recovery time for post‐prostatectomy urinary incontinence.

Low incidence of benign lesions in resected suspicious renal masses greater than 2 cm: Single-center experience from Japan

Objective:  To assess the incidence of benign renal lesions in our Japanese clinical experience with surgical resection.

Identification of differentially methylated CpG islands in prostate cancer

Epigenetic change such as DNA methylation is one important mechanism for regulating gene expression as genetic change, such as mutation or loss of heterozygosity. Methylation of cancer‐related genes has been shown to play an important role in carcinogenesis and tumor progression. Using methylated CpG island amplification (MCA)/representational difference analysis (RDA), we identified four CpG islands in neurotrophin tyrosine kinase receptor type 2 (NTRK2), Protocadherine Flamingo1 and MFPC (Methylated Fragments in Prostate Cancer) 7 and 8. Bisulfite sequencing revealed that 2 regions of NTRK2 as well as MFPC7 and MFPC8 were aberrantly methylated in prostate cancer cell lines, and COBRA showed that 48 (76.24%), 37 (58.7%) and 14 (22.2%) of 63 prostate cancer tissues were methylated, respectively, for these sites. On the other hand, none of 13 benign prostate samples were methylated, except for 1 (7.7%) with NTRK2. For NTRK2, mRNA expression was negative in prostate cancer cell lines (LNCaP and DU145) but was recovered on a methyltransferase inhibitor (5‐Aza‐CdR) treatment. The role of NTRK2 within NTRK remains unclear. Our results suggest that these 3 hypermethylated DNA fragments also may be markers of prostate cancer detection.

The usefulness of diffusion-weighted magnetic resonance imaging in bladder cancer staging and functional analysis

AIM We assessed the effect of adding diffusion-weighted magnetic resonance imaging (DW-MRI) to conventional MRI for T staging and the correlation between apparent diffusion coefficient (ADC) values and clinicopathological parameters for patients with bladder cancer. MATERIALS AND METHODS We retrospectively reviewed the records of 160 patients with bladder cancer who underwent MRI at our institute. All patients were routinely assessed with conventional MR imaging. Since January 2008, we added DW-MRI. RESULTS In these 160 patients, 127 (79.4%) tumors were detectable by MRI. In all patients with detectable tumors, on a stage-by-stage basis, 96 (75.6%) of 127 patients received the correct diagnosis. With DW-MRI, accurate diagnosis was obtained in 80 (80.0%) of 100 cases; without DWI in only 16 (59.3%) of 27 cases (P=0.026). For T staging, the accuracy for distinguishing muscle invasion (T≦1 vs T≧2) with DW-MRI (83.0%) was superior to that without DW-MRI (66.7%). The accuracy for distinguishing perivesical fat invasion (T≦2 vs T≧3) with DW-MRI (98.0%) was also superior to that without DW-MRI (92.6%). The ADC values were significantly related with tumor diameter (<3 cm vs ≧3 cm, P<0.001), histopathological grade (low grade vs high grade, P<0.001), T stage (≦T1 vs ≧T2, P<0.001), and operative method (transurethral resection vs total cystectomy, P<0.001). CONCLUSIONS We demonstrated that DW-MRI is not only useful for bladder cancer T staging, but also a prognostic factor for patients with bladder cancer.