Chietaka Ohmi

Overexpression of Polo-Like Kinase 1 (PLK1) and Chromosomal Instability in Bladder Cancer

Polo-like kinase 1 (PLK1) participates in bipolar spindle formation and entry into mitosis. Chromosomal instability (CIN) is caused by abnormalities in spindle formation and chromosome segregation. In this study, we investigated the relationship of PLK1 overexpression to CIN, and compared the PLK1 status with clinicopathological parameters in 101 human urothelial carcinomas of the urinary bladder. Expression of PLK1 and the number of centrosomes were assessed by immunohistochemistry. Numerical aberrations of chromosomes 7, 9 and 17 spots that allowed estimation of CIN were evaluated by fluorescence in situhybridization, and DNA ploidy was assessed by laser scanning cytometry. Cancers with a large intercellular variation in centromere copy number were defined as CIN cancers.Tumors with PLK1 overexpression were associated more frequently with CIN (p < 0.0001), DNA aneuploidy (p = 0.0007) and centrosome amplification (p = 0.0013) than those without. Overexpression of PLK1 was significantly related to higher pathological grade (p = 0.0024), multiple tumors (p = 0.0241) and positive urine cytology (p = 0.0192). These data suggest that a high level expression of PLK1 confers tumor progression advantages to urothelial cancer cells, although other factors are also involved.

Human chorionic gonadotrophin treatment prior to microdissection testicular sperm extraction in non-obstructive azoospermia

BACKGROUND Despite the improved success rate of sperm retrieval by microdissection testicular sperm extraction (micro-TESE), methods to stimulate spermatogenesis in men with non-obstructive azoospermia (NOA) remain unexplored. The aim of this study was to evaluate the effects of hCG-based hormonal stimulation in men with NOA on the success of sperm retrieval by micro-TESE. METHODS Forty-eight men with NOA who had negative sperm retrieval results by the micro-TESE procedure were included. A second micro-TESE was subsequently performed on these men: 20 were not treated by any hormonal therapy, and 28 subjects received daily subcutaneous injections of hCG for 4-5 months prior to the second micro-TESE. Recombinant FSH was added if endogenous gonadotrophin levels decreased during the hCG stimulation. The sperm retrieval rate at the second micro-TESE; the levels of gonadotrophins, testosterone and estradiol; and the effects of hormonal therapy on testicular histology were evaluated. RESULTS Among the 28 men with hCG stimulation, 15 (54%) showed decreased LH and FSH levels (0.67 ± 0.10 and 0.96 ± 0.14 mIU, mean ± SEM, respectively) due to elevated serum testosterone (9.5 ng/dl). Sperm were obtained at the second micro-TESE from six men who had received hormonal therapy (21%), whereas no sperm were retrieved from untreated men (P < 0.05). Success at the second micro-TESE was more likely if histology at the first micro-TESE showed hypospermatogenesis. CONCLUSIONS The Leydig cells of the testis can respond positively to exogenous hCG even under hypergonadotropic conditions. HCG-based hormonal therapy prior to a second micro-TESE attempt is effective in men with hypospermatogenesis.

Clinical significance of lymphovascular invasion in upper urinary tract urothelial cancer

To clarify the significance of lymphovascular invasion (LVI) in patients with pT3N0M0 upper urinary tract (UUT) urothelial carcinoma (UC) relative to prognosis in terms of disease‐specific survival, as LVI, which implies both blood vessel and lymph vessel involvement, is reportedly a poor prognostic factor in patients with UUT‐UC.

Risk of concomitant carcinoma in situ determining biopsy candidates among primary non‐muscle‐invasive bladder cancer patients: Retrospective analysis of 173 Japanese cases

Objectives:  To determine candidates for bladder biopsies among Japanese primary non‐muscle‐invasive bladder cancer patients according to the risk of concomitant carcinoma in situ (CIS).

Association between DNA Repair Gene Polymorphisms and p53 Alterations in Japanese Patients with Muscle-Invasive Bladder Cancer

Objective: DNA repair enzymes play a vital role in protecting the genome from carcinogens, several of which can cause mutations in the TP53 gene in bladder cancer. Some single nucleotide polymorphisms (SNPs) in DNA repair genes reportedly modulate the repair capacity. This study aimed to clarify the effect of these functional SNPs on the alteration of p53 in muscle-invasive bladder cancer. Methods: We investigated the association between SNPs in xeroderma pigmentosum complementation groups C (XPC), D and G and X-ray repair cross-complementing group 1 and 3 genes, and p53 expression and allelic imbalance at the TP53 locus in Japanese patients with muscle-invasive bladder cancer. p53 expression and the allelic imbalance were evaluated using immunohistochemistry and a microsatellite marker, respectively. Results: Positive p53 expression was significantly less frequent in patients with the CC genotype of the XPC gene than in those with the AA or AC genotype (p = 0.0005). C alleles of the XPC gene were also less frequent in patients with positive p53 expression (p = 0.01). Conclusion: Our results suggested that the XPC polymorphism might affect p53 alteration and the molecular pathway defined by the p53 alteration in the development of muscle-invasive bladder cancer.

Preoperative Erythrocyte Sedimentation Rate Is an Independent Prognostic Factor in Japanese Patients with Localized Clear Cell Renal Cell Carcinoma

Introduction: Few studies have examined the prognostic significance of common laboratory variables in Japanese patients with localized clear cell renal cell carcinoma (CCRCC). We evaluate the prognostic significance of preoperative laboratory variables in Japanese patients with localized CCRCC. Patients and Methods: The study included 110 Japanese patients who were pathologically confirmed as nonmetastatic CCRCC (pT1–3 N0M0) after radical nephrectomy at our institution. We assessed the clinical (including laboratory measurements) and pathological findings, with the survival rates after surgery. Results: Tumor stage and erythrocyte sedimentation rate (ESR) were identified as significant independent prognostic factors of progression-free survival in multivariate analysis. As for the prognostic factors for disease-specific survival, tumor stage and ESR had prognostic significance both in univariate and multivariate analyses. When the analysis was limited to pT1, multivariate analysis showed that only ESR was an independent prognostic factor for disease-specific survival. Conclusions: Preoperative ESR is an independent prognostic factor in Japanese patients with localized CCRCC, especially in patients with pT1.

Granulocyte colony-stimulating factor may promote proliferation of human bladder cancer cells mediated by basic fibroblast growth factor.

Objectives: To investigate whether granulocyte colony-stimulating factor (G-CSF) promotes the proliferation of two bladder cancer cell lines, and to assess the mechanism of tumor proliferation in terms of cytokine expression. Material and Methods: The proliferation of two bladder cancer cell lines derived from transitional cell carcinoma (KK-47 and T-24) was assessed by using the double-layer soft agarose colony assay in combination with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Seven cytokines were measured in the culture supernatant. Expression of granulocyte colony-stimulating factor (G-CSF) receptor and fibroblast growth factor (FGF) receptor mRNA was studied by means of reverse transcriptase polymerase chain reaction (RT-PCR). Results: Recombinant human G-CSF (rhG-CSF) caused greater induction of the proliferation of KK-47 cells in the presence than in the absence of peripheral blood mononuclear cells (PBMCs) and its effect was dose-dependent. In contrast, rhG-CSF did not stimulate the proliferation of T-24 cells. Among several cytokines measured, only basic FGF was elevated in cultures of KK-47 cells with or without PBMCs. The basic FGF level was significantly increased by rhG-CSF stimulation in a dose-dependent manner. Specific PCR products for the G-CSF and FGF receptors were observed in KK-47 cells as well as PBMC, while no G-CSF receptor was detected in T-24 cells. Conclusion: rhG-CSF may promote the proliferation of KK-47 cells, probably via an increase in basic FGF production.

Cytogenetic Analysis of False-Positive Mucosa by Photodynamic Diagnosis Using 5-Aminolevulinic Acid – Possible Existence of Premalignant Genomic Alterations Examined by in vitro Experiment

Objective: Although photodynamic diagnosis is a powerful tool for the detection of flat urothelial tumors, false-positive fluorescent mucosa still requires further elucidation. Thus, we aimed to study the significance of nonmalignant fluorescent mucosa by a cytogenetic approach. Methods: Sixty specimens of bladder mucosa were collected from 20 patients who were suspected of having carcinoma in situ by fluorescence cystoscopy with 5-aminolevulinic acid. To detect the copy number aberrations, the multi-color fluorescence in situ hybridization technique was performed, and the variant fractions (total fractions other than those of the modal copy number) of chromosomes 7, 9 and 17 and the chromosomal instability were determined. To delineate the relevant gene to the fluorescent mucosa, a comparative genomic hybridization technique was applied for 8 established bladder cancer cell lines, and these results were compared with the in vitro fluorescent expression experiment. Results: Fluorescent mucosa was detected in 33 of the 34 malignant tissue specimens (16 carcinoma in situ, 18 other transitional cell carcinomas) and in 11 of the 26 nonmalignant tissue specimens (6 dysplasia, 20 normal mucosa), with a false-positive rate of 42.3%. The variant fraction of chromosome 9 was significantly higher in fluorescent than in non-fluorescent mucosa, not only for all tissues (33 vs. 17%; p = 0.0069), but also for nonmalignant tissues (28 vs. 15%; p = 0.0225). There was no alteration in chromosome 9 in 1 cell line without fluorescent mucosa, while 5 of the 7 cell lines with fluorescent mucosa had a common deleted region on 9q24.1. Conclusion: These data suggest that a substantial portion of nonmalignant fluorescent mucosa harbors alterations in chromosome 9.

Discrepancies between cytology, cystoscopy and biopsy in bladder cancer detection after Bacille Calmette‐Guerin intravesical therapy

Objectives:  To evaluate discrepancies in the detection of Bacille Calmette‐Guerin (BCG)‐resistant bladder cancer by cystoscopy, bladder biopsy and urinary cytology.

Metronomic Outpatient-Based Chemotherapy With 5′-DFUR and Low-Dose Cisplatin for Conventional Platinum-Based Chemotherapy-Resistant Advanced Urothelial Cancer

Background Metronomic chemotherapy is aimed at lessening the adverse effects of treatment while rendering cancer cells cytostatic. The oral 5-fluorouracil prodrug “5′-DFUR” has been shown to inhibit angiogenesis and is regarded as a good candidate agent for metronomic chemotherapy. Moreover, cisplatin and 5′-DFUR have been shown to synergistic cytotoxic effects. Methods We evaluated the safety and efficacy of metronomic chemotherapy using daily oral 5′-DFUR at the dose of 600 mg/day and biweekly cisplatin infusion at the dose of 20 mg/person in 23 patients with urothelial cancer resistant to conventional platinum-based chemotherapy. Results Twenty-three patients were enrolled between August 2000 and December 2004. The median survival time after the initiation of metronomic chemotherapy was 15.2 months. The 1-year, 2-year and 3-year survival rates were 55.1%, 45.1% and 5.9%, respectively. Grade 3 fatigue was observed as severe toxicity in one patient. No cases showed nephrotoxicity and adverse effects necessitating medical intervention. Conclusions Although a large-scale prospective study would be necessary before the therapy is established as a standard, our metronomic chemotherapy regimen appears to be a potentially useful palliative treatment alternative for patients with advanced urothelial cancer resistant to conventional platinum-based chemotherapy. Abbreviations M-VAC: methotrexate, vinblastine, doxorubicin, and cisplatin; GC: gemcitabine and carboplatin; 5′-DFUR: 5′-deoxy-5-fluorouridine; 5-FU: 5-fluorouracil; CDDP: cisplatin; TCC: transitional cell carcinoma; ECOG: Eastern Cooperative Oncology Group; PS: performance status; UICC: Union International Contre le Cancer; WHO: World Health Organization; NCI-CTC: National Cancer Institute Common Toxicity Criteria; CI: confidence interval; PR: partial response; NC: no change; PD: progressive disease; TP: thymidine phosphorylase; AUC: areas under the curve.