Tohru Miyagi

Putative Transport Mechanism and Intracellular Fate of Trans-1-Amino-3-18F-Fluorocyclobutanecarboxylic Acid in Human Prostate Cancer

Trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid (anti–18F-FACBC) is an amino acid PET tracer that has shown promise for visualizing prostate cancer. Therefore, we aimed to clarify the anti–18F-FACBC transport mechanism in prostate cancer cells. We also studied the fate of anti–18F-FACBC after it is transported into cells. Methods: For convenience, because of their longer half-lives, 14C compounds were used instead of 18F-labeled tracers. Trans-1-amino-3-fluoro-1-14C-cyclobutanecarboxylic acid (14C-FACBC) uptake was examined in human prostate cancer DU145 cells with the following substrates of amino acid transporters: α-(methylamino) isobutyric acid (a system A–specific substrate) and 2-amino-2-norbornanecarboxylic acid (a system L–specific substrate). The messenger RNA expression of amino acid transporters in human prostate cancer specimens was analyzed by complementary DNA microarray and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Gene expression in DU145 cells was analyzed by qRT-PCR. We also examined the knockdown effect of the amino acid transporters system ASC transporter 2 (ASCT2) and sodium-coupled neutral amino acid transporter 2 (SNAT2) on 14C-FACBC uptake. In addition, the possibility of 14C-FACBC incorporation into proteins was examined. Results: 14C-FACBC uptake by DU145 cells was markedly decreased to approximately 20% in the absence of Na+, compared with that in its presence, indicating that Na+-dependent transporters are mainly responsible for the uptake of this tracer. Moreover, 2-amino-2-norbornanecarboxylic acid inhibited the transport of 14C-FACBC to the basal level in Na+-free buffer. In contrast, α-(methylamino) isobutyric acid did not inhibit 14C-FACBC accumulation in DU145 cells. Human prostate tumor specimens and DU145 cells had similar messenger RNA expression patterns of amino acid transporter genes. Although SNAT2 and ASCT2 are 2 major amino acid transporters expressed in prostate tumor tissues and DU145 cells, ASCT2 knockdown using small interfering RNA was more effective in lowering 14C-FACBC transport than SNAT2. Almost all intracellular 14C-FACBC was recovered from the nonprotein fraction. Conclusion: ASCT2, which is a Na+-dependent amino acid transporter, and to a lesser extent Na+-independent transporters play a role in the uptake of 14C-FACBC by DU145 cells. Among the Na+-independent transporters, system L transporters are also involved in the transport of 14C-FACBC. Moreover, 14C-FACBC is not incorporated into proteins in cells. These findings suggest a possible mechanism of anti–18F-FACBC PET for prostate cancer.

Acute bacterial prostatitis after transrectal prostate needle biopsy: clinical analysis

We investigated the incidence and characteristics of acute bacterial prostatitis after transrectal prostate biopsy, based on urine and blood cultures, treatment method, and outcome. Four hundred and fifty-seven patients who underwent transrectal prostate biopsy in our hospital between November 2003 and October 2006 were reviewed. These patients were treated with 200 mg levofloxacin orally twice daily for 4 days, beginning 12 h before biopsy, and with 200 mg isepamicin sulfate given intravenously just before the biopsy. In patients who developed acute prostatitis urine and blood cultures were checked. All organisms isolated in urine or blood cultures were tested for antibiotic susceptibility of the 457 patients, first-biopsy was performed in 371 and re-biopsy was done in 86. Acute bacterial prostatitis developed in 6 patients (1.3%). Acute prostatitis developed after a first-biopsy in 2 patients (0.5%) and after re-biopsy in 4 patients (4.7%), showing a significant difference. All of the urine and blood cultures yielded levofloxacin-resistant Escherichia coli. Immediate intravenous cephalosporin or carbapenem was effective for all of these patients. We concluded that the use of levofloxacin could be a risk factor for acute bacterial prostatitis after transrectal prostate biopsy, due to an increase in fluoroquinolone-resistant E. coli in the rectum. The incidence of prostatitis was higher in re-biopsy patients. We consider that patients should receive levofloxacin for a shorter period before biopsy to avoid generating fluoroquinolone-resistant strains. Treatment with cephalosporin or carbapenem is recommended for patients with acute prostatitis after prostate biopsy.

Gene therapy for prostate cancer using the cytosine deaminase/uracil phosphoribosyltransferase suicide system

Cytosine deaminase (CD) activates prodrug 5‐FC to 5‐FU and is used for suicide gene therapy (the CD/5‐FC system). E. coli uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage enzyme that directly converts 5‐FU into 5‐fluorouridine monophosphate and improves the antitumoral effect of 5‐FU. This study demonstrates the effectiveness of transduction of the UPRT gene in addition to CD/5‐FC cancer suicide gene therapy.

Antitumor effect of reduction of 150-kDa oxygen-regulated protein expression on human prostate cancer cells

Background: The 150‐kDa oxygen‐regulated protein ORP150, a new member of the heat shock protein family that functions as a molecular chaperone in the endoplasmic reticulum, was found to increase in infiltrating cancer cells. Since enhancement of ORP150 expression and the presence of vascular endothelial growth factor (VEGF) in human prostate cancer glands were immunohistochemically demonstrated, we examined whether transduced antisense ORP150 cDNA can reduce angiogenicity and tumorigenicity through suppression of VEGF secretion.

A novel microtubule-modulating agent induces mitochondrially driven caspase-dependent apoptosis via mitotic checkpoint activation in human prostate cancer cells

Hormone-refractory prostate cancer, its skeletal metastasis and complications remain a therapeutic challenge. Here we show that treatment with (S)-3-((R)-9-bromo-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo[4,5-g]isoquinolin-5-yl)-6,7-dimethoxyiso-benzofuran-1(3H)-one (EM011), the brominated analogue of a plant-derived non-toxic antitussive alkaloid, noscapine, achieved significant inhibition of hormone-refractory human prostate cancer implanted intratibially in the bone as shown by non-invasive, real-time bioluminescent imaging of tumour growth in nude mice. Mechanistically, in vitro data suggested that the antiproliferative and proapoptotic effects of EM011 in human prostate cancer cell lines were through blockade of cell-cycle progression by impairing the formation of a bipolar spindle apparatus. The G2/M arrest was accompanied by activation of the mitotic checkpoint, a pre-requisite for induction of optimal apoptosis. Attenuation of mitotic checkpoint by siRNA duplexes led to a reduction in mitotic arrest and subsequent apoptosis. Our results further demonstrated participation of an intrinsic mitochondrially mediated apoptotic pathway that ultimately triggered caspase-driven EM011-induced apoptosis. EM011 did not exert any detectable toxicity in normal tissues with frequently dividing cells such as the gut and bone marrow. Thus, these data warrant further evaluation of EM011 for the management of prostate cancer.

Etiological role of human papillomavirus infection for inverted papilloma of the bladder

The status of human papillomavirus (HPV) infection in urothelial inverted papilloma was examined in the present study. Formalin‐fixed and paraffin‐embedded tissues from eight cases of inverted papilloma of the bladder were studied. The presence of HPV‐DNA was examined by modified GP5/6+PCR using archival tissue sections by microdissection. HPV genotype was determined with a Hybri‐Max HPV genotyping kit. Immunohistochemical analysis for p16‐INK4a, mcm7, HPV‐E4, and L1, and in situ hybridization for the HPV genome were performed. HPV was detected in seven of eight cases (87.5%) of inverted papilloma. Three cases were diagnosed as inverted papilloma with atypia, while the remaining five were typical cases. HPV‐18 was detected in two cases, including one inverted papilloma with atypia, and HPV‐16 was detected in four cases, including one inverted papilloma with atypia. Multiple HPV type infection was detected in one typical case and one atypical case. High‐risk HPV was present in all HPV‐positive cases. Cellular proteins, p16‐INK4a and mcm7, which are surrogate markers for HPV‐E7 expression, were detected in all HPV‐positive cases, and their levels were higher in inverted papilloma with atypia than in typical cases. In contrast, HPV‐E4 and L1, which are markers for HPV propagation, were observed in some parts of the typical inverted papilloma tissue. High‐risk HPV infection may be one of the causes of urothelial inverted papilloma, and inverted papilloma with atypia may have malignant potential. J. Med. Virol. 83:277–285, 2011.

Severe renal hemorrhage in a pregnant woman complicated with antiphospholipid syndrome: A case report

Antiphospholipid syndrome is a systemic autoimmune disease with thrombotic tendency. Consensus guidelines for pregnancy with antiphospholipid syndrome recommend low-dose aspirin combined with unfractionated or low-molecular-weight heparin because antiphospholipid syndrome causes habitual abortion. We report a 36-year-old pregnant woman diagnosed with antiphospholipid syndrome receiving anticoagulation treatment. The patient developed left abdominal pain and gross hematuria at week 20 of pregnancy. An initial diagnosis of left ureteral calculus was made. Subsequently abdominal-pelvic computed tomography was required for diagnosis because of the appearance of severe contralateral pain. Computed tomography revealed serious renal hemorrhage, and ureteral stent placement and pain control by patient-controlled analgesia were required. After treatment, continuance of pregnancy was possible and vaginal delivery was performed safely. This is the first case report of serious renal hemorrhage in a pregnant woman with antiphospholipid syndrome receiving anticoagulation treatment and is an instructive case for urological and obstetrical practitioners.

Cardiovascular and respiratory effects of the degree of head-down angle during robot-assisted laparoscopic radical prostatectomy

Robot‐assisted laparoscopic radical prostatectomy (RALP) requires a steep Trendelenburg position and CO2 pneumoperitoneum for several hours to secure the surgical visual field. The present study was performed to investigate the influence of each angle of Trendelenburg position during RALP on cardiovascular and respiratory homeostasis.

Urodynamic Evaluation Before and Immediately After Robot-assisted Radical Prostatectomy

OBJECTIVE To evaluate continence status and mechanism of urinary incontinence immediately after robot-assisted radical prostatectomy (RARP) by performing urodynamic evaluation. METHODS A total of 87 patients with localized prostate cancer who underwent RARP were included. Filling cystometry, urethral pressure profilometry, and abdominal leak point pressure (ALPP) tests were performed before and immediately after RARP. RESULTS The mean urine loss ratio (ULR), calculated by dividing the total urine volume by the weight of urine loss after RARP, was 17.8%. Nerve-sparing (NS) surgery significantly affected ULR compared with non-NS surgery. In the comparison between preoperative and postoperative results, the mean maximal cystometric capacity (MCC) and maximal closure urethral pressure (MUCP) decreased from 341 mL and 84.6 cm H2O to 250 mL and 35.6 cm H2O, respectively. No urine leakage was observed in ALPP test preoperatively; however, urine leakage was observed postoperatively in 75 patients (86%), with a mean ALPP of 47.7 cm H2O. Multivariate analysis revealed that MCC, MUCP, and ALPP after RARP were predictive factors for ULR. Linear correlations were found between ULR and MUCP and between ULR and ALPP after RARP. NS status and MUCP after RARP (r=0.247; P=.021) and the ALPP (r=0.254; P=.018) were significantly correlated. CONCLUSION In urodynamic evaluation immediately after RARP, MCC, MUCP, and ALPP were found to predictive factors for urinary incontinence. The NS procedure contributed to continence status after RARP.

Antitumor effect of reduction of 150-kDa oxygen-regulated protein expression in human prostate cancer cells.

Heat shock proteins (HSPs)/stress proteins are molecular chaperones that are induced by various environmental and physiological stimuli. Evidence of the relations between the expression of HSPs and the regulation of cell growth or transformation has accumulated. The 150-kDa oxygen-regulated protein (ORP150), a new member of HSP family, functions as a molecular chaperone in the endoplasmic reticulum. We have examined whether transduced antisense ORP150 cDNA reduces tumorigenicity and angiogenicity. Relations between these stress proteins and cancer and possibilities for anticancer gene therapy are described.