Akira Miyajima

AN ESSENTIAL ROLE FOR NUCLEAR FACTOR KAPPA B IN PREVENTING TNF-alpha-INDUCED CELL DEATH IN PROSTATE CANCER CELLS

PURPOSEnAlthough tumor necrosis factor-alpha (TNF-alpha) induces a strong cytotoxic effect on cell growth, many authors have reported that various cancer cells are resistant to TNF-alpha and the basis for this sensitivity or resistance to TNF-alpha remains to be elucidated. Since nuclear factor kappa B (NF-kappaB) activation has recently been reported to inhibit TNF-alpha-induced cell death, we studied whether NF-kappaB also assumes a protective role in TNF-alpha-induced cell death in prostate cancer cells.nnnMATERIALS AND METHODSnWe used two human prostate cancer cell lines of DU145 and PC-3. We prepared two different NF-kappaB inhibitors, pyrrolidine dithiocarbamate (PDTC) and NF-kappaB decoy. NF-kappaB DNA binding activity was detected by electrophoretic mobility shift assay (EMSA). Cell survivals were measured by MTT assay. Induction of apoptosis was detected by nuclear staining and measured by fragmented DNA ELISA.nnnRESULTSnEMSA showed that NF-kappaB inhibitors continuously inhibited TNF-alpha-induced NF-kappaB activation. Cell growth was not inhibited by either TNF-alpha (50 ng./ml. or less) or NF-kappaB inhibitors. However, both PCA cells treated with TNF-alpha (20 ng./ml.) plus NF-kappaB inhibitors showed significant growth inhibition compared with controls (p<0.05). Nuclei of PCA cells appeared severely fragmented by this combination therapy. Furthermore, the levels of DNA fragmentation were significantly elevated in PCA cells treated with TNF-alpha (20 ng./ml.) plus NF-kappaB inhibitors compared with controls (p<0.05).nnnCONCLUSIONSnNF-kappaB activation is suggested to produce the resistance of DU145 and PC-3 to TNF-alpha and that the combination of TNF-alpha and NF-kappaB inhibitors could be constituted an effective therapy to TNF-alpha-resistant human prostate cancer cells.

Does cyclooxygenase-2 inhibitor prevent renal tissue damage in unilateral ureteral obstruction?

PURPOSEnWe determined whether the cyclooxygenase-2 inhibitor etodolac affects renal tubular damage and interstitial fibrosis in unilateral ureteral obstruction.nnnMATERIALS AND METHODSnEtodolac (10 mg./kg.) was administered to rats 1 day before unilateral ureteral obstruction and every day thereafter. Kidneys were harvested at day 14 after unilateral ureteral obstruction. Tissue transforming growth factor-beta and prostaglandin E2 were measured by bioassay using mink lung epithelial cells and enzyme linked immunosorbent-sandwich assay. Renal tubular proliferation and apoptosis were detected by immunostaining with proliferating cellular nuclear antigen and by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling, respectively. Cyclooxygenase-2 expression was detected by immunohistochemistry. Fibrosis was assessed by measuring collagen deposition in trichrome stained slides.nnnRESULTSnBioassay showed that in the control group obstructed kidneys contained significantly higher mean transforming growth factor-beta1 than unobstructed kidneys (79.1 +/- 8.3 versus 33.6 +/- 4.2 ng./gm. tissue) and etodolac significantly decrease the mean value in obstructed kidneys (46.2 +/- 10.0 ng./gm. tissue). Assay demonstrated that obstructed control kidneys had significantly more mean tubular apoptosis than their unobstructed counterparts (26.6 +/- 5.4 versus 2.2 +/- 1.4 nuclei per high power field) and etodolac significantly decreased mean renal tubular apoptosis in the obstructed kidneys (16.2 +/- 1.9 nuclei per high power field). In addition, immunostaining with proliferating cellular nuclear antigen showed that obstructed kidneys in the control group had significantly more mean renal tubular proliferation than unobstructed kidneys (9.8 +/- 3.4 versus 3.9 +/- 0.1 per high power field) and etodolac significantly increased mean proliferating renal tubule in the obstructed kidneys (24.9 +/- 4.3 per high power field). Control obstructed kidneys had significantly more fibrosis and prostaglandin E2 production, which were also significantly blunted by etodolac.nnnCONCLUSIONSnThe cyclooxygenase-2 inhibitor etodolac significantly reduces tissue transforming growth factor-beta, resulting in decreased tubular damage and interstitial fibrosis. This finding suggests that etodolac is a promising agent for preventing renal tissue damage in unilateral ureteral obstruction.

TRANILAST AMELIORATES RENAL TUBULAR DAMAGE IN UNILATERAL URETERAL OBSTRUCTION

PURPOSEnWe determined whether tranilast, the anti-allergic agent N-(3, 4-dimethoxyciannamoyl)-anthranilic acid, would diminish renal transforming growth factor-beta (TGF-beta) levels in unilateral ureteral obstruction and concomitantly affect renal tubular apoptosis and proliferation in that condition.nnnMATERIALS AND METHODSnTranilast (150 mg./kg.) was administered to rats 1 day before unilateral ureteral obstruction and each day thereafter. Kidneys were harvested day 14 after unilateral ureteral obstruction. Tissue TGF-beta was measured by bioassay using mink lung epithelial cells. Renal tubular proliferation and apoptosis were detected by immunostaining proliferating cell nuclear antigen and the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay, respectively. Fibrosis was assessed by measuring collagen deposition with trichrome stained slides.nnnRESULTSnTGF-beta bioassay showed that obstructed kidneys in controls contained significantly higher mean TGF-beta plus or minus standard deviation than unobstructed kidneys in controls (73.7 +/- 13.6 versus 14.1 +/- 5.5 pg./mg. tissue) and tranilast significantly decreased tissue TGF-beta in obstructed kidneys (15.9 +/- 4.8 pg./mg. tissue). The terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay demonstrated that obstructed kidneys in controls had significantly more mean tubular apoptosis than the unobstructed counterparts (36.6 +/- 6.7 versus 5.8 +/- 5.5 nuclei per high power field) and tranilast significantly decreased mean renal tubular apoptosis in obstructed kidneys (16.2 +/- 1.7 nuclei per high power field). In addition, immunostaining proliferating cell nuclear antigen showed that obstructed kidneys in controls had significantly more mean renal tubular proliferation than unobstructed kidneys (20.7 +/- 3.4 versus 6.2 +/- 2.1 per high power field) and tranilast significantly increased proliferating renal tubules in obstructed and unobstructed kidneys (26.5 +/- 8.3 and 14.5 +/- 3.4 per high power field, respectively). Control obstructed kidneys exhibited significantly more fibrosis, which was also blunted by tranilast.nnnCONCLUSIONSnTranilast significantly decreases tissue TGF-beta, resulting in a reduction in tubular apoptosis and an increase in tubular proliferation. This finding suggests that tranilast is a promising agent for preventing renal tubular damage in unilateral ureteral obstruction.

N-Acetylcysteine Modifies cis-Dichlorodiammineplatinum-induced Effects in Bladder Cancer Cells

We previously demonstrated a role of reactive oxygen species (ROS) in cytotoxicity induced by cis‐dichlorodiammineplatinum (CDDP) in combination with glutathione (GSH) depletors in bladder cancer cells. However, the relationship between CDDP and ROS is still unclear, although many mechanisms of drug resistance have been well characterized. The present study was undertaken to investigate the effects of N‐acetylcysteine (NAC), a GSH precursor, on the CDDP‐induced effects in bladder cancer cells (KU1). The cytotoxic effects of CDDP were significantly blunted by NAC (1 mM) in KU1 cells. The IC50 of CDDP only (10.2±1.2 μM) is significantly lower than that of CDDP with NAC (IC50: 20.3±1.6 μM) in KU1 cells. NAC also significantly increased the intracellular concentration of GSH in KU1 cells (37.2±1.6 nmol/106 cells), compared to controls (15.9±7.6 nmol/106 cells). While CDDP produced a significant increase in ROS as measured in terms of dichlorofluorescein (DCF) production in KU1 cells in a time‐dependent manner, pretreatment with NAC significantly reduced CDDP‐induced intracellular DCF in KU1 cells. Moreover, TdT‐mediated dUTP‐biotin nick‐end labeling (TUNEL) assay showed that CDDP‐induced apoptosis (31.1±3.8%) was significantly inhibited by pretreatment with NAC in KU1 cells (11.2±2.6%). These results demonstrated that NAC scavenges CDDP‐induced ROS and inhibits CDDP‐induced cytotoxicity, suggesting that ROS mediate the CDDP‐induced cytotoxicity in bladder cancer cells.

Loss of expression of transforming growth factor-beta receptor as a prognostic factor in patients with renal cell carcinoma.

OBJECTIVESnTo determine the clinical implication of the loss of transforming growth factor-beta (TGF-beta) receptor (TbetaR) expression for the pathologic features in renal cell carcinoma (RCC) and the prognosis of 62 patients (Stage I, 4; Stage II, 28; Stage III, 11; and Stage IV, 19) who underwent radical nephrectomy for RCC. Loss of expression in TbetaR could result in escape from the growth inhibitory effect of TGF-beta in TGF-beta-secreting cancer.nnnMETHODSnTbetaR and apoptosis in the tumor were detected by immunohistochemistry using samples from 62 patients. We statistically investigated the relationship among the TbetaR expression pattern, pathologic features, and the prognosis of patients with RCC.nnnRESULTSnA loss of expression of TbetaR-I and TbetaR-II was identified in 29 patients (46.7%) and 31 patients (50.0%), respectively. Although the loss of TbetaR-I was not associated with clinical stage, the loss of TbetaR-II was associated with clinical stage (P <0.01). Univariate analysis of all patients demonstrated that Stage T3 or greater, clinical Stage III or greater, loss of TbetaR-II, and a tumor apoptotic index of less than 35 were associated with a significantly lower survival rate than their respective counterparts. Multivariate analysis showed that the only two significant prognostic factors were clinical stage and loss of TbetaR-II. In addition, TbetaR-negative RCC had significantly lower apoptosis than did TbetaR-positive RCC.nnnCONCLUSIONSnThese results suggest that a loss of TbetaR-II expression in the primary tumor is a significant prognostic factor in patients with RCC.

CAPTOPRIL RESTORES TRANSFORMING GROWTH FACTOR-β TYPE II RECEPTOR AND SENSITIVITY TO TRANSFORMING GROWTH FACTOR-β IN MURINE RENAL CELL CANCER CELLS

Purpose: Captopril is known to inhibit the growth of renal cancer but the mechanism involved has been unclear. The current study elucidates the mechanism of captopril induced inhibition of the growth of the Renca mouse renal cancer cell line involving transforming growth factor-β, which is known to be a growth inhibitory cytokine in epithelial cells and tissues.Materials and Methods: Transforming growth factor-β in conditioned medium was measured by bioassay. Levels of transforming growth factor-β and transforming growth factor-β type II receptor expression messenger RNA were determined by reverse transcriptase-polymerase chain reaction and flow cytometry. Cell viability was determined by bromodeoxyuridine (BrdU) incorporation and tetrazolium bromide assay.Results: Captopril (0.01 to 1 mM.) showed no significant effect on transforming growth factor-β synthesis or transforming growth factor-β messenger RNA in Renca cells. On the other hand, 1 mM. captopril significantly inhibited Renca cell growth. Reverse...

Inverted papilloma arising in a juvenile.

A 15-year-old man presented with painless, gross hematuria. Excretory pyelography showed a filling defect in the bladder and ultrasonography revealed a solitary bladder tumor. Cystoscopy showed a solitary, papillary tumor on the bladder neck. Transurethral resection was then performed and histological examination showed an inverted papilloma. In addition, the expression of proliferative cellular nuclear antigen and p53 in the surgical specimen were 37.1 and 0%, respectively. Since an inverted papilloma arising during the first two decades of life is quite rare, we herein report the above case and review previous reports.

Transluminal vascular stent implantation for a patient with renovascular hypertension due to renal artery stenosis

In recent years, transluminal vascular stents have been implanted in patients with renal artery stenosis. At present, controversy remains as to whether the long-term outcome of stent implantation is better than that of percutaneous transluminal renal angioplasty (PTRA). However, until now, no clinical experience of a stent placement for renal artery stenosis has been reported in our country. We implanted a Palmaz stent in a patient with renovascular hypertenstion due to renal artery restenosis who had already undergone PTRA. The renal function and blood pressure of the patient improved remarkably.