Masahide Matsuyama

Expression of peroxisome proliferator-activated receptors (PPARs) in human urinary bladder carcinoma and growth inhibition by its agonists.

Recent studies have demonstrated that peroxisome proliferator activator‐receptors(PPAR)‐γ is expressed in various cancer tissues and its ligand induces growth arrest of these cancer cells through apoptosis. In our study, we investigated the expression of PPAR‐α, β and γ in human bladder tumor (BT) and normal bladder (NB) tissues as well as the effects of PPAR‐γ ligands. Specimens were obtained from 170 patients with BT and 20 with NB. The expressions were investigated using RT‐PCR and immunohistochemical methods. We also investigated the inhibitory effect of PPAR‐γ ligands on BT‐derived cell line. Immunoreactive PPAR‐α and ‐β were significantly apparent in both BT and NB tissues. Although no marked expression of PPAR‐γ was observed in NB tissue, significant expression was found in BT tissue. The extent and intensity of immunoreactive PPAR‐γ polypeptides in BT cells were statistically much greater than those of NB cells. Correlation between PPAR‐γ expression and tissue type or progression of bladder cancer was observed; PPAR‐γ expression was higher in G3 of bladder cancer than in G1 and was higher in advanced than in early cancer. PPAR‐γ agonists, troglitazone and 15‐deoxy‐Δ12, 14‐prostaglandin J2 inhibited the growth of the BT cells. PPAR‐γ is expressed in bladder tumor, and results suggest that PPAR‐γ ligands may mediate potent antiproliferative effects against BT cells. Thus, PPAR‐γ has the ability to become a new target in treatment of bladder tumor.

Tissue factor antisense oligonucleotides prevent renal ischemia-reperfusion injury.

Background. Tissue factor (TF) expression is induced on macrophages and endothelial cells during the immune response. We designed an antisense (AS) phosphorothioate oligodeoxynucleotide (ODN) to specifically inhibit the expression of rat TF to study the effects of the AS ODN on renal ischemia-reperfusion injury in the rat. Method. AS-1 ODN for TF was delivered intravenously to inhibit the expression of TF in endothelial cells. After 8 hr, the right kidney was harvested and the left renal artery and vein were clamped. The kidney was reperfused after 90 min of ischemia, and rats were killed at 0, 1.5, 5, 12, and 24 hr after reperfusion. TF expression was analyzed by immunohistochemical staining using monoclonal antibody. Results. In the untreated ischemic group, 0 of 20 rats survived beyond day 3. However, treatment with AS-1/TF led to 12 of 20 rats surviving beyond day 4. TF was detected on distal tubular epithelial cells, endothelial cells, and blood vessels but not on necrotic and proximal tubular epithelial cells. The necrotic area extended and encompassed nearly all of the ischemic kidney within 12 hr after reperfusion. The necrotic area and the grade of TF staining were more significantly reduced in the AS-1/TF-treated group than in the control group. Furthermore, fluorescein isothiocyanate-labeled AS-1/TF was significantly intense in tubular epithelial cells 8 hr after intravenous administration. Conclusions. The results indicate that AS-1/TF inhibited the ischemia-reperfusion injury of the kidney. Microcirculatory incompetence resulting from microthrombus may cause the formation and development of necrosis.

Cyclooxygenase-1 and -2 in human testicular tumours

In this study, we investigated the expression of cyclooxygenase (COX)-1 and -2 in human testicular cancer (TC) and normal testis (NT) tissues, as well as the effects of COX ligands on viability and proliferation. Tumour specimens were obtained from 72 patients with TC and 20 patients with NT. RT-PCR and immunohistochemical methods were used to determine COX expression. While COX expression was not noted in any of the NT tissues, a marked expression was observed in the TC samples. The extent and intensity of immunoreactive COX-1 and -2 polypeptides in the TC tissues was statistically greater than the expression in the NT tissues. The synthetic COX inhibitors inhibited the growth of the TC cells. Both COX-1 and COX-2 are induced in testicular cancer, and these results indicate that both COX-1 and COX-2 are essential for the growth of TC cells.

Peroxisome Proliferator-Activated Receptor- Is a Potent Target for Prevention and Treatment in Human Prostate and Testicular Cancer

Peroxisome proliferator-activated receptor-γ (PPAR)-γ is a ligand-activated transcriptional factor belonging to steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and tumorigenesis. Up to date, PPAR-γ is expressed in various cancer tissues, and PPAR-γ ligand induces growth arrest of these cancer cells. In this study, we examined the expression of PPAR-γ in prostate cancer (PC) and testicular cancer (TC) by RT-PCR and immunohistochemistry, and we also examined the effect of PPAR-γ ligand in these cells by MTT assay, hoechest staining, and flow cytometry. PPAR-γ expression was significantly more extensive and intense in malignant tissues than in normal tissues. PPAR-γ ligand induced the reduction of malignant cell viability through apoptosis. These results demonstrated that the generated PPAR-γ in PC and TC cells might play an important role in the tumorigenesis. PPAR-γ may become a new target in the treatment of PC and TC.

Relationship Between Cysteinyl-Leukotriene-1 Receptor and Human Transitional Cell Carcinoma in Bladder

OBJECTIVES To investigate the leukotriene (LT) D(4) (LTD(4)) receptor (cysteinyl-LT(1) receptor [CysLT(1)R]) expression in transitional cell carcinoma (TCC) of the bladder, as well as the effects of the CysLT(1)R antagonist on cell proliferation in TCC cell lines. The metabolism of arachidonic acid by either cyclooxygenase or lipoxygenase is thought to play an important role in carcinogenesis. LTD(4) is a pro-inflammatory mediator derived from arachidonic acid through various enzymatic steps, and 5-lipoxygenase is an important factor in generating LTD(4). METHODS CysLT(1)R expression in TCC tissue and normal bladder tissue was examined. CysLT(1)R expression was detected using immunohistochemistry. The effects of the CysLT(1)R antagonist on TCC cell growth were examined by 3-(4,5-dimethylthiazol-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay and reverse transcriptase-polymerase chain reaction. Flow cytometry was used to determine whether the CysLT(1)R antagonist induced apoptosis. RESULTS Initially, only slight CysLT(1)R expression was detected in normal bladder tissues and marked CysLT(1)R expression was detected in the TCC tissues. CysLT(1)R expression was greater in high-grade cancer than in low-grade cancer. Furthermore, CysLT(1)R expression was also greater in advanced-stage cancer than in early-stage cancer. Finally, the CysLT(1)R antagonist caused marked inhibition of TCC cells by inducing early apoptosis. CONCLUSIONS CysLT(1)R was induced in TCC. The results suggest that the CysLT(1)R antagonist might mediate potent antiproliferative effects on TCC cells. Thus, the target of the CysLT(1)R is potentially a new therapy in the treatment of TCC.

The target of arachidonic acid pathway is a new anticancer strategy for human prostate cancer

Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX) is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of carcinogenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX) is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR)-γ is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and carcinogenesis. PPAR-γ is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-γ in human prostate cancer tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.

Arachidonic acid pathway: A molecular target in human testicular cancer (Review)

Recent epidemiological studies and animal experiments have demonstrated that non-steroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX), the first oxidase in the process of prostaglandin production from arachidonic acid, is the principal target of NSAIDs. Due to its inhibition by NSAIDs, the COX enzyme may be involved in the initiation and/or promotion of carcinogenesis. Lipoxygenase (LOX) is also an enzyme active in the early stages of the pathway for producing leukotrienes from arachidonic acid, and may, like COX, be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR)-γ is a ligand-activated transcriptional factor belonging to the steroid receptor super-family. PPAR-γ plays a role in both adipocyte differentiation and carcinogenesis, and is a target for the cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-γ in human testicular cancer tissues, as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligands.

Telmisartan as a peroxisome proliferator-activated receptor-γ ligand is a new target in the treatment of human renal cell carcinoma.

Angiotensin II receptor blockers (ARBs) are widely used as hypertensive therapeutic agents. However, it has been reported that Telmisartan (a type of ARB) additionally activates peroxisome proliferator-activated receptor (PPAR)-γ. We previously reported that PPAR-γ ligand induced the growth arrest of renal cell carcinoma (RCC) cells through apoptosis, and that Telmisartan had the potential to inhibit prostate cancer cell growth through apoptosis. In this study, we evaluated the effects of Telmisartan and other ARBs on cell proliferation in an RCC cell line using normal proximal tubular endothelial cells (PRTECs) and the human RCC (Caki-1) cell line. The effects of Telmisartan as well as of other ARBs (Candesartan, Valsartan, Irbesartan and Losartan) on RCC cell growth were examined by MTT assay. Flow cytometry and Hoechst staining were used to determine whether or not the ARBs induced apoptosis. Telmisartan caused marked inhibition in RCC cells in a concentration- and time-dependent manner. Treatment with 100 µM of Telmisartan induced early apoptosis and DNA fragmentation in the RCC cells, but not in the PRTECs. None of the other ARBs had an effect on cell proliferation in the RCC cells or the PRTECs. Telmisartan may mediate potent antiproliferative effects against RCC cells through PPAR-γ. Thus, Telmisartan is a potential target for prevention and treatment in RCC.

The Efficacy and Safety of High-Dose Mizoribine in ABO-Incompatible Kidney Transplantation Using Anti-CD20 and Anti-CD25 Antibody Without Splenectomy Treatment

BACKGROUND Mizoribine (MZR) has been developed as an immunosuppressive agent in Japan, but it shows less potent immunosuppressive effects at doses up to 3 mg/kg/d. In this study, we investigated whether high-dose MZR (6 mg/kg/d) was effective for ABO-incompatible (ABO-i) living donor kidney transplantation (LKT) using treatment with anti-CD25 and anti-CD20 monoclonal antibodies without splenectomy. METHODS Since 2007, we encountered 24 cases of ABO-i LKT using anti-CD20 and anti-CD25 monoclonal antibody without splenectomy. The pretransplant immunosuppressive regimen consisted of two doses of anti-CD20 antibody, mycophenolate mofetil (MMF), prednisolone, a calcineurin inhibitor (cyclosporine [7 mg/kg] or tacrolimus [0.2 mg/kg] and two doses of anti-CD25 antibody. Antibody removal by plasmapheresis was performed before LKT up to several times according to the antibody titer. The posttransplant regimen consisted of high-dose mizoribine (6 mg/kg/d) instead of MMF (MZR group, n = 12). RESULTS The 1-year graft survival rates for the MZR and MMF groups were both 100%. The rejection rate in the MZR group (eight %) was not significantly higher than that in the MMF group (seventeen %) Serum creatinine level was not significantly different between the two groups. In the MZR group 6 (50%) patients developed CMV antigenemia-positivity versus 11 (92%) in the MMF group (P < .05). The number of patients who developed CMV disease was 0 in the MZR group and 1 (8%) in the MMF group. The number of patients treated with ganciclovir was 0% and 8%, respectively (not significant). CONCLUSIONS We obtain good clinical results with high-dose MZR in ABO-i LKT using anti-CD20 and anti-CD25 antibody treatment without splenectomy.

The Excellent Outcomes of ABO-Incompatible Kidney Transplantation With High Titer (>×2048) Using Anti-CD20 and Anti-CD25 Antibody Without Splenectomy: Two Case Reports

BACKGROUND Due to the shortage of deceased donors, we have expanded the indications for living-donor kidney transplantation (LKT) to include ABO-incompatible (ABO-i) individuals. However, which patients with high-titer anti-blood-group antibody can be transplanted successfully is unclear. METHODS Since 2009 we have performed 2 high-titer ABO-i spousal LKT using anti-CD20 and anti-CD25 monoclonal antibody without splenectomy. In both cases, anti-type A antibody was 2048-fold before antibody removal. The immunosuppressive regimen consisted of 2 doses of anti-CD20 antibody (200 mg/body, day -14 to day -7), mycophenolate mofetil (1000 mg), prednisolone (10 mg starting from day -14), calcineurin inhibitor (cyclosporine [7 mg/kg] or tacrolimus [0.2 mg/kg] starting from day -7), and 2 doses of anti-CD25 antibody (20 mg/body, days 0 and 4). Antibody removal by plasmapheresis was performed up to 4 times before LKT according to the antibody titer. The posttransplantation regimen consisted of mycophenolate mofetil or mizoribine as antimetabolite. A protocol biopsy was performed at 1 month and 1 year after LKT. RESULT The 60- and 62-year-old men had renal graft transplantation performed in the right hemipelvis without complication. After LKT, urinary output and serum creatinine decrease were within acceptable ranges without evidence of an acute rejection episode for 12 and 7 months, respectively. Patient and graft survival rates were 100%. A protocol biopsy at 1 month after LKT showed additional treatment to be unnecessary. Serious viral infection was not seen, even in the 1 patient who temporarily experienced positive changes in cytomegalovirus antigenemia. CONCLUSIONS We obtained good clinical results among 2 high-titer ABO-i LKT using anti-CD20 and anti-CD25 antibodies without splenectomy, in conjunction with a calcineurin inhibitor plus mycophenolate mofetil or mizoribine.