Transarterial chemoembolisation for palliative treatment of renal cell carcinoma in two dogs with pulmonary metastasis.

Two dogs with anorexia and rapid weight loss were referred to our hospital due to a right renal mass and several pulmonary nodules. Both dogs underwent needle core biopsy of the mass, followed by transarterial chemoembolisation of the renal mass. A catheter was inserted from the femoral artery and advanced into the right renal artery. A suspension of carboplatin (100 mg/m2 ) and equivalent lipiodol was administered via the inserted multipurpose catheter. Immediately after, under fluoroscopic guidance, pulse injections of small amounts of gelatin particles (diameter 1 mm) dissolved in iohexol were administered until complete embolisation of the renal artery. Histopathologic diagnosis was renal cell carcinoma in both dogs. Clinical signs improved for 134 and 358 days after transarterial chemoembolisation. In addition, postoperative radiographs demonstrated a decrease in the tumour size. The dogs died 215 and 525 days after the initial evaluation, respectively. As a palliative treatment, transarterial chemoembolisation might help reduce the tumour volume and improve the quality of life in dogs with renal cell carcinoma and distant metastases.

Congenital portopulmonary shunt in a cat.

A 9-year-old spayed female crossbreed cat with chief complaints of anorexia and hypersalivation had high serum concentrations of ammonia and fasting and postprandial total bile acid. Therefore, she was referred to our hospital. On the first evaluation, haematology, serum chemistry, radiography and ultrasonography findings suggested that she had a congenital portosystemic shunt. CT revealed a shunt vessel from the left gastric vein to the left pulmonary vein. During median celiotomy and sternotomy, gross findings and mesenteric portography revealed abnormal vessel shunting from the left gastric vein to the left pulmonary vein. Complete ligation of the shunt vessel was achieved. She recovered without any complications. Postoperative serum chemistry revealed that ammonia and total bile acid levels decreased to within the reference intervals. This report is the first to describe the clinical features and surgical outcome of a cat with a congenital portopulmonary shunt.

DAP12 deficiency in liver allografts results in enhanced donor DC migration, augmented effector T cell responses and abrogation of transplant tolerance.

Liver interstitial dendritic cells (DC) have been implicated in immune regulation and tolerance induction. We found that the transmembrane immuno-adaptor DNAX-activating protein of 12 kDa (DAP12) negatively regulated conventional liver myeloid (m) DC maturation and their in vivo migratory and T cell allostimulatory ability. Livers were transplanted from C57BL/6(H2(b) ) (B6) WT or DAP12(-/-) mice into WT C3H (H2(k) ) recipients. Donor mDC (H2-K(b+) CD11c(+) ) were quantified in spleens by flow cytometry. Anti-donor T cell reactivity was evaluated by ex vivo carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte reaction and delayed-type hypersensitivity responses, while T effector and regulatory T cells were determined by flow analysis. A threefold to fourfold increase in donor-derived DC was detected in spleens of DAP12(-/-) liver recipients compared with those given WT grafts. Moreover, pro-inflammatory cytokine gene expression in the graft, interferon gamma (IFNγ) production by graft-infiltrating CD8(+) T cells and systemic levels of IFNγ were all elevated significantly in DAP12(-/-) liver recipients. DAP12(-/-) grafts also exhibited reduced incidences of CD4(+) Foxp3(+) cells and enhanced CD8(+) T cell IFNγ secretion in response to donor antigen challenge. Unlike WT grafts, DAP12(-/-) livers failed to induce tolerance and were rejected acutely. Thus, DAP12 expression in liver grafts regulates donor mDC migration to host lymphoid tissue, alloreactive T cell responses and transplant tolerance.

Intraoperative identification of canine hepatocellular carcinoma with indocyanine green fluorescent imaging.

OBJECTIVES: To evaluate the feasibility of high-sensitivity near-infrared fluorescence imaging with indocyanine green for intraoperative identification of hepatocellular carcinoma in dogs. METHODS: Twelve hepatic nodules were surgically resected from six dogs. In each dog, 0 · 5 mg/kg indocyanine green was intravenously injected for 12 to 18 hours preoperatively. The hepatic nodules were investigated under laparotomy using a near-infrared fluorescence imaging light camera system prior to resection. Resected nodules were histopathologically diagnosed and their fluorescence images were evaluated. RESULTS: Of the 12 hepatic nodules, 6 were diagnosed as hepatocellular carcinoma and 6 as nodular hyperplasia. Indocyanine green-fluorescence was observed in four large hepatocellular carcinoma nodules and one case of nodular hyperplasia, whereas it was absent in the remaining nodules. The sensitivity and positive predictive values of indocyanine green fluorescent imaging for hepatocellular carcinoma was 71 · 4 and 80 · 0%, respectively. Complete resection of the hepatic masses was achieved in all dogs. CLINICAL SIGNIFICANCE: Near-infrared fluorescence imaging may be feasible for intraoperative mapping of hepatocellular carcinomas in hepatic lobes and may help increase the chance of complete resection of hepatocellular carcinoma in dogs.

Activations of mitogen-activated protein kinases and regulation of their downstream molecules after rat lung transplantation from donors after cardiac death.

OBJECTIVES: Accepting organs donated after cardiac death (DCD) is an effective approach to the donor shortage. However, lung transplantations from DCD donors show severe rapid pulmonary graft dysfunction (PGD) followed by warm ischemia-reperfusion injury (IRI). This study sought to clarify the molecular mediators in warm IRI, including activation of mitogen-activated protein kinase (MAPK) and the downstream cascades. METHODS: We performed single left lung transplantation using organs from male Sprague-Dawley rats after 0 (CIT group), 30 (30WIT group), or 180 (180WIT group) minutes of warm ischemia time. Pulmonary graft functions were estimated by blood gas analysis. At 1 hour after reperfusion, the phosphorylation status of MAPKs (ERK, p38, and JNK) and the gene expression levels of transcription factors (Egr-1 and ATF-3) and immune mediators (MCP-1, MIP-2, PAI-1, ICAM-1, TNF-α, IL-1ß, IL-6, and COX-2) in the grafts were examined using Western blotting and real-time polymerase chain reaction assays. RESULTS: Severe PGD was observed in the 180WIT group compared with transplanted lungs in the other groups, which exhibited good pulmonary graft function. ERK and JNK activations, as well as mRNA levels of transcription factors (Egr-1 and ATF3) significantly increased with greater warm ischemic times. The pattern of JNK activation correlated with the severity of PGD. MCP-1, ICAM-1, IL-1ß, IL-6, and COX-2 were also up-regulated among the 180WIT group, although MIP-2 and PAI-1 showed no significant differences among the groups. CONCLUSIONS: We suggest that the ERK and JNK pathways may play important roles to induce the injury caused by prolonged warm ischemia followed by reperfusion in the setting of lung transplantation from DCD donors.

Impaired dendritic cell functions because of depletion of natural killer cells disrupt antigen-specific immune responses in mice: restoration of adaptive immunity in natural killer-depleted mice by antigen-pulsed dendritic cell.

The primary aim of this study was to evaluate the role of natural killer (NK) cells on antigen-specific adaptive immune responses. After analysing the mechanism of impaired adaptive immune responses of NK-depleted mice, an immune interventional approach was developed to restore adaptive immunity in NK-depleted mice. NK cells were depleted from mice by administration of anti-asialo GM1 antibody (100 mul/mouse), twice, at an interval of 48 h. Hepatitis B surface antigen (HBsAg) was administered intraperitoneally to normal C57BL/6 mice (control mice) and NK-depleted mice. The levels of antibody to HBsAg (anti-HBs) in the sera and HBsAg-specific lymphocytes in the spleen were assessed. The functions of T lymphocytes, B lymphocytes and dendritic cells (DCs) were evaluated in vitro. HBsAg-pulsed DCs were prepared by culturing spleen DCs with HBsAg for 48 h and administered once to NK-depleted mice. The levels of anti-HBs in the sera and HBsAg-specific lymphocytes were significantly lower in NK-depleted mice compared with control mice (P < 0.05). The functions of T and B lymphocytes were similar between control mice and NK-depleted mice. However, the functions of spleen DC and liver DC were significantly lower in NK-depleted mice compared with control mice (P < 0.05). Administration of HBsAg-pulsed DCs, but not HBsAg, induced HBsAg-specific humoral and cellular immune responses in NK-depleted mice. Our study suggests that cross-talk between NK cells and DCs regulates the magnitude of adaptive immunity. In addition, antigen-pulsed immunogenic DCs represent potent immune modulator even if subjects with diminished innate immunity.

[Staged operation of off-pump coronary artery bypass grafting using aortic connector system, and concomitant surgery for abdominal aortic aneurysm and gastric cancer; report of a case].

Recently the patient of the atherosclerotic disease associated with malignant disease has been increased. A 75-year-old man was referred to our section with an infrarenal abdominal aortic aneurysm (AAA) and a gastric cancer (GC). Preoperative coronary angiogram revealed the significant stenoses of the right coronary and the left anterior descending coronary artery. We selected the staged operation of off-pump coronary artery bypass grafting (CABG) [OPCAB] and the concomitant surgery for the AAA and the GC. Operative invasion could decrease with the surgical procedure of the OPCAB and the concomitant surgery compared to the conventional CABG or the separate operation. We used the aortic connector system during OPCAB to prevent such the serious complications of the aortic dissection or the systemic embolism due to the calcified ascending aorta.

[The ischemic mitral valve regurgitation due to acute coronary thromboembolism; report of a case].

A 71-year-old man with congestive heart failure due to acute myocardial infarction was referred to our hospital. He was under the support of mechanical ventilation and the intraaortic balloon pumping (IABP) and coronary angiogram revealed the thromboembolism of the obtuse marginal artery. We completed the revascularization by the direct percutaneous coronary intervention. However, grade II mitral valve regurgitation and heart failure were worsening. Mitral valvuloplasty and the modified maze procedure through the partial lower sternotomy were performed. He is still in good condition 4 years later. Ischemic mitral valve regurgitation due to the coronary thromboembolism is very rare. Careful follow-up on the grade of ischemic mitral valve regurgitation is necessary even after the early coronary recanalization. The surgical approach of the partial sternotomy should be used in such a case of acute mitral valve regurgitation.

Significance of dihydropyrimidine dehydrogenase activity in renal cell carcinoma.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme in the pathway of uracil and thymine catabolism. DPD is also the principal enzyme involved in the degradation of 5-fluorouracil (5-FU), an anticancer chemotherapeutic agent that is used clinically to treat renal cell carcinoma (RCC). Little is known about the significance of DPD activity in human cancers. We investigated the activity of DPD in 68 RCC and the relationship between DPD activity and the sensitivity to 5-FU. The levels of DPD activity in RCC and normal kidney samples were determined by the 5-FU degradation assay. The sensitivity to 5-FU was assessed by the microculture tetrazolium dye assay. The activity of DPD was approximately 2-fold higher in normal kidney compared with RCC. DPD activity in Stage I/II RCC was approximately 2-fold higher than that in Stage III/IV RCC. The levels of DPD activity in Grade 1 and Grade 2 RCC were 3 and 2-fold higher, respectively, than that in the Grade 3 cancers. There was an inverse correlation between DPD activity in RCC cells and their sensitivity to 5-FU. Furthermore, 5-chloro-2,4-dihydroxypyridine (CDHP), a potent DPD inhibitor, enhanced the sensitivity to 5-FU. The current study is the first to demonstrate that the level of DPD activity was inversel correlated with both the progression of the disease and increased grade of RCC, and that DPD activity was inversely associated with the sensitivity of RCC to 5-FU, which was enhanced by a DPD inhibitor. These results suggest that a low DPD activity may be associated with the malignant potential of RCC. In addition, it may be possible to overcome 5-FU resistance by using DPD inhibitors in the treatment protocols of 5-FU-based chemotherapy for RCC.

Clinical evaluation of Ramosetron injections in the treatment of cisplatin-induced nausea and vomiting.

A phase III, double-blind, placebo-controlled study was performed to examine the safety and efficacy of ramosetron in cancer patients with cisplatin-induced nausea/vomiting. Patients were divided into two groups: group R received 0.3 mg ramosetron intravenously and group P received placebo. Eighty-eight patients were enrolled, 44 in each group; 84 (43 in group R, 41 in group P) were included in the clinical efficacy analysis and 86 (44 in group R, 42 in group P) in the safety analysis. Ramosetron was significantly more clinically effective than placebo against nausea, vomiting and anorexia; 65.1% of patients in group R experienced no vomiting in the first 6 h of observation compared with 7.3% of those receiving placebo. No serious adverse reactions or significant differences in safety were observed between the groups. Based on these results, ramosetron injection is effective in the treatment of cisplatin-induced nausea/vomiting and its clinical usefulness is demonstrated here.

Potentiation of the sensitivity of renal cell carcinoma cells to TRAIL-mediated apoptosis by subtoxic concentrations of 5-fluorouracil.

Cytotoxic chemotherapy has shown little antitumour activity against renal cell carcinoma (RCC). Although immunotherapy is relatively effective against RCC, the response rate is approximately 20%. Therefore, there is an urgent need to increase this response rate. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo-2L) is one member of the tumour necrosis factor ligand family that selectively induces apoptosis of cancer cells. Since several cytotoxic anticancer drugs including 5-fluorouracil (5-FU) also mediate apoptosis, we reasoned that combined treatment of cancer cells with TRAIL and drugs might result in synergy and overcome the resistance of the cancer cell. This study has examined whether TRAIL can synergise with 5-FU in both cytotoxic and apoptotic assays against drug-resistant RCC cells. Cytotoxicity was determined by an 1-day microculture tetrazolium dye assay. Synergy was assessed by isobolographic analysis. Treatment of Caki-1 cells with TRAIL in combination with 5-FU resulted in a synergistic cytotoxic effect. Synergy was also achieved in freshly derived RCC cells from 3 patients. The enhanced cytotoxicity was obtained irrespective of the sequence of the treatment, but the highest cytotoxicity was observed when Caki-1 cells were treated with TRAIL and 5-FU simultaneously. The synergy achieved in cytotoxicity with TRAIL and 5-FU was shown to be due to apoptosis. The mechanisms responsible for the synergistic cytotoxicity and apoptosis were examined. Treatment of Caki-1 cells with 5-FU enhanced the expression of p53 and bax, but had no effect on the expression of bcl-2. Incubation of Caki-1 cells with TRAIL enhanced the intracellular accumulation of 5-FU and 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP). Treatment of Caki-1 cells with TRAIL downregulated the expression of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) modestly, and upregulated the expression of orotate phosphoribosyltransferase (OPRT). However, the expression level of thymidine phosphorylase (TP) was not affected by TRAIL. This study demonstrates that combined treatment of RCC cells with TRAIL and 5-FU overcomes their resistance. The sensitisation obtained with freshly isolated RCC cells required low subtoxic concentrations of 5-FU. These findings support the potential application in vivo of a combination of TRAIL and 5-FU in the treatment of TRAIL/5-FU-resistant RCC.

Prognostic significance of thymidylate synthase activity in bladder carcinoma.

BACKGROUND: 5-fluorouracil (5-FU) is an anticancer agent clinically used against various cancers including bladder carcinoma. 5-FU inhibits thymidylate synthase (TS) and blocks DNA synthesis. TS is the key enzyme in the catalysis of the methylation from deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate. Little is known about the significance of TS in bladder carcinoma. The authors investigated the activity of TS in 82 bladder cancers and prognostic significance of the levels of TS and/or activities of dihydropyrimidine dehydrogenase (DPD), an important enzyme in the degradation of 5-FU. METHODS: The levels of TS and DPD activities in nonfixed, fresh, frozen, bladder carcinoma and normal bladder specimens were determined biochemically by the FdUMP binding assay and the 5-FU degradation assay, respectively. RESULTS: The activity of TS was 10-fold higher in bladder carcinoma compared with normal bladder. TS activity in muscle-invasive bladder carcinoma was threefold higher than that in Ta and T1 cancer. In addition, the activity of TS in T1 bladder carcinoma was threefold higher than that in Ta cancer. The level of TS activity in Grade 3 bladder carcinoma was 4.5-fold and 3.5-fold higher than that in Grade 1 and Grade 2 cancers, respectively. Patients with Ta and T1 bladder carcinoma with low TS activity had a longer postoperative tumor-free period than those with high activity in the 2-year follow-up. Patients with Ta and T1 bladder carcinoma with high or low TS activity were divided into four subgroups: high or low DPD activity subgroups. Patients with low TS activity and high DPD activity had the longest postoperative disease-free period among the 4 subgroups during the 2-year follow-up. CONCLUSIONS: To the authors' knowledge, the current study is the first study that demonstrated that the level of TS activity correlates with both the progression of the stage and the increase of the grade of bladder carcinoma and that elevated TS activity predicts early recurrence in Ta and T1 bladder carcinoma. These results suggested that elevated TS activity might have been associated with a higher chance of progression and recurrence of bladder carcinoma in the patients who participated in this study.

Significance of serum soluble Fas ligand in patients with bladder carcinoma.

BACKGROUND: The interaction of Fas and Fas ligand (FasL) plays an important role in cytotoxic T-lymphocyte-mediated and natural killer cell-mediated apoptosis against tumor cells. Circulating soluble FasL (sFasL) has been suggested to provide protection from Fas-mediated apoptosis. The current study examined this possibility in patients with bladder carcinoma. METHODS: The levels of sFasL in the serum of 163 patients with bladder carcinoma were determined using an enzyme-linked immunoadsorbent assay. Antiautologous tumor cytotoxic activity was assessed by the 12-hour chromium isotope ((51)Cr) release assay. RESULTS: The mean serum level of sFasL in patients with bladder carcinoma was 2.5-fold higher than that in healthy donors. The level of serum sFasL in patients with muscle-invasive bladder carcinoma was 2.5-fold higher than that in patients with superficial bladder carcinoma. In addition, serum sFasL levels in patients with T1 and Tis bladder carcinoma was 2-fold and 2.7-fold higher, respectively, than levels in patients with Ta bladder carcinoma. The serum level of patients with sFasL in Grade 3 bladder carcinoma were 2.4-fold and 1.7-fold higher than that in patients with Grade 1 and Grade 2 bladder carcinoma, respectively. Patients with Ta bladder carcinoma with a low level of serum sFasL (less than the median value) had a longer postoperative tumor-free interval than patients with a high sFasL level (greater than the median value) in the 5-year follow-up. There was an apparent inverse correlation between the level of serum sFasL and antiautologous tumor cytotoxic activity. CONCLUSIONS: The results of the current study demonstrated that the level of serum sFasL is correlated with both disease progression and increase in the tumor grade, and that an elevated serum sFasL level predicted early recurrence in patients with Ta bladder carcinoma. These findings suggest that elevated serum sFasL levels might be associated with a greater risk of disease progression and recurrence in patients with bladder carcinoma.

The significance of dihydropyrimidine dehydrogenase (DPD) activity in bladder cancer.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme in the pathway of uracil and thymine catabolism. DPD is also the principal enzyme involved in the degradation of 5-fluorouracil (5-FU), which is one of the anticancer chemotherapeutic agents currently used in the treatment of bladder cancer. Little is known about the significance of DPD activity in human cancers. We investigated the activity of DPD in 74 bladder cancers and the relationship between the DPD activity and the sensitivity to 5-FU. The levels of DPD activity in bladder cancer and normal bladder tissues were determined by the 5-FU degradation assay. The sensitivity to 5-FU was assessed by the microculture tetrazolium dye (dimethylthiazolyl-2-5-diphenyltetrazolium bromide; MTT) assay. The activity of DPD was approximately 2-fold higher in bladder cancer tissues compared with normal bladder tissues. DPD activity in invasive bladder cancers was approximately 2-fold higher than that in superficial cancers. In addition, the levels of DPD activity in grade 2 and grade 3 bladder cancers were approximately 3-fold and 4-fold higher than that in grade 1 cancers, respectively. Patients with superficial bladder cancer with a low DPD activity had a slightly longer postoperative tumour-free period than those with a high DPD activity over a 2-year follow-up period, but this was not significant. There was an inverse correlation between DPD activity in bladder cancer cells and their sensitivity to 5-FU. Furthermore, 5-chloro-2,4-dihydroxypyridine (CDHP), a potent DPD inhibitor, enhanced the sensitivity to 5-FU. The present study has demonstrated that the level of DPD activity correlated with the progression of the stage and an increase in the grade of the bladder cancer. These results suggest that an elevated DPD activity might be associated with the malignant potential of the bladder cancer. In addition, it might be possible to overcome 5-FU insensitivity by using DPD inhibitors in the treatment protocols of 5-FU-based chemotherapy for bladder cancers.

Arterial remodeling influences the development of intimal hyperplasia after stent implantation.

OBJECTIVES: We examined whether preinterventional arterial remodeling influenced the interventional results after stenting. BACKGROUND: Arterial remodeling is seen in atherosclerotic lesions, and it may play an important role in the early stage of atherosclerosis. METHODS: We examined 113 lesions that underwent elective stenting using tubular slotted stents under intravascular ultrasound guidance. The lesions were divided into three groups--adequate, intermediate and inadequate remodeling group--according to preinterventional arterial remodeling. The patients were subjected to coronary angiography and intravascular ultrasound evaluation on average 6.4 months after stenting. RESULTS: At baseline and immediately after stenting, there were no differences in quantitative angiographic analysis among remodeling groups. However, the plaque cross-sectional area (CSA) in the minimal lumen CSA at preintervention and intimal hyperplasia CSA at follow-up were significantly larger in the adequate remodeling group than in the inadequate remodeling group. The restenosis rate of stenting for the lesions with inadequate arterial remodeling was very low (9.4%). A significant positive correlation was found between preinterventional plaque CSA and intimal hyperplasia CSA at follow-up (r = 0.47, p < 0.0001). Moreover, remodeling index significantly correlated with relative intimal hyperplasia CSA (r = 0.28, p < 0.01). CONCLUSIONS: Preinterventional arterial remodeling influenced the development of intimal hyperplasia after stenting.

[Renal cell carcinoma in the Birt-Hogg-Dubé syndrome: report of a case].

Birt-Hogg-Dubé (BHD) syndrome is a rare dermatological condition appearing with an autosomal dominant mode of inheritance. It was first reported in 1977 by Birt et al. and 28 cases have been reported since then. BHD syndrome is characterized by asymptomatic dome-shaped, skin-colored papules on the face and upper trunk. Recently, various neoplasms have been reported to associate with BHD syndrome, including three familial and one sporadic cases of renal tumors. We report another sporadic case with renal tumor. A 53-year-old woman complained of gross hematuria and visited our institute on November 1996. She visited the Department of Dermatology, Wakayama Medical College because of skin lesions on the face and upper trunk at her age of 44. These skin lesions were present since her mid twenties. Her daughter also had similar skin lesions and visited the same Department. There was no family history of renal tumor. The patient was diagnosed to have a right renal tumor, and radical nephrectomy was performed. Pathological diagnosis was renal cell carcinoma, papillary type. She underwent interferon injection therapy postoperatively, but died because of lung metastases on April 1997. This is the first reported case of renal tumor occurring in BHD syndrome in Japan.

Serous retinal detachment in patients under systemic corticosteroid treatment.

PURPOSE: To understand the pathophysiology of central serous chorioretinopathy or bullous retinal detachment in patients under systemic corticosteroid treatment. Little is understood about the mechanism of the development of serous retinal detachment. METHODS: Three patients who had developed central serous chorioretinopathy or bullous retinal detachment during systemic corticosteroid administration were examined by fluorescein angiography and indocyanine green angiography. RESULTS: Indocyanine green angiography revealed dilated choroidal veins, delayed choroidal filling, intrachoroidal hyperfluorescence, and patchy hypofluorescence at or near the sites of dye leakage examined by fluorescein angiography. CONCLUSIONS: The primary change caused by central serous chorioretinopathy is thought to occur in the choroid, followed by the breakdown of the outer blood-retinal barrier in the pigment epithelium, resulting in the development of serous retinal detachment.

Enhanced sensitivity of bladder cancer cells to tumor necrosis factor related apoptosis inducing ligand mediated apoptosis by cisplatin and carboplatin.

PURPOSE: The development and acquisition of multiple drug resistance in cancer cells are a consequence of cancer chemotherapy and remain a major obstacle in treatment. Therefore, there is an obvious need for alternative approaches, such as immunotherapy and gene therapy. Tumor necrosis factor related apoptosis inducing ligand (TRAIL) is one of the tumor necrosis factor ligand families and it selectively induces apoptosis against cancer cells. Several cytotoxic anticancer drugs also mediate apoptosis and may share the common intracellular pathways leading to apoptosis. We reasoned that combination treatment of cancer cells with TRAIL and drugs may overcome this resistance. We evaluated whether bladder cancer cells are sensitive to TRAIL mediated cytotoxicity and whether TRAIL may synergize with anticancer agents in cytotoxicity and apoptosis against bladder cancer cells. MATERIALS AND METHODS: Cytotoxicity was determined by a 1-day microculture tetrazolium dye assay. Synergy was assessed by isobolographic analysis. RESULTS: Human T24 bladder cancer line was relatively resistant to TRAIL and TRAIL was not cytotoxic against normal bladder cells. Treatment of T24 cells with TRAIL in combination with 5-fluorouracil or mitomycin C did not overcome resistance to these agents. However, treatment of T24 cells with a combination of TRAIL and cisplatin resulted in a synergistic cytotoxic effect. Synergy was also achieved in the cisplatin resistant T24 line (T24/CDDP), 2 other bladder cancer lines and 3 freshly derived bladder cancer cells. The combination of TRAIL and carboplatin resulted in a synergistic cytotoxic effect on T24 cells. However, the combination of TRAIL and trans-diamminedichloroplatinum (II) resulted in an antagonistic cytotoxic effect. The synergy achieved in cytotoxicity with TRAIL and cisplatin was also achieved in apoptosis. Treating T24 cells with cisplatin enhanced the expression of bax but not bcl-2. Incubation of T24 cells with TRAIL increased the intracellular accumulation of cisplatin. CONCLUSIONS: This study demonstrates that combination treatment of bladder cancer cells with TRAIL and cisplatin overcomes their resistance. The sensitization obtained with established cisplatin resistant and freshly isolated bladder cancer cells required low subtoxic concentrations of cisplatin, supporting the in vivo potential application of a combination of TRAIL and cisplatin for treating TRAIL resistant and cisplatin resistant bladder cancer.

p21(WAF-1/CIP-1), a downstream regulator of functional p53 loss, in transitional cell carcinoma of urothelium.

OBJECTIVES: The expression of p21(WAF-1/CIP-1), a downstream regulator of p53, is a universal cycline-dependent kinase inhibitor. The aim of this study is to determine whether p21 expression could be used as a prognostic marker in urothelial carcinomas. METHODS: By use of immunohistochemistry, we examined the expression of p21(WAF-1/CIP-1) in 60 patients with urothelial carcinomas and compared the results with the status of nuclear p53 and mdm2 accumulation, expression of type IV collagen in the basement membranes and upregulation of metalloproteinases (MMP-1, MMP-2, MMP-9). RESULTS: p21(WAF-1/CIP-1) immunoreactivity was observed in 51.7% of the tumors, and in only 39% of the tumors with functional p53 loss (nuclear accumulation of p53 and/or mdm2). p21(WAF-1/CIP-1) overexpression was not associated with grade and stage of the tumors and presence or absence of concomitant CIS. Moreover, p21(WAF-1/CIP-1) overexpression was not associated with upregulation of metalloproteinases or destruction of type IV collagen of basement membranes. CONCLUSIONS: Our results suggest that p21(WAF-1/CIP-1) expression is regulated by both p53-dependent and independent pathways and is not related to grade, stage or potential markers of invasion in urothelial carcinomas.

Adenine-induced selective apoptosis toward HIV chronically infected cells in vitro.

A novel strategy for anti-HIV therapy is the clearance of the residual infected cells from the body. Here, we show that 6-aminopurine, adenine, induced selective apoptosis toward HIV-1 producing chronically infected MOLT4 cells (MOLT4/HIV) without augmentation of virus production, whereas the growth of uninfected MOLT4 was stimulated. This selective apoptosis did not occur with other adenine nucleotides or with other bases. The purine ring and the amino residue of adenine were responsible for the apoptosis induction and selectivity, respectively. In addition, adenine slightly but consistently reduced viable cell numbers and the production of virus in a fraction of HIV-1 chronically infected human peripheral blood mononuclear cells (PBMCs/HIV) at day 7. On the other hand, blastogenic response of normal PBMCs to PHA, PWM and Candida albicans were potentiated in the presence of adenine. These results indicated that the effect of adenine may be attributable to activation-induced selective apoptosis toward virus-infected cells.