Rat Bladder Cancer Research Articles

Comparative Study of Apoptotic Antitumor Effect between Angiogenesis Inhibitor AGM-1470 and MVAC Chemotherapy on Rat Urinary Bladder Cancer

Objectives: To investigate the antitumor apoptotic effect of AGM-1470 by comparing it to that induced by methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) therapy, currently the standard chemotherapy for bladder cancer, in a rat bladder cancer model. Materials and Methods: A total of 45 six-week-old female rats were divided into 3 equal groups: those receiving AGM-1470 treatment; those receiving MVAC treatment, and controls. All rats were cystectomized to evaluate the therapeutic effect with regard to macroscopic tumor findings, hematoxylin and eosin pathology, apoptosis detection, and immunohistochemistry (IHC) for bcl-2. Results: Our experimental protocol succeeded in producing invasive bladder tumors in the majority of rats. Tumor volume was significantly reduced in the AGM-1470 and MVAC treatment groups compared with that in the control group. The apoptotic indices of tumor cells was significantly higher in the AGM-1470 and MVAC treatment groups than in the control group. IHC for bcl-2 demonstrated no statistical difference in expression among the groups. However, the apoptotic indices of high-level bcl-2 expression were significantly lower than the indices of low-level expression in the AGM-1470 group. Conclusions: AGM-1470 and MVAC appear to exert a prominent mass reduction effect via tumor cell apoptosis in cases of invasive bladder tumor, although these therapies did not demonstrate any obvious modulation of bcl-2 protein expression status. Bcl-2 overexpression might be an obstacle to AGM-1470 therapy because of its significant inhibitory effect on apoptosis.

Mitochondrial DNA mutations in chemical carcinogen-induced rat bladder and human bladder cancer

Mitochondrial (mt) DNA mutations have been described recently in different tumors, whereas similar studies focusing on bladder cancer are scarce. In an effort to understand the significance of mtDNA mutations in bladder cancer, we investigated the mtDNA alterations in both clinical human bladder cancer and in a carcinogen-induced rat bladder cancer model. Human bladder cancer tissues were obtained by radical cystectomy and transurethral resection of bladder tumors. Rat bladder tumors were induced in SD rats by treatment with N-butyl-N-(4-hydroxybutyl) nitrosamine in drinking water for 24-28 weeks. Genomic DNA was extracted from tumor specimens and microdissected normal bladder mucosae. Mitochondrial genes and D-loop region were amplified by PCR. The amplified PCR fragments were either cloned into plasmid vector or used for direct DNA sequencing. The results of DNA sequence revealed numerous point mutations in the non-coding D-loop region and different mtDNA genes in both human and rat bladder cancers. In addition, we also detected deletions of variable lengths in mononucleotide repeats in the D-loop region, ND2, ATPase 8 and COIII genes in human bladder cancer samples. Our results show that mtDNA exhibits a high rate of mutations in both human and rat bladder cancers. We also demonstrate that the repetitive sequences of mononucleotides within the mt genome are unstable and subjected to deletions. The high incidence of mtDNA mutations in bladder cancer suggests that mtDNA and mitochondria could play an important role in the process of carcinogenesis and also mtDNA could be valuable as a marker for early bladder cancer diagnosis.

Evaluation of hyperdiploidy in the bladder epithelial cells of male F344 rats treated with ortho-phenylphenol

Ortho-phenylphenol (OPP) is a broad-spectrum fungicide and anti-bacterial agent that has been shown to cause bladder cancer in male F344 rats. An earlier study to investigate the potential role of aneuploidy in OPP-induced bladder carcinogenicity, failed to detect increases in frequencies of hyperdiploidy/polyploidy in treated animals, presumably due to the presence of polyploid cells in the bladder. To overcome this problem, we utilized a novel approach to determine increases in numerical alterations in the slowly dividing replicating cells of the rat bladder following treatment with OPP. Collagenase digestion of the bladder was used to enrich for actively-dividing cells and FISH in conjunction with BrdU was employed to detect hyperdiploidy in the replicating interphase cells. Initial studies were performed using FISH with a chromosome 4 probe. Follow-up studies were conducted with OPP and a positive control, vinblastine sulfate using probes for chromosomes 4 and 19. No significant increases in hyperdiploidy/polyploidy were seen in the replicating bladder cells of the OPP-treated rats using FISH with either the chromosome 4 or 19 probes. As expected, no significant increases in hyperdiploidy were seen in the non-replicating cells. In contrast, highly significant increases in hyperdiploidy/polyploidy, as detected using FISH with probes for either chromosome 4 or 19, were seen in the replicating cells from rats treated with a combination of OPP and vinblastine. The inability to detect increases in hyperdiploidy/polyploidy in the bladder of OPP-treated rats indicates that chromosome gain is unlikely to play a major role in the early genotoxic effects of OPP. However, the increase in hyperdiploidy/polyploidy induced by vinblastine sulfate in OPP-treated rats, clearly demonstrates that this approach using FISH in combination with BrdU is capable of detecting changes in chromosome number even in slowly-dividing tissues, such as the urinary bladder.

Whole Bladder Photodynamic Therapy for Orthotopic Superficial Bladder Cancer in Rats: A Study of Intravenous and Intravesical Administration of Photosensitizers

Photodynamic therapy after intravenous injection of Photofrin (QLT Phototherapeutics, Vancouver, British Columbia, Canada) results in a contracted bladder and skin photosensitivity, which limits its clinical application. In an attempt to overcome these limitations photodynamic therapy after intravesical instillation of Photofrin or 5-aminolevulinic acid (ALA) in an orthotopic rat bladder tumor model was explored and compared with intravenous Photofrin for photodynamic therapy efficacy and phototoxicity. At 2 weeks after bladder implantation of 1.5 x 10(6) AY-27 tumor cells animals were randomly grouped. Photofrin was administered (5 mg./kg. intravenously and 2 mg./ml. intravesically). The ALA concentration for intravesical instillation was 300 mM. Whole bladder photodynamic therapy with graded doses of light (lambda = 630 nm.) was performed 4 hours after drug administration. Tumor control and complications were evaluated. Photodynamic therapy with intravenous Photofrin plus 100 J./cm.(2) light resulted in severe bladder damage. Of 10 rats 6 died and 2 of the 10 that received 50 J./cm.(2) died. There were no photodynamic therapy related deaths in groups receiving intravesical instillation of Photofrin or ALA that also received 50 to 100 J./cm.(2) Median survival in rats treated with ALA intravesically plus 75 J./cm.(2) (77 days), Photofrin intravesically plus 50 (67) or 100 J./cm.(2) (76) and Photofrin intravenously plus 50 J./cm.(2) (60) were significantly different from that in controls (44). Intravesical instillation of Photofrin or ALA can achieve the same photodynamic therapy efficacy as intravenous Photofrin in this orthotopic rat bladder tumor model with less phototoxicity to normal tissues.

Whole Bladder Photodynamic Therapy for Orthotopic Superficial Bladder Cancer in Rats: A Study of Intravenous and Intravesical Administration of Photosensitizers

Whole Bladder Photodynamic Therapy for Orthotopic Superficial Bladder Cancer in Rats: A Study of Intravenous and Intravesical Administration of Photosensitizers

Massive apoptotic cell death in chemically induced rat urinary bladder carcinomas following in situ HSVtk electrogene transfer.

Gene delivery in current gene therapy studies relies largely on recombinant viral vectors. However, the safety of this method is still under investigation. The effectiveness of in vivo electrogene transfer as a means of gene therapy for rat bladder cancers using the herpes simplex virus 1 thymidine kinase (HSVtk) gene in combination with ganciclovir (GCV) was therefore investigated. The killing effects of HSVtk/GCV therapy were evaluated in transitional cell carcinoma (TCC) cells in vitro and in vivo. In animal experiments, electrogene transfer of HSVtk into N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced rat bladder tumors was conducted followed by GCV administration. In vitro studies demonstrated that approximately 50-70% of the TCC cells died as a result of transfection with pHSVtk and GCV administration and that this treatment was associated with decreased DNA synthesis and elevated activities of caspase-3, -8 and -9. A significantly decreased mitochondrial membrane potential was also noted in TCC cells given pHSV tk + GCV. A direct single injection of HSVtk into bladder tumors using in vivo electrogene transfer followed by GCV i.p. administration resulted in significant increases in the levels of apoptosis and histopathological necrosis accompanied by marked inflammation. Active caspase-3 was strongly expressed in the cell death areas of the TCC in rats given pHSVtk/GCV therapy. In vivo electrogene transfer results in efficient gene transfer in BBN-induced rat bladder tumors and the HSVtk/GCV prodrug system induces significant cell death which appears to be, at least, mediated via the mitochondrial apoptotic pathway.

A review of animal model studies of tomato carotenoids, lycopene, and cancer chemoprevention.

There are relatively few reports on the cancer chemopreventive effects of lycopene or tomato carotenoids in animal models. The majority, but not all, of these studies indicate a protective effect. Inhibitory effects were reported in two studies using aberrant crypt foci, an intermediate lesion leading to colon cancer, as an end point and in two mammary tumor studies, one using the dimethylbenz(a)anthracene model, and the other the spontaneous mouse model. Inhibitory effects were also reported in mouse lung and rat hepatocarcinoma and bladder cancer models. However, a report from the author's laboratory found no effect in the N-nitrosomethylurea-induced mammary tumor model when crystalline lycopene or a lycopene-rich tomato carotenoid oleoresin was administered in the diet. Unfortunately, because of differences in routes of administration (gavage, intraperitoneal injection, intra-rectal instillation, drinking water, and diet supplementation), species and strain differences, form of lycopene (pure crystalline, beadlet, mixed carotenoid suspension), varying diets (grain-based, casein based) and dose ranges (0.5-500 ppm), no two studies are comparable. It is clear that the majority of ingested lycopene is excreted in the feces and that 1000-fold more lycopene is absorbed and stored in the liver than accumulates in other target organs. Nonetheless, physiologically significant (nanogram) levels of lycopene are assimilated by key organs such as breast, prostate, lung, and colon, and there is a rough dose-response relationship between lycopene intake and blood levels. Pure lycopene was absorbed less efficiently than the lycopene-rich tomato carotenoid oleoresin and blood levels of lycopene in rats fed a grain-based diet were consistently lower than those in rats fed lycopene in a casein-based diet. The latter suggests that the matrix in which lycopene is incorporated is an important determinant of lycopene uptake. A number of issues remain to be resolved before any definitive conclusions can be drawn concerning the anticancer effects of lycopene. These include the following: the optimal dose and form of lycopene, interactions among lycopene and other carotenoids and fat soluble vitamins such as vitamin E and D, the role of dietary fat in regulating lycopene uptake and disposition, organ and tissue specificity, and the problem of extrapolation from rodent models to human populations.

Selective cytotoxicity of gemcitabine in bladder cancer cell lines.

We have examined the cytotoxic effect of gemcitabine in intravesical therapy using an in vitro co-cultured spheroid model composed of transitional cell carcinoma (TCC) and fibroblasts from both human and rat species. Immunohistochemistry analysis of the co-cultured spheroids, using cytokeratin-13 and vimentin antibodies against TCC and fibroblasts, respectively, showed the central location of fibroblasts within the spheroid, whereas TCC formed the peripheral layers. Spheroids composed of human TCC and fibroblasts (MGH-U3/CRL-1120 or RT-112/CRL-1120) as well as rat TCC and their corresponding fibroblasts (AY-27/RF-Ed1) displayed the same drug tolerance profile after an exposure of 0, 1, 3, 5, 7 and 14 days. As confirmed by time-lapse photography, MTT essay and vital dye staining, gemcitabine selectively killed the human and rat bladder cancer cell lines, but did not affect un-transformed human and rat fibroblast lines.

Influence of pertussis toxin on superficial bladder carcinoma in rats.

The proliferation and migration of cells is a fundamental process for the metastasis of malignant tumour cells. In several in vitro studies, pertussis toxin (PTX) inhibited cell proliferation and cell motility in the human transitional cell carcinoma cell line J82. The present study investigated the effect of the intravesical application of PTX on the development of superficial bladder cancer in rats. We used the model of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN, 0.05% via drinking water x10 weeks) to induce superficial bladder carcinomas in 40 female rats. After 16 weeks the rats were treated in two groups with 0.4 ml PTX (1 microg/ml) or 0.4 ml phosphate buffered saline (PBS) by intravesical application (once a week for 10 weeks). In the 25th week urine cytology was determined and all rats were killed at week 26 followed by histological evaluation. In the control group, the urine cytology was positive for G2/G3 cells in ten of 17 rats. In the PTX group G2/G3 cells were determined in five of 20 rats ( P two tailed <0.05). Histopathologically 12 rats (71%) of the control group and 11 rats (55%) of the PTX group developed T1-T2 transitional-cell carcinomas. No local or systemic side effects were disclosed. PTX treatment reduces the development of G3 transitional cell carcinomas in rats and may represent a new approach for local therapy in superficial bladder cancer.

A concise review of the toxicity and carcinogenicity of dimethylarsinic acid

Dimethylarsinic acid (DMA) has been used as a herbicide (cacodylic acid) and is the major metabolite formed after exposure to tri- (arsenite) or pentavalent (arsenate) inorganic arsenic (iAs) via ingestion or inhalation in both humans and rodents. Once viewed simply as a detoxification product of iAs, evidence has accumulated in recent years indicating that DMA itself has unique toxic properties. DMA induces an organ-specific lesion — single strand breaks in DNA — in the lungs of both mice and rats and in human lung cells in vitro. Mechanistic studies have suggested that this damage is due mainly to the peroxyl radical of DMA and production of active oxygen species by pulmonary tissues. Multi-organ initiation-promotion studies have demonstrated that DMA acts as a promotor of urinary bladder, kidney, liver and thyroid gland cancers in rats and as a promotor of lung tumors in mice. Lifetime exposure to DMA in diet or drinking water also causes a dose-dependent increase in urinary bladder tumors in rats, indicating that DMA is a complete carcinogen. These data collectively suggest that DMA plays a role in the carcinogenesis of inorganic arsenic.

Long-term feeding of sodium saccharin to nonhuman primates: implications for urinary tract cancer.

It was observed in the early 1970s that saccharin produced bladder cancer in rats. However, it has been unclear whether sodium saccharin when consumed by humans poses a substantial carcinogenic hazard. Numerous epidemiologic studies have not shown any evidence of increased urothelial proliferation associated with ingestion of sodium saccharin. Our purpose was to determine the effects of long-term feeding of sodium saccharin to three species of nonhuman primates. Twenty monkeys of three species (six African green, seven rhesus, six cynomolgus, and one hybrid [of rhesus male and cynomolgus female parentage]) were treated with sodium saccharin (25 mg in the diet/kg body weight daily for 5 days a week) beginning within 24 hours after birth and continuing for up to 24 years. Sixteen monkeys (seven rhesus and nine cynomolgus) served as controls. During their last 2 years of life, urine was collected from selected treated and control animals and evaluated for various urinary chemistries and for the presence of calculi, microcrystalluria, and precipitate. Urinary bladders were examined by light microscopy and by scanning electron microscopy. Sodium saccharin treatment had no effect on the urine or urothelium in any of these monkeys. There was no evidence of increased urothelial cell proliferation, and there was no evidence of formation of solid material in the urine. Although the dose of sodium saccharin administered to these monkeys was only five to 10 times the allowable daily intake for humans, the results provide additional evidence that sodium saccharin is without a carcinogenic effect on the primate urinary tract.

M-VAC chemotherapy induced apoptosis in the rat bladder cancer: correlation with p53 alterations

M-VAC chemotherapy induced apoptosis in the rat bladder cancer: correlation with p53 alterations

Human mammary cancer cell lines and other epithelial cells cultured as organoid tissue in lenticular pouches of reinforced collagen membranes

A system has been developed for the culture of cells that provides conditions favoring the formation of tissues comparable to conditions existing in nature. The culture chamber is a lens-shaped pouch composed of two thin-walled, reinforced, waffled collagen membranes facing each other. The chamber is immersed in medium in a closed transparent container and incubated on a rocker. On histologic study, after days to weeks in culture, human mammary cancer cell lines BT-20, MCF-7, MDA-231, MDA-468, and T47D grow in the chamber as distinctive structured epithelial tissue. Dog kidney cell line MDCK grows as a papillary adenocarcinoma and rat bladder cancer line NBT-II as an epidermoid carcinoma; cells from clinical effusion tumors produce distinct tissue. Changes in histologic phenotype may be driven by molecular changes at the level of the genome. Resulting alteration of the biochemical functions essential for the integrity of specific durable tissue organization should alter or reset the pattern of tissue organization and of biological behavior, including malignancy and response to cytotoxic chemicals. Lenticular pouch culture promises to be an effective tool for exploring the molecular changes associated with histogenesis and malignancy.

Lack of involvement of p53 gene mutations in N-methyl-N-nitrosourea-induced bladder tumor progression in N-butyl-N-(4-hydroxybutyl)nitrosamine-treated rats and no suppression by indomethacin.

The relevance of p53 mutations to rat bladder cancer progression induced by a single injection of N-methyl-N-nitrosourea (MNU) and the chemopreventive effects of indomethacin (IM) were investigated in male F344 rats, initially given N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) at a dose of 500 ppm in the drinking water for 10 weeks. The animals were subsequently treated with a single intraperitoneal injection of MNU at a dose of 50 mg/kg b.w. at week 20. A subgroup was then given IM dissolved in the drinking water at a concentration of 20 ppm for 20 weeks. The experiment was terminated at week 40 when transitional cell carcinomas (TCC) were observed in all animals given BBN, regardless of the administration of MNU and/or IM (incidences ranged from 80 to 100%). The extent of invasion was significantly greater with the additional MNU treatment but no inhibitory effects of IM were noted. A low frequency of p53 mutations was detected without relation to the extent of tumor invasion. Thus, only two mutations were found, one in a Ta and the other in a T1 carcinoma. The present study thus demonstrated that p53 mutations are not involved in MNU-induced progression in rat urinary bladder cancers, suggesting that they are not critical for malignancy.

Morphological changes in the basement membrane during progression from non-invasive to invasive rat bladder cancer induced by N-butyl-N-(4-hydoxybutyl) nitrosamine.

To investigate the ultrastructural changes in the basement membrane (BM) in the rat model of bladder cancer when progressing from non-invasive to invasive disease. N-butyl-N-(4-hydoxybutyl) nitrosamine (BBN) was administered to 50 rats (7 weeks old) in their drinking water (0.05% BBN) for 28 weeks. At between 20 and 28 weeks, 10 rats were killed every 2 weeks and morphological changes of the BM were investigated by transmission electron microscopy and histological changes by light microscopy. At between 20 and 28 weeks, the transitional cell carcinoma (TCC) of the rat bladder induced by BBN progressed from non-invasive (stage Ta) to invasive (stage T1-2) disease. Focal thinning and discontinuity of the BM occurred in five of 26 rats with non-invasive TCC and in all 24 rats with invasive TCC. Stage Ta bladder cancer in the rat model may be associated with degradative changes in the BM and can be divided into two types, Ta1 where there is no degradation of the BM and Ta2, where the BM is degraded.

Subcellular localization and characterization of interleukin-1α produced by rat bladder cancer cells

A rat bladder cancer cell line BC31ad, previously reported to constitutively release tumor necrosis factor α (TNFα), was found to produce an interleukin (IL)-1-like factor inducing proliferation of murine thymocytes in a standard costimulation assay (LAF activity). IL-1-like factor was partially purified by DEAE-Sephacel, Sephacryl S-200 and MonoQ-FPLC chromatographies from the serum-free conditioned medium of a BC31ad-derived clone, C19, to the specific activity of 3.2 × 10 6 U/mg and characterized as a protein of molecular weight 17 kDa with isoelectric point 5.2. LAF activity of IL-1-like factor was specifically neutralized with anti-rat IL-1α but not with anti-rat IL-1β. These findings show that the IL-1-like factor is rat IL-1α, although the precise molecular relationship with monocyte IL-1α is unclear. Futhermore, IL-1α was shown to be primarily located in the cytosol and plasma membrane without spontaneous release. A kinetics study indicated that it was leaked into the medium late in culture resulting from cell destruction, in contrast to TNFα which was released as the cell number was increased. We discussed the possible role of IL-1α as an autocrine or paracrine growth regulator.

Characterization of a cytotoxic factor produced by rat bladder cancer cell line: its identity to TNF alpha.

Clone C19 derived from a rat bladder cancer cell line BC31ad constitutively released cytotoxic factor RCF. The serum-free C19-conditioned medium was partially purified by DEAE-Sephacel, Sephacryl S-200 and MonoQ-FPLC chromatographies to the specific activity of 6.4 x 10(6) U/mg protein (LM assay). RCF was a 17-kDa protein with pI 4.6-5.0. Anti-RCF serum neutralized the cytotoxic activity of rat and mouse, but not human, tumor necrosis factor-alpha (TNF alpha) as well as RCF. The partial amino acid sequence of RCF was homologous with the sequence 43-58 of rat TNF alpha. RCF and rat TNF alpha showed a similar cytotoxic spectrum against several tumor cells. Furthermore, they induced a marked proliferation of mouse T cells in combination with a suboptimal dose of ConA or anti-CD3 antibody, however, human TNF alpha almost not. Taken together, RCF was substantially regarded as rat TNF alpha.

The role of alkalizing and neutral potassium salts in urinary bladder carcinogenesis in rats.

Using an initiation-promotion rat model, we have previously shown that the alkalizing salt KHCO3 is a strong and the neutral salt KCl a weak promoter of urinary bladder carcinogenesis. We have now studied the effects of these salts on rat urinary bladder epithelium without prior exposure to a bladder tumour initiator. In four studies ranging in duration from 4 to 130 weeks, (equimolar) amounts of K+ were administered in the diet to male and female rats (85 rats/sex/group) as KHCO3 or KCl. Comparable increases in urinary volume and potassium levels were found with both KHCO3 and KCl, but only KHCO3 induced an elevated urinary pH. The feeding of KHCO3 resulted in simple epithelial hyperplasia and, after prolonged administration, in papillary/nodular hyperplasia, papillomas and transitional cell carcinomas of the urinary bladder. With KCl, only a slight increase in proliferative urothelial lesions was found; one male showed papillary hyperplasia and one female exhibited nodular hyperplasia and a papilloma. Our results allow the conclusion that KHCO3, a strong promoter of bladder carcinogenesis, is capable of inducing urinary bladder cancer in rats without prior application of an initiator, whereas KCl, a weak tumour promoter, induced only a few (pre)neoplastic lesions.

Influence of Lactobacillus casei on rat bladder carcinogenesis

The inhibitory effect of Lactobacillus casei (L. casei) in superficial bladder tumors was investigated in an experimental study using N-butyl-N (4-hydroxybutyl) nitrosamine (BBN)-induced rat bladder cancer as an experimental system. The study consisted of two experiments; in a short-term experiment, the inhibitory effect of 6-week treatment with L. casei was assessed in vitro in terms of the capacity for agglutination by concanavalin A (Con A) of bladder epithelial cells in their incipient stage of malignant transformation induced by 1-week exposure to BBN. As a result, the number of bladder epithelial cell aggregates caused by Con A was significantly smaller in the L. casei-treated group than in the non-L. casei-treated group (p < 0.001). In a long-term experiment, treatment with L. casei of varying duration was investigated for effectiveness against bladder tumors induced by 7-weeks exposure to BBN that arose 22 weeks. The results indicate that both bladder weight and tumor volume per organ were significantly lower in the L. casei-treated than non-L. casei-treated group (p < 0.05). The inhibitory effect on these parameters was more pronounced with treatment with L. casei of longer duration. While there was no significant difference among the treatment groups in the degree of extension of induced malignancy, tumors with a high degree of extension (T1b, T2) developed only in the non-L. casei-treated group. The degree of malignancy of induced tumors was significantly lower in those groups receiving L. casei while BBN was being administered as compared to the non-L. casei-treated group (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cell-mediated cytotoxicity of tumor infiltrating lymphocytes on rat bladder cancer

Cell-mediated cytotoxicity of tumor infiltrating lymphocytes on rat bladder cancer