Effects of interferon in combination with cytotoxic drugs on mouse bladder tumor (MBT-2) growth in vitro and in vivo

The effects of interferon alone and in combination with either adriamycin, mitomycin C or thiotepa were evaluated for antiproliferative activity for the mouse bladder tumor, MBT-2. In vitro dose response studies with adriamycin, mitomycin C and thiotepa showed dose dependent antiproliferative activity over a concentration range of .001 microgram./ml. to 10 microgram./ml. Interferon also exhibited dose dependent inhibition over a dose range of 250 units/ml. to 4000 units/ml. Comparative in vitro antiproliferative studies showed adriamycin to consistently be the most inhibitory cytotoxic drug followed by mitomycin C and thiotepa. Interferon and thiotepa produce similar (35%) inhibition at the highest concentrations studied. In vitro studies assessing the effects of interferon (1000 units/ml.) combined with each cytotoxic drug (0.01 to 1.0 microgram./ml.) were performed. The most effective combination was observed to be interferon and adriamycin. In three of four experiments either additivity or synergism was observed while consistently augmented activity was not observed with interferon combined with either thiotepa or mitomycin C. In vivo studies on MBT-2 tumors implanted intravesically showed no antitumor activity for adriamycin alone, interferon alone or a combination of both. These results show that combination intravesical therapy with interferon and adriamycin is not an effective treatment regimen in the mouse model when administered as described in this report. These data further suggest that combinations of interferon and cytotoxic drugs may not provide improved response rates in patients treated for superficial bladder tumors.     

Enhanced anti-tumor effects of recombinant human tumor necrosis factor plus VP-16 on metastatic renal cell carcinoma in a xenograft model

A nude mouse renal subcapsular and subcutaneous implantation xenograft model utilizing the SN12C human renal carcinoma cell line was investigated. In the absence of treatment, renal subcapsular implantation of SN12C resulted in metastatic spread (lung, liver and lymph nodes) and death of all animals. Radical nephrectomy of the tumor-bearing kidney after various periods of tumor implantation demonstrated that surgery alone after 18 days of tumor growth resulted in no statistically significant increase in survival with 100% of the nephrectomized animals succumbing to local recurrence and distant metastases. Recombinant human tumor necrosis factor (rTNF) and VP16 (etoposide), both well known cytotoxic and cytostatic anticancer agents, were tested singly and in combination against this metastatic model of human renal adenocarcinoma. Single agent rTNF or VP16 therapy after radical nephrectomy demonstrated only minimal efficacy with no significant decrease in local recurrence and distant metastases as compared to nephrectomy only control animals. In contrast, the combination of rTNF plus VP16 when given after nephrectomy resulted in a significant decrease in local recurrence and no gross evidence of metastasis in any animal. Subcutaneously growing SN12C tumor nodules were also treated with the same rTNF, VP16 and combination regimens. Regression in tumor size was noted only in the combination treatment group. rTNF or VP16, as single agents, demonstrated only slight growth inhibition that was not statistically significant. These results suggest that by combining TNF plus VP16, a synergistic enhancement of antineoplastic activity against local as well as metastatic human renal cell carcinoma can be produced.     

Effects of photodynamic therapy in combination with intravesical drugs in a murine bladder tumor model.

This study was designed to evaluate the interaction of photodynamic therapy (PDT) and intravesical drugs (thiotepa, adriamycin, mitomycin C and BCG) in a murine transitional cell carcinoma (MBT-2) model. C3H/He mice with implanted MBT-2 flank tumors were treated with either thiotepa (TT), adriamycin (ADM), mitomycin C, Bacillus Calmette-Guerin (BCG), photodynamic therapy (PDT) or a combination of the drug and PDT. The MBT-2 tumor showed sensitivity to adriamycin, MMC or PDT compared to control. PDT combined with either adriamycin, MMC or BCG, produced a greater retardation in the growth of the MBT-2 tumor than monotherapy with adriamycin, MMC, BCG or PDT. PDT combined with the anticancer agents currently used in intravesical therapy for bladder cancer is well tolerated. The combination of PDT and intravesical drugs may enhance the tumoricidal effect of either treatment used alone.     

Antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on bladder cancer cell lines

OBJECTIVES: To investigate the antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on human bladder cancer cell lines (KU-1 and EJ-1) and a murine bladder cancer cell line (MBT-2). METHODS: Bladder cancer cells were incubated with various concentrations of the agents. Antiproliferative activity against the bladder cancer cell lines was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diplenyl tetrazolium bromide assay. In an in vivo experiment, the mice were subcutaneously injected with MBT-2 cells, and Scutellariae radix was orally administered at a dose of 2 or 10 mg per mouse one time daily for 10 days from day 11 to day 20. RESULTS: All the drugs inhibited cell proliferation in a dose-dependent manner, but baicalin exhibited the greatest antiproliferative activity. The concentration of baicalin necessary to obtain 50% inhibition was 3.4 microg/mL for KU-1, 4.4 microg/mL for EJ-1, and 0.93 microg/mL for MBT-2. For KU-1 and MBT-2, the percentage of cell survival significantly decreased (P <0.05) at a baicalin concentration of 1 microg/mL. In an in vivo experiment, antitumor effects of Scutellariae radix on C3H/HeN mice implanted with MBT-2 were investigated. All the control mice showed a progressive increase in tumor volume, reaching 2.81 +/- 0.18 cm(3) on day 20 and 5.36 +/- 0.44 cm(3) on day 25. However, when Scutellariae radix was orally administered at a dose of 10 mg per mouse one time daily for 10 days from day 11 to day 20, the tumor volume was 1.99 +/- 0.19 cm(3) on day 20 and 3.86 +/- 0.26 cm(3) on day 25, a significant inhibition of tumor growth (P <0.05). Conclusions. These results suggest that Chinese herbal medicines may become an attractive and promising treatment for bladder cancer.     

Combination effects of CDDP and hyperthermia in mouse bladder tumor (MBT-2)

The combination effects of CDDP and hyperthermia in mouse bladder tumor (MBT-2) were investigated both in vivo and in vitro. MBT-2 was transplanted into the hind leg of a C3H/He mouse. Then the leg was dipped in a hot water bath immediately after the intraperitoneal administration of CDDP. The antitumor effects were evaluated from tumor volume. The CDDP plus hyperthermia (43 degrees C) group showed remarkable tumor growth retardation. The in vitro colony forming assay showed that MBT-2 cultured cells treated with CDDP at 42 degrees C exhibited great colony forming inhibition in comparison with the CDDP alone cells. The effects of CDDP plus hyperthermia on the cell cycle progression of MBT-2 cultured cells were studied by using flow cytometry. The results showed that the cells treated with CDDP at 42 degrees C exhibited an accumulation of cells in the C2 phase for many hours as compared with the CDDP alone cells, indicating thermal enhancement of DNA damage in MBT-2 cultured cells treated with CDDP.     

Antitumor effect of combined use of purified human natural tumor necrosis factor (N-TNF) and cis-diamminedichoroplatinum (II) (cisplatin) on the implanted bladder carcinoma (MBT-2) in mice]

The antitumor effect of tumor necrosis factor (TNF) in combination with Cis-diammine-dichloroplatinum (II) (Cisplatin) upon implanted bladder carcinoma (MBT-2) in mice was analysed together with the toxicity. Mice were implanted into the bladder wall with about 10(4) cells MBT-2 viable cells. TNF was the purified human natural tumor necrosis factor. The antitumor effects were evaluated by the volume of the tumor thus implanted and the drug-toxicity by the body weight of mice and microscopic as well as macroscopic findings of the main organs. As a result, 1) The toxicity of TNF to mice was not enhanced in a dose-dependent fashion when combined with Cisplatin. 2) The antitumor effect by combination of TNF and Cisplatin was significantly increased compared to control group. 3) The effects of TNF was enhanced in a dose-dependent fashion when combined with Cisplatin. 4) The antitumor effects was confirmed by pathological findings. These results suggest that the combined use of n-TNF and Cisplatin is promising as a clinically effective treatment against bladder cancer in human.     

Chemosensitivity test on superficial urinary bladder cancer using the dye exclusion assay--model of intravesical chemotherapy

A chemosensitivity test was carried out on superficial bladder cancers using the trypan blue dye exclusion assay for the purpose of screening chemosensitive drugs for intravesical chemotherapy. Transplantable murine bladder tumor cells (MBT-2) were incubated, in vitro, in the presence of adriamycin (4, 40, 400, 1000 micrograms/ml) as well as verapamil (3, 30, 100, 500 micrograms/ml) at 5% CO2, 37 degrees C for two hours. After cellular viabilities were calculated, MBT-2 cells were inoculated into the hind limbs of mice. The cellular viability was correlated well with the ratio of tumor appearance, tumor growth inhibition and prolongation of survival, and was dose dependent in the adriamycin treated groups. On the other hand, a reduction of cellular viability, tumor growth inhibition and prolongation of survival were seen in the high dose verapamil (100, 500 micrograms/ml) treated groups. Human superficial bladder cancer cells were incubated in the presence of adriamycin, 4'-0-tetrahydropyranyladriamycin, mitomycin C and pepleomycin (1000 micrograms/ml) and/or verapamil (500 micrograms/ml). The reduction rates of cellular viability markedly varied with the kind of anticancer drugs. A reduction of cellular viability of human tumor cells as well as MBT-2 cells was seen in the verapamil treated groups. This rapid and handy assay seems to be useful for the purpose of screening chemosensitive drugs for intravesical chemotherapy.     

Antineoplastic activity of honey in an experimental bladder cancer implantation model: In vivo and in vitro studies

OBJECTIVES: The antitumor effect of bee honey against bladder cancer was examined in vitro and in vivo. Methods: Three human bladder cancer cell lines (T24, 253J and RT4) and one murine bladder cancer cell line (MBT-2) were used in these experiments. In an in vitro study, the antitumor activity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay, 5-Bromodeoxyuridine (BrdU) labeling index and flowcytometry (FCM). In the in vivo study, cancer cells were implanted subcutaneously in the abdomens of mice, and the effects were assessed by the tumor growth. RESULTS: In vitro studies revealed significant inhibition of the proliferation of T24 and MBT-2 cell lines by 1-25% honey and of RT4 and 253J cell lines by 6-25% honey. BrdU labeling index was significantly lower. FCM showed lower S-phase fraction, as well as absence of aneuploidy compared with control cells. In the in vivo studies, intralesional injection of 6 and 12% honey as well as oral ingestion of honey significantly inhibited tumor growth. CONCLUSION: Bee honey is an effective agent for inhibiting the growth of T24, RT4, 253J and MBT-2 bladder cancer cell lines in vitro. It is also effective when administered intralesionally or orally in the MBT-2 bladder cancer implantation models. Our results are promising, and further research is needed to clarify the mechanisms of the antitumor activity of honey.     

The activity of etoposide (VP16) in combination chemotherapy against human bladder cancer cells in vitro]

The activity of Etoposide (VP16) in combination chemotherapy against four human transitional cell carcinoma cell lines of bladder (TCCaB) was determined by in vitro colony formation assay. Four anti-tumor agents (methotrexate: MTX, vinblastine: VBL, adriamycin: ADM, cisplatin: DDP) were used for combination chemotherapy with VP16. The ADM + VP16 combination exhibited a strong synergistic antitumor effect against the human TCCaBs compared with other combinations in this study. The combination chemotherapy of ADM + VP16 may be useful as a new chemotherapeutic regimen for advanced bladder cancer.     

Two hour exposure to sodium butyrate sensitizes bladder cancer to anticancer drugs

Objectives:   To investigate the inhibitory effect of sodium butyrate (NaB) on the proliferation of human bladder cancer cell lines and its synergetic effect with anticancer drugs in treating bladder cancer in vitro and in vivo .
Methods:   The inhibitory effects of NaB on human bladder cancer cell lines in vitro and the synergetic effect of NaB with mitomycin c, cisplatin (CDDP) and adriamycin were detected by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Hoechst staining and electron microscopy were used to observe morphology for apoptotic cells after NaB treatment. Fas, bcl-2 and caspase-3 were determined with flow cytometry. In vivo synergetic effects were detected in N-methyl-N-nitrosourea induced bladder cancer model rats.
Results:   NaB significantly inhibited the growth of bladder cancer cell lines in a concentration and time dependent manner. Better results of tumor inhibition have been achieved when NaB was combined with CDDP, mitomycin c and adriamycin, rather than used alone. Furthermore, 2 h exposure to NaB can sensitize bladder cancer to chemotherapy agents. The Bcl-2 expression in bladder cancer cells is decreased and caspase-3 expression increased after NaB treatment. Intravesical application of NaB combined with CDDP can significantly inhibit tumor growth and progression.
Conclusions:   NaB has a direct anticancer effect and can markedly enhance the action of several chemotherapy agents. 2 h expose to NaB can also sensitize bladder cancer to anticancer drugs. NaB may be an excellent candidate agent for intravesical application in treating bladder cancer.     

In vitro and in vivo activity of two second generation platinum analogs in murine bladder cancer

The activity of cis-diamminedichloroplatinum(II) was compared to two second generation platinum analogs, cis-diammine-1,1-cyclobutane dicarboxylate platinum(II) and cis-dichlorotransdihydroxybisisopropylamine platinum(IV) in the N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide-induced murine bladder tumor model and a tumor colony assay. Murine drug testing revealed that all three drugs were active against the MBT-2 tumor line, although cis-diamminedichloroplatinum(II) was more active than its analogs. All drugs produced enhanced inhibition of clonal growth with increasing drug exposure times. Cis-diamminedichloroplatinum(II) was more active against MBT-2 cells in the plateau growth phase versus the log growth phase after a one hour drug exposure. Similar differential activity depending upon the proliferative state of MBT-2 was not seen with the two platinum analogs. These two platinum analogs have somewhat less activity in vivo and in vitro than cis-diamminedichloroplatinum(II) and would be predicted to be less effective clinically in human bladder cancer than the parent compound.     

In vitro and in vivo anti-tumor activity of recombinant mouse tumor necrosis factor (TNF) in a mouse bladder tumor (MBT-2)

Tumor necrosis factor (TNF) has confirmed anti-tumor activity. When used in combination with interferon gamma (IFNG) or chemotherapeutic drugs targeted at DNA topoisomerase II, synergistic cytotoxicity has been observed. Investigations of the anti-tumor activity of recombinant mouse TNF in a mouse bladder tumor model (MBT-2) were performed. The cytotoxicity of TNF and low dose actinomycin-D (AMD) against MBT-2 in vitro was examined alone and following preincubation with IFNG. The activity of TNF/AMD in vivo utilizing an intravesical implantation mode (MBT-2) was also evaluated. TNF alone had no cytotoxic effect in vitro. TNF/AMD was cytotoxic for MBT-2 growth in vitro. Maximum cytotoxicity (86%) occurred at one microgram./ml. TNF/one microgram./ml. AMD with 50% cytotoxicity at .64 micrograms./ml. TNF/one/microgram./ml. AMD. A two hour preincubation with IFNG markedly increased the cytotoxicity of TNF/AMD whereas longer incubations did not enhance cytotoxic activity. TNF alone and in combination with AMD did not significantly reduce the percentage of intravesical tumor outgrowth in vivo compared to controls. This study demonstrated that TNF/AMD exhibits cytotoxicity for MBT-2 cells in vitro but is ineffective in reducing implantation of intravesical tumors in vivo. The in vitro data suggest brief exposure of MBT-2 cells to IFNG augments the subsequent anti-tumor activity of TNF/AMD.     

Potentiation of effects of anticancer agents by local electric pulses in murine bladder cancer

Electrochemotherapy is a novel cancer treatment in which electric pulses (EP) are used as a means of delivering anticancer agents to the cytoplasm of cancer cells (electroporation). The present study evaluates whether electrochemotherapy has in vitro and in vivo anticancer effects in murine bladder cancer. Using mouse bladder tumor cells (MBT-2 cells), in vitro electrochemotherapy was performed by applying EP to the cell suspension immediately after the addition of anticancer agents. The cytotoxicity of adriamycin (ADM), bleomycin (BLM) and cis-diamminedichloroplatinum(II) (CDDP) was determined by measuring succinate dehydrogenase (SD) activity in both electroporated and non-electroporated cells. In addition, intracellular concentrations of these anticancer agents were also measured. In the in vivo study, tumor-bearing C3H/He mice were treated with an intraperitoneal injection of anticancer agents followed by a local delivery of EP at the tumor site. Then, tumor growth rate (TGR) was determined and compared to that in the sham-treated control group, the EP-only group and the drug-only group. The in vitro study showed that, with electroporation, the cytotoxicity of BLM in electroporated cells was increased by as much as 95.7-fold compared to that of non-electroporated MBT-2 cells; CDDP showed only an increase of 1.8-fold and ADM showed no increase. After electroporation, the intracellular concentration of BLM, CDDP and ADM showed an increase of 120-, 1.7- and 0.8-fold, respectively. In electrochemotherapy for in vivo growing tumors, the potentiation of the antitumor effect was most prominent when combined with BLM, only slightly with CDDP, and totally absent with ADM. It is clear from in vitro and in vivo studies that, in a murine bladder tumor, the anticancer effect of BLM can be considerably potentiated by applying EP. Thus, BLM seems to be the most suitable anticancer agent for electrochemotherapy of bladder cancer. Received: 28 August 1999 / Accepted: 27 July 2000     

Internalization of bacille Calmette-Guerin by bladder tumor cells

Mechanisms by which intravesical bacille Calmette-Guerin (BCG) treatment mediates antitumor activity are currently poorly understood. We have determined that both human bladder tumor (T-24) and mouse bladder tumor (MBT-2) cells are capable of internalizing the BCG and have characterized this process in vitro. The internalization of BCG by T-24 and MBT-2 cells was verified by histochemistry and electron microscopy. Time dependent internalization of BCG was observed with a maximum occurring at three hrs. Internalization was significantly inhibited by both incubation at 4C and cytochalasin B; conditions known to inhibit phagocytosis. Ultrastructural studies suggested that BCG were transported to membrane bound intracellular compartments and were degraded. The compartments containing the degraded mycobacteria labeled with the fluid phase marker HRP which is known to be transported to lysosomes in a variety of cell types. To determine if the internalization process occurred in vivo, we examined bladder washings of patients treated with intravesical BCG. The majority of the cells in the bladder washings were inflammatory cells which contained ingested BCG. In addition, internalized and degraded BCG were identified in urothelial cells. These data demonstrate that BCG are internalized by transitional epithelial cells both in vitro and in vivo. The internalization process is inhibitable by temperature and microfilament disruption. The potential therapeutic implications of this process and its relationship to antitumor activity of BCG therapy are currently being investigated.     

Inhibition of mouse bladder tumor proliferation by alpha difluoromethylornithine and interferon in vitro and in vivo

Previous studies have reported that alpha difluoromethylornithine (DFMO), an enzyme-activated, irreversible inhibitor of ornithine decarboxylase (ODC), has anti-tumor activity in several tumor systems. Recently, investigations have revealed that combinations of DFMO and Interferon (IFN) are synergistic in inhibiting tumor cell growth. We tested the effects of DFMO and IFN alpha, beta alone and in combination on the growth of mouse bladder tumor (MBT-2) cells both in vitro and in vivo. MBT-2 cells were incubated for 72 hours in 96 well microtiter plates with DFMO, IFN alpha, beta and combinations of both agents and percentage inhibition was calculated. In vivo studies utilized the intravesical implantation method as well as subcutaneous implantation. DFMO was administered as a 1% solution in the drinking water. IFN alpha, beta was given bi-weekly by intravesical administration. DFMO effectively inhibited MBT-2 growth in vitro. The ID50 was 0.08 mM and peak inhibitory activity was reached at concentrations of 0.16 mM and remained constant with concentrations of up to 10 mM. IFN alpha, beta also inhibited the in vitro proliferation of MBT-2 with maximum inhibition (46%) at 2,000 U/ml. Combinations of DFMO and IFN alpha, beta showed increased anti-proliferative activity. The degree of enhancement varied with synergism, additivity, or sub-additivity at varying drug concentrations. In vivo, DFMO significantly retarded the growth of tumors implanted subcutaneously (p less than .05) and significantly delayed the outgrowth of tumors implanted intravesically (p less than .01). IFN alpha, beta alone was ineffective in vivo and produced no additive effect in vivo when used in combination with DFMO. Results of our investigation show that DFMO inhibits proliferation of MBT-2 cells in vitro and exhibits a similar effect in vivo against subcutaneous and intravesical tumor implants. IFN alpha, beta alone demonstrated anti-proliferative activity in vitro but did not affect MBT-2 growth in vivo. Although the combination of DFMO and IFN alpha, beta exhibited enhanced activity in vitro, no enhancement was observed with combination therapy in vivo.     

In vitro effects of epidermal growth factor (EGF) on growth of urological malignant tumor cells

It is well known that Epidermal Growth Factor (EGF) is a cell-regulating factor for variety of tissues in vitro including normal and malignant cells. Furthermore, Takano et al reported that a decreased expression of EGF receptor in clones of human cancer KB cell line might be one of the pleiotropic properties of multidrug-resistant cells. However, both the influence of EGF on human urological cancer cell lines and the relation between EGF receptors and sensitivities of antitumor drugs on these cell lines have not been fully described. We have studied the effects of EGF on growth of 4 transitional carcinoma cell lines of bladder (TCCaB), 1 squamous cell carcinoma cell line of bladder (SCCaB), 5 renal cell carcinoma cell lines (RCC) and 3 prostatic carcinoma cell lines (CaP), as well as the relationship between the number of EGF receptors and drug sensitivities of these cell lines in vitro against methotrexate, vinblastine, adriamycin, cisplatin and etoposide (VP16). The present results determined by the in vitro colony forming efficiency method showed that exogenous addition of EGF to cell cultures at 0.1 ng/ml stimulated the growth of SCCaB by 169.0%, and at 1 ng/ml inhibited that of RCC by 2.9%-79.0%, relative to control. The more EGF receptors by 125I-EGF binding assay, the higher inhibition of VP16 on the growth of these cell lines. These results suggested that EGF stimulated the growth of SCCaB and inhibited the growth of RCC in vitro, and we found that these phenomena were correlated with neither the number of EGF receptors nor affinities of that receptors.(ABSTRACT TRUNCATED AT 250 WORDS)     

人膀胱癌细胞耐药株多基因蛋白表达的意义

为研究膀胱肿瘤细胞耐药机制，使用药物浓度递增的方法，分别采用阿霉素（ＡＤＭ）或足叶乙甙（ＶＰ１６）建立了人膀胱癌耐药细胞株ＢＩＵ８７／Ａ和ＢＩＵ８７／Ｖ，并进行了耐药倍数分析。ＢＩＵ８７／Ａ对ＡＤＭ、ＶＰ１６的耐药倍数分别为５７４、５９４；ＢＩＵ８７／Ｖ对ＡＤＭ、ＶＰ１６的耐药倍数分别为６５、５４。采用免疫组化的方法分析Ｐ５３、ｂｃｌ２蛋白和Ｐ糖蛋白（Ｐｇｐ）在细胞中的表达，结果显示ＢＩＵ８７三种蛋白均阴性，而ＢＩＵ８７／Ａ、ＢＩＵ８７／Ｖ的三种蛋白均阳性，且ＢＩＵ８７／Ａ的表达量均多于ＢＩＵ８７／Ｖ。结果说明突变型Ｐ５３蛋白、ｂｃｌ２蛋白和Ｐｇｐ表达在细胞耐药机制中可能起重要作用     

Antitumor activity of interleukin-12 against murine bladder cancer

PURPOSE: We investigated the antitumor activity of interleukin-12 (IL-12) against MBT-2, a murine bladder carcinoma, to clarify whether or not IL-12 is effective against urothelial tumors. MATERIALS AND METHODS: MBT-2, a murine carcinogen-induced, poorly differentiated transitional cell carcinoma of C3H/He origin, was used. Three or 10 days after the subcutaneous administration of MBT-2 cells, C3H/He mice were injected intraperitoneally with IL-12 five times per wk. for 2 wk. Tumor growth was measured twice weekly. Spleen cells from the C3H/He mice that had rejected MBT-2 after the IL-12 treatment were examined for MBT-2-specific cytolytic T lymphocytes (CTL) activity and cytokine production. RESULTS: Tumor growth and acceptance was obviously suppressed when C3H/He mice were treated with IL-12 from 3 days after the tumor inoculation. In the spleen cells from the C3H/He mice that had rejected MBT-2, MBT-2-specific CTL activity and secretion of IL-2 and interferon (IFN)-gamma were clearly detected. However, the established MBT-2 tumor cells were not rejected when C3H/He mice were given IL-12 from 10 days after the tumor inoculation, although the tumor growth was transiently suppressed during the IL-12 treatment. CONCLUSION: These data demonstrate that IL-12 is considerably effective against murine bladder cancer and suggest the clinical application of IL-12 against human bladder cancer.     

In vivo effects of high energy shock waves on urological tumors: an evaluation of treatment modalities

We have studied the effect of high energy shock waves (HESW) alone or in combination with cytotoxic drugs on the growth of urological tumors. The effects of HESW on kidney or prostatic tumors depend largely on the tumor line used. In the rapidly growing prostate tumor no antitumor effect was evident in vivo, but in vitro examination of the in vivo shocked cells showed that the clonogenic potential of HESW treated cells was inhibited. In the more slowly growing tumors, like human kidney xenografts, a temporary growth delay is observed in vivo. The effect on tumor growth depends not only on the number of HESW administered but also on the initial tumor volume. The smaller the tumor burden, the better the antitumor effect. Single shock wave administration may cause a growth delay, and repeated administration leads to a prolonged delay in growth. This effect is temporary and several days after stopping the HESW administration the tumor regains its original growth potential (same doubling time). Finally we could show that tumor growth was suppressed in different tumor models for a longer period by a combination of HESW and a single dose of adriamycin. The effect of combined treatment resulted in a persistent longer doubling time.     

Comparison of the efficacy of intravesical Bacillus Calmette-Guérin with thiotepa, mitomycin C, poly I:C/poly-L-lysine and cis platinum in murine bladder cancer

The efficacy of intravesical Bacillus Calmette-Guérin for the treatment of the mouse bladder tumor MBT-2 was compared with that of thiotepa, mitomycin C, cis-diamminedichloroplatinum II and poly I:C/poly-L-lysine. MBT-2 cells were instilled into the bladder immediately after electrocauterization. Drug instillations were initiated 24 hours later and continued on a weekly basis for 4 weeks. Both Bacillus Calmette-Guérin and cis-diamminedichloroplatinum II significantly (p less than .0004) inhibited MBT-2 tumor implantation when compared to diluent-treated controls. Neither mitomycin C, thiotepa nor poly I:C/poly-L-lysine significantly inhibited tumor implantation. Mean tumor weights also were significantly (p less than .05) reduced in Bacillus Calmette-Guérin and cis-diamminedichloroplatinum II-treated mice, while tumor mean weights in mice treated with thiotepa, mitomycin C or poly I:C/poly-L-lysine were not significantly different than controls. These results suggest that the efficacy of intravesical Bacillus Calmette-Guérin in comparison with other drugs in the MBT-2 mouse bladder tumor model is similar to observations reported in human clinical trials in which intravesical Bacillus Calmette-Guérin was shown to be more effective than other cytotoxic drugs. These data further support the utility of the MBT-2 model for the study of the mechanisms by which Bacillus Calmette-Guérin inhibits bladder tumor growth.