In vivo efficacy of griseofulvin against multiple myeloma

We recently confirmed that ciclopirox olamine inhibits Wnt/beta catenin signalling in myeloma. Griseofulvin (GF) has similar chemical features as compared to ciclopirox olamine. In this study the anti-tumor effect of GF was investigated. GF demonstrated a major apoptotic activity in various human and murine myeloma and lymphoma cell lines as well as in human primary cells. In vivo, tumor growth as well as overall survival were significantly reduced in mice treated with GF as compared to untreated mice. In conclusion, our results reveal a significant selective induction of apoptosis by GF and suggest a significant in vivo effect against myeloma.     

In vivo toxicity of phenothiazines to cells of a transplantable tumor

Summary The toxicities of three phenothiazines, promazine, chlorpromazine, and trifluoperazine, towards cells of a mouse fibrosarcoma were quantified by means of an in vitro assay of clonogenic cell survival.For all three drugs cell kill was proportional to the amount of drug injected. Following injection of equimolar (0.2 mM/kg) amounts, cell survival was progressively reduced for a period of at least 48 h. On the basis of cell survival at 48 h after administration the ranking of the drugs for cytotoxicity, in ascending order, was trifluoperazine, chlorpromazine, promazine.A period of acute hypoxia prior to processing of the tumor did not enhance the toxicity of any of the drugs, and no change in the size of the hypoxic fraction of the tumor was seen 24 h after the injection of chlorpromazine. On this basis it was concluded that there was no evidence of enhanced toxicity of drugs for either chronically or acutely hypoxic tumor cells.A reduction in the number of clonogenic tumor cells per gram of tumor was largely the result of a fall in the number of viable cells recovered from the tumor. The plating efficiency of surviving cells remained constant or was only slightly depressed.The investigations reported in this paper were supported by the National Cancer Institute of Canada and by the Cancer Research Society Inc. of Montreal     

In vivo efficacy of the diuretic agent ethacrynic acid against multiple myeloma

It was recently confirmed that the diuretic agent ethacrynic acid (EA) inhibits Wnt/beta catenin signaling in myeloma. This study investigated the antitumor effect of EA in vivo in a murine myeloma model. In vivo, tumor growth was significantly reduced and overall survival significantly prolonged in mice treated with EA as compared to untreated mice. Interestingly, this effect was higher as compared to the effect by lenalidomide, a commonly used drug against myeloma. These results reveal a significant in vivo effect by EA against myeloma.     

In vivo evaluation of 188Re-labeled alpha-melanocyte stimulating hormone peptide analogs for melanoma therapy

The purpose of our study was to optimize melanoma tumor uptake of 188Re-CCMSH and reduce its nonspecific kidney retention. Nephrotoxicity is often a serious problem associated with targeted radiotherapy, therefore, increasing the tumor/kidney uptake ratio of 188Re-CCMSH is crucial for optimizing its therapeutic efficacy. Structural modification of the peptide and amino acid co-infusion were investigated as strategies to improve the tumor/kidney uptake ratio of 188Re-CCMSH. The substitution of Lys11 with Arg11 was examined to determine if removal of lysine from the peptide would improve kidney clearance without sacrificing tumor uptake. The pharmacokinetics of 188Re-CCMSH and 188Re-(Arg(11))CCMSH were determined in B16/F1 murine melanoma-bearing C57 mice. Tumor uptake values of (188)Re-CCMSH and 188Re-(Arg(11))CCMSH were 15.03 +/- 5.20% ID/g and 20.44 +/- 1.91% ID/g at 1 hr postinjection and 1.94 +/- 0.47% ID/g and 3.50 +/- 2.32% ID/g at 24 hr postinjection. Renal retention of 188Re-(Arg(11))CCMSH was 11.79 +/- 1.29 ID/g and 3.67 +/- 0.51 ID/g at 1 hr and 4 hr postinjection, which was a greater than 50% reduction compared to 188Re-CCMSH. The Arg for Lys substitution in 188Re-(Arg(11))CCMSH resulted in improved tumor uptake and reduced kidney retention. Renal retention of both 188Re-CCMSH and 188Re-(Arg(11))CCMSH were significantly reduced by co-injection of 20 mg of L-lysine, L-arginine and a combination of L-lysine:L-arginine. Tumor/kidney uptake values for 188Re-CCMSH and 188Re-(Arg(11))CCMSH were maximally reduced by 52.9% and 46.3%, respectively. However, even with amino acid co-injection, the tumor/kidney ratio of 188Re-CCMSH was lower than that of 188Re-(Arg(11))CCMSH. Improved tumor uptake and reduced kidney retention of 188Re-(Arg(11))CCMSH will facilitate targeted irradiation of melanoma tumors while minimizing the dose to the kidneys.     

Contribution of host-derived growth factors to in vivo growth of a transplantable murine mammary carcinoma.

The contribution of host-derived growth factors to tumour growth in vivo was studied using the transplantable murine mammary carcinoma, MT1, grown in syngeneic mice. Promotion of growth of the mammary carcinoma by a factor(s) from the host was evident in experiments in which the carcinoma cells were inoculated intraperitoneally. In this environment, tumours develop as multiple solid nodules, each probably arising from an individual cell or a small cluster of cells. Tumour growth was found to occur in the peritoneal cavity following inoculation of 10(3) cells, but an inoculum of as few as ten cells grew if a leucocyte-rich exudate had first been induced. To determine which host-derived growth factors might contribute to growth of MT1, extracts of the tumour were first examined for growth factor activity. Fractionation of tumour extracts by either ion-exchange chromatography or gel filtration revealed several peaks of mitogenic activity, but none of this could be attributed to epidermal growth factor (EGF). Accordingly, an anti-EGF antibody was tested as a putative inhibitor of tumour growth as any effect of this antibody could be ascribed to removal of EGF derived from the host. The antibody was found to have potent anti-tumour activity when tested against MT1 tumours that had been inoculated into the peritoneal cavity. In contrast, the antibody had little effect on growth of the discrete tumour mass which formed when MT1 was transplanted subcutaneously. The results suggest that host-derived EGF contributes to establishment of microcolonies of MT1 carcinoma within the peritoneal cavity. This may be directly, by providing growth factors to supplement those produced by the tumour until it reaches a certain critical mass to sustain autocrine growth, or indirectly, by affecting the production of other growth-stimulatory factors or cytokines.     

Protective effects of amphotericin B against spontaneous and transplantable murine tumors.

Two tumor systems were used to test prophylactic effects of amphotericin B (AmB). When 0.5 mg AmB was given ip every 2 weeks to AKR mice beginning at 8 weeks of age, the 50% tumor incidence for spontaneous lymphoma development was delayed 2-3 months. In the second tumor system, BALB/c mice received injections of either 20 or 50 mug AmB before receiving MOPC-315-C cells sc. The mice given the low dose of AmB demonstrated a decreased tumor incidence and a reduced tumor growth rate, when compared with controls. Opposite effects were found for the group administered the high dose; tumor incidence and rate of growth were increased.     

Preclinical in vivo efficacy of two 9-dihydrotaxane analogues against human and murine tumours.

Two 9-dihydrotaxane analogues were synthesised and tested for in vitro potency and in vivo efficacy against murine and human tumour xenografts in mice. The in vitro potency of 9-dihydrotaxol (9-DH-t) and 10-deacetyl-9-dihydrotaxol (10-DeAc-9-DH-t) was generally less than that of paclitaxel against human and murine tumour cells. However, both analogues were at least 20-fold more soluble than paclitaxel in water. The analogues yielded cure rates > or = 60% against human MX-1 solid tumour xenografts in mice, compared with a cure rate of 10% for mice treated with paclitaxel. Both of the analogues were more effective than paclitaxel for treatment of murine M109 solid tumour in mice. 10-DeAc-9-DH-t was as effective as paclitaxel against murine B16 ascites tumour, while 9-DH-t was less effective. Both 10-DeAc-9-DH-t and 9-DH-t were demonstrably less toxic than paclitaxel. At equal dosages 9-DH-t produced serum concentrations greater than paclitaxel, while 10-DeAc-9-DH-t yielded serum concentrations less than paclitaxel. However, the decrease in toxicity of 9-DH-t and 10-DeAc-9-DH-t allowed a 4-fold increase in daily dosage. These two 9-dihydrotaxane analogues yielded favourable preclinical data and demonstrated good potential for further development.     

Effects of levamisole on in vivo and in vitro murine host response to syngeneic transplantable tumor.

The effects of levamisole were studied in vivo and in vitro on two murine tumors, B16 melanoma and adenocarcinoma 15091, syngeneic to the mouse strains used. Administration of levamisole before tumor transplantation enhanced the early appearance of neoplasms but did not affect the overall incidence or course of tumor growth as compared with that observed in controls given saline injections or animals given levamisole with lethally X-irradiated tumor cells. Administration of the drug 1 day before iv injection of tumor cells significantly reduced the incidence of pulmonary nodules, but if the drug was given 3 or 5 days before tumor challenge, the incidence of nodules was increased. Lymphocytes or macrophages from normal mice given levamisole had no effect on tumor cells in vitro, whereas lymphocytes incubated with levamisole in vitro enhanced tumor cell growth. When lymphocytes and tumor cells were mixed in vitro, lymphocytes from animals treated with the drug formed larger multicell clumps with tumor cells than did those from normal controls. We concluded that levamisole did not protect the mice against the tested tumors.     

The effects of purine nucleoside analogs on the response of the RIF-1 tumor to melphalan in vivo

The effect of several purine nucleoside analogs on the cytotoxicity of melphalan (L-PAM) in the RIF-1 tumor in vivo was investigated. All the analogs tested--3'-deoxyguanosine (3'-dG), 3'-deoxyadenosine (3'-dA), and N6-butyryl-3'-deoxyadenosine (N6-BC)--at a dose of 100 mg/kg, enhanced the tumor cell killing by L-PAM as measured by an in vivo/in vitro procedure. This enhancement was maximal when the drugs were given simultaneously. The mean enhancement ratios (ER's) determined from the L-PAM dose response curves were 1.4 for 3'-dG, 1.3 for 3'-dA, and 1.4 for N6-BC. A similar modification of the L-PAM-induced depression of white blood cell counts was not obtained. A large single dose of L-PAM (8 mg/kg) produced a transient drop in mouse body temperature. The analog 3'-dG (100 mg/kg) increased and prolonged this hypothermic effect. In addition 3'-dG also delayed the clearance of L-PAM from the plasma of C3H mice, such that the half-life of the chemotherapeutic agent was extended from 28 minutes to 35 minutes. The enhancement of the efficacy of L-PAM by these analogs probably results from this pharmacokinetic effect.     

Antitumor efficacy of activated macrophages against murine glioma cells

A crucial manifestation of malignant gliomas is the regrowth of already-invaded neoplastic cells after surgical intervention. One possible approach for inhibiting such tumor growth is to utilize the tumoricidal potential of macrophages. In order to investigate the clinical application of this concept, peritoneal exudate cells (PEC) activated in vitro and in vivo by immunomodulating agents were tested for cytotoxic activity against murine glioma (203-glioma) cells. As immunomodulating agents, heat-killed Propionibacterium acnes (P. acnes), OK-432 and Concanavilin A supernatant (Con A sup) were used in these experiments. P. acnes was provided by Kowa Pharmaceutical Co., Tokyo, and OK-432 by Chugai Pharmaceutical Co., Ltd., Tokyo. Klinische Einheit (KE) units were used to express the strength of the preparation, with 1 KE equal to 0.1 mg of dried streptococci. Con A sup was produced by Con A pulsing of BALB/c splenocytes resuspended in complete medium. PEC harvested from mice to which 5% glycogen in saline had been inoculated intraperitoneally 6 d previously were activated in vitro by P. acnes (P. acnes-PEC), OK-432 (OK-432-PEC) and Con A sup (Con A-PEC). The cytotoxic activities of P. acnes-PEC, OK-432-PEC and Con A-PEC were approximately 25%, 65% and 60%, respectively. PEC were then collected from mice into which either 100 micrograms of P. acnes or 1 KE of OK-432 had been injected intraperitoneally several times. The antitumor effects of P. acnes-PEC and OK-432-PEC were about 35% and 50%, respectively. These activated PEC demonstrated cytotoxic activity against murine glioma in the tumor neutralization assay (Winn assay). Also, the antitumor efficacy of OK-432-PEC belonged mainly to adherent cells. Meningeal gliomatosis (MG) models were prepared for clinical studies. Viable 203-glioma cells (5 X 10(6) were injected percutaneously into the cisterna magna of C57BL/6 mice. The median survival time (MST) of the untreated group was 8.5 days. The MST of the groups treated by intraperitoneal and intracisternal administration of P. acnes were 26 and 33 days. This therapy significantly prolonged the survival time of these models, particularly by the intracisternal treatment. The differential cell count by Giemsa staining and latexphagocytic cell findings revealed that macrophages accounted for more than 90% of the P. acnes-PEC. These results may indicate that activated (PEC) macrophages were induced intracisternally by P. acnes and that activated macrophages induced intraperitoneally exerted antitumor effects in MG models.     

In vivo selection of human tumor cells resistant to monoclonal antibody-Vinca alkaloid immunoconjugates

UCLA-P3 human lung adenocarcinoma cells were grown in nude mice and given repetitive treatments of a monoclonal antibody-Vinca alkaloid immunoconjugate. Although this therapy resulted in a greater than 4-fold reduction in mean tumor mass of the established tumors, some animals experienced a reinitiation of tumor growth after cessation of conjugate treatment. Two such animals were treated again with high doses of monoclonal antibody-Vinca but one of the tumors was no longer regressed by the drug conjugate. The tumor was excised, enzymatically dissociated, and grown in tissue culture. Cultured cells were reimplanted in nude mice and subjected to further therapy with a monoclonal antibody-Vinca conjugate. The resulting tumors were also refractory to the immunoconjugate therapy. This cycle was repeated for a total of three times and resulted in the serial in vivo selection of three conjugate resistant variants. The mechanism responsible for the in vivo resistance of human tumor cells to the monoclonal antibody-Vinca immunoconjugate is unknown but does not appear to involve antigen modulation, altered tumor cell growth rate, or an apparent decrease in tumor targeting in vivo. The resistance was also not accompanied by any detectable elevation in multidrug resistance 1 mRNA or P-glycoprotein expression. Significantly, the resistance pattern was observed only in vivo and was not maintained by cells grown in vitro.     

Modest efficacy of voriconazole against murine infections by Sporothrix schenckii and lack of efficacy against Sporothrix brasiliensis

The efficacy of voriconazole (VRC) was evaluated against two strains of each of the two most common species causing sporotrichosis, Sporothrix schenckii sensu stricto and Sporothrix brasiliensis, using a murine model of disseminated infection. Voriconazole was administered at doses of 20 or 40 mg kg^?1 per day by gavage. The drug showed some efficacy, especially at 40 mg kg^?1 per day, in prolonging the survival and reducing fungal load in spleen and liver in mice infected with S. schenckii, whereas in animals infected with S. brasiliensis the drug did not work.     

Activation of nuclear factor kappaB In vivo selectively protects the murine small intestine against ionizing radiation-induced damage

Exposure of mice to total body irradiation induces nuclear factor kappaB (NFkappaB) activation in a tissue-specific manner. In addition to the spleen, lymph nodes, and bone marrow, the tissues that exhibit NFkappaB activation now include the newly identified site of the intestinal epithelial cells. NFkappaB activated by total body irradiation mainly consists of NFkappaB p50/RelA heterodimers, and genetically targeted disruption of the NFkappaB p50 gene in mice significantly decreased the activation. By comparing tissue damage and lethality in wild-type and NFkappaB p50 knockout (p50-/-) mice after they were exposed to increasing doses of total body irradiation, we additionally examined the role of NFkappaB activation in total body irradiation-induced tissue damage. The results show that p50-/- mice are more sensitive to total body irradiation-induced lethality than wild-type mice (LD50/Day 7: wild-type = 13.12 Gy versus p50-/- = 7.75 Gy and LD50/Day 30: wild-type = 9.31 Gy versus p50-/- = 7.81 Gy). The increased radiosensitivity of p50-/- mice was associated with an elevated level of apoptosis in intestinal epithelial cells and decreased survival of the small intestinal crypts compared with wild-type mice (P < 0.01). In addition, RelA/TNFR1-deficient (RelA/TNFR1-/-) mice also exhibited a significant increase in intestinal epithelial cell apoptosis after they were exposed to total body irradiation as compared with TNFR1-deficient (TNFR1-/-) mice (P < 0.01). In contrast, no significant increase in total body irradiation-induced apoptosis or tissue injury was observed in bone marrow cells, spleen lymphocytes, and the liver, heart, lung, and kidney of p50-/- mice in comparison with wild-type mice. These findings indicate that activation of NFkappaB selectively protects the small intestine against ionizing radiation-induced damage.     

DEVELOPMENT OF AN ADRIAMYCIN RESISTANT MURINE TUMOR S-180 CELL LINE IN VIVO

Adriamycin resistant cells were obtained from low dotage treated BABL/c mice Inoculated with S-180 cells. Resistance of these cells for adriamycin was 66-fold more than their parental cells. The resistance for a typical DNA topoisomerase Ⅱ inhibitor VP16 (Etopcaide) was increased 9 times. Overexpression of multidrug resistant gene (MDR gene) products, P-glycoproteins (P-1 70), was also demonstrated by immunohistochemistry. Furthermore, the ability of the resistant cells to reduce net cellular drug accumulation measured by flow fluorescence cytometry was 89-fold higher than their parental cells. These results support the hypothesis that the resistance of S-180R cells to adriamycin was mainly due to the overexpression of P-glycoproteins. The S-180R cells will be useful to select drugs or some other therapeutic strategies to overcome multidrug resistance in vivo.     

In vivo antitumor activity of neocarzinostatin (NCS)-tumor antibody conjugate against a transplantable human leukemia cell line (BALL-1)

The in vivo antitumor activity of NCS-immune immunoglobulinG (IgG) [Neocarzinostatin (NCS) conjugated with rabbit IgG antibodyagainst a human leukemia cell line (NALL-1)] was evaluated inimmunosuppressed newborn Syrian hamsters into which a transplantablehuman leukemia cell line, BALL-1 was implanted. After intraperitoneaJ(i.p.) injection of the conjugate, hamsters preinoculated i.p.with BALL-1 cells survived longer than hamsters treated withcontrol solutions (p < 0.01). The control solutions wereNCS, immune IgG, a mixture of NCS and immune IgG, NCS-normalIgG conjugate and physiological saline. There was no changein body weight in the NCS-immune IgG-treated hamsters. The growthof subcutaneously (s.c.) implanted BALL-1 tumors was also inhibitedby i.p. administration of NCS-immune IgG; however, the degreeof inhibition was not significantly different from that obtainedby administration of NCS alone, a mixture of NCS and immuneIgG or NCS-normal IgG conjugate. These results indicate thatNCS-immune IgG was effective against i.p. BALL-1 tumors, butwas less effective against s.c. implanted tumors.     

In vivo quantitative analysis of immune reactions to solid murine tumors in syngeneic hosts

The dose-response curves and the TD50 are considered to be biological characteristics of tumors. Further these parameters vary according to the immunological status of the host. By using the TD50 method, a quantitative in vivo determination has been made of immune reactions directed against tumor-associated transplantation antigens (TATA) of three solid murine tumors. The intensity of the primary immune reaction is evaluated by the difference between the TD50 values in normal and immune-depressed animals. On the other hand, the secondary immune response is estimated by the difference between the TD50 in normal and specifically immunized recipients. According to these criteria, the results show that the intensity of the primary and secondary immune reactions cannot be compared from one tumor to another. For one tumor, the secondary reaction is quantitatively much greater than the primary reaction. For another tumor, the exact opposite is the case. These results suggest that there is no correlation between the primary and secondary immune responses and that they are quantitatively dependent upon multiple factors. The results are discussed in relation to the determination of antigenic strength of tumors.