Effects of in vitro polyamine treatment on LDH isoenzyme patterns in Yoshida sarcoma cells and in former macrophages.

LDH isoenzyme shifts are frequently observed in several malignant neoplasm when compared with the corresponding normal tissues. In the present work, we studied LDH isoenzyme behaviour both in Yoshida cells and in founder macrophages, before and after polyamine treatment. The choice of polyamine was prompted in that these polycations also act on the enzymatic and metabolic steps. Results obtained evidenced: i) LDH activity was higher in Yoshida cells than in macrophages; ii) polyamine treatment provoked in tumour cells a very strong increase of LDH activity whereas in macrophages only a slight decrease; iii) Yoshida cells showed the presence of 4 LDH isoenzymes only.

In-vivo experimental demonstration that hyperhistaminism counteracts tumor-growth.

Induction of hyperhistaminism in peritoneum of rats by daily intraperitoneal supply of 0.005 mu g of histamine, counteracts the growth of 10(3) Yoshida ascite sarcoma cells only if administration precedes inoculation of tumor cells and has a long duration. Treating animals for two weeks before tumor cell inoculation we observed significant 70% survival, that was increased to 80% continuing the supply for 20-days after the inoculation; treatment for 3 days before or 20 days after the inoculation did not show significant results. The condition created in rat peritoneum is similar to that in allergic people, and our data in animals confirm statistical data observed in allergic people showing decreased incidence of neoplastic disease due to histamine, that appears to be integrated in a highly potent immunoregulatory circuit.

Glutathione metabolism during Yoshida ascites sarcoma growth.

Glutathione (GSH) metabolism and protein synthesis were observed over a period of about two weeks in Yoshida ascites sarcoma and intracellular concentration relative to days 7, 10 and 13 assumed as 'markers' of different stages of tumor development. During this period the decrease in rate of cell proliferation was followed by decrease in protein synthesis, GSH, oxidized glutathione (GSSG), adenosine triphosphate (ATP), glutathione-S-transferase (GSH-S-transferase) and gamma-glutamyl-cysteine synthatase (gamma-GCS); by increase in glutathione-peroxidase (GSH-peroxidase); while glutathione-reductase (GSH-reductase) and glucose-6-phosphate-dehydrogenase (G-6-PD) remained unchanged. In relation to growth curve of the tumor, GSH concentration was very high up to day 7 (logaritmic phase), decreased till quantity similar to that of corresponding normal cells up to day 10 (plateau phase) and on day 13 was significantly smaller. Correlation between high concentration of GSH in tumor cells and their survival and proliferation after intraperitoneal implantation is discussed.

Effect of resveratrol on some activities of isolated and in whole blood human neutrophils.

Resveratrol, which is a polyphenol present in red wines and vegetables included in human diets, exerts many biological effects. The aim of the present study was to investigate its effect on some activities of polymorphonuclear leukocytes, particularly the generation of superoxide anion ((O2)(-)) in whole blood, hypochlorous acid (HOCl) and nitric oxide (NO) production by isolated cells, and chemotaxis. Resveratrol showed significant dose-dependent inhibitory effect on all these activities. In particular, it inhibited O2(-) generation in stimulated but not in resting neutrophils, decreased HOCl much more than O2(-) production indicating an effect on myeloperoxidase secretion since HOCl production is directly and proportionally dependent on O2(-) generation and reduced cell motility. The small dose of resveratrol (4.38 nM) used is attainable with a diet including red wine and vegetables confirming its protective role against some pathological processes such as inflammation, coronary heart disease, and cancer.

Effects of vitamin E and prostaglandin E2 on expression of CREB1 and CREB2 proteins by human T lymphocytes.

Both prostaglandins (PGs) and vitamin E are known to deeply affect immune responses. It is shown here that they both influence T cell-mediated immunity through reciprocal interference on the expression of cyclic-AMP responsive element binding (CREB) family proteins. CREB1 protein of human T lymphocytes was significantly modulated by a brief treatment of 5 to 10 min with PGE2. On the contrary, vitamin E appeared to be ineffective on the CREB1 behavior, while it abolished the PGE2-induced modulation of this protein. The CREB2 protein expression was also affected by PGE2 treatment, but a longer period of incubation (>20 min) was needed to observe these changes. Vitamin E showed a strong enhancing effect on CREB2 that was partially reversed by the subsequent treatment with PGE2. Our results support the idea that there is reciprocal interference between PGE2 and vitamin E on PGE2-induced signals in T lymphocytes. These data are in agreement with the reports concerning different cell systems and experimental conditions.

Antitumor effect of the new rhodium (II) complex: Rh2 (form)2 (O2 CCF3)2 (H2O)2 (form = N,N'-di-p-tolyl formamidinate).

The new rhodium(II) complex Rh2(Form) (O2CCF3)2(H2O)2 (Form = N,N'-di-p-tolyl formamidinate) was evaluated for its toxicity on the rat and for its efficacy against two tumors of this animal: the Yoshida ascites sarcoma and the T8 sarcoma of Guérin. The rhodium(II) formamidinate shows very low toxicity: in fact 150 mg/kg (the highest quantity of drug soluble in 4 ml of dimenthyl sulfoxide) is not toxic for rats. We were unable to establish the lethal dose or the highest nontoxic dose since larger mounts of complex require a dose of dimethyl sulfoxide (DMSO) that is itself toxic and the compound is insoluble in other solvents such as water or Tween. Doses of rhodium(II) formamidinate, varying from 3 to 30 mg/kg, were administered once by i.p., i.v., i.m. and intratumor (i.t.) route from 1 to 7 days after i.p. injection of 10(6) Yoshida ascites sarcoma cells and subcutaneous (s.c.) implantation of approximately 300 mg (corresponding to 2-3 x 10(7) living tumor cells) of T8 sarcoma of Guérin. The compound is active when administered i.p. 24 hours after Yoshida ascites sarcoma at the smallest dose tested (3 mg/Kg), increasing the average life span of 62.3% and allowing the survival of 50% of the rats. It is also active when administered i.p. at the highest dose tested (30 mg/Kg) 7 days after tumor cell challenge, increasing the average life span in 43.8% and allowing survival in 20% of the rats; it is not active after i.v. or i.m administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Does the antitumoral activity of platinum (IV) derivatives result from their in vivo reduction?

The antitumoral activity of some octahedral platinum(IV) and square-planar platinum(II) derivatives against Yoshida ascites tumor in the rat is reported. It is shown that only those octahedral platinum(IV) complexes which give active reduction products are active. These results support the hypothesis that the antitumor activity of octahedral complexes involves activation by in vivo reduction. Anticancer drugs functioning by this mechanism may be preferentially toxic to or may localize in hypoxic areas of tumors.

In vivo effect of didemnin B on two tumors of the rat.

Didemnin B administered at a dose of 0.06 mg/kg, highest nontoxic dose for the rat, shows a high antitumor activity against Yoshida ascites tumor only after intraperitoneal injection of the drug; supplied by other routes both against T8 sarcoma of Guérin and Yoshida ascites tumor is ineffective.

Peritoneal macrophage is the cell transformed by Yoshida ascites tumor virus.

Resident peritoneal macrophages purified by adhesion on plastic surface, suspended in 1 ml of cell-free fluid from Yoshida ascites tumor for 2 h, washed three times and reinjected in the original rat, produce the development of a neoplasia with the same properties as the Yoshida ascites tumor.

Antitumor effect of a mycotoxin: rubratoxin B.

The antitumor effect of rubratoxin B, a mycotoxin, has been studied. Yoshida ascites sarcoma cells, in vitro in contact for 30 min with the drug and injected immediately afterwards into young rats by the intraperitoneal route, produced the survival of 80% of the animals and the doubling of the median survival time of the rats developing neoplasia. In vivo administration of the drug by the intraperitoneal route 24 h after implantation of tumor cells determined the prolongation of median survival time; supplied by other routes both against T8 sarcoma of Guérin and Yoshida ascites sarcoma it was ineffective. The differences between in vitro and in vivo results can be explained by a rapid neutralization of the drug on behalf of the organism's enzymes or by being bound to proteins and peritoneal cells unlike tumor cells.

Anti-tumor properties of the organometallic complex cis-dimethylbis[sulfinylbis[methane]-S]platinum(II).

The water-soluble organometallic complex cis-[Pt(Me)2(Me2SO)2] (Me = methyl; Me2SO = dimethyl sulfoxide) (cis-dimethyl platinum(II); CDMP) was evaluated for its toxicity on the rat and for its efficacy against two tumors of this animal: the Yoshida ascites sarcoma and the T8 sarcoma of Guérin. The lethal dose for 50% of normal animals was 46.4 mg/kg; the predominant toxic effects were loss of weight, decrease in leukocytes and necrosis of the kidneys after i.v. or of the liver after i.p. administration. Doses of drug varying from 2 to 40 mg/kg were administered once by i.p., i.v., i.m. and intra-tumor (i.t.) route from 1 to 7 days after i.p. injection of 10(6) Yoshida ascites sarcoma cells and s.c. implantation of approximately 300 mg of T8 sarcoma of Guérin. The compound showed anti-tumor activity increasing both the average life span and survival of the rats. A comparison between the therapeutic properties of the title complex with those of cis-[PtCl2(NH3)2] (CDDP) reveals that cis-dimethyl platinum(II) exhibits the same anti-tumor activity associated with 6 times reduced toxicity.

Cytochemical and immunocytochemical characterization of Yoshida ascites sarcoma cells.

Some cytochemical and immunocytochemical investigations were carried out on actively growing Yoshida ascites sarcoma cells. These cells displayed an intense granular alpha-naphthylacetate esterase (ANAE) staining while the alpha-naphthylbutyrate esterase (ANBE) reaction was in part fluoride-sensitive and marked particularly in the large-size malignant cells. Acid phosphatase as well as peroxidase activities were not detected. The lack of immunoreactive lysozyme and alpha 1-antitrypsin suggested a poor differentiation of the above-mentioned tumor cells, but fibronectin and S-100 protein where highly expressed, as in tumors arising from the mononuclear phagocyte system.

Immunomodulatory effect of the homoeopathic drug Engystol-N on some activities of isolated human leukocytes and in whole blood.

Engystol-N at the doses of 10(-4) and 10(-8) in isolated human leukocytes stimulates the superoxide anion generation by neutrophils and the cytokine(s) production by T lymphocytes. In whole blood the same concentrations of the drug produce the decrease of the superoxide anion generation of neutrophils, this inhibiting activity appears 6 h after the administration of the drug and persists only in presence of lymphocytes. Culture media of T lymphocytes treated with Engystol-N show the same inhibiting effect on superoxide anion generation by neutrophils. From these data it is possible to conclude that the drug stimulates the secretion of lymphokine(s) with inhibiting action on superoxide anion generation of neutrophils that prevail over the direct stimulating effect, confirming and extending the immunomodulatory ability of the drug.

Inosine pranobex-BAN increases the resistance to the challenge with cells or cell-free fluid from Yoshida ascites tumor.

Inosine pranobex-BAN injected intraperitoneally at a daily dose of 500 mg/kg for 15 days into young Sprague-Dawley rats, beginning 24 hours after the implantation of Yoshida ascites tumor cells and the injection of cell-free ascites fluid from the same neoplasia, increased the resistance to the tumor in both cases. This antitumor activity of the drug was mediated by its action on cellular immunity of the host. In our model we considered the role of macrophages.

Interaction between prostaglandins and human T lymphocytes: effect of PGE2 on E-receptor expression.

E-rosette formation is not modified by preincubation of lymphocytes with prostaglandins (PGs) E1, F1 alpha, and F2 alpha. On the contrary, short preincubation with PGE2 affects active rosette-forming cells (Ea-RFC) and, only slightly, total RFC. This effect appears to be dose-dependent and relatively temperature-independent; it does not require calcium ions. Incubation with a fraction enriched in late RFC showed that PGE2 does not affect late rosette formation. It is postulated that PGE2 may redistribute surface receptors for sheep erythrocytes on T lymphocyte membranes. Thus, sensitivity to PGE2 may be considered another difference between early and late RFC.

IL-2R gamma gene microdeletion demonstrates that canine X-linked severe combined immunodeficiency is a homologue of the human disease.

X-linked severe combined immunodeficiency (SCID) is characterized by profound defects in cellular and humoral immunity and, in humans, is associated with mutations in the gene for the gamma chain of the IL-2 receptor (IL-2R gamma). We have examined this gene in a colony of dogs established from a single X-linked SCID carrier female. Affected dogs have a 4-bp deletion in the first exon of the IL-2R gamma gene, which precludes the production of a functional protein, demonstrating that the canine disease is a true homologue of human X-linked SCID.