Enhancement of interleukin-2 release in rats by treatment with bleomycin and adriamycin in vivo

The in vitro action of FK 565, bleomycin and cyclosporin A on different cell populations, with respect to the release of GM-CSF in the mouse

The experimental immunostimulatory tripeptide FK 565, the anti-tumor antibiotic Bleomycin and the immunosuppressive agent Cyclosporin A were examined for their in vitro effects on granulocyte-macrophage colony stimulating factor (GM-CSF) production utilizing different cell populations from three distinct murine stains. FK 565 produced an increase in GM-CSF release in all three experimental models used, providing evidence that FK 565 is among other things, a macrophage stimulating agent. Bleomycin increased GM-CSF release in the BALB/c and the 'Scid' mouse. Paradoxically with cells from the 'nude' mouse a significant decrease was observed, indicating that Bleomycin may induce a suppressive effect on B-cells. Cyclosporin A was found to inhibit the release of GM-CSF from BALB/c mice, however, no effect was observed in either 'nude' or 'Scid' mice.

Effect of anticancer drugs on the release of interleukin-3 in vitro

In this study several anticancer drugs were tested for their effect on the release of interleukin-3 (IL-3) from concanavalin A (Con A) stimulated mouse splenocytes in vitro. When Adriamycin or vincristine were added to the cultures at non-cytotoxic concentrations, the release of IL-3 was inhibited. However, bleomycin, FK156, FK565 and 4-OOH-cyclophosphamide (the in vitro active analogue of the anticancer and immunosuppressive drug cyclophosphamide) did not alter the release of IL-3 under the same conditions. It was confirmed that cyclosporin A inhibited the release of IL-3 in the same experimental system.

Immunoregulatory cytokine release in rat spleen cell cultures after treatment with bleomycin and its analogues in vivo

We have studied the immunological effects that accompany a change in the chemical structure of a group of antineoplastic antibiotics by comparing the immunoregulatory cytokine release during mitogen-stimulated spleen cell culture after in vivo drug treatment. Whereas bleomycin and peplomycin increased cytokine levels in culture supernatants when compared with supernatants from untreated control rat spleen cell cultures, liblomycin generally reduced cytokine levels under the same culture conditions. We then compared these results with the antitumor effects of equivalent doses of the three drugs against a highly antigenic rat fibrosarcoma, KMT-17, both in vivo and in vitro. The results suggest that the immunoaugmenting effects of these antitumor antibiotics are essential for an optimal antitumor effect in vivo, and that these effects can be drastically altered by modification of the chemical structure of the drugs employed.

The improved effects of specific active immunotherapy on a rat fibrosarcoma by antitumor drugs

We have tried to find out if the combination of a xenogenized tumor cell vaccine and antitumor drugs is able to induce a synergistic increase in the antitumor therapeutic effect. The degree of increase in the LTD50 (50% lethal tumor dose) is expressed numerically, as a quantitative index designed to compare degrees of transplantation resistance to tumor cell challenge. A LTD50 was achieved by an intradermal (i.d.) immunization with xenogenized tumor cells when challenged with tumor cells implanted intraperitoneally 2 weeks after the immunization: this LTD50 value was 527,000 times higher than that of the non-immunized group. When we combined this type of immunization with appropriate doses of bleomycin (BLM) or cyclophosphamide (CY), which are able to augment antitumor immunity, the LTD50 was 723,000-1,190,000 times higher than that of the non-immunized group. This increase in the LTD50 is definitely higher than that achieved by a single immunization with irradiated tumor cells (x 33,000) and combined with either BLM (x 93,000) or CY (x 140,000). We also studied the therapeutic effect of a tumor cell vaccine combined with antitumor drugs BLM or CY in tumor-bearing rats. We observed a synergistic effect caused by BLM or CY after i.d. immunization with xenogenized tumor cells: this showed a significant increase when compared with the therapeutic effects obtained by chemotherapy alone (P less than 0.01). Nevertheless, there was no evidence that the above antitumor effects is superior to the effect achieved by irradiated tumor cells.

Effect of combined intrapleural administration of Lactobacillus casei (LC9018) and adriamycin on experimental malignant pleurisy in mice

The combined effect of Lactobacillus casei YIT9018 (LC9018) and adriamycin (ADR) on malignant pleurisy was investigated using an experimental model in BALB/c mice in which Meth A fibrosarcoma cells were intrapleurally implanted. The control mice died from dyspnea due to pleural effusion, before significant growth of tumor nodules could be achieved in the thoracic cavity. Intrapleural (ipl) administration of LC9018 (20-200 micrograms/head) on days 1 and 5 reduced the effusion volume and induced pleural adhesions in a dose-related manner. A statistically significant and reproducible prolongation of survival was observed at a dose of LC9018 200 micrograms/head: increase of lifespan (ILS) values of 15-39% were obtained. An ipl administration of ADR (2-4 mg/kg) on day 1 was also effective in prolonging survival without severe toxicity (ILS values of 100-122%). The combined use of ADR and LC9018 induced a high incidence of pleural adhesions, a delay in effusion accumulation, and an additive prolongation of lifespan (ILS values of 133-178%), compared with ADR monotherapy. In the combination therapy group, a marked and continuous ipl exudation of neutrophils, macrophages, and lymphocytes was observed with a significant decrease in pleural tumor cells. These findings suggest that ipl administration of LC9018 enhances the effect of ADR, probably through both host-mediated tumoricidal activity and sclerosing effects on the pleura.

Effect of anticancer drugs on the release of interferon gamma in vitro

Some conventional and experimental anti-cancer drugs were tested for their effect on concanavalin-A-induced interferon gamma release from rat splenocytes in vitro. When 2.5 x 10(6) rat splenocytes/ml, stimulated with 1 microgram/ml concanavalin A, were incubated with various non-cytotoxic doses of the vinca alkaloid vincristine, there was an inhibition of the release of interferon gamma in culture supernatants. The antitumour antibiotics bleomycin and Adriamycin, alkylating agents 4-hydroperoxycyclophosphamide and mafosfamide, and the immunoactive peptides FK156 and FK565 did not affect the release of interferon gamma under similar conditions. However, cyclosporin A, in similar experiments, markedly inhibited the release of interferon gamma.