Myeloinhibitory effect of the action of some antitumor antibiotics and its comparative assessment]

General toxic and myeloinhibitory effects of some antitumor antibiotics, such as rubomycin, olivomycin, bruneomycin and karminomycin administered intraperitoneally in a single LD50 to mice were studied. It was found that the general toxicity of bruneomycin and karminomycin was almost the same and 5 to 8 times higher than that of rubomycin and olivomycin. The use of the above antibiotics resulted in definite shifts in the blood systems of healthy mice. The most significant suppression of hemopoesis accompanied by a pronounced depression of the number of the myelocariocytes was observed after the use of olivomycin. The effect of karminomycin was characterized by suppression of erythro-, myelo- and lymphopoesis and depression of the number of the granulocytes and lymphocytes of the blood. Bruneomycin and rubomycin had a short-time myeloinhibitory effect. The erythroid cords of the bone marrow proved to be most sensitive to the inhibitory effect of the antibiotics. However, inhibition of the erythropoesis accompanied by deep reticulocytopenia did not induce the respective depression of the erythrocyte number. The lymphoid cords was in the 2nd place by its sensitivity to the antibiotics and the myeloid and megocariocytal cords were in the 3rd and the 4th places respectively. Complete reduction of hemopoesis in the animals was observed by the 10th day of the drugs use.     

Morphological changes in the digestive organs on the administration of the antineoplastic antibiotics, rubomycin and carminomycin

The effect of antitumour antibiotics, such as rubomycin and karminomycin on the digestive tract as one of the most vulnerable systems during chemotherapy was studied. Investigation of the tongue, oesophagus, stomach, small and large intestine of mice with the current morphological and some histochemical methods showed that the most pronounced changes in the above organs occurred during the first 10 days after the drug administration. The damages were of the same type, i.e. dystrophic changes in the tegmental and granular epithelium with edema and infiltration of the mucosa and tunica submucosa. The drugs induced a decrease in the levels of the nucleic acids, protein and hydrolytic enzymes and impairement of the distribution pattern of these substances in the cells. Karminomycin had a more pronounced effect and its damaging effect was more stable as compared to rubomycin.     

Toxicity and cumulative properties of carminomycin, rubomycin and adriamycin at different times of use]

LD50 of karminomycin, rubomycin and adriamycin were determined after their single administration or 3-, 5-, 10- and 15-fold administration once a day to 540 hybrid male mice F1(C57B1 X CBA). Comparison of the cumulative indices for these antibiotics showed that after injections they were close. After 5 injections the cumulative properties were more pronounced for adriamycin. After 10 or 15 injections the cumulative properties were less pronounced for karminomycin.     

Antitumor activity of carminomycin antibiotic used orally]

Antitumor activity of karminomycin used perorally was studied with respect to 3 strains of mouse transplantable tumors, i. e. one ascitic strain of lymphadenosis NK/LI and two solid strains of lymphosarcoma L10-1 and sarcoma 180. Karminomycin was shown to have a high antitumor activity against the above tumors on its oral administration. In the experiments with lymphadenosis NK/LI the efficiency of karminomycin was higher when it was used perorally as compared to its intravenous administration. It was found that karminomycin had practically the same inhibitory effect on growth of lymphosarcoma L10-1 and sarcoma 180 on its peroral and intravenous administration in doses equivalent by their toxicity.     

Synthesis and properties of new rubomycin derivatives

Condensation of rubomycin (daunorubicin) with respective hydrazides yielded novel substituted hydrazones: 13-cyanoacetyl hydrazone rubomycin, 13-L-phenylalanyl hydrazone rubomycin, 13-BOC-3-(uracilyl-1)-DL-alanyl hydrazone rubomycin and 13-BOC-3-(adenylyl-9)-DL-alanyl hydrazone rubomycin. With successive treatment of rubomycin with hydrazine hydrate and respective ketones novel asymmetric azines were prepared: 13-cyclopentylidene hydrazone rubomycin, 13-alpha,alpha'-dimethyl-cyclopentylidene hydrazone rubomycin and 13-(1-phenylethylidene-1) hydrazone rubomycin. 14-Adenylyl-N9-rubomycin was synthesized by interaction of 14-bromorubomycin with adenine and hydrogenation of its analog, 14-N-imidazolyl rubomycin by sodium borhydrite yielded 13-dihydro-14-N-imidazolyl rubomycin. There was observed correlation between the antimicrobial activity of the derivatives against B. mycoides and their cytostatic effect on the cells of murine leukemia NK/LI. The high in vitro activity of 13-cyclopentylidene hydrazone rubomycin showed satisfactory correlation with the results of the study on the antitumor effect in animals.     

Role of the adrenal glands in the cytostatic action mechanism of antitumor antibiotics

The state of the steroidogenic function of the adrenal glands, lipid spectrum of the adrenal gland tissue and metabolism rate of 11-oxycorticosteroids (11-OCS) in the liver tissue and their levels in the blood plasma were studied on rats after a single administration of karminomycin in a dose of LD50 (1.55 mg/kg). The hormones of the adrenal cortex were shown to play a definite role in the mechanism of the karminomycin damaging effect. Dependence of the changes on the time of the drug effect was noted. The shifts were of a reversible character. No direct toxic damages in the tissue of the adrenal glands were observed. Only an increase in the 11-OCS blood levels and a decrease in the steroid metabolism in the liver tissue were shown. The latter must be due to the direct cytotoxic effect of karminomycin on the tissue of this organ.     

Serum enzymatic activity in oncological patients treated with carminomycin]

Karminomycin effect on the activity of some serum enzymes, such as hexokinase (HK), lactate dehydrogenase (LDG), its isoenzymes and glucose-6-phosphatase (G-6-P-ase) was studied. Biochemical assays were applied to 52 patients with neglected malignant tumors. The course dose of the drug was on the average 72mg. The objective antitumor effect was registered in 15 patients. A reliable increase in the values of LDG-5 and G-6-P-ase was observed after the treatment course in the combined group consisting of all the patients subjected to the biochemical assay. Normalization of the serum enzyme spectrum was observed in 15 patients effectively treated with karminomycin: activity of HK and the cathode fractions of LDG decreased. When treatment with karminomycin was ineffective (37 cases), the changes in the enzymatic activity recorded before the treatment further aggraviated. It was found that the level of G-6-P-ase in the patients' treated with karminomycin increased independent of the treatment effect which was probably associated with its toxic effect on the liver. The increase was reversible.     

Comparative study of the effect of daunorubicin and its nitroxyl derivative on in vitro function of rat liver mitochondria

The effect of rubomycin (daunorubicin) and its nitroxyl derivative, ruboxyl, on respiration and oxidative phosphorylation of the rat liver mitochondria was comparatively studied. It was shown that ruboxyl had a more pronounced uncoupling effect than rubomycin, especially during respiration in the presence of the glutamate mixture with malate. Unlike rubomycin, ruboxyl in concentrations of 0.05 to 0.5 mM induced stimulation under metabolic conditions rather than respiration. When the antibiotic concentration increased ruboxyl started to inhibit the respiration as compared to the control and the inhibition level appeared to be higher than that induced by rubomycin. Possible mechanisms for decreasing rubomycin toxicity by its modification with the nitroxyl radical are discussed.     

Comparative study of the cardiotoxicity of the anthracycline antibiotics, carminomycin and adriamycin, in white mice]

The cardiotoxic effect of karminomycin and adriamycin administered intravenously for 5 times in equitoxic doses constituting equal portions of LD50 of the respective antibiotic on its single intravenous administration was studied on albino mice. Histological examination of the heart showed that almost identical damages of the myocardium occured after administration of karminomycin and adriamycin in doses of 0.45 of LD50 (1.5 mg/kg) and 0.3 of LD50 (6.3 mg/kg) respectively. The character of the damages due to the antibiotics was close, the most significant changes were observed when the animals were sacrificed 1 month after the last administration of the drug. The histological method is of value in estimation of the cardiotoxic effect of the drugs, using mice as the model suitable for the investigation. Adriamycin had more pronounced cumulative properties as compared to karminomycin: suppression of the weight gain in the mice and their death rate were higher with the use of adriamycin.     

Effect of rubomycin (daunorubicin) and its nitroxyl analog on the functioning of rat heart mitochondria

Changes in the functional parameters of the rat heart mitochondria were studied in time after a single intraperitoneal administration of rubomycin, the rubomycin combination with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO-OH) and ruboxyl, a nitroxyl derivative of rubomycin. The administration of rubomycin resulted in inhibition of the heart mitochondria bioenergetic functions (a decrease in the respiration control coefficient, RCC, and the respiration rate, RR, on phosphorylation) during respiration in the presence of NAD(+)-dependent substrates 6 to 24 hours after the administration. Later the mitochondria functions recovered while in 2 to 3 weeks a secondary decrease in the RCC and RR was observed. During respiration in the presence of succinate the inhibitory effect on the antibiotics was higher. The combined administration of rubomycin and TEMPO-OH eliminated the primary inhibition. In the presence of ruboxyl the inhibitory effect in regard to the NAD(+)-dependent substrates was not detected. The mechanisms of the toxic action of the anthracycline antibiotics are discussed.     

Synthesis and antitumor properties of 3'-desamino-3'-dimethylformamidinorubomycin

Interaction of rubomycin (daunorubicin) chlorhydrate with dimethylformamidine diethyl acetal yielded 3'-desamino-3'dimethylformamidinorubomycin chlorhydrate (DFR). Comparative antitumor activity of DFR and rubomycin was studied on mice with respect to ascitic lymphadenosis NK/Ly and Ehrlich carcinoma, hemocytoblastosis La, leukemia P-388 and two solid tumors i. e. lymphosarcoma LIO-I and sarcoma 180. The highest antitumor effect of DFR was observed in the mice with Ehrlich carcinoma and lymphadenosis NK/Ly after the drug intravenous administration for 4 times. By selectivity of the antitumor effect DFR was inferior to rubomycin with respect to lymphosarcoma LIO-I and sarcoma 180. It was shown that the antileukemic activity of DFR and rubomycin with respect to hemocytoblastosis La was practically the same. In the experiments with leukemia P-388 DFR was inferior to rubomycin.     

Use of carminomycin on adult patients with acute leukemias]

The data on the clinical trials of karminomycin, a new antitumor antibiotic are presented. The drug was used in the treatment of 46 adult patients with leukemia. Karminomycin was used in primary inducing therapy and treatment of relapses. The results of the trials showed that karminomycin had a definite therapeutic activity in treatment of acute myeloblast leukemia at various stages of the process. A rapid effect of the antibiotic provided its use in emergency cases with rapidly progressing variants of the disease.     

Production and antitumor properties of carminazone

Karminazon (13-benzoylhydrazon) was prepared by condensation of karminomycin with benzoylhydrazine. In its intravenous use in the treatment of mice with lymphosarcoma L10-1 karminazon was less toxic and had lower antitumor activity than karminomycin. Karminazon had a lower selective antitumor activity with respect to lymphosarcoma than karminomycin.     

Interaction with DNA of semisynthetic carminomycin and rubomycin derivatives

The apparent binding constants and the effect of semisynthetic derivatives of carminomycin and rubomycin (anthracycline antibiotics) on DNA fusion were studied. The following semisynthetic derivatives were used. 13-dihydrocarminomycin, 14-hydroxycarminomycin, 13-(4-methylpiperazinyl) imine carminomycin, 13-benzoylhydrazone carminomycin (carminazone), 13-tret-butoxycarbonyl hydrazone rubomycin, 13-(4-methylpiperazinyl) imine rubomycin, 14-(1-hydroxyl-2,2,6,6-tetramethylpiperidyl-4)-acetoxyrubomycin (spin-labeled rubomycin). The above derivatives slightly differed from the initial antibiotics by their affinity to DNA. The binding constants of methylpiperazinyl imines was 2-3 times higher than those of the respective antibiotics.     

Effect of the diuretic diacarb on the antitumor activity of the antibiotics rubomycin and olivomycin]

Combined use of rubomycin and olivomycin with diacarb in treatment of rats with Pliss lymphosarcoma increased the antiblastomic activity of the antibiotics. The antitumor effect of rubomycin and olivomycin was increased by diacarb in the same degree as that of dipin, a synthetic cytostatic.     

Preparation of dihydrocarminomycin and a comparison of its antitumor activity with the activity of carminomycin]

A dihydro derivative of karminomycin was prepared using chemical reduction with potassium boron hydride. When dihydrokarminomycin was administered intravenously to healthy albino mice in a single dose it practically showed the same toxicity as karminomycin. However, unlike the latter dihydrokarminomycin induced the death of the animals at later periods of time. Studies on mice with transplantable tumours showed high antitumor activity of dihydrokarminomycin against lymphosarcoma L10-1, sarcoma 180, Garding-Passy melanoma, lymphoid leukosis L-1210 and lymphocytal leukosis P-388. In treatment of the mice with leukosis L-1210 and Garding-Passy melanoma dihydrokapminomycin was much inferior by its efficiency than karminomycin.     

Carminomycin in drug combination in breast cancer and soft tissue sarcomas]

Thirteen patients with neglected mammary cancer were treated with karminomycin in combination with hexamethylmelamine. Twelve out of the 13 patients were previously subjected many times to cytostatic and hormonal therapy. A significant therapeutic effect was registered in 5 out the 13 patients (38 per cent), the total rate of the objective effect being 54 per cent. The remission period with a significant effect was 6 to 9 months. Fifteen patients with sarcoma metastases in the soft tissue were treated with karminomycin in combnation with methotrexate and cyclophosphane. A significant therapeutic effect was observed in 45 per cent of the cases with synovial sarcoma, hemangyopericitoma and leuomyosarcoma, the remission period being 4 to 12 months. The side effects of the above combinations were determined.     

Inhibition of synthesis of nucleic acids, proteins and respiration in isolated thymocytes by anthracyclines

The effect of anthracycline antibiotics such as carminomycin, daunomycin (rubomycin) and adriamycin on respiration and synthesis of nucleic acids and protein was studied comparatively. The anthracyclines inhibited the processes. By their efficacy in that respect they could be arranged in the following order: carminomycin greater than rubomycin greater than adriamycin. Thus, 50 per cent inhibition of nucleic acid synthesis in the thymocytes required 0.027, 0.044 and 0,173 mM of carminomycin, rubomycin and adriamycin respectively. Protein synthesis and respiration in the thymocytes were less sensitive to the effect of the anthracyclines than synthesis of nucleic acids. The study results were compared with the literature data on the effect of the compounds on respiration and synthesis of nucleic acids and protein in tumour and bacterial cells.     

Effect of rubomycin and carminomycin on antibody formation during the immunization of mice with various antigens

The maximum immunodepressive effect of rubomycin and carminomycin was observed when the antibiotics were administered intravenously 24 hours after the immunization. The immune response induced by the sheep erythrocytes or the lipopolysaccharide was equally inhibited by rubomycin. Carminomycin in a dose of 0.5 mg/kg (0.1 of the LD50) to a larger extent inhibited the immune response stimulated by the lipopolysaccharide. Dependence of the immunodepressive effect of the antibiotics on their dose was found when the drugs were administered intravenously or orally.     

Antitumor activity of doxorubicin in the treatment of hemocytoblastosis La and various ascites tumors in mice

Antitumor activity of doxorubicin made in the USSR was studied on mice in respect to three transplantable tumors (lymphadenosis NK/LI, sarcoma 37 and Ehrlich's carcinoma) and hemocytoblastosis La. Doxorubicin injected intravenously 4 times was shown to be highly active against the above ascites tumors. The highest inhibitory effect of doxorubicin was observed in respect to the development of Ehrlich's carcinoma. By the selectivity of the therapeutic effect on this tumor it was superior to rubomycin and carminomycin. A high antileukemic activity of doxorubicin in respect to hemocytoblastosis La was shown. In experiments with this leukemia, intravenous injection of doxorubicin provided a higher efficacy than intraperitoneal injection. When used intravenously in the doses equivalent by their toxicity doxorubicin was inferior to rubomycin in terms of the therapeutic effect on leukemia La. However, on intraperitoneal injection of the drugs rubomycin showed no such advantage. Doxorubicin made in the USSR did not differ by its antitumor activity from the analogous foreign drug.