Comparative characteristics of the antitumor and immunodepressive activity of carminomycin on the L-1210 experimental model]

The antitumor activity of carminomycin was estimated by the number of lymphoma colonies formed in the spleen of DBA/2 mice on their inoculation with the bone marrow cells from mice with transplantable leukemia L-1210. The immunodepressive properties of carminomycin were determined by the number of the antibody forming cells in the spleen of CBA and DBA/2 mice with leukemia L-1210 after immunization with sheep red blood cells. It was found that in a single dose of 1.5 mg/kg carminomycin inhibited the lymphoma colonies by 50 per cent. The maximum immunodepressive effect was observed when carminomycin was used in a single dose of 1.5 mg/kg 48 hours after the antigen stimulation. In this case the number of the antibody forming cells in DBA/2 mice with leukemia L-1210 was lower than that in CBA mice without leukemia.     

Immunodepressive action of carminomycin and rubomycin derivatives]

The immunodepressive effects of carminomycin and its 3 semi-synthetic derivatives, as well as rubomycin and its derivative R-103 were compared. It was found that 14-hydroxycarminomycin was much superior to the other substances in the experiments with synthesis induction suppression of antibodies against sheep red cells in mice. Suppression of the rejection of the skin allogenic grafts in the mice by carminomycin was higher as compared to that by the other substances. Probably different populations of the immune competent cells have selective sensitivity to separate anthracyclines.     

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.     

Synthesis and antitumor properties of carminomycin 13-cyclohexylidenhydrazone

Carminomycin 13-cyclohexylidenhydrazone (CCH) was prepared by interaction of carminomycin 13-hydrazone with cyclohexane. The antiblastomic properties of CCH were studied on mice with transplantable tumors. The preparation was administered intravenously or orally. The studies showed a high antitumor activity of CCH. When CCH was administered intravenously to mice with lymphosarcoma LIO-1, the antitumor effect selectivity of it was practically equal to that of carminomycin. When used in doses equivalent by their toxicity to those of carminomycin, CCH had practically the same inhibitory effect on sarcoma 180 as carminomycin. When used orally in doses equivalent by their toxicity to those of carminomycin, CCH was more effective than carminomycin in treatment of mice with lymphosarcoma LIO-1, sarcoma 180 and lymphadenosis NK/Ly.     

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.     

New derivatives of carminomycin and rubomycin

For preparing new semisynthetic analogs of anthracycline antibiotics, hydrolysis of 13-dimethylketals of 14-bromrubomycin and 14-brom-arminomycin in solution of diluted hydrochloric acid was studied. It was shown that such hydrolysis yielded 14-chlorrubomycin and 14-chlorcarminomycin. Conditions for separating the mixture of 14-chlor- and 14-bromrubomycins and the mixture of 14-chlor- and 14-bromcarminomycins by HPLC were developed. Interaction of 14-chlorine derivatives of rubomycin and carminomycin with potassium formate in the presence of the crown ether yielded 14-formyloxy derivatives of rubomycin and carminomycin. Interaction of rubomycin and carminomycin with formic acid in the presence of N-oxysuccinimide and dicyclohexylcarbodiimide resulted in formation of N-formyl derivatives of rubomycin and carminomycin.     

Antiviral action of carminomycin and some of its derivatives]

Carminomycin was shown to inhibit the development of both the DNA-containing variolovaccine virus and the RNA-containing grippe virus in chick embryos. Comparison of the effects of rubomycin, carminomycin, 14-oxy-carminomycin and carminomycin complex with bovine serum albumin in experiments with chick embryos showed that the inhibitory effect of carminomycin and its derivatives on the development of the grippe virus was much higher than that of rubomycin. The carminomycin derivatives proved to be much more active in this respect than the initial antibiotic. Carminomycin and its derivatives had a therapeutic effect on mice with experimental grippe pneumonia also on their oral use.     

Comparison of the action of carminomycin and rubomycin on the dynamics of the primary and secondary immune responses

The effect of rubomycin and carminomycin on the dynamics of the primary and secondary immune response and formation of the immunologic memory to sheep red cells in mice was studied. Differences in the character of the antibiotics effect indicative of the higher selective action of carminomycin on multiplying cells, precursors of the antibody-forming plasmids, were found. Theoretically interesting discrepancies in the effect of the antibiotics on the content of the antibodies in the serum and the antibody-producing cells in the spleen were shown. It was demonstrated that carminomycin had no effect on formation of the immunologic memory inspite of a noticeable decrease in the total number of the spleen nuclear cells and the number of the antibody-forming cells at the moment of immunization under the effect of the antibiotic.     

Determination of carminomycin in its preparations by high-performance liquid chromatography

A three component system for separating a mixture of carminomycin, carminomycinone and 13-dihydrocarminomycinone by HPLC was developed. Spherisorb ODS Column, 4.6 X 250 mm, the particle size of 10 micron was used. The impact of the mobile phase composition, temperature during chromatography and buffer solution pH on the capacity factors K' for every of the above compounds was studied. For determining purity of carminomycin dosage forms the procedure with an external standard was applied. The procedure provides routine quantitative assay of carminomycin hydrochloride dosage forms.     

Acute toxicity of carminomycin administered perorally to laboratory animals

Rather high species sensitivity to carminomycin was found in the experiment with albino mice, rats, guinea pigs, rabbits and dogs. The highest difference in the antibiotic toxicity for various species of the laboratory animals was shown on oral administration of the drug which was due to the differences in the antibiotic absorption from the gastro-intestinal tract. On single oral administration to the dogs in toxic or lethal doses the antibiotic suppressed the blood formation up to aplasia of the bone marrow. The equitoxic doses of carminomycin on its single oral and intravenous administration differed approximately by 3 times. Carminomycin had no effect on the smooth muscles of the isolated rabbit ear vessels and cat intestine in situ. The antibiotic had an irritating effect on the rabbit eye mucosa. Carminomycin had no skin-irritating effect.     

Experience with using carminomycin in oncological clinical practice]

Carminomycin is an original antitumor antibiotic from the anthracycline group isolated at the Institute of New Antibiotics (USSR) in 1973. Pharmacological investigation of carminomycin revealed its satisfactory absorption from the gastrointestinal tract which proved to be a distinguishing property of the antibiotic as compared to other anthracyclines such as adriamycin and rubomycin. The clinical trials of carminomycin showed that it was mainly active against soft tissue sarcoma and breast cancer, lymphosarcoma, neuroblastoma, Wilms' tumor and Ewing's sarcoma in children, as well as acute leukemia. Various regimens for the antibiotic administration were applied: short-term, single and long-term. Suppression of hemopoiesis was considered as a limiting toxic effect. By the data available carminomycin had lower cardiotoxicity as compared with rubomycin and adriamycin. Development of oral carminomycin is believed promising.     

Comparison of the antitumor, immunodepressive and toxic properties of carminomycin-albumin complexes differing in carminomycin content

Bovine serum albumin (BSA) and carminomycin, an anthracycline antibiotic, were subjected to conjugation with glutaraldehyde and their complexes with various contents of the antibiotic were prepared. The molar ratios of carminomycin and BSA were 8:1, 4:1, and 2:1. The antitumor effect of the preparations was studied on the models of mouse transplantable lymphosarcoma LIO equal 1 and ascitic forms of mouse lymphadenosis NK/Ly in vivo and in vitro. Their immunodepressant effect was evaluated from the decrease in the hemagglutinin titers in the mice immunized with sheep red blood cells. It was shown that when the toxicity of the complexes was the same, their antitumor and immunodepressant activities were different. The therapeutic activity of carminomycin in the four- and eight-substituted complexes was much higher than that of carminomycin alone. It is suggested that the differences in the activity of the complexes were connected with differences in their pharmacokinetics. It was found that the chemotherapeutic properties of the complexes may have changed by variation of the number of the cytostatic residues in the albumin molecule. The findings indicate that the whole complex molecule interacts with the malignant cell and not carminomycin preliminarily detached from it.     

Thiol-dependent protective systems in alimentary prevention of the toxic effect of carminomycin

The state of the thiol-dependent systems i.e. concentration of the SH-groups, activity of glutathione reductase and glutathione-S-transferase, carminomycin antitumor and toxic effects was studied under conditions of tumor growth and carminomycin therapy with the use of prophylactic rations (PR) aimed at stimulating the cell thiol-dependent and antioxidant systems for decreasing the drug toxic action. It was shown that addition of sulfur-containing amino acids, selenium and vitamin E to the ration of healthy and tumor-bearing rats (Walker carcinosarcoma 256) induced a decrease in the level of the SH-groups in the liver just likely promoting efficient extrahepatic usage of glutathione. After administration of carminomycin a long with the PR use, the liver showed the thiol-preserving capacity evidenced by a decrease or complete elimination of the above effect of the ration. The use of PR resulted in a marked increase in the glutathione-S-transferase activity in cytosol and to a lesser extent in the liver microsomes. A regulating effect of the PR on the activity of glutathione reductase was observed: its inhibition in the healthy animals and stimulation after carminomycin administration in the heart of the healthy animals and the liver of the tumor-bearing animals.     

Action of carminomycin on leukemic cell proliferation and some problems of its use in the combined therapy of leukemias

The effect of carminomycin on the mitotic cycle of the cells of the transplantable leukemia L-1210 and the therapeutic activity of other antitumor drugs, such as phopurine and cyclophosphane was studied on mice BDF1. It was found that the cells in phases S and G2 of the mitotic cycle were most sensitive to carminomycin. Transfer G1--S and phase G1 were characterized by resistance to the antibiotic effect. When carminomycin was used in combination with phopurine or cyclophosphane, clear dependence of the therapeutic efficacy on the treatment scheme was noted. Simultaneous administration of all the three drugs resulted in potentiation of the antileukemic effect. An analogous effect was observed when carminomycin was administered prior to phopurine or cyclophosphane. When the order of the drugs use was reverse, the efficacy of the combined therapy was significantly lower than the summation antileukemic effect of the drugs.     

Use of carminomycin in combination with UHF hyperthermia in the therapy of sarcoma 180]

It was found that combined treatment of sarcoma 180 with local U. H. F.-hyperthermia and carminomycin resulted in the tumor growth inhibition by more than 90 per cent, which was much higher than the effect of every agent alone. The thermochemotherapy allowed a decrease in the dose of the antibiotic without decreasing the antitumor effect. The U. H. F.-hyperthermia has an independent tumorolytic effect and promotes selective accumulation of carminomycin by the tumor.     

Effect of carminomycin on the energy metabolism of the liver in rats]

The effect of carminomycin on the liver energetic metabolism was studied experimentally on rats in dynamics after its intraperitoneal administration in a single LD50 and the therapeutic doses for a treatment course. It was found that changes in the rat liver tissues on the part of the energetic metabolism occurred irrespective of the antibiotic dose and the administration multiplicity. Mainly they were of reversible nature: the balance of consumption and resynthesis of the phosphate macroergs was impaired, the glycolytic processes increased, shifts in the activity of the enzymes of the pentose phosphate pathway of oxydation were observed. The level of the above changes was more pronounced when carminomycin was administered in LD50. The adrenal system played an important role in the mechanism of the shifts noted.     

Immobilization and properties of carminomycin 4-O-methyltranferase, the enzyme which catalyzes the final step in the biosynthesis of daunorubicin in Streptomyces peucetius

The carminomycin 4-O-methyltransferase enzyme from Streptomyces peucetius was covalently immobilized on 3M Emphaze ABI-activated beads. Optimal conditions of time, temperature, pH, ionic strength, enzyme, substrate (carminomycin), and cosubstrate (S-adenosyl-L-methionine) concentrations were defined for the immobilization reaction. Protein immobilization yield ranged from 52% to 60%. Including carminomycin during immobilization had a positive effect on the activity of the immobilized enzyme but a strongly negative effect on the coupling efficiency. The immobilized enzyme retained at least 57% of its maximum activity after storage at 4 degrees C for more than 4 months. The properties of the free and immobilized enzyme were compared to determine whether immobilization could alter enzyme activity. Both soluble and bound enzyme exhibited the same pH profile with an optimum near 8.0. Immobilization caused an approximately 50% decrease in the apparent K(m) (K'(m)) for carminomycin while the K'(m) for S-adenosyl-L-methionine was approximately doubled. A 57% decrease in the V(max) value occurred upon immobilization. These changes are discussed in terms of active site modifications as a consequence of the enzyme immobilization. This system has a potential use in bioreactors for improving the conversion of carminomycin to daunorubicin. (c) 1995 John Wiley & Sons, Inc.     

Minor components from the carminomycin complex

Three components differing by their properties from the carminomycins described earlier were isolated from the carminomycin complex. Comparison of the IR and UV spectra, as well as chromatographic and physicochemical properties of 2 of them showed that they were dihydrocarminomycin and its aglycone or dihydrocarminomycinone, which was prepared earlier by synthesis. The third component was a chromophore belonging to 1,4,6-trihydroxyanthraquinone. Investigation of its IR spectrum, physicochemica properties and PMR spectrum showed it to be carboxymethylethylcarminomycinone identical to epsilon-rodomycinone. The data were confirmed by 13C-NMR spectrometry.     

Antitumor activity of the components of a carminomycin complex

The antiblastomic activity of the carminomycin complex components was studied with respect to 8 strains of transplantable tumors of mice: lymphosarcoma L10-1, prestomach cancer OZh-5, sarcoma 180, lymphoid leucosis L 1210, lung bronchogenic cancer RL, lymphodenosis NK/LI, Ehrlich carcinoma and Garding-Passy melanoma. It was shown that components I, II and III possessed almost the same high antiblastomic activity and the same optimal administration schemes should be used for them. The scheme consisted of two-fold administration of the drug at intervals of 96-120 hours. Component I had broader therapeutic ranges and was more active against the lung bronchogenic cancer as compared to component II. All 3 components had no selective antiblastomic effect on the ascitic form of Ehrlich carcinoma. A comparative study of the component toxicity and pharmacology is required for final conclusion as to the recommendation of one of the components for clinical trials.     

Antitumor properties and toxicity of a carminomycin and protein complex

The properties of carminomycin complexes with protein, a bovine serum albumin prepared with two different methods using glutaraldehyde or carbodiimine were studied. The complex prepared with the use of carbodiimine was biologically inactive. The complex prepared with the use of glutaraldehyde had a molecular mass of about 15 000 000 dalton, was more toxic than carminomycin and possessed proportionally higher antitumor activity and a wider antitumor spectrum. The studies on the use of the method of carminomycin complex formation with antitumor immunoglobulins are promising.