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EN
Previously performed experiments showed that methylxanthines, especially caffeine, may protect cells against cytostatic or cytotoxic effects of several aromatic compounds. One of the proposed mechanisms of this protection is based on stacking interactions between π electron systems of polycyclic aromatic molecules. In this work, we demonstrate that caffeine and other methylxanthines - pentoxifylline and theophylline - significantly decrease mutagenicity of the anticancer aromatic drugs daunomycin, doxorubicin and mitoxantrone. The spectrophotometric titration of these aromatic compounds by methylxanthines indicated formation of mixed aggregates. The concentrations of free active forms of the drugs decreased when the concentrations of methylxanthines increased in the mixture. Therefore, likely methylxanthines may play a role of scavengers of the free active forms of daunomycin, doxorubicin and mitoxantrone.
EN
Numerous adverse effects limit the applicability of mitoxantrone for the treatment of drug-resistant tumors, including carcinosarcoma. Here, we estimated the additive effects of mitoxantrone and curcumin, a plant-derived biomolecule isolated from Curcuma longa, on the neoplastic and invasive potential of carcinosarcoma cells in vitro. Curcumin augmented the cytostatic, cytotoxic and anti-invasive effects of mitoxantrone on the Walker-256 cells. It also strengthened the inhibitory effects of mitoxantrone on the motility of drug-resistant Walker-256 cells that had retained viability after a long-term mitoxantrone/curcumin treatment. Thus, curcumin reduces the effective doses of mitoxantrone and augments its interference with the invasive potential of drug-resistant carcinosarcoma cells.
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EN
Idarubicin is an anthracycline antibiotic used in cancer therapy. Mitoxantrone is an anthracycline analog with presumed better antineoplastic activity and lesser toxicity. Using the alkaline comet assay we showed that the drugs at 0.01-10 μM induced DNA damage in normal human lymphocytes. The effect induced by idarubicin was more pronounced than by mitoxantrone (P < 0.001). The cells treated with mitoxantrone at 1 μM were able to repair damage to their DNA within a 30-min incubation, whereas the lymphocytes exposed to idarubicin needed 180 min. Since anthracyclines are known to produce free radicals, we checked whether reactive oxygen species might be involved in the observed DNA damage. Catalase, an enzyme inactivating hydrogen peroxide, decreased the extent of DNA damage induced by idarubicin, but did not affect the extent evoked by mitoxantrone. Lymphocytes exposed to the drugs and treated with endonuclease III or formamidopyrimidine-DNA glycosylase (Fpg), enzymes recognizing and nicking oxidized bases, displayed a higher level of DNA damage than the untreated ones. 3-Methyladenine-DNA glycosylase II (AlkA), an enzyme recognizing and nicking mainly methylated bases in DNA, increased the extent of DNA damage caused by idarubicin, but not that induced by mitoxantrone. Our results indicate that the induction of secondary malignancies should be taken into account as side effects of the two drugs. Direct strand breaks, oxidation and methylation of the DNA bases can underlie the DNA-damaging effect of idarubicin, whereas mitoxantrone can induce strand breaks and modification of the bases, including oxidation. The observed in normal lymphocytes much lesser genotoxicity of mitoxantrone compared to idarubicin should be taken into account in planning chemotherapeutic strategies.
EN
Intercalative binding of the antitumor drugs ametantrone and mitoxantrone to the dodecamer duplex d(CGCGAGCTCGCG)2 was studied by applying molecular dynamics in water with the GROMOS 87 force field. A number of reasonable binding orientations were tested by short pre-simulations. It was shown that in energetically favorable orientation the anthraquinone chromophore is perpendicular to the direction of inter-base hydrogen bonds. Helically shaped side-chains of the drugs fit to the minor groove. The best orientation obtained in pre-simulations was applied in the main simulations. Small but significant differences were found between structures of intercalation complexes of the two drugs with the dodecamer duplex, the mitoxantrone complex possessing more favorable energy. The molecular nature of interactions responsible for those differences has been discussed.
EN
Multiple sclerosis is a chronic autoimmune disease of the central nervous system which has an unknown origin and variable course. In about 85% of cases it starts as the relapsing-remitting form that, in different periods of time depending on the patient, turns into the secondary progressive form with constant progression of disability, sometimes with preserved relapse and magnetic resonance imaging activity at the beginning. The treatment options for the secondary progressive form of multiple sclerosis are still limited. Based on the results of Mitoxantrone in Multiple Sclerosis Study, mitoxantrone has been registered for the treatment of secondary progressive multiple sclerosis. In addition, the drugs that have received registration in Europe are interferon beta-1b and interferon beta-1a given subcutaneously. These drugs have a proven effect in slowing the progression of disability (interferon beta-1b, mitoxantrone) as well as reducing the annualised relapse rate (interferon beta-1b, interferon beta-1a, mitoxantrone) and the number of new outbreaks in magnetic resonance imaging (interferon beta-1a, interferon beta-1b). The study of North American Study Group on Interferon β-1b in Secondary Progressive MS showed no effect of the therapy with interferon beta-1b on the inhibition of disability progression and as a result, the drug has not obtained registration for the treatment of secondary progressive multiple sclerosis in the United States. The patients who benefit most from the therapy which modifies the course of the progressive form of multiple sclerosis are younger, with a shorter history of the disease, preserved relapse activity and rapidly increasing disability.
PL
Stwardnienie rozsiane jest przewlekłą autoimmunologiczną chorobą ośrodkowego układu nerwowego o nieznanej przyczynie i zmiennym przebiegu. W około 85% przypadków najpierw występuje postać rzutowo-remisyjna, która po pewnym czasie (różniącym się w zależności od pacjenta) przechodzi w postać wtórnie postępującą ze stałą progresją niesprawności, niekiedy z początkowo zachowaną aktywnością rzutową i rezonansową choroby. Możliwości leczenia wtórnie postępującej postaci stwardnienia rozsianego są ograniczone. Na podstawie wyników badania Mitoxantrone in Multiple Sclerosis Study do leczenia tej postaci choroby zarejestrowany został mitoksantron. Ponadto w Europie rejestrację uzyskały interferon beta-1b oraz interferon beta-1a podawany podskórnie. Udowodniono wpływ tych leków na hamowanie progresji niesprawności (interferon beta-1b, mitoksantron) oraz spadek rocznego wskaźnika rzutów (interferon beta-1b, interferon beta-1a, mitoksantron) i liczby nowych ognisk w obrazach rezonansu magnetycznego (interferon beta-1a, interferon beta-1b). Badanie North American Study Group on Interferon β-1b in Secondary Progressive MS nie wykazało wpływu terapii interferonem beta-1b na hamowanie postępu niesprawności, więc nie uzyskał on rejestracji do leczenia tej postaci stwardnienia rozsianego w Stanach Zjednoczonych. Największe korzyści z terapii modyfikującej przebieg postępującej postaci choroby odnoszą pacjenci młodsi, chorujący krócej, z zachowaną aktywnością rzutową i szybko narastającą niesprawnością.
EN
Idarubicin is an anthracycline antibiotic used in cancer therapy. Mitoxantrone is an anthracycline analog with presumed better antineoplastic activity and lesser toxicity. Using the alkaline comet assay we showed that the drugs at 0.01-10 uM induced DNA damage in normal human lymphocytes. The effect induced by idarubicin was more pronounced than by mitoxantrone (P < 0.001). The cells treated with mitoxantrone at 1 uM were able to repair damage to their DNA within a 30-min incubation, whereas the lymphocytes exposed to idarubicin needed 180 min. Since anthracyclines are known to produce free radicals, we checked whether reactive oxygen species might be involved in the observed DNA damage. Catalase, an enzyme inactivating hydrogen peroxide, decreased the extent of DNA damage induced by idarubicin, but did not af­fect the extent evoked by mitoxantrone. Lymphocytes exposed to the drugs and treated with endonuclease III or formamidopyrimidine-DNA glycosylase (Fpg), en­zymes recognizing and nicking oxidized bases, displayed a higher level of DNA dam­age than the untreated ones. 3-Methyladenine-DNA glycosylase II (AlkA), an enzyme recognizing and nicking mainly methylated bases in DNA, increased the extent of DNA damage caused by idarubicin, but not that induced by mitoxantrone. Our results indicate that the induction of secondary malignancies should be taken into account as side effects of the two drugs. Direct strand breaks, oxidation and methylation of the DNA bases can underlie the DNA-damaging effect of idarubicin, whereas mitoxantrone can induce strand breaks and modification of the bases, including oxi­dation. The observed in normal lymphocytes much lesser genotoxicity of mitoxantrone compared to idarubicin should be taken into account in planning chemotherapeutic strategies.
EN
Previously performed experiments showed that methylxanthines, especially caffeine, may protect cells against cytostatic or cytotoxic effects of several aromatic compounds. One of the proposed mechanisms of this protection is based on stacking interactions between π electron systems of polycyclic aromatic molecules. In this work, we demonstrate that caffeine and other methylxanthines  -  pentoxifylline and theophylline - significantly decrease mutagenicity of the anticancer aromatic drugs daunomycin, doxorubicin and mitoxantrone. The spectrophotometric titration of these aromatic compounds by methylxanthines indicated formation of mixed aggregates. The concentrations of free active forms of the drugs decreased when the concentrations of methylxanthines increased in the mixture. Therefore, likely methylxanthines may play a role of scavengers of the free active forms of daunomycin, doxorubicin and mitoxantrone.
8
58%
EN
The aim of this review is the presentation of molecular mechanisms of action of cytostatic drugs used in the therapy of neurological disorders, mostly of multiple sclerosis (MS). From many years cytostatics like mitoxantrone, cyclophosphamide, cladribine and methotrexate were used in the MS clinical trials. So far only mitoxantrone has been approved by FDA for the treatment of progressive MS. The other cytostatics are still studied in clinical trials, the main problem with their approval for human therapy are their numerous side effects. So far those drugs are mostly used in oncology and haematology where the usage of this type of drugs is better justified. Now there are many studies leading to better understanding of mechanisms of action of cytostatics at the cellular and subcellular level. Mitoxantrone induces apoptosis and reduce the population of inflammatory egzocells capable to initiate demyelination in the central nervous system (CNS). At the molecular level mitoxantrone damages genome of inflammatory cells by inhibition of activity of topoisomerase II (TOP II) or direct interaction with DNA structure. Cyclophosphamide is a cytostatic acting mainly on dividing cells, in which it alkylates DNA and interferes with replication and cell apoptosis. Methotrexate inhibits activity of dehydrofolate reductase what leads to disturbance of replication and blocks phase S of the cell cycle in leukocytes. Cladribine is an antagonist of transcription. The detailed analysis of these mechanisms may lead to diminishing of the level of their side effects and to increase of their therapeutic potential, also in neurological therapy.
PL
Celem niniejszej pracy jest przedstawienie molekularnych mechanizmów działania cytostatyków stosowanych w próbach terapii niektórych chorób neurologicznych, głównie stwardnienia rozsianego (SM). Od wielu lat w terapii tego schorzenia próbuje się wykorzystywać takie cytostatyki, jak mitoksantron, cyklofosfamid, metotreksat i kladrybina. W chwili obecnej jedynym lekiem z tej grupy zatwierdzonym przez FDA do leczenia postępującego SM jest mitoksantron. Pozostałe cytostatyki wciąż poddawane są badaniom, a główny problem we wprowadzeniu ich do terapii neurologicznej stanowią liczne efekty uboczne. Leki te wykorzystywane są głównie w onkologii i hematologii, gdzie stosowanie tego typu leków jest bardziej uzasadnione. W chwili obecnej prowadzone są liczne badania zmierzające do lepszego poznania mechanizmów działania cytostatyków na poziomach komórkowym i subkomórkowym. Przyjmuje się, że mitoksantron indukuje apoptozę, co zmniejsza pulę komórek zapalnych zdolnych do wywoływania demielinizacji w obrębie ośrodkowego układu nerwowego (OUN). Na poziomie molekularnym mechanizm jego działania polega na uszkodzeniu genomu tych komórek poprzez hamowanie aktywności topoizomerazy II (TOPII) lub bezpośrednie wbudowywanie się w strukturę ich DNA. Cyklofosfamid jest cytostatykiem działającym w głównej mierze na komórki dzielące się, w których alkiluje on DNA, co indukuje zaburzenia replikacji oraz apoptozę tych komórek. Działanie lecznicze metotreksatu wynika ze zdolności do hamowania aktywności reduktazy dehydrofolianowej. W ten sposób zaburzony zostaje metabolizm zasad azotowych prowadzący do zaburzeń replikacji i bloku fazy S cyklu komórkowego leukocytów. Kladrybina działa jako antagonista procesu transkrypcji. Dokładne poznanie mechanizmów działania prezentowanych leków może doprowadzić do zmniejszenia nasilenia ich efektów ubocznych oraz do zwiększenia ich potencjału leczniczego, również w terapii neurologicznej.
EN
Triterpene saponosides are widely distributed plant secondary metabolites characterized by relatively low systemic cytotoxicity and a range of biological activities. These include anti-inflammatory, antimicrobial, vasoprotective and antitumor properties. In particular, the ability of saponins to enhance the cytotoxicity of chemotherapeutic drugs opened perspectives for their application in combined cancer chemotherapy. Here, we used human prostate cancer DU-145 cells as an in vitro model to elucidate the synergy of the interactions between biological activities of an oleanane type 13β,28-epoxy triterpene saponoside (Lclet 4) and mitoxantrone, which is a cytostatic drug commonly used in prostate cancer therapy. No cytotoxic or pro-apoptotic effect of Lclet 4 and mitoxantrone administered at the concentrations between 0.05 and 0.1 µg/ml could be seen. In contrast, cocktails of these agents exerted synergistic pro-apoptotic effects, accompanied by the activation of the caspase 3/7 system. This effect was paralleled by attenuating effects of Lclet 4/mitoxantrone cocktails on the invasive potential, metalloproteinase expression and motility of DU-145 cells. Multifaceted and additive effects of Lclet 4 and mitoxantrone on basic cellular traits crucial for prostate cancer progression indicate that the combined application of both agents at systemically neutral concentrations may provide the basis for new promising strategies of prostate cancer chemotherapy.
EN
The effect of DNR and MIT on erythrocyte membrane structure was examined using Electron Spin Resonance spectroscopy and the fluorimetric technique. The results suggest that the in vivo interaction of the drugs with the RBCs of AML patients led to a perturbation in the structure of plasma membrane components. Differences between DNR and MIT were only noted in the interaction of the drugs with deeper regions of the lipid bilayer.
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