RESUMO
Apart from cardiotoxicity, the chemotherapeutic agent doxorubicin (DOX) provokes acute and long-term vascular toxicity. Dexrazoxane (DEXRA) is an effective drug for treatment of DOX-induced cardiotoxicity, yet it remains currently unknown whether DEXRA prevents vascular toxicity associated with DOX. Accordingly, the present study aimed to evaluate the protective potential of DEXRA against DOX-related vascular toxicity in a previously-established in vivo and ex vivo model of vascular dysfunction induced by 16 hour (h) DOX exposure. Vascular function was evaluated in the thoracic aorta in organ baths, 16h after administration of DOX (4 mg/kg) or DOX with DEXRA (40 mg/kg) to male C57BL6/J mice. In parallel, vascular reactivity was evaluated after ex vivo incubation (16h) of murine aortic segments with DOX (1 µM) or DOX with DEXRA (10 µM). In both in vivo and ex vivo experiments, DOX impaired acetylcholine-stimulated endothelium-dependent vasodilation. In the ex vivo setting, DOX additionally attenuated phenylephrine-elicited vascular smooth muscle cell (VSMC) contraction. Importantly, DEXRA failed to prevent DOX-induced endothelial dysfunction and hypocontraction. Furthermore, RT-qPCR and Western blotting showed that DOX decreased the protein levels of topoisomerase-IIß (TOP-IIß), a key target of DEXRA, in the heart, but not in the aorta. Additionally, the effect of N-acetylcysteine (NAC, 10 µM), a reactive oxygen species (ROS) scavenger, was evaluated ex vivo. NAC did not prevent DOX-induced impairment of acetylcholine-stimulated vasodilation. In conclusion, our results show that DEXRA fails to prevent vascular toxicity resulting from 16h DOX treatment. This may relate to DOX provoking vascular toxicity in a ROS- and TOP-IIß-independent way, at least in the evaluated acute setting. However, it is important to mention that these findings only apply to the acute (16h) treatment period, and further research is warranted to delineate the therapeutic potential of DEXRA against vascular toxicity associated with longer-term repetitive DOX dosing.
Assuntos
Dexrazoxano , Camundongos , Animais , Masculino , Dexrazoxano/farmacologia , Dexrazoxano/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/prevenção & controle , Cardiotoxicidade/metabolismo , Acetilcolina/metabolismo , Doxorrubicina/toxicidade , Doxorrubicina/metabolismo , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Antibióticos Antineoplásicos/farmacologiaRESUMO
The anticancer efficacy of doxorubicin (DOX) is dose-limited because of cardiomyopathy, the most significant adverse effect. Initially, cardiotoxicity develops clinically silently, but it eventually appears as dilated cardiomyopathy with a very poor prognosis. Dexrazoxane (DEX) is the only FDA-approved drug to prevent the development of anthracycline cardiomyopathy, but its efficacy is insufficient. Carvedilol (CVD) is another product being tested in clinical trials for the same indication. This study's objective was to evaluate anthracycline cardiotoxicity in rats treated with CVD in combination with DEX. The studies were conducted using male Wistar rats receiving DOX (1.6 mg/kg b.w. i.p., cumulative dose: 16 mg/kg b.w.), DOX and DEX (25 mg/kg b.w. i.p.), DOX and CVD (1 mg/kg b.w. i.p.), or a combination (DOX + DEX + CVD) for 10 weeks. Afterward, in the 11th and 21st weeks of the study, echocardiography (ECHO) was performed, and the tissues were collected. The addition of CVD to DEX as a cardioprotective factor against DOX had no favorable advantages in terms of functional (ECHO), morphological (microscopic evaluation), and biochemical alterations (cardiac troponin I and brain natriuretic peptide levels), as well as systemic toxicity (mortality and presence of ascites). Moreover, alterations caused by DOX were abolished at the tissue level by DEX; however, when CVD was added, the persistence of DOX-induced unfavorable alterations was observed. The addition of CVD normalized the aberrant expression of the vast majority of indicated genes in the DOX + DEX group. Overall, the results indicate that there is no justification to use a simultaneous treatment of DEX and CVD in DOX-induced cardiotoxicity.
Assuntos
Cardiomiopatias , Dexrazoxano , Masculino , Ratos , Animais , Dexrazoxano/farmacologia , Dexrazoxano/uso terapêutico , Antraciclinas/efeitos adversos , Carvedilol/farmacologia , Carvedilol/uso terapêutico , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/etiologia , Cardiotoxicidade/prevenção & controle , Ratos Wistar , Antibióticos Antineoplásicos/toxicidade , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/prevenção & controle , Cardiomiopatias/tratamento farmacológico , Doxorrubicina/farmacologia , Inibidores da Topoisomerase II/uso terapêuticoRESUMO
Despite high anticancer activity, doxorubicin (DOX)-induced cardiotoxicity (DIC) limits the extensive utility of DOX in a clinical setting. Amongst various strategies explored, dexrazoxane (DEX) remains the only cardioprotective agent to be approved for DIC. In addition, altering the dosing regimen of DOX has also proved to be somewhat beneficial in decreasing the risk of DIC. However, both approaches have limitations and further studies are required to better optimize them for maximal beneficial effects. In the present work, we quantitatively characterized DIC as well as the protective effects of DEX in an in vitro model of human cardiomyocytes, by means of experimental data and mathematical modeling and simulation (M&S) approaches. We developed a cellular-level, mathematical toxicodynamic (TD) model to capture the dynamic in vitro drug-drug interaction, and relevant parameters associated with DIC and DEX cardio-protection were estimated. Subsequently, we executed in vitro-in vivo translation by simulating clinical PK profiles for different dosing regimens of DOX alone and in combinations with DEX and using the simulated PK profiles to drive the cell-based TD models to evaluate the effects of long-term, clinical dosing regimens of these drugs on the relative cell viability of AC16 and to determine optimal drug combinations with minimal cellular toxicity. Here, we identified that the Q3W (once every three weeks) DOX regimen with 10:1 DEX:DOX dose ratio over three cycles (nine weeks) may offer maximal cardio-protection. Overall, the cell-based TD model can be effectively used to better design subsequent preclinical in vivo studies aimed for further optimizing safe and effective DOX and DEX combinations to mitigate DIC.
Assuntos
Dexrazoxano , Humanos , Dexrazoxano/farmacologia , Doxorrubicina/farmacologia , Miócitos Cardíacos/metabolismo , Cardiotônicos/farmacologia , Cardiotoxicidade/prevenção & controleRESUMO
Aims: Cancer patients treated with anthracyclines are susceptible to atrial fibrillation (AF), while the mechanisms remain unclear. Due to sudden and unpredictable features, prediction of anthracycline-induced AF at early phase is difficult. Clinically, we tested whether anthracycline-induced early atrial remodeling in patients could be detected by echocardiography. Experimentally, we investigated the mechanisms of doxorubicin-induced atrial remodeling and AF in mice, and the protective effects of dexrazoxane and antioxidants. Methods and Results: Postsurgery breast cancer patients with an anthracycline-containing or anthracycline exclusion regimen were recruited for echocardiography before chemotherapy, and 3 and 6 months after chemotherapy. Mice were injected with doxorubicin or vehicle (5 mg/kg/week, 4 weeks), and left atrial diameter, electrical transmission, and AF inducibility were measured. Meanwhile, the level of reactive oxygen species (ROS), activity of antioxidant enzymes, cardiomyocyte size, vacuolization, inflammation, and fibrosis were also measured in mouse atria. The therapeutic effects of dexrazoxane and antioxidants on doxorubicin-induced changes in the aforementioned parameters were also determined. While ventricular parameters and functions were unchanged in cancer patients receiving anthracyclines before and after chemotherapy, left atrial reservoir and conduit function were decreased at 3 months postchemotherapy versus prechemotherapy. Doxorubicin-induced susceptibility to AF occurred in mice before onset of ventricular dysfunction. Doxorubicin-induced AF was via inducing structural remodeling (cardiomyocyte death, hypotrophy, and vacuolization) and electrical remodeling (reduction and redistribution of connexin 43) in atria, which was effectively prevented by dexrazoxane or antioxidants through inhibiting ROS generation or enhancing ROS elimination. Innovation and Conclusion: AF inducibility was induced after doxorubicin injection, which can be inhibited by repressing the ROS level. Antioxid. Redox Signal. 37, 19-39. The Clinical Trial Registration number is PJ-KS-KY-2019-73.
Assuntos
Fibrilação Atrial , Remodelamento Atrial , Neoplasias da Mama , Dexrazoxano , Animais , Antraciclinas/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Antioxidantes/uso terapêutico , Fibrilação Atrial/induzido quimicamente , Fibrilação Atrial/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Cardiotoxicidade/etiologia , Dexrazoxano/farmacologia , Dexrazoxano/uso terapêutico , Doxorrubicina , Feminino , Humanos , Camundongos , Espécies Reativas de OxigênioRESUMO
BACKGROUND: Anthracycline-induced heart failure has been traditionally attributed to direct iron-catalyzed oxidative damage. Dexrazoxane (DEX)-the only drug approved for its prevention-has been believed to protect the heart via its iron-chelating metabolite ADR-925. However, direct evidence is lacking, and recently proposed TOP2B (topoisomerase II beta) hypothesis challenged the original concept. METHODS: Pharmacokinetically guided study of the cardioprotective effects of clinically used DEX and its chelating metabolite ADR-925 (administered exogenously) was performed together with mechanistic experiments. The cardiotoxicity was induced by daunorubicin in neonatal ventricular cardiomyocytes in vitro and in a chronic rabbit model in vivo (n=50). RESULTS: Intracellular concentrations of ADR-925 in neonatal ventricular cardiomyocytes and rabbit hearts after treatment with exogenous ADR-925 were similar or exceeded those observed after treatment with the parent DEX. However, ADR-925 did not protect neonatal ventricular cardiomyocytes against anthracycline toxicity, whereas DEX exhibited significant protective effects (10-100 µmol/L; P<0.001). Unlike DEX, ADR-925 also had no significant impact on daunorubicin-induced mortality, blood congestion, and biochemical and functional markers of cardiac dysfunction in vivo (eg, end point left ventricular fractional shortening was 32.3±14.7%, 33.5±4.8%, 42.7±1.0%, and 41.5±1.1% for the daunorubicin, ADR-925 [120 mg/kg]+daunorubicin, DEX [60 mg/kg]+daunorubicin, and control groups, respectively; P<0.05). DEX, but not ADR-925, inhibited and depleted TOP2B and prevented daunorubicin-induced genotoxic damage. TOP2B dependency of the cardioprotective effects was probed and supported by experiments with diastereomers of a new DEX derivative. CONCLUSIONS: This study strongly supports a new mechanistic paradigm that attributes clinically effective cardioprotection against anthracycline cardiotoxicity to interactions with TOP2B but not metal chelation and protection against direct oxidative damage.
Assuntos
Antraciclinas/farmacologia , Cardiotoxicidade/prevenção & controle , Dexrazoxano/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Inibidores da Topoisomerase II/metabolismo , Antraciclinas/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Antibióticos Antineoplásicos/farmacologia , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/metabolismo , DNA Topoisomerases Tipo II/efeitos adversos , DNA Topoisomerases Tipo II/metabolismo , Daunorrubicina/metabolismo , Daunorrubicina/farmacologia , Dexrazoxano/efeitos adversos , Cardiopatias/tratamento farmacológico , Humanos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Estresse Oxidativo/efeitos dos fármacosRESUMO
Cancer is one of the leading causes of deaths worldwide with 18.1 million deaths per year. Although there have been significant advances in anti-cancer therapies, they can often result in side effects with cardiovascular complications being the most severe. Dexrazoxane is the only currently approved treatment for prevention of anthracycline induced cardiotoxicity but there are concerns about its use due to the development of secondary malignancies and myelodysplastic syndrome. Additionally, it is only recommended in patients who are due to receive a total cumulative dose of 300 mg/m2 of doxorubicin or 540 mg/m2 of epirubicin. Thus, there exists an urgent need to develop new therapeutic strategies to counteract anthracycline induced cardiotoxicity. The h9c2 cardiomyoblast was investigated for its differentiation capacity and used to screen and compare promising prophylactics for doxorubicin induced cardiotoxicity. The half maximal inhibitory concentration of doxorubicin was determined in differentiated h9c2 cells after 24 h of exposure, to establish a model for drug screening. Cells were treated with dexrazoxane, resveratrol, and carvedilol either 3 h or 24 h prior to doxorubicin treatment. The ability of these cardioprotectants to prevent cardiotoxicity was analysed using the cck-8 cell viability assay and the dichlorofluorescin diacetate (DCFDA) reactive oxygen species (ROS) assay. There was no significant increase in survival in treatment groups after 3 h, however, at 24 h, resveratrol significantly improved survival compared to all other groups (p < 0.05). Additionally, dexrazoxane and resveratrol significantly decreased ROS formation at 3 h (p < 0.05) and all groups significantly decreased ROS production at 24 h (p < 0.001). This work is the first comparison of these cardioprotectants and suggests that resveratrol may be a more effective treatment in the prevention of anthracycline induced cardiotoxicity, compared to dexrazoxane and carvedilol. However, further work will be needed in order to decipher the exact mechanism and potential of this drug in the clinic.
Assuntos
Antibióticos Antineoplásicos , Cardiotônicos/farmacologia , Cardiotoxicidade/tratamento farmacológico , Doxorrubicina , Resveratrol/farmacologia , Animais , Carvedilol/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dexrazoxano/farmacologia , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
PURPOSE: To report the interim analysis of the phase II single-arm noninferiority trial, testing the upfront use of dexrazoxane with doxorubicin on progression-free survival (PFS) and cardiac function in soft-tissue sarcoma (STS). PATIENTS AND METHODS: Patients with metastatic or unresectable STS who were candidates for first-line treatment with doxorubicin were deemed eligible. An interim analysis was initiated after 33 of 65 patients were enrolled. Using the historical control of 4.6 months PFS for doxorubicin in the front-line setting, we tested whether the addition of dexrazoxane affected the efficacy of doxorubicin in STS. The study was powered so that a decrease of PFS to 3.7 months would be considered noninferior. Secondary aims included cardiac-related mortality, incidence of heart failure/cardiomyopathy, and expansion of cardiac monitoring parameters including three-dimensional echocardiography. Patients were allowed to continue on doxorubicin beyond 600 mg/m2 if they were deriving benefit and were not demonstrating evidence of symptomatic cardiac dysfunction. RESULTS: At interim analysis, upfront use of dexrazoxane with doxorubicin demonstrated a PFS of 8.4 months (95% confidence interval: 5.1-11.2 months). Only 3 patients were removed from study for cardiotoxicity, all on > 600 mg/m2 doxorubicin. No patients required cardiac hospitalization or had new, persistent cardiac dysfunction with left ventricular ejection fraction remaining below 50%. The median administered doxorubicin dose was 450 mg/m2 (interquartile range, 300-750 mg/m2). CONCLUSIONS: At interim analysis, dexrazoxane did not reduce PFS in patients with STS treated with doxorubicin. Involvement of cardio-oncologists is beneficial for the monitoring and safe use of high-dose anthracyclines in STS.See related commentary by Benjamin and Minotti, p. 3809.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dexrazoxano/administração & dosagem , Doxorrubicina/administração & dosagem , Sarcoma/tratamento farmacológico , Neoplasias de Tecidos Moles/tratamento farmacológico , Idoso , Anticorpos Monoclonais/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Dexrazoxano/farmacologia , Intervalo Livre de Doença , Doxorrubicina/farmacologia , Feminino , Coração/efeitos dos fármacos , Coração/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Prospectivos , Sarcoma/secundário , Neoplasias de Tecidos Moles/patologiaRESUMO
Treatment of thoracic tumors with radiotherapy can lead to severe cardiac injury. We investigated the effects of dexrazoxane, a USFDA-approved cardioprotective drug administered with chemotherapy, on radiation-induced heart disease (RIHD) in a rat model. Male Sprague-Dawley rats were irradiated with a single dose of 20 Gy to the heart and treated with dexrazoxane at the time of irradiation and for 12 subsequent weeks. Dexrazoxane suppressed radiation-induced myocardial apoptosis and significantly reversed changes in serum cardiac troponin I levels and histopathological characteristics six months post-radiation. Treatment with dexrazoxane did not alter the radiosensitivity of thoracic tumors in a tumor formation experiment using male nude Balb/C mice with tumors generated by H292 cells. Dexrazoxane reduced the accumulation of reactive oxygen species in rat cardiac tissues, but not in tumors in nude mice. Transcriptome sequencing showed that IKBKE, MAP3K8, NFKBIA, and TLR5, which are involved in Toll-like receptor signaling, may be associated with the anti-RIHD effects of dexrazoxane. Immunohistochemistry revealed that dexrazoxane significantly decreased NF-κB p65 expression in cardiomyocytes. These findings suggest dexrazoxane may protect against RIHD by suppressing apoptosis and oxidative stress in cardiomyocytes.
Assuntos
Dexrazoxano/farmacologia , Cardiopatias/patologia , Coração/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Lesões Experimentais por Radiação/patologia , Animais , Apoptose/efeitos dos fármacos , Coração/efeitos da radiação , Masculino , Camundongos , Camundongos Nus , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
The significant role of topoisomerases in the control of DNA chain topology has been confirmed in numerous research conducted worldwide. The prevalence of these enzymes, as well as the key importance of topoisomerase in the proper functioning of cells, have made them the target of many scientific studies conducted all over the world. This article is a comprehensive review of knowledge about topoisomerases and their inhibitors collected over the years. Studies on the structure-activity relationship and molecular docking are one of the key elements driving drug development. In addition to information on molecular targets, this article contains details on the structure-activity relationship of described classes of compounds. Moreover, the work also includes details about the structure of the compounds that drive the mode of action of topoisomerase inhibitors. Finally, selected topoisomerases inhibitors at the stage of clinical trials and their potential application in the chemotherapy of various cancers are described.
Assuntos
Antineoplásicos/química , DNA Topoisomerases/metabolismo , Inibidores da Topoisomerase/química , Acridinas/química , Acridinas/farmacologia , Animais , Antineoplásicos/farmacologia , Dexrazoxano/química , Dexrazoxano/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Quinolonas/química , Quinolonas/farmacologia , Relação Estrutura-Atividade , Tiobarbitúricos/química , Tiobarbitúricos/farmacologia , Inibidores da Topoisomerase/farmacologiaRESUMO
PURPOSE: To determine whether dexrazoxane provides effective cardioprotection during frontline treatment of pediatric acute myeloid leukemia (AML) without increasing relapse risk or noncardiac toxicities of the chemotherapy regimens. PATIENTS AND METHODS: This was a multicenter study of all pediatric patients with AML without high allelic ratio FLT3/ITD treated in the Children's Oncology Group trial AAML1031 between 2011 and 2016. Median follow-up was 3.5 years. Dexrazoxane was administered at the discretion of treating physicians and documented at each course. Ejection fraction (EF) and shortening fraction (SF) were recorded after each course and at regular intervals in follow-up. Per protocol, anthracyclines were to be withheld if there was evidence of left ventricular systolic dysfunction (LVSD) defined as SF < 28% or EF < 55%. Occurrence of LVSD, trends in EF and SF, 5-year event-free survival (EFS) and overall survival (OS), and treatment-related mortality (TRM) were compared by dexrazoxane exposure. RESULTS: A total of 1,014 patients were included in the analyses; 96 were exposed to dexrazoxane at every anthracycline course, and 918 were never exposed. Distributions of sex, age, race, presenting WBC count, risk group, treatment arm, and compliance with cardiac monitoring were similar for dexrazoxane-exposed and -unexposed patients. Dexrazoxane-exposed patients had significantly smaller EF and SF declines than unexposed patients across courses and a lower risk for LVSD (26.5% v 42.2%; hazard ratio, 0.55; 95% CI, 0.36 to 0.86; P = .009). Dexrazoxane-exposed patients had similar 5-year EFS (49.0% v 45.1%; P = .534) and OS (65.0% v 61.9%; P = .613) to those unexposed; however, there was a suggestion of lower TRM with dexrazoxane (5.7% v 12.7%; P = .068). CONCLUSION: Dexrazoxane preserved cardiac function without compromising EFS and OS or increasing noncardiac toxicities. Dexrazoxane should be considered for cardioprotection during frontline treatment of pediatric AML.
Assuntos
Cardiotônicos/uso terapêutico , Dexrazoxano/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Função Ventricular Esquerda/efeitos dos fármacos , Cardiotônicos/farmacologia , Criança , Pré-Escolar , Dexrazoxano/farmacologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Resultado do TratamentoRESUMO
Bisdioxopiperazine agent dexrazoxane (ICRF-187) has been the only effective and approved drug for prevention of chronic anthracycline cardiotoxicity. However, the structure-activity relationships (SARs) of its cardioprotective effects remain obscure owing to limited investigation of its derivatives/analogs and uncertainties about its mechanism of action. To fill these knowledge gaps, we tested the hypothesis that dexrazoxane derivatives exert cardioprotection via metal chelation and/or modulation of topoisomerase IIß (Top2B) activity in chronic anthracycline cardiotoxicity. Dexrazoxane was alkylated in positions that should not interfere with the metal-chelating mechanism of cardioprotective action; that is, on dioxopiperazine imides or directly on the dioxopiperazine ring. The protective effects of these agents were assessed in vitro in neonatal cardiomyocytes. All studied modifications of dexrazoxane molecule, including simple methylation, were found to abolish the cardioprotective effects. Because this challenged the prevailing mechanistic concept and previously reported data, the two closest derivatives [(±)-4,4'-(propane-1,2-diyl)bis(1-methylpiperazine-2,6-dione) and 4-(2-(3,5-dioxopiperazin-1-yl)ethyl)-3-methylpiperazine-2,6-dione] were thoroughly scrutinized in vivo using a rabbit model of chronic anthracycline cardiotoxicity. In contrast to dexrazoxane, both compounds failed to protect the heart, as demonstrated by mortality, cardiac dysfunction, and myocardial damage parameters, although the pharmacokinetics and metal-chelating properties of their metabolites were comparable to those of dexrazoxane. The loss of cardiac protection was shown to correlate with their abated potential to inhibit and deplete Top2B both in vitro and in vivo. These findings suggest a very tight SAR between bisdioxopiperazine derivatives and their cardioprotective effects and support Top2B as a pivotal upstream druggable target for effective cardioprotection against anthracycline cardiotoxicity. SIGNIFICANCE STATEMENT: This study has revealed the previously unexpected tight structure-activity relationships of cardioprotective effects in derivatives of dexrazoxane, which is the only drug approved for the prevention of cardiomyopathy and heart failure induced by anthracycline anticancer drugs. The data presented in this study also strongly argue against the importance of metal-chelating mechanisms for the induction of this effect and support the viability of topoisomerase IIß as an upstream druggable target for effective and clinically translatable cardioprotection.
Assuntos
Antraciclinas/efeitos adversos , Cardiotoxicidade/tratamento farmacológico , DNA Topoisomerases Tipo II/metabolismo , Dexrazoxano/farmacologia , Coração/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Inibidores da Topoisomerase II/farmacologia , Animais , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/metabolismo , Linhagem Celular Tumoral , Células HL-60 , Humanos , Masculino , Modelos Animais , Miocárdio/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Coelhos , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
The usage of doxorubicin is hampered by its life-threatening cardiotoxicity in clinical practice. Dexrazoxane is the only cardioprotective medicine approved by the FDA for preventing doxorubicin-induced cardiac toxicity. Nevertheless, the mechanism of dexrazoxane is incompletely understood. The aim of our study is to investigate the possible molecular mechanism of dexrazoxane against doxorubicin-induced cardiotoxicity. We established a doxorubicin-induced mouse and cardiomyocyte injury model. Male C57BL/6J mice were randomly distributed into a control group (Con), a doxorubicin treatment group (DOX), a doxorubicin plus dexrazoxane treatment group (DOX+DEX), and a dexrazoxane treatment group (DEX). Echocardiography and histology analyses were performed to evaluate heart function and structure. DNA laddering, qRT-PCR, and Western blot were performed on DOX-treated cardiomyocytes with/without DEX treatment in vitro. Cardiomyocytes were then transfected with miR-17-5p mimics or inhibitors in order to analyze its downstream target. Our results demonstrated that dexrazoxane has a potent effect on preventing cardiac injury induced by doxorubicin in vivo and in vitro by reducing cardiomyocyte apoptosis. MicroRNA plays an important role in cardiovascular diseases. Our data revealed that dexrazoxane could upregulate the expression of miR-17-5p, which plays a cytoprotective role in response to hypoxia by regulating cell apoptosis. Furthermore, the miRNA and protein analysis revealed that miR-17-5p significantly attenuated phosphatase and tensin homolog (PTEN) expression in cardiomyocytes exposed to doxorubicin. Taken together, dexrazoxane might exert a cardioprotective effect against doxorubicin-induced cardiomyocyte apoptosis by regulating the expression of miR-17-5p/PTEN cascade.
Assuntos
Apoptose/efeitos dos fármacos , Dexrazoxano/farmacologia , Doxorrubicina/efeitos adversos , MicroRNAs/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Animais , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/patologia , Sobrevivência Celular/efeitos dos fármacos , Dexrazoxano/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , PTEN Fosfo-Hidrolase/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Bioflavonoids have a similar chemical structure to etoposide, the well-characterized topoisomerase II (Top2) poison, and evidence shows that they also induce DNA double-strand breaks (DSBs) and promote genome rearrangements. The purpose of this study was to determine the kinetics of bioflavonoid-induced DSB appearance and repair, and their dependence on Top2. Cells were exposed to bioflavonoids individually or in combination in the presence or absence of the Top2 catalytic inhibitor dexrazoxane. The kinetics of appearance and repair of γH2AX foci were measured. In addition, the frequency of resultant MLL-AF9 breakpoint cluster region translocations was determined. Bioflavonoids readily induced the appearance of γH2AX foci, but bioflavonoid combinations did not act additively or synergistically to promote DSBs. Myricetin-induced DSBs were mostly reduced by dexrazoxane, while genistein and quercetin-induced DSBs were only partially, but significantly, reduced. By contrast, luteolin and kaempferol-induced DSBs increased with dexrazoxane pre-treatment. Sensitivity to Top2 inhibition correlated with a significant reduction of bioflavonoid-induced MLL-AF9 translocations. These data demonstrate that myricetin, genistein, and quercetin act most similar to etoposide although with varying Top2-dependence. By contrast, luteolin and kaempferol have distinct kinetics that are mostly Top2-independent. These findings have implications for understanding the mechanisms of bioflavonoid activity and the potential of individual bioflavonoids to promote chromosomal translocations. Further, they provide direct evidence that specific Top2 inhibitors or targeted drugs could be developed that possess less leukemic potential or suppress chromosomal translocations associated with therapy-related and infant leukemias.
Assuntos
Reparo do DNA/efeitos dos fármacos , Flavonoides/toxicidade , Genisteína/toxicidade , Quempferóis/toxicidade , Luteolina/toxicidade , Quercetina/toxicidade , Animais , Linhagem Celular , Pontos de Quebra do Cromossomo/efeitos dos fármacos , Cromossomos de Mamíferos/efeitos dos fármacos , DNA/química , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/metabolismo , Dexrazoxano/farmacologia , Etoposídeo/toxicidade , Histonas/genética , Histonas/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/efeitos dos fármacos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Embrionárias Murinas/ultraestrutura , Inibidores da Topoisomerase II/farmacologia , Translocação Genética/efeitos dos fármacosRESUMO
BACKGROUND: Adeno-associated Virus (AAV) vectors are the most promising vehicles for therapeutic gene delivery to the retina. To develop a practical gene delivery tool, achieving high AAV transduction efficiency in specific cell types is often required. AAV-mediated targeted expression in retinal bipolar cells is needed in certain applications such as optogenetic therapy, however, the transduction efficiency driven by endogenous cell-specific promoters is usually low. Methods that can improve AAV transduction efficiency in bipolar cells need to be developed. OBJECTIVE: The study aimed to examine the effect of proteasome inhibitors on AAV-mediated transduction efficiency in retinal bipolar cells. METHODS: Quantitative analysis of fluorescent reporter protein expression was performed to assess the effect of two proteasome inhibitors, doxorubicin and MG132, on AAV-mediated transduction efficiency in retinal bipolar cells in mice. RESULTS: Our results showed that doxorubicin can increase the AAV transduction efficiency in retinal bipolar cells in a dose-dependent manner. We also observed doxorubicin-mediated cytotoxicity in retinal neurons, but the cytotoxicity could be mitigated by the coapplication of dexrazoxane. Three months after the coapplication of doxorubicin (300 µM) and dexrazoxane, the AAV transduction efficiency in retinal bipolar cells increased by 33.8% and no cytotoxicity was observed in all the layers of the retina. CONCLUSION: Doxorubicin could enhance the AAV transduction efficiency in retinal bipolar cells in vivo. The potential long-term cytotoxicity caused by doxorubicin to retinal neurons could be partially mitigated by dexrazoxane. The coapplication of doxorubicin and dexrazoxane may serve as a potential adjuvant regimen for improving AAV transduction efficiency in retinal bipolar cells.
Assuntos
Expressão Gênica/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Células Bipolares da Retina/efeitos dos fármacos , Células Bipolares da Retina/metabolismo , Animais , Dependovirus/genética , Dexrazoxano/farmacologia , Doxorrubicina/farmacologia , Vetores Genéticos , Leupeptinas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Retina/metabolismo , Retina/virologia , Células Bipolares da Retina/virologia , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/virologia , Transdução Genética/métodosRESUMO
Dose-dependent cardiotoxicity is the leading adverse reaction seen in cancer patients treated with doxorubicin. Currently, dexrazoxane is the only approved drug that can partially protect against this toxicity in patients, however, its administration is restricted to those patients receiving a high cumulative dose of anthracyclines. Investigations into the mechanisms of cardiotoxicity and efforts to improve cardioprotective strategies have been hindered by the limited availability of a phenotypically relevant in vitro adult human cardiac model system. Here, we adapted a readily reproducible, functional 3D human multi-cell type cardiac system to emulate patient responses seen with doxorubicin and dexrazoxane. We show that administration of two NRF2 gene inducers namely the semi-synthetic triterpenoid Bardoxolone methyl, and the isothiocyanate sulfurophane, result in cardioprotection against doxorubicin toxicity comparable to dexrazoxane as evidenced by an increase in cell viability and a decrease in the production of reactive oxygen species. We further show a synergistic attenuation of cardiotoxicity when the NRF2 inducers and dexrazoxane are used in tandem. Taken together, our data indicate that the 3D spheroid is a suitable model to investigate drug induced cardiotoxicity and we reveal an essential role of the NRF2 pathway in cardioprotection providing a novel pharmacological mechanism and intervention route towards the alleviation of doxorubicin-induced toxicity.
Assuntos
Antibióticos Antineoplásicos/toxicidade , Doxorrubicina/toxicidade , Coração/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/biossíntese , Esferoides Celulares/efeitos dos fármacos , Cardiotoxicidade/prevenção & controle , Sobrevivência Celular/efeitos dos fármacos , Dexrazoxano/farmacologia , Sinergismo Farmacológico , Humanos , Técnicas In Vitro , Isotiocianatos/farmacologia , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Esferoides Celulares/metabolismo , SulfóxidosRESUMO
The chemotherapeutic effect of doxorubicin (Dox) is limited by cumulative dose-dependent cardiotoxicity in cancer survivors. Dexrazoxane (DRZ) is approved to prevent Dox-induced cardiotoxicity. Humanin and its synthetic analog HNG have a cytoprotective effect on the heart. To investigate the cardioprotective efficacy of HNG alone or in combination with DRZ against Dox-induced cardiotoxicity, 80 adult male mice were randomly divided into 8 groups to receive the following treatments via intraperitoneal injection: saline dailym HNG (5 mg/kg) daily, DRZ (60 mg/kg) weekly, Dox (3 mg/kg) weekly, DRZ + HNG, Dox + HNG, Dox + DRZ, and Dox + HNG + DRZ. Echocardiograms were performed before and at 4, 8, and 9.5 wk after the beginning of treatment. All mice were euthanized at 10 wk. In the absence of Dox, HNG, DRZ, or DRZ + HNG had no adverse effect on the heart. Dox treatment caused decreases in ejection fraction and cardiac mass and increases in cardiomyocyte apoptosis and intracardiac fibrosis. HNG or DRZ alone blunted the Dox-induced decrease in left ventricle posterior wall thickness and modestly ameliorated the Dox-induced decrease in ejection fraction. HNG + DRZ significantly ameliorated Dox-induced decreases in ejection function, cardiac fibrosis, and cardiac mass. Using a targeted analysis for the mitochondrial gene array and protein expression in heart tissues, we demonstrated that HNG + DRZ reversed DOX-induced altered transcripts that were biomarkers of cardiac damage and uncoupling protein-2. We conclude that HNG enhances the cardiac protective effect of DRZ against Dox-induced cardiotoxicity. HNG + DRZ protects mitochondria from Dox-induced cardiac damage and blunts the onset of cardiac dysfunction. Thus, HNG may be an adjuvant to DRZ in preventing Dox-induced cardiotoxicity. NEW & NOTEWORTHY Doxorubicin (Dox) is commonly used for treating a wide range of human cancers. However, cumulative dosage-dependent carditoxicity often limits its clinical applications. We demonstrated in this study that treating young adult male mice with synthetic humanin analog enhanced the cardiac protective effect of dexrazoxane against chemotherapeutic agent Dox-induced cardiac dysfunction. Thus, humanin analog can potentially serve as an adjuvant to dexrazoxane in more effectively preventing Dox-induced cardiac dysfunction and cardiomyopathy.
Assuntos
Cardiotônicos/farmacologia , Dexrazoxano/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Animais , Cardiotônicos/administração & dosagem , Cardiotoxicidade , Dexrazoxano/administração & dosagem , Doxorrubicina/toxicidade , Sinergismo Farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismoRESUMO
Resveratrol, a polyphenol found in various plant sources, has gained attention as a possible agent responsible for the purported health benefits of certain foods, such as red wine. Despite annual multi-million dollar market sales as a nutriceutical, there is little consensus about the physiological roles of resveratrol. One suggested molecular target of resveratrol is eukaryotic topoisomerase II (topo II), an enzyme essential for chromosome segregation and DNA supercoiling homeostasis. Interestingly, resveratrol is chemically similar to ICRF-187, a clinically approved chemotherapeutic that stabilizes an ATP-dependent dimerization interface in topo II to block enzyme activity. Based on this similarity, we hypothesized that resveratrol may antagonize topo II by a similar mechanism. Using a variety of biochemical assays, we find that resveratrol indeed acts through the ICRF-187 binding locus, but that it inhibits topo II by preventing ATPase domain dimerization rather than stabilizing it. This work presents the first comprehensive analysis of the biochemical effects of both ICRF-187 and resveratrol on the human isoforms of topo II, and reveals a new mode for the allosteric regulation of topo II through modulation of ATPase status. Natural polyphenols related to resveratrol that have been shown to impact topo II function may operate in a similar manner.
Assuntos
Resveratrol/farmacologia , Inibidores da Topoisomerase II/farmacologia , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Regulação Alostérica , Substituição de Aminoácidos , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/metabolismo , Dexrazoxano/química , Dexrazoxano/farmacologia , Humanos , Modelos Moleculares , Estrutura Molecular , Mutagênese Sítio-Dirigida , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/química , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Resveratrol/química , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Inibidores da Topoisomerase II/químicaRESUMO
Idarubicin is an anthracycline antileukemic agent widely used in the treatment of hematological malignancies. However, cardiotoxicity and secondary leukemia have been reported after idarubicin treatment. Dexrazoxane is the only medication approved by FDA to prevent anthracycline-evoked cardiotoxicity. However, lack of information on the genomic damage caused by the combination of these 2 drugs prompted us to conduct the current study. We treated mice with different doses of idarubicin and/or dexrazoxane. Genomic DNA damage, apoptosis, and reactive oxygen species (ROS) were evaluated in the bone marrow cells. Our results demonstrate that mice pretreated of with dexrazoxane had significant lower genomic damage, apoptosis and ROS generation compared with that of mice treated with idarubicin alone, an effect that was dependent on dexrazoxane dose. The expression of 84 genes implicated in DNA damage-signaling pathways was quantified using an RT2 Profiler PCR Array. Idarubicin treatments altered the expression of 58 genes, and 16 of those were expressed at significantly different level. In treatments combining idarubicin and dexrazoxane, substantial restorations of mRNA expression of these genes were observed. RT-qPCR was performed for selected genes and the alteration of these genes was confirmed. Alterations in mRNA expression of a subset of genes were further proved by Western blotting analysis of protein levels, which nearly showed similar alterations. Conclusively, dexrazoxane can be safely co-administered with idarubicin. Moreover, dexrazoxane minimizes idarubicin-evoked genomic damage via its radical scavenging and DNA repair-enhancing activities. Thus, dexrazoxane may help avert secondary malignancies in cancer patients in remission who are exposed to idarubicin.
Assuntos
Antibióticos Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dexrazoxano/farmacologia , Idarubicina/toxicidade , Transdução de Sinais/efeitos dos fármacos , Transcriptoma , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Ensaio Cometa , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Camundongos Endogâmicos BALB C , Testes para Micronúcleos , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Novel dexrazoxane derivative JR-311 was prepared to investigate structure-activity relationships and mechanism(s) of protection against anthracycline cardiotoxicity. Its cardioprotective, antiproliferative, iron (Fe) chelation and inhibitory and/or depletory activities on topoisomerase IIbeta (TOP2B) were examined and compared with dexrazoxane. While in standard assay, JR-311 failed in both cardioprotection and depletion of TOP2B, its repeated administration to cell culture media led to depletion of TOP2B and significant protection of isolated rat neonatal ventricular cardiomyocytes from daunorubicin-induced damage. This effect was explained by a focused analytical investigation that revealed rapid JR-311 decomposition, resulting in negligible intracellular concentrations of the parent compound but high exposure of cells to the decomposition products, including Fe-chelating JR-H2. Although chemical instability is an obstacle for the development of JR-311, this study identified a novel dexrazoxane analogue with preserved pharmacodynamic properties, contributed to the investigation of structure-activity relationships and suggested that the cardioprotection of bis-dioxopiperazines is likely attributed to TOP2B activity of the parent compound rather than Fe chelation of their hydrolytic metabolites/degradation products. Moreover, this study highlights the importance of early stability testing during future development of novel dexrazoxane analogues.
Assuntos
Cardiotônicos/farmacologia , DNA Topoisomerases Tipo II/metabolismo , Dexrazoxano/farmacologia , Quelantes de Ferro/farmacologia , Animais , Animais Recém-Nascidos , Antraciclinas/toxicidade , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/etiologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Daunorrubicina/toxicidade , Dexrazoxano/análogos & derivados , Dicetopiperazinas/farmacologia , Ferro/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
Doxorubicin (Dox) is an effective chemotherapeutic agent used in the treatment of various cancers. Its clinical use is often limited due to its potentially fatal cardiotoxic side effect. Increasing evidence indicates that tumour protein p53 (p53), adenosine monophosphate-activated protein kinase (AMPK), nucleoporin p62 (p62), and the mammalian target of rapamycin (mTOR) are critical mediators of Dox-induced apoptosis, and subsequent dysregulation of autophagy. Aspalathin, a polyphenolic dihydrochalcone C-glucoside has been shown to activate AMPK while decreasing the expression of p53. However, the role that aspalathin could play in the inhibition of Dox-induced cardiotoxicity through increased autophagy flux remained unexplored. H9c2 cardiomyocytes and Caov-3 ovarian cancer cells were cultured in Dulbecco's Modified Eagle's medium and treated with or without Dox for five days. Thereafter, cells exposed to 0.2 µM Dox were co-treated with either 20 µM Dexrazozane (Dexra) or 0.2 µM aspalathin (ASP) daily for 5 days. Results obtained showed that ASP mediates its cytoprotective effect in a p53-dependent manner, by increasing the Bcl-2/Bax ratio and decreasing apoptosis. The latter effect was diminished through ASP-induced activation of autophagy-related genes (Atgs) with an associated decrease in p62 through induction of AMPK and Fox01. Furthermore, we showed that ASP was able to potentiate this effect without decreasing the anti-cancer efficacy of Dox, as could be observed in Caov-3 ovarian cancer cells. Taken together, the data presented in this study provides a credible mechanism by which ASP co-treatment could protect the myocardium from Dox-induced cardiotoxicity.