Anthracycline anticancer agents, such as daunorubicin and doxorubicin, rank among the most effective and widely used anticancer drugs. However, their benefit is markedly reduced by the risk of severe cardiotoxicity. Anthracyclines undergo metabolic reduction of the side chain carbonyl group, producing hydroxy metabolites implicated in the cardiotoxicity. This study investigated toxicity, metabolism and cellular disposition of daunorubicin and its hydroxy metabolite, daunorubicinol, in isolated rat neonatal cardiomyocytes. Daunorubicin induced concentration-dependent cytotoxicity, whereas the toxicity of exogenously administered daunorubicinol was significantly lower despite induction of similar DNA damage. UHPLC-MS analyses revealed that daunorubicin rapidly penetrates cardiomyocytes and is metabolized to daunorubicinol, which is then released from the cells. The intracellular concentration of daunorubicinol was consistently lower than that of daunorubicin, indicating a reduced tendency for daunorubicinol to accumulate in cardiomyocytes. P-glycoprotein 1 has been shown to actively facilitate the efflux of both daunorubicin and daunorubicinol from cardiomyocytes. Dexrazoxane, the only approved agent for anthracycline cardiotoxicity prevention, did not affect the cellular metabolism or disposition of daunorubicin or its hydroxy metabolite, but it effectively reduced not only daunorubicin-induced cardiotoxicity, but also provided protection against the lower toxicity of daunorubicinol. Moreover, dexrazoxane reduced DNA damage induced by both daunorubicin and its hydroxy metabolite. These findings suggest that daunorubicin is the primary driver of cardiomyocyte cytotoxicity, while its hydroxy metabolite, daunorubicinol, plays a more limited role, challenging the notion that it serves as a significant toxic reservoir.

• Keywords
• Anthracycline cardiotoxicity, DNA damage, Daunorubicin, Daunorubicinol, Dexrazoxane protection,
• Publication type
• Journal Article MeSH

Topoisomerase II alpha and beta (TOP2A and TOP2B) isoenzymes perform essential and non-redundant cellular functions. Anthracyclines induce their potent anti-cancer effects primarily via TOP2A, but at the same time they induce a dose limiting cardiotoxicity through TOP2B. Here we describe the development of the obex class of TOP2 inhibitors that bind to a previously unidentified druggable pocket in the TOP2 ATPase domain to act as allosteric catalytic inhibitors by locking the ATPase domain conformation with the capability of isoform-selective inhibition. Through rational drug design we have developed topobexin, which interacts with residues that differ between TOP2A and TOP2B to provide inhibition that is both selective for TOP2B and superior to dexrazoxane. Topobexin is a potent protectant against chronic anthracycline cardiotoxicity in an animal model. This demonstration of TOP2 isoform-specific inhibition underscores the broader potential to improve drug specificity and minimize adverse effects in various medical treatments.

• MeSH
• Anthracyclines * adverse effects   pharmacology   MeSH
• DNA Topoisomerases, Type II * metabolism   chemistry   MeSH
• Topoisomerase II Inhibitors * pharmacology   chemistry   MeSH
• Cardiotonic Agents * pharmacology   chemistry   MeSH
• Cardiotoxicity * prevention & control   MeSH
• Humans MeSH
• Mice MeSH
• Poly-ADP-Ribose Binding Proteins antagonists & inhibitors   metabolism   chemistry   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anthracyclines * MeSH
• DNA Topoisomerases, Type II * MeSH
• Topoisomerase II Inhibitors * MeSH
• Cardiotonic Agents * MeSH
• Poly-ADP-Ribose Binding Proteins MeSH
• TOP2A protein, human MeSH Browser
• TOP2B protein, human MeSH Browser

The efforts to utilize microflow liquid chromatography hyphenated to tandem mass spectrometry (μLC-MS/MS) for deep-scale proteomic analysis are still growing. In this work, two-dimensional LC separation and peptide derivatization by a tandem mass tag (TMT) were used to assess the capability of μLC-MS/MS to reveal protein changes associated with the severe chronic anthracycline cardiotoxicity phenotype in comparison with nanoflow liquid chromatography (nLC-MS/MS). The analysis of the control and anthracycline-treated rabbit myocardium by μLC-MS/MS and nLC-MS/MS allowed quantification of 3956 and 4549 proteins, respectively, with 84% of these proteins shared in both data sets. Both nLC-MS/MS and μLC-MS/MS revealed marked global proteome dysregulation in severe anthracycline cardiotoxicity, with a significant change in approximately 55% of all detected proteins. The μLC-MS/MS analysis allowed less compressed and more precise determination of the TMT channel ratio and correspondingly broader fold-change protein distribution than nLC-MS/MS. The total number of significantly changed proteins was higher in nLC-MS/MS (2498 vs 2183, 1900 proteins shared), whereas the opposite was true for a number of significantly changed proteins with a fold-change cutoff ≥ 2 (535 vs 820). The profound changes concerned mainly proteins of cardiomyocyte sarcomeres, costameres, intercalated discs, mitochondria, and extracellular matrix. In addition, distinct alterations in immune and defense response were found with a remarkable involvement of type I interferon signaling that has been recently hypothesized to be essential for anthracycline cardiotoxicity pathogenesis. Hence, μLC-MS/MS was found to be a sound alternative to nLC-MS/MS that can be useful for comprehensive mapping of global myocardial proteome alterations such as those associated with severe anthracycline cardiotoxicity.

• Publication type
• Journal Article MeSH

Background: Anthracycline cardiotoxicity is a well-known complication of cancer treatment, and miRNAs have emerged as a key driver in the pathogenesis of cardiovascular diseases. This study aimed to investigate the expression of miRNAs in the myocardium in early and late stages of chronic anthracycline induced cardiotoxicity to determine whether this expression is associated with the severity of cardiac damage. Method: Cardiotoxicity was induced in rabbits via daunorubicin administration (daunorubicin, 3 mg/kg/week; for five and 10 weeks), while the control group received saline solution. Myocardial miRNA expression was first screened using TaqMan Advanced miRNA microfluidic card assays, after which 32 miRNAs were selected for targeted analysis using qRT-PCR. Results: The first subclinical signs of cardiotoxicity (significant increase in plasma cardiac troponin T) were observed after 5 weeks of daunorubicin treatment. At this time point, 10 miRNAs (including members of the miRNA-34 and 21 families) showed significant upregulation relative to the control group, with the most intense change observed for miRNA-1298-5p (29-fold change, p < 0.01). After 10 weeks of daunorubicin treatment, when a further rise in cTnT was accompanied by significant left ventricle systolic dysfunction, only miR-504-5p was significantly (p < 0.01) downregulated, whereas 10 miRNAs were significantly upregulated relative to the control group; at this time-point, the most intense change was observed for miR-34a-5p (76-fold change). Strong correlations were found between the expression of multiple miRNAs (including miR-34 and mir-21 family and miR-1298-5p) and quantitative indices of toxic damage in both the early and late phases of cardiotoxicity development. Furthermore, plasma levels of miR-34a-5p were strongly correlated with the myocardial expression of this miRNA. Conclusion: To the best of our knowledge, this is the first study that describes alterations in miRNA expression in the myocardium during the transition from subclinical, ANT-induced cardiotoxicity to an overt cardiotoxic phenotype; we also revealed how these changes in miRNA expression are strongly correlated with quantitative markers of cardiotoxicity.

• Keywords
• DNA damage response, anthracyclines, cardiotoxicity, chronic cardiomyopathy, miRNA, myocardium,
• Publication type
• Journal Article MeSH

Doxorubicin (DOX) is a chemotherapeutic drug widely used for cancer treatment, but its use is limited by cardiotoxicity. Although free radicals from redox cycling and free cellular iron have been predominant as the suggested primary pathogenic mechanism, novel evidence has pointed to topoisomerase II inhibition and resultant genotoxic stress as the more fundamental mechanism. Recently, a growing list of microRNAs (miRNAs) has been implicated in DOX-induced cardiotoxicity (DIC). This review summarizes miRNAs reported in the recent literature in the context of DIC. A particular focus is given to miRNAs that regulate cellular responses downstream to DOX-induced DNA damage, especially p53 activation, pro-survival signaling pathway inhibition (e.g., AMPK, AKT, GATA-4, and sirtuin pathways), mitochondrial dysfunction, and ferroptosis. Since these pathways are potential targets for cardioprotection against DOX, an understanding of how miRNAs participate is necessary for developing future therapies.

• Keywords
• cardiotoxicity, doxorubicin, genotoxic stress, microRNA, p53,
• Publication type
• Journal Article MeSH
• Review MeSH

Aims: Doxorubicin cardiomyopathy is a lethal pathology characterized by oxidative stress, mitochondrial dysfunction, and contractile impairment, leading to cell death. Although extensive research has been done to understand the pathophysiology of doxorubicin cardiomyopathy, no effective treatments are available. We investigated whether monoamine oxidases (MAOs) could be involved in doxorubicin-derived oxidative stress, and in the consequent mitochondrial, cardiomyocyte, and cardiac dysfunction. Results: We used neonatal rat ventricular myocytes (NRVMs) and adult mouse ventricular myocytes (AMVMs). Doxorubicin alone (i.e., 0.5 μM doxorubicin) or in combination with H2O2 induced an increase in mitochondrial formation of reactive oxygen species (ROS), which was prevented by the pharmacological inhibition of MAOs in both NRVMs and AMVMs. The pharmacological approach was supported by the genetic ablation of MAO-A in NRVMs. In addition, doxorubicin-derived ROS caused lipid peroxidation and alterations in mitochondrial function (i.e., mitochondrial membrane potential, permeability transition, redox potential), mitochondrial morphology (i.e., mitochondrial distribution and perimeter), sarcomere organization, intracellular [Ca2+] homeostasis, and eventually cell death. All these dysfunctions were abolished by MAO inhibition. Of note, in vivo MAO inhibition prevented chamber dilation and cardiac dysfunction in doxorubicin-treated mice. Innovation and Conclusion: This study demonstrates that the severe oxidative stress induced by doxorubicin requires the involvement of MAOs, which modulate mitochondrial ROS generation. MAO inhibition provides evidence that mitochondrial ROS formation is causally linked to all disorders caused by doxorubicin in vitro and in vivo. Based upon these results, MAO inhibition represents a novel therapeutic approach for doxorubicin cardiomyopathy.

• Keywords
• cardiomyopathy, doxorubicin, mitochondria, monoamine oxidase, reactive oxygen species (ROS),
• MeSH
• Doxorubicin pharmacology   MeSH
• Myocytes, Cardiac drug effects   metabolism   MeSH
• Rats MeSH
• Mitochondria MeSH
• Monoamine Oxidase metabolism   MeSH
• Mice MeSH
• Oxidative Stress drug effects   MeSH
• Reactive Oxygen Species analysis   metabolism   MeSH
• Heart Ventricles drug effects   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Doxorubicin MeSH
• Monoamine Oxidase MeSH
• Reactive Oxygen Species MeSH

The bisdioxopiperazine topoisomerase IIβ inhibitor ICRF-193 has been previously identified as a more potent analog of dexrazoxane (ICRF-187), a drug used in clinical practice against anthracycline cardiotoxicity. However, the poor aqueous solubility of ICRF-193 has precluded its further in vivo development as a cardioprotective agent. To overcome this issue, water-soluble prodrugs of ICRF-193 were prepared, their abilities to release ICRF-193 were investigated using a novel UHPLC-MS/MS assay, and their cytoprotective effects against anthracycline cardiotoxicity were tested in vitro in neonatal ventricular cardiomyocytes (NVCMs). Based on the obtained results, the bis(2-aminoacetoxymethyl)-type prodrug GK-667 was selected for advanced investigations due to its straightforward synthesis, sufficient solubility, low cytotoxicity and favorable ICRF-193 release. Upon administration of GK-667 to NVCMs, the released ICRF-193 penetrated well into the cells, reached sufficient intracellular concentrations and provided effective cytoprotection against anthracycline toxicity. The pharmacokinetics of the prodrug, ICRF-193 and its rings-opened metabolite was estimated in vivo after administration of GK-667 to rabbits. The plasma concentrations of ICRF-193 reached were found to be adequate to achieve cardioprotective effects in vivo. Hence, GK-667 was demonstrated to be a pharmaceutically acceptable prodrug of ICRF-193 and a promising drug candidate for further evaluation as a potential cardioprotectant against chronic anthracycline toxicity.

• MeSH
• Anthracyclines adverse effects   MeSH
• Dexrazoxane chemistry   pharmacology   MeSH
• Diketopiperazines chemistry   pharmacology   MeSH
• DNA Topoisomerases, Type II metabolism   MeSH
• Topoisomerase II Inhibitors chemistry   pharmacology   MeSH
• Myocytes, Cardiac drug effects   metabolism   MeSH
• Cardiotonic Agents chemistry   pharmacology   MeSH
• Cardiotoxicity drug therapy   metabolism   MeSH
• Rabbits MeSH
• Piperazine chemistry   pharmacology   MeSH
• Prodrugs chemistry   pharmacology   MeSH
• Razoxane chemistry   pharmacology   MeSH
• Water chemistry   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 4,4'-(1,2-dimethyl-1,2-ethanediyl)bis-2,6-piperazinedione MeSH Browser
• Anthracyclines MeSH
• Dexrazoxane MeSH
• Diketopiperazines MeSH
• DNA Topoisomerases, Type II MeSH
• Topoisomerase II Inhibitors MeSH
• Cardiotonic Agents MeSH
• Piperazine MeSH
• Prodrugs MeSH
• Razoxane MeSH
• Water MeSH

Sobuzoxane (MST-16) is an approved anticancer agent, a pro-drug of bisdioxopiperazine analog ICRF-154. Due to the structural similarity of ICRF-154 to dexrazoxane (ICRF-187), MST-16 deserves attention as a cardioprotective drug. This study presents for the first time UHPLC-MS/MS assay of MST-16, ICRF-154 and its metabolite (EDTA-diamide) in cell culture medium, buffer, plasma and cardiac cells and provides data on MST-16 bioactivation under conditions relevant to investigation of cardioprotection of this drug. The analysis of these compounds that differ considerably in their lipophilicity was achieved on the Zorbax SB-Aq column using a mixture of aqueous ammonium formate and methanol as a mobile phase. The biological samples were either diluted or precipitated with methanol, which was followed by acidification for the assay of MST-16. The method was validated for determination of all compounds in the biological materials. The application of the method for analysis of samples from in vitro experiments provided important findings, namely, that (1) MST-16 is quickly decomposed in biological environments, (2) the cardiac cells actively metabolize MST-16, and (3) MST-16 readily penetrates into the cardiac cells and is converted into ICRF-154 and EDTA-diamide. These data are useful for the in-depth examination of the cardioprotective potential of this drug.

• MeSH
• Edetic Acid chemistry   MeSH
• Myocytes, Cardiac cytology   metabolism   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Piperazines analysis   MeSH
• Rats, Wistar MeSH
• Antineoplastic Agents analysis   metabolism   MeSH
• Razoxane analogs & derivatives   chemistry   metabolism   MeSH
• Tandem Mass Spectrometry MeSH
• Chromatography, High Pressure Liquid MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 1,2-bis(3,5-dioxopiperazin-1-yl)ethane MeSH Browser
• Edetic Acid MeSH
• Piperazines MeSH
• Antineoplastic Agents MeSH
• Razoxane MeSH
• sobuzoxane MeSH Browser

Amifostine is well known cytoprotector which is efficient when administered before a wide range of antineoplastic agents. The aim of our study was to investigate amifostine effects on doxorubicin-induced toxic changes in rats. Amifostine (75 mg/kg ip) was given 30 min before each dose of doxorubicin (cumulatively 20 mg/kg ip, for 28 days). The animals' whole-body, liver, and kidney weight, serum biochemical examination, as well as microscopic examination of bone marrow, peripheral blood, liver, and kidney, were done on day 56 of the study. Hepatic and renal alterations were carefully quantified by semiquantitative grading scales-hepatic and renal damage score, respectively. In amifostine-pretreated rats, the number of peripheral blood leukocytes was significantly higher in comparison to doxorubicin-only treated group, preferentially protecting neutrophils. In the same group of rats, hepatic and renal alterations associated with polymorphonuclear cell infiltrates were significantly less severe than those observed in animals receiving only doxorubicin. Our results showed that amifostine successfully protected rats against multiple-dose doxorubicin-induced toxicity by complex, and still not fully elucidated mechanisms of action.

• Keywords
• amifostine, bone marrow, doxorubicin, hepatotoxicity, nephrotoxicity, rats,
• MeSH
• Amifostine pharmacology   MeSH
• Doxorubicin adverse effects   pharmacology   MeSH
• Rats MeSH
• Chemical and Drug Induced Liver Injury metabolism   pathology   prevention & control   MeSH
• Kidney Diseases chemically induced   metabolism   pathology   prevention & control   MeSH
• Organ Specificity drug effects   MeSH
• Rats, Wistar MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Amifostine MeSH
• Doxorubicin MeSH

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

• Keywords
• dysrhythmia, heart failure, hypertension, myocardial infarction, stroke,
• MeSH
• Alkaloids adverse effects   MeSH
• Amphetamines adverse effects   MeSH
• Anti-Arrhythmia Agents adverse effects   MeSH
• Anti-Inflammatory Agents, Non-Steroidal adverse effects   MeSH
• Adrenergic beta-Antagonists adverse effects   MeSH
• Calcium Channel Blockers adverse effects   MeSH
• Stroke drug therapy   MeSH
• Digoxin adverse effects   MeSH
• Hormones adverse effects   MeSH
• Cardiovascular Diseases chemically induced   drug therapy   MeSH
• Cardiovascular System drug effects   MeSH
• Cocaine adverse effects   MeSH
• Humans MeSH
• Antineoplastic Agents adverse effects   MeSH
• Heart Rate drug effects   MeSH
• Steroids adverse effects   MeSH
• Vascular Endothelial Growth Factor A MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Alkaloids MeSH
• Amphetamines MeSH
• Anti-Arrhythmia Agents MeSH
• Anti-Inflammatory Agents, Non-Steroidal MeSH
• Adrenergic beta-Antagonists MeSH
• Calcium Channel Blockers MeSH
• cathinone MeSH Browser
• Digoxin MeSH
• Hormones MeSH
• Cocaine MeSH
• Antineoplastic Agents MeSH
• Steroids MeSH
• Vascular Endothelial Growth Factor A MeSH