Review on the Role of Epigenetic Modifications in Doxorubicin-Induced Cardiotoxicity

Cardioprotection strategies for anthracycline cardiotoxicity

Thanks to the fantastic progress in cancer therapy options, there is a growing population of cancer survivors. This success has resulted in a need to focus much effort into improving the quality of life of this population. Cancer and cardiovascular disease share many common risk factors and have an interplay between them, with one condition mechanistically affecting the other and vice versa. Furthermore, widely prescribed cancer therapies have known toxic effects in the cardiovascular system. Anthracyclines are the paradigm of efficacious cancer therapy widely prescribed with a strong cardiotoxic potential. While some cancer therapies cardiovascular toxicities are transient, others are irreversible. There is a growing need to develop cardioprotective therapies that, when used in conjunction with cancer therapies, can prevent cardiovascular toxicity and thus improve long-term quality of life in survivors. The field has three main challenges: (i) identification of the ultimate mechanisms leading to cardiotoxicity to (ii) identify specific therapeutic targets, and (iii) more sensible diagnostic tools to early identify these conditions. In this review we will focus on the cardioprotective strategies tested and under investigation. We will focus this article into anthracycline cardiotoxicity since it is still the agent most widely prescribed, the one with higher toxic effects on the heart, and the most widely studied.

Arsenic induced cardiotoxicity: An approach for molecular markers, Epigenetic predictors and targets

Arsenic, a ubiquitous environmental toxicant, has been acknowledged as a significant issue for public health due to its widespread pollution of drinking water and food supplies. The present review aimed to study the toxicity associated with the cardiac system. Prolonged exposure to arsenic has been associated with several harmful health outcomes, especially cardiotoxicity. Arsenic-induced cardiotoxicity encompasses a range of cardiovascular abnormalities, including cardiac arrhythmias, ischemic heart disease, and cardiomyopathy. To tackle this toxicity, understanding the molecular markers, epigenetic predictors, and targets involved in arsenic-induced cardiotoxicity is essential for creating preventative and therapeutic approaches. For preventive measures against this heavy metal poisoning of groundwater, it is crucial to regularly monitor water quality, re-evaluate scientific findings, and educate the public about the possible risks. This review thoroughly summarised what is currently known in this field, highlighting the key molecular markers, epigenetic modifications, and potential therapeutic targets associated with arsenic-induced cardiotoxicity.

Precision Treatment of Anthracycline-Induced Cardiotoxicity: An Updated Review

OPINION STATEMENT

Anthracycline (ANT)-induced cardiotoxicity (AIC) is a particularly prominent form of cancer therapy-related cardiovascular toxicity leading to the limitations of ANTs in clinical practice. Even though AIC has drawn particular attention, the best way to treat it is remaining unclear. Updates to AIC therapy have been made possible by recent developments in research on the underlying processes of AIC. We review the current molecular pathways leading to AIC: 1) oxidative stress (OS) including enzymatic-induced and other mechanisms; 2) topoisomerase; 3) inflammatory response; 4) cardiac progenitor cell damage; 5) epigenetic changes; 6) renin-angiotensin-aldosterone system (RAAS) dysregulation. And we systematically discuss current prevention and treatment strategies and novel pathogenesis-based therapies for AIC: 1) dose reduction and change; 2) altering drug delivery methods; 3) antioxidants, dexrezosen, statina, RAAS inhibitors, and hypoglycemic drugs; 4) miRNA, natural phytochemicals, mesenchymal stem cells, and cardiac progenitor cells. We also offer a fresh perspective on the management of AIC by outlining the current dilemmas and challenges associated with its prevention and treatment.

Anthracycline-Induced Cardiomyopathy in Cancer Survivors: Management and Long-Term Implications

Recent advancements in personalized treatments, such as anthracycline chemotherapy, coupled with timely diagnoses, have contributed to a decrease in cancer-specific mortality rates and an improvement in cancer prognosis. Anthracyclines, a potent class of antibiotics, are extensively used as anticancer medications to treat a broad spectrum of tumors. Despite these advancements, a considerable number of cancer survivors face increased risks of treatment complications, particularly the cardiotoxic effects of chemotherapeutic drugs like anthracyclines. These effects can range from subclinical manifestations to severe consequences such as irreversible heart failure and death, highlighting the need for effective management of chemotherapy side effects for improved cancer care outcomes. Given the lack of specific treatments, early detection of subclinical cardiac events post-anthracycline therapy and the implementation of preventive strategies are vital. An interdisciplinary approach involving cardiovascular teams is crucial for the prevention and efficient management of anthracycline-induced cardiotoxicity. Various factors, such as age, gender, duration of treatment, and comorbidities, should be considered significant risk factors for developing chemotherapy-related cardiotoxicity. Tools such as electrocardiography, echocardiography, nuclear imaging, magnetic resonance imaging, histopathologic evaluations, and serum biomarkers should be appropriately used for the early detection of anthracycline-related cardiotoxicity. Furthermore, understanding the underlying biological mechanisms is key to developing preventive measures and personalized treatment strategies to mitigate anthracycline-induced cardiotoxicity. Exploring specific cardiotoxic mechanisms and identifying genetic variations can offer fresh perspectives on innovative, personalized treatments. This chapter aims to discuss cardiomyopathy following anthracycline therapy, with a focus on molecular mechanisms, preventive strategies, and emerging treatments.

PARP-2 mediates cardiomyocyte aging and damage induced by doxorubicin through SIRT1 Inhibition

Doxorubicin (DOX) is an anthracycline antibiotic used as an antitumor treatment. However, its clinical application is limited due to severe side effects such as cardiotoxicity. In recent years, numerous studies have demonstrated that cellular aging has become a therapeutic target for DOX-induced cardiomyopathy. However, the underlying mechanism and specific molecular targets of DOX-induced cardiomyocyte aging remain unclear. Poly (ADP-ribose) polymerase (PARP) is a family of protein post-translational modification enzymes in eukaryotic cells, including 18 members. PARP-1, the most well-studied member of this family, has become a potential molecular target for the prevention and treatment of various cardiovascular diseases, such as DOX cardiomyopathy and heart failure. PARP-1 and PARP-2 share 69% homology in the catalytic regions. However, they do not entirely overlap in function. The role of PARP-2 in cardiovascular diseases, especially in DOX-induced cardiomyocyte aging, is less studied. In this study, we found for the first time that down-regulation of PARP-2 can inhibit DOX-induced cellular aging in cardiomyocytes. On the contrary, overexpression of PARP-2 can aggravate DOX-induced cardiomyocyte aging and injury. Further research showed that PARP-2 inhibited the expression and activity of SIRT1, which in turn was involved in the development of DOX-induced cardiomyocyte aging and injury. Our findings provide a preliminary experimental basis for establishing PARP-2 as a new target for preventing and treating DOX cardiomyopathy and related drug development.

The role and mechanism of epigenetics in anticancer drug-induced cardiotoxicity

Cardiovascular disease is the main factor contributing to the global burden of diseases, and the cardiotoxicity caused by anticancer drugs is an essential component that cannot be ignored. With the development of anticancer drugs, the survival period of cancer patients is prolonged; however, the cardiotoxicity caused by anticancer drugs is becoming increasingly prominent. Currently, cardiovascular disease has emerged as the second leading cause of mortality among long-term cancer survivors. Anticancer drug-induced cardiotoxicity has become a frontier and hot topic. The discovery of epigenetics has given the possibility of environmental changes in gene expression, protein synthesis, and traits. It has been found that epigenetics plays a pivotal role in promoting cardiovascular diseases, such as heart failure, coronary heart disease, and hypertension. In recent years, increasing studies have underscored the crucial roles played by epigenetics in anticancer drug-induced cardiotoxicity. Here, we provide a comprehensive overview of the role and mechanisms of epigenetics in anticancer drug-induced cardiotoxicity.

Ultrasensitive Upconversion Nanoparticle Immunoassay for Human Serum Cardiac Troponin I Detection Achieved with Resonant Waveguide Grating

Selective detection of biomarkers at low concentrations in blood is crucial for the clinical diagnosis of many diseases but remains challenging. In this work, we aimed to develop an ultrasensitive immunoassay that can detect biomarkers in serum with an attomolar limit of detection (LOD). We proposed a sandwich-type heterogeneous immunosensor in a 3 × 3 well array format by integrating a resonant waveguide grating (RWG) substrate with upconversion nanoparticles (UCNPs). UCNPs were used to label a target biomarker captured by capture antibody molecules immobilized on the surface of the RWG substrate, and the RWG substrate was used to enhance the upconversion luminescence (UCL) of UCNPs through excitation resonance. The LOD of the immunosensor was greatly reduced due to the increased UCL of UCNPs and the reduction of nonspecific adsorption of detection antibody-conjugated UCNPs on the RWG substrate surface by coating the RWG substrate surface with a carboxymethyl dextran layer. The immunosensor exhibited an extremely low LOD [0.24 fg/mL (9.1 aM)] and wide detection range (1 fg/mL to 100 pg/mL) in the detection of cardiac troponin I (cTnI). The cTnI concentrations in human serum samples collected at different times during cyclophosphamide, epirubicin, and 5-fluorouracil (CEF) chemotherapy in a breast cancer patient were measured by an immunosensor, and the results showed that the CEF chemotherapy did cause cardiotoxicity in the patient. Having a higher number of wells in such an array-based biosensor, the sensor can be developed as a high-throughput diagnostic tool for clinically important biomarkers.

Anthracycline-induced cardiotoxicity: mechanisms, monitoring, and prevention

Anthracyclines are the most fundamental and important treatment of several cancers especially for lymphoma and breast cancer. However, their use is limited by a dose-dependent cardiotoxicity which may emerge early at the initiation of anthracycline administration or several years after termination of the therapy. A full comprehending of the mechanisms of anthracycline-induced cardiotoxicity, which has not been achieved and is currently under the efforts, is critical to the advance of developing effective methods to protect against the cardiotoxicity, as well as to early detect and treat it. Therefore, we review the recent progress of the mechanism underlying anthracycline-induced cardiotoxicity, as well as approaches to monitor and prevent this issue.

Unlocking the secrets: the power of methylation-based cfDNA detection of tissue damage in organ systems

BACKGROUND

Detecting organ and tissue damage is essential for early diagnosis, treatment decisions, and monitoring disease progression. Methylation-based assays offer a promising approach, as DNA methylation patterns can change in response to tissue damage. These assays have potential applications in early detection, monitoring disease progression, evaluating treatment efficacy, and assessing organ viability for transplantation. cfDNA released into the bloodstream upon tissue or organ injury can serve as a biomarker for damage. The epigenetic state of cfDNA, including DNA methylation patterns, can provide insights into the extent of tissue and organ damage.

CONTENT

Firstly, this review highlights DNA methylation as an extensively studied epigenetic modification that plays a pivotal role in processes such as cell growth, differentiation, and disease development. It then presents a variety of highly precise 5-mC methylation detection techniques that serve as powerful tools for gaining profound insights into epigenetic alterations linked with tissue damage. Subsequently, the review delves into the mechanisms underlying DNA methylation changes in organ and tissue damage, encompassing inflammation, oxidative stress, and DNA damage repair mechanisms. Next, it addresses the current research status of cfDNA methylation in the detection of specific organ tissues and organ damage. Finally, it provides an overview of the multiple steps involved in identifying specific methylation markers associated with tissue and organ damage for clinical trials. This review will explore the mechanisms and current state of research on cfDNA methylation-based assay detecting organ and tissue damage, the underlying mechanisms, and potential applications in clinical practice.

iGEM as a human iPS cell-based global epigenetic modulation detection assay provides throughput characterization of chemicals affecting DNA methylation

Chemical-induced dysregulation of DNA methylation during the fetal period is known to contribute to developmental disorders or increase the risk of certain diseases later in life. In this study, we developed an iGEM (iPS cell-based global epigenetic modulation) detection assay using human induced pluripotent stem (hiPS) cells that express a fluorescently labeled methyl-CpG-binding domain (MBD), which enables a high-throughput screening of epigenetic teratogens/mutagens. 135 chemicals with known cardiotoxicity and carcinogenicity were categorized according to the MBD signal intensity, which reflects the degree of nuclear spatial distribution/concentration of DNA methylation. Further biological characterization through machine-learning analysis that integrated genome-wide DNA methylation, gene expression profiling, and knowledge-based pathway analysis revealed that chemicals with hyperactive MBD signals strongly associated their effects on DNA methylation and expression of genes involved in cell cycle and development. These results demonstrated that our MBD-based integrated analytical system is a powerful framework for detecting epigenetic compounds and providing mechanism insights of pharmaceutical development for sustainable human health.

Potential role of the apelin-APJ pathway in sex-related differential cardiotoxicity induced by doxorubicin in mice

Preclinical and clinical findings suggest sexual dimorphism in cardiotoxicity induced by a chemotherapeutic drug, doxorubicin (DOX). However, molecular alterations leading to sex-related differential vulnerability of heart to DOX toxicity are not fully explored. In the present study, RNA sequencing in hearts of B6C3F₁ mice indicated more differentially expressed genes in males than females (224 vs. 19; ≥1.5-fold, False Discovery Rate [FDR] < 0.05) at 1 week after receiving 24 mg/kg total cumulative DOX dose that induced cardiac lesions only in males. Pathway analysis further revealed probable inactivation of cardiac apelin fibroblast signaling pathway (p = 0.00004) only in DOX-treated male mice that showed ≥1.25-fold downregulation in the transcript and protein levels of the apelin receptor, APJ. In hearts of DOX-treated females, the transcript levels of apelin (1.24-fold) and APJ (1.47-fold) were significantly (p < 0.05) increased compared to saline-treated controls. Sex-related differential DOX effect was also observed on molecular targets downstream of the apelin-APJ pathway in cardiac fibroblasts and cardiomyocytes. In cardiac fibroblasts, upregulation of Tgf-β2, Ctgf, Sphk1, Serpine1, and Timp1 (fibrosis; FDR < 0.05) in DOX-treated males and upregulation of only Tgf-β2 and Timp1 (p < 0.05) in females suggested a greater DOX toxicity in hearts of males than females. Additionally, Ryr2 and Serca2 (calcium handling; FDR < 0.05) were downregulated in conjunction with 1.35-fold upregulation of Casp12 (sarcoplasmic reticulum-mediated apoptosis; FDR < 0.05) in DOX-treated male mice. Drug effect on the transcript level of these genes was less severe in female hearts. Collectively, these data suggest a likely role of the apelin-APJ axis in sex-related differential DOX-induced cardiotoxicity in our mouse model.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

Calanus oil attenuates isoproterenol-induced cardiac hypertrophy by regulating myocardial remodeling and oxidative stress

Calanus oil, an oil extracted from the marine crustacean Calanus finmarchicus, is one of the richest sources of omega-3 and poly-unsaturated fatty acids. Although calanus oil has been shown to have a significant anti-hypertensive, anti-inflammatory, anti-fibrotic and anti-obesity effects in various cardiovascular diseases, but little is known about its effect on pathological cardiac hypertrophy. Thus, the present study was carried out to evaluate the therapeutic effect of calanus oil on cardiac hypertrophy. Cardiac hypertrophy was induced by subcutaneous injections with isoproterenol (5 mg/kg b.w) for 14 consecutive days. Calanus oil (400 mg/kg) was given orally for 4 weeks. Cardiac pathological remodeling was evaluated by echocardiography, after which morphometric, biochemical, histological and ultrastructural analyses were performed. Calanus oil treatment significantly ameliorated isoproterenol-induced structural and functional alterations in echocardiography. Calanus oil also reduced the relative heart weight, significantly decreased the elevated cardiac enzymes (LDH and CK-MB) and the lipid peroxidation marker (MDA), augmented the myocardial antioxidant status (TAC), and ameliorated the histopathological and ultrastructural changes in cardiac tissues and prevented interstitial collagen deposition. The present study, for the first time, provided morphometric, biochemical, histological and ultrastructural evidences supporting the promising anti-hypertrophic effect of calanus oil against ISO-induced cardiac hypertrophy. This anti-hypertrophic effect of calanus oil is via regulating myocardial remodeling and oxidative stress. Therefore, it could be used as potential pharmacological intervention in the management of cardiac hypertrophy.

Discovery of AHCY as an Off-Target of Doxorubicin by Integrative Analysis of Photoaffinity Labeling Chemoproteomics and Untargeted Metabolomics

Target identification is critically important for understanding the mechanism of action of drugs. Here, we reported a new strategy for deconvolution of drug targets (or off-targets) with photoaffinity labeling chemoproteomics in combination with untargeted metabolomics by using doxorubicin (DOX) as a model. The DOX-derived photoaffinity probes were prepared and applied to capture DOX-interacting proteins in living cells. The captured DOX-interacting proteins were then identified by label-free quantitative proteomics. Totally, 151 significant proteins were identified with high confidence (fold change >4, p-value < 0.005). The gene ontology enrichment analysis suggested that the proteins were mainly involved in carbon metabolism, citrate cycle, fatty acid metabolism, and metabolic pathways. Therefore, untargeted metabolomics was applied to quantify the significantly altered metabolites in cells upon drug treatment. The pathway enrichment analysis suggested that DOX mainly interrupted with the processes of pyrimidine and purine metabolism, carbon metabolism, methionine metabolism, and phosphatidylcholine biosynthesis. Integrative analysis of chemoproteomics and metabolomics indicated that adenosylhomocysteinase (AHCY) is a new target (off-target) of DOX leading to the accumulation of S-adenosyl homocysteine. This deduced DOX target was confirmed by the cellular thermal shift assay, affinity competitive pull-down assay, biochemical assay, and siRNA knock down experiments. Our result suggested that AHCY is the uncovered off-target of DOX.

Pharmacogenetics of Drug Metabolism: The Role of Gene Polymorphism in the Regulation of Doxorubicin Safety and Efficacy

Simple Summary

The effectiveness and safety of the anti-cancer agent doxorubicin (anthracycline group medicine) depend on the metabolism and retention of the drug in the human organism. Polymorphism of cytochrome p450 (CYP)-encoding genes and detoxifying enzymes such as CYP3A4 and CYP2D6 were found responsible for variations in the doxorubicin metabolism. Transmembrane transporters such as p-glycoproteins were reported to be involved in cancer tissue retention of doxorubicin. ATP-binding cassette (ABC) family members, including ABCB1 transporters (also known as Multi-Drug Resistance 1 (MDR1)) proteins, were determined to pump out doxorubicin from breast cancer cells, therefore reducing the drug effectiveness. This study critically discusses the latest data about the role of CYP3A4, CYP2D6, and ABCB1 gene polymorphism in the regulation of doxorubicin’s effects in breast cancer patients. The assessment of genetic differences in the expression of doxorubicin metabolizing and transporting enzymes should be explored for the development of personalized medical treatment of breast cancer patients.

Abstract

Breast cancer (BC) is the prevailing malignancy and major cause of cancer-related death in females. Doxorubicin is a part of BC neoadjuvant and adjuvant chemotherapy regimens. The administration of anthracycline derivates, such as doxorubicin, may cause several side effects, including hematological disfunction, gastrointestinal toxicity, hepatotoxicity, nephrotoxicity, and cardiotoxicity. Cardiotoxicity is a major adverse reaction to anthracyclines, and it may vary depending on individual differences in doxorubicin pharmacokinetics. Determination of specific polymorphisms of genes that can alter doxorubicin metabolism was shown to reduce the risk of adverse reactions and improve the safety and efficacy of doxorubicin. Genes which encode cytochrome P450 enzymes (CYP3A4 and CYP2D6), p-glycoproteins (ATP-binding cassette (ABC) family members such as Multi-Drug Resistance 1 (MDR1) protein), and other detoxifying enzymes were shown to control the metabolism and pharmacokinetics of doxorubicin. The effectiveness of doxorubicin is defined by the polymorphism of cytochrome p450 and p-glycoprotein-encoding genes. This study critically discusses the latest data about the role of gene polymorphisms in the regulation of doxorubicin’s anti-BC effects. The correlation of genetic differences with the efficacy and safety of doxorubicin may provide insights for the development of personalized medical treatment for BC patients.

The role of ivabradine in doxorubicin-induced cardiotoxicity: exploring of underlying argument

This study investigated the potential role of ivabradine (IVN) in the attenuation of doxorubicin (DXR)-induced cardiotoxicity in rats. A total of 28 Swiss-Albino male mice were used, divided into four equal groups: the negative control did not receive any agents (n = 7), the DXR group received a single dose of DXR 20 mg/kg (n = 7), the treated group A was pretreated with IVN 5 mg/kg plus DXR (n = 7), and the treated group B was pretreated with IVN 10 mg/kg plus DXR (n = 7). The duration of this study was 10 days. Inflammatory biomarkers, including tumor necrosis factor alpha (TNF-α), lactate dehydrogenase (LDH), malondialdehyde (MDA), and cardiac troponin (cTn-I) serum levels were measured. TNF-α, LDH, MDA, and cTn-I serum levels were higher in the DXR-treated mice compared with the control (P˂0.01). IVN produced a dose-dependent effect in the reduction of MDA and cTn-I compared to DXR-treated mice (P˂0.05). Our findings suggest that IVN is an effective agent in mitigating DXR-induced cardiotoxicity due to its anti-inflammatory and antioxidant effects. IVN illustrated a dose-dependent effect in the attenuation of DXR-induced cardiotoxicity through inhibition of lipid peroxidation and cardiomyocyte injury.

Cytarabine-Induced Bradycardia: A Case Report

Cardiotoxicity is damage to the heart muscle, which affects its function. Chemotherapy is known to cause cardiotoxicity along with many other medications and etiologies. Many chemotherapeutic cocktails are known to be associated with cardiotoxicities, such as taxane and cisplatin. Patients might have arrhythmias, severe bradycardia, cardiomyopathy, and even cardiac arrest, so precautions are taken when such medications are started. This report presents a patient who developed severe symptomatic bradycardia after receiving idarubicin and cytarabine and was managed conservatively, along with a literature review of this entity.

Cardio-Oncology: Mechanisms, Drug Combinations, and Reverse Cardio-Oncology

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy have brought hope to cancer patients. With the prolongation of survival of cancer patients and increased clinical experience, cancer-therapy-induced cardiovascular toxicity has attracted attention. The adverse effects of cancer therapy that can lead to life-threatening or induce long-term morbidity require rational approaches to prevention and treatment, which requires deeper understanding of the molecular biology underpinning the disease. In addition to the drugs used widely for cardio-protection, traditional Chinese medicine (TCM) formulations are also efficacious and can be expected to achieve “personalized treatment” from multiple perspectives. Moreover, the increased prevalence of cancer in patients with cardiovascular disease has spurred the development of “reverse cardio-oncology”, which underscores the urgency of collaboration between cardiologists and oncologists. This review summarizes the mechanisms by which cancer therapy induces cardiovascular toxicity, the combination of antineoplastic and cardioprotective drugs, and recent advances in reverse cardio-oncology.

Welson N, Mostafa-Hedeab G, Qasem AH, Conte-Junior CA. Combination of Panax ginseng C. A. Mey and Febuxostat Boasted Cardioprotective Effects Against Doxorubicin-Induced Acute Cardiotoxicity in Rats

Doxorubicin (DOX) is an anticancer agent for treating solid and soft tissue malignancies. However, the clinical use of DOX is restricted by cumulative, dose-dependent cardiotoxicity. Therefore, the present study aimed to assess the cardioprotective effects of P. ginseng C. A. Mey, febuxostat, and their combination against DOX-induced cardiotoxicity. Thirty-five Sprague Dawley male rats were used in this study. The animals were randomly divided into five groups, with seven rats per group. The control group received normal saline, the induced group received DOX only, and the treated group received P. ginseng, febuxostat, and their combination before DOX treatment. Biomarkers of acute cardiac toxicity were assessed in each group. Results showed that treatment with the combination of febuxostat and P. ginseng before DOX led to a significant improvement in the biomarkers of acute DOX-induced cardiotoxicity. In conclusion, the combination of P. ginseng and febuxostat produced more significant cardioprotective effects against DOX-induced cardiotoxicity when compared to either P. ginseng or febuxostat when used alone. The potential mechanism of this combination was mainly mediated by the anti-inflammatory and antioxidant effects of P. ginseng and febuxostat.

Tumor-Microenvironment-Activated NIR-II Nanotheranostic Platform for Precise Diagnosis and Treatment of Colon Cancer

Rational design of tumor-microenvironment (TME)-activated nanoformulation for precisely targeted cancer treatment has recently attracted an enormous attention. However, the all-in-one TME-activated theranostic nanosystems with a simple preparation and high biocompatibility are still rarely reported. Herein, catalase nanocrystals (CatCry) are first introduced as a tumor microenvironment activatable nanoplatform for selective theranostics of colon cancer. They are engaged as (i) a "nanoreactor" for silver nanoparticles (AgNP) synthesis, (ii) a nanovehicle for tumor delivery of anticancer drug doxorubicin (DOX), and (iii) an in situ O2 generator to relief tumor hypoxia. When CatCry-AgNP-DOX nanoformulation is within a tumor, the intratumoral H2S turns AgNP into Ag2S nanoparticles, inducing a photothermal effect and NIR-II emission under 808 nm laser irradiation and also triggering DOX release. Simultaneously, CatCry catalyzes intratumoral H2O2 into O2, relieving hypoxia and enhancing chemotherapy. In contrast, when delivered to healthy tissue without increased concentration of H2S, the developed nanoformulation remains in the "off" state and no theranostic action takes place. Studies with colon cancer cells in vitro and a murine colon cancer model in vivo demonstrated that CatCry-AgNP-DOX delivered a synergistic combination of PTT and enhanced chemotherapy, enabling complete eradication of tumor with minimal side effects. This work not only introduces nanoplatform for theranostics of H2S-rich tumors but also suggests a general strategy for protein-crystal-based nanomedicine.

Novel molecular biomarkers of cancer therapy-induced cardiotoxicity in adult population: a scoping review

Aim

Cancer treatments are associated with cardiotoxic events that predispose to cardiac pathology and compromise the survival of patients, making necessary the identification of new molecular biomarkers to detect cardiotoxicity. This scoping review aims to identify the available evidence on novel molecular biomarkers associated with cardiotoxicity in the adult population undergoing cancer therapy.

Methods and results

The databases Medline, Web of Science, Scopus, and Embase were screened for the identification of published studies until 23 August 2020, searching for novel molecular biomarkers reported in cancer therapy‐related cardiac dysfunction in adult patients. A total of 42 studies that met the eligibility criteria were included. Fourteen studies reported 44 new protein biomarkers, 18 studies reported 57 new single nucleotide polymorphism biomarkers, and 11 studies reported 171 new gene expression profiles associated with cardiotoxicity. Data were extracted for 272 novel molecular biomarkers reported and evaluated in 7084 cancer patients, of which only 13 were identified in more than one study (MPO, sST2, GDF‐15, TGF‐B1, rs1056892, rs1883112, rs4673, rs13058338, rs1695, miR‐1, miR‐25‐3p, miR‐34a‐5p, and miR‐423‐5p), showing values for area under the curve > 0.73 (range 0.74–0.85), odds ratio 0.26–7.17, and hazard ratio 1.28–1.80.

Conclusions

Multiple studies presented a significant number of novel molecular biomarkers as promising predictors for risk assessment of cardiac dysfunction related to cancer therapy, but the characteristics of the studies carried out and the determinations applied do not allow suggesting the clinical use of these molecular biomarkers in the assessment of cancer therapy‐induced cardiotoxicity.

Doxorubicin induces cardiotoxicity in a pluripotent stem cell model of aggressive B cell lymphoma cancer patients

Cancer therapies with anthracyclines have been shown to induce cardiovascular complications. The aims of this study were to establish an in vitro induced pluripotent stem cell model (iPSC) of anthracycline-induced cardiotoxicity (ACT) from patients with an aggressive form of B-cell lymphoma and to examine whether doxorubicin (DOX)-treated ACT-iPSC cardiomyocytes (CM) can recapitulate the clinical features exhibited by patients, and thus help uncover a DOX-dependent pathomechanism. ACT-iPSC CM generated from individuals with CD20⁺ B-cell lymphoma who had received high doses of DOX and suffered cardiac dysfunction were studied and compared to control-iPSC CM from cancer survivors without cardiac symptoms. In cellular studies, ACT-iPSC CM were persistently more susceptible to DOX toxicity including augmented disorganized myofilament structure, changed mitochondrial shape, and increased apoptotic events. Consistently, ACT-iPSC CM and cardiac fibroblasts isolated from fibrotic human ACT myocardium exhibited higher DOX-dependent reactive oxygen species. In functional studies, Ca²⁺ transient amplitude of ACT-iPSC CM was reduced compared to control cells, and diastolic sarcoplasmic reticulum Ca²⁺ leak was DOX-dependently increased. This could be explained by overactive CaMKIIδ in ACT CM. Together with DOX-dependent augmented proarrhythmic cellular triggers and prolonged action potentials in ACT CM, this suggests a cellular link to arrhythmogenic events and contractile dysfunction especially found in ACT engineered human myocardium. CamKIIδ inhibition prevented proarrhythmic triggers in ACT. In contrast, control CM upregulated SERCA2a expression in a DOX-dependent manner, possibly to avoid heart failure conditions. In conclusion, we developed the first human patient-specific stem cell model of DOX-induced cardiac dysfunction from patients with B-cell lymphoma. Our results suggest that DOX-induced stress resulted in arrhythmogenic events associated with contractile dysfunction and finally in heart failure after persistent stress activation in ACT patients.

Long non-coding RNAs and microRNAs as crucial regulators in cardio-oncology

Cancer is one of the leading causes of morbidity and mortality worldwide. Significant improvements in the modern era of anticancer therapeutic strategies have increased the survival rate of cancer patients. Unfortunately, cancer survivors have an increased risk of cardiovascular diseases, which is believed to result from anticancer therapies. The emergence of cardiovascular diseases among cancer survivors has served as the basis for establishing a novel field termed cardio-oncology. Cardio-oncology primarily focuses on investigating the underlying molecular mechanisms by which anticancer treatments lead to cardiovascular dysfunction and the development of novel cardioprotective strategies to counteract cardiotoxic effects of cancer therapies. Advances in genome biology have revealed that most of the genome is transcribed into non-coding RNAs (ncRNAs), which are recognized as being instrumental in cancer, cardiovascular health, and disease. Emerging studies have demonstrated that alterations of these ncRNAs have pathophysiological roles in multiple diseases in humans. As it relates to cardio-oncology, though, there is limited knowledge of the role of ncRNAs. In the present review, we summarize the up-to-date knowledge regarding the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in cancer therapy-induced cardiotoxicities. Moreover, we also discuss prospective therapeutic strategies and the translational relevance of these ncRNAs.

Therapeutic Targets for DOX-Induced Cardiomyopathy: Role of Apoptosis vs. Ferroptosis

Doxorubicin (DOX) is the most widely used anthracycline anticancer agent; however, its cardiotoxicity limits its clinical efficacy. Numerous studies have elucidated the mechanisms underlying DOX-induced cardiotoxicity, wherein apoptosis has been reported as the most common final step leading to cardiomyocyte death. However, in the past two years, the involvement of ferroptosis, a novel programmed cell death, has been proposed. The purpose of this review is to summarize the historical background that led to each form of cell death, focusing on DOX-induced cardiotoxicity and the molecular mechanisms that trigger each form of cell death. Furthermore, based on this understanding, possible therapeutic strategies to prevent DOX cardiotoxicity are outlined. DNA damage, oxidative stress, intracellular signaling, transcription factors, epigenetic regulators, autophagy, and metabolic inflammation are important factors in the molecular mechanisms of DOX-induced cardiomyocyte apoptosis. Conversely, the accumulation of lipid peroxides, iron ion accumulation, and decreased expression of glutathione and glutathione peroxidase 4 are important in ferroptosis. In both cascades, the mitochondria are an important site of DOX cardiotoxicity. The last part of this review focuses on the significance of the disruption of mitochondrial homeostasis in DOX cardiotoxicity.

The therapeutic effect of hesperetin on doxorubicin-induced testicular toxicity: Potential roles of the mechanistic target of rapamycin kinase (mTOR) and dynamin-related protein 1 (DRP1)

Clinical utilization of doxorubicin (DOX), which is a commonly used chemotherapeutic, is restricted due to toxic effects on various tissues. Using hesperetin (HST), an antioxidant used in Chinese traditional medicine protects testis against DOX-induced toxicity although the molecular mechanisms are not well-known. The study was aimed to examine the possible role of the mechanistic target of rapamycin kinase (mTOR) and dynamin 1-like dynamin-related protein 1 (DRP1) in the therapeutic effects of HST on the DOX-induced testicular toxicity. Rats were divided into Control, DOX, DOX + HST, and HST groups (n = 7). Single-dose DOX (15 mg/kg) was administered intraperitoneally and HST (50 mg/kg) was administered by oral gavage every other day for 28 days. Total antioxidant status (TAS), histopathological evaluations, immunohistochemistry, and gene expression level detection analyses were performed. Histopathologically, DOX-induced testicular damage was ameliorated by HST treatment. DOX reduced testicular TAS levels and increased oxidative stress markers, 8-Hydroxy-deoxyguanosine (8-OHdG), and 4-Hydroxynonenal (4-HNE). Also, upregulated mTOR and DRP1 expressions with DOX exposure were decreased after HST treatment in the testis (p < 0.05). On the other hand, DOX-administration downregulated miR-150-5p and miR-181b-2-3p miRNAs, targeting mTOR and mRNA levels of beclin 1 (BECN1) and autophagy-related 5 (ATG5), autophagic markers. Furthermore, these levels were nearly similar to control testis samples in the DOX + HST group (p < 0.05). The study demonstrated that HST may have a therapeutic effect on DOX-induced testicular toxicity by removing reactive oxygen species (ROS) and by modulating the mTOR and DRP1 expressions, which have a critical role in regulating the balance of generation/elimination of ROS.

Sirt6 protects cardiomyocytes against doxorubicin-induced cardiotoxicity by inhibiting P53/Fas-dependent cell death and augmenting endogenous antioxidant defense mechanisms

Sirt6, a class III NAD⁺-dependent deacetylase of the sirtuin family, is a highly specific H3 deacetylase and plays important roles in regulating cellular growth and death. The induction of oxidative stress and death is the critical mechanism involved in cardiomyocyte injury and cardiac dysfunction in doxorubicin-induced cardiotoxicity, but the regulatory role of Sirt6 in the fate of DOX-impaired cardiomyocytes is poorly understood. In the present study, we exposed Sirt6 heterozygous (Sirt6^+/-) mice and their littermates as well as cultured neonatal rat cardiomyocytes to DOX, then investigated the role of Sirt6 in mitigating oxidative stress and cardiac injury in the DOX-treated myocardium. Sirt6 partial knockout or silencing worsened cardiac damage, remodeling, and oxidative stress injury in mice or cultured cardiomyocytes with DOX challenge. Cardiomyocytes infected with adenoviral constructs encoding Sirt6 showed reversal of this DOX-induced damage. Intriguingly, Sirt6 reduced oxidative stress injury by upregulating endogenous antioxidant levels, interacted with oxidative stress-stirred p53, and acted as a co-repressor of p53 in nuclei. Sirt6 was recruited by p53 to the promoter regions of the target genes Fas and FasL and further suppressed p53 transcription activity by reducing histone acetylation. Sirt6 inhibited Fas/FasL signaling and attenuated both Fas-FADD-caspase-8 apoptotic and Fas-RIP3 necrotic pathways. These results indicate that Sirt6 protects the heart against DOX-induced cardiotoxicity by upregulating endogenous antioxidants, as well as suppressing oxidative stress and cell death signaling pathways dependent on ROS-stirred p53 transcriptional activation, thus reducing Fas-FasL-mediated apoptosis and necrosis. •Sirt6 is significantly decreased in DOX-insulted mouse hearts and cardiomyocytes. •Sirt6 attenuates DOX-induced cardiac atrophy, dysfunction and oxidative stress. • Sirt6 reduces oxidative stress injury by upregulating endogenous antioxidants. • Sirt6 interacts with p53 as a co-repressor to suppress p53 transcriptional regulation and inhibits Fas-FasL-mediated apoptosis and necrosis downstream of p53.

Integrating analysis of circular RNA and mRNA expression profiles in doxorubicin induced cardiotoxicity mice

Doxorubicin (DOX)-induced cardiotoxicity impedes its clinical application, but the mechanisms have not been thoroughly elucidated. Based on circRNA and mRNA expression profiles, we illustrated RNA expression signature changes during DOX-induced cardiotoxicity; mechanism exploration and biomarkers screening were also conducted. Twelve mice were randomly divided into two groups, induction group was treated with doxorubicin, and the control group was given an equal quantity of saline. After the confirmation of myocardial injury in induction group, the heart tissues from both groups were isolated for RNA high-throughput sequencing. The expression profiles were compared between the two groups; a total of 295 mRNAs and 11 circRNAs were shown as biased expression in DOX-induced cardiotoxicity mouse hearts. The dysregulation of three circRNAs were validated by quantitative real-time PCR: mmu_circ_0015773, mmu_circ_0002106, and mmu_circ_001606. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the differentially expressed RNAs were performed; the results implied that DOX might cause cardiotoxicity by interfering hemoglobin-based oxygen delivery and DNA-associated signal pathways. We integrated the differential expressed mRNA and validated circRNAs by constructing a competing endogenous RNA (ceRNA) network, which indicated that the alteration of the three circRNAs could activate apoptosis process of myocardial cells. This study provided novel insight into the mechanisms of DOX induced cardiotoxicity, and potential biomarkers or therapeutic targets were also proposed.

Benazepril hydrochloride protects against doxorubicin cardiotoxicity by regulating the PI3K/Akt pathway

Doxorubicin (DOX) stimulates the generation of reactive oxygen species, thereby impairing mitochondrial functions. Angiotensin-converting enzyme inhibitors (ACEIs) have been identified to exhibit protective effects on cardiovascular diseases. The present study aimed to test the hypothesis that an ACEI benazepril hydrochloride (HCl) may protect against DOX-induced cardiotoxicity. The DOX injury model was established using rat embryonic cardiac myoblast cells (H9c2 cell line) treated with DOX in vitro. H9c2 cells were treated with benazepril-HCl, DOX or a mixture of DOX and benazepril-HCl to measure the activities of myocardial enzymes including lactate dehydrogenase (LDH), superoxide dismutase, catalase and glutathione peroxidase, in addition to the concentration of malondialdehyde in the culture medium. Cells without any treatment were used as a control. DOX treatment increased the levels of activity of myocardial enzymes in H9c2 cells compared with those in the untreated control cells. Additionally, co-treatment with benazepril-HCl significantly reduced the levels of apoptosis occurring due to DOX-mediated cellular damage. The mechanistic experiment revealed that pretreatment with benazepril-HCl counteracted the DOX-induced oxidative stress and suppressed the activation of apoptosis via the PI3K/Akt signaling pathway. By contrast, an Akt inhibitor (MK2206) inhibited the protective effects of benazepril-HCl against DOX-induced H9c2 cell injury, as revealed by increased LDH release in H9c2 cells. These results suggested that benazepril-HCl may potentially be administered as an adjuvant for DOX in long-term clinical use.

Doxorubicin-induced cardiotoxicity: An update on the molecular mechanism and novel therapeutic strategies for effective management

Doxorubicin (Dox) is a secondary metabolite of the mutated strain of Streptomyces peucetius var. Caesius and belongs to the anthracyclines family. The anti-cancer activity of Dox is mainly exerted through the DNA intercalation and inhibiting topoisomerase II enzyme in fast-proliferating tumors. However, Dox causes cumulative and dose-dependent cardiotoxicity, which results in increased risks of mortality among cancer patients and thus limiting its wide clinical applications. There are several mechanisms has been proposed for doxorubicin-induced cardiotoxicity and oxidative stress, free radical generation and apoptosis are most widely reported. Apart from this, other mechanisms are also involved in Dox-induced cardiotoxicity such as impaired mitochondrial function, a perturbation in iron regulatory protein, disruption of Ca²⁺ homeostasis, autophagy, the release of nitric oxide and inflammatory mediators and altered gene and protein expression that involved apoptosis. Dox also causes downregulation of DNA methyltransferase 1 (DNMT1) enzyme activity which leads to a reduction in the DNA methylation process. This hypomethylation causes dysregulation in the mitochondrial genes like peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1-alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) unit in the heart. Apart from DNA methylation, Dox treatment also alters the micro RNAs levels and histone deacetylase (HDAC) activity. Therefore, in the current review, we have provided a detailed update on the current understanding of the pathological mechanisms behind the well-known Dox-induced cardiotoxicity. Further, we have provided some of the most plausible pharmacological strategies which have been tested against Dox-induced cardiotoxicity.

Molecular mechanisms and cardiovascular implications of cancer therapy-induced senescence

Cancer treatment has been associated with accelerated aging that can lead to early-onset health complications typically experienced by older populations. In particular, cancer survivors have an increased risk of developing premature cardiovascular complications. In the last two decades, cellular senescence has been proposed as an important mechanism of premature cardiovascular diseases. Cancer treatments, specifically anthracyclines and radiation, have been shown to induce senescence in different types of cardiovascular cells. Additionally, clinical studies identified increased systemic markers of senescence in cancer survivors. Preclinical research has demonstrated the potential of several approaches to mitigate cancer therapy-induced senescence. However, strategies to prevent and/or treat therapy-induced cardiovascular senescence have not yet been translated to the clinic. In this review, we will discuss how therapy-induced senescence can contribute to cardiovascular complications. Thereafter, we will summarize the current in vitro, in vivo, and clinical evidence regarding cancer therapy-induced cardiovascular senescence. Then, we will discuss interventional strategies that have the potential to protect against therapy-induced cardiovascular senescence. To conclude, we will highlight challenges and future research directions to mitigate therapy-induced cardiovascular senescence in cancer survivors.

Epigenetic Mechanisms Involved in the Cardiovascular Toxicity of Anticancer Drugs

The cardiovascular toxicity of anticancer drugs promotes the development of cardiovascular diseases. Therefore, cardiovascular toxicity is an important safety issue that must be considered when developing medications and therapeutic applications to treat cancer. Among anticancer drugs, members of the anthracycline family, such as doxorubicin, daunorubicin and mitoxantrone, are known to cause cardiotoxicity and even heart failure. Using human-induced pluripotent stem cell-derived cardiomyocytes in combination with "Omic" technologies, we identified several cardiotoxicity mechanisms and signal transduction pathways. Moreover, these drugs acted as cardiovascular toxicants through a syndrome of mechanisms, including epigenetic ones. Herein, we discuss the main cardiovascular toxicity mechanisms, with an emphasis on those associated with reactive oxygen species and mitochondria that contribute to cardiotoxic epigenetic modifications. We also discuss how to mitigate the cardiotoxic effects of anticancer drugs using available pharmaceutical "weapons."