Identification of Drug Transporter Genomic Variants and Inhibitors That Protect Against Doxorubicin-Induced Cardiotoxicity

Akkermansia muciniphila ameliorates doxorubicin-induced cardiotoxicity by regulating PPARα-dependent mitochondrial biogenesis

Doxorubicin (DOX) is a key chemotherapeutic agent but is also a leading cause of DOX-induced cardiotoxicity (DIC), limiting its clinical use. Akkermansia muciniphila (A. muciniphila), known for its benefits as a probiotic in treating metabolic syndrome, has uncertain effects in the context of DIC. Here, 16S rRNA sequencing of fecal samples from anthracycline-treated patients and DIC mice revealed marked depletion of A. muciniphila. Cardiac transcriptomics, supported by in vitro experiments, showed that A. muciniphila colonization improved mitochondrial function and alleviated DIC by activating the PPARα/PGC1α signaling pathway in both normal and antibiotic-treated C57BL/6 mice. Further analysis uncovered a restructured microbiome-metabolome network following A. muciniphila administration, which contributed to DIC protection. Notably, A. muciniphila supplementation increased serum levels of the tryptophan metabolite indole-3-propionic acid (IPA), which binds to the cardiac aryl hydrocarbon receptor (AhR), leading to the activation of the PPARα/PGC1α signaling pathway. In conclusion, our study sheds light on the potential of A. muciniphila as a probiotic in mitigating DIC.

Understanding the Mechanisms of Chemotherapy-Related Cardiotoxicity Employing hiPSC-Derived Cardiomyocyte Models for Drug Screening and the Identification of Genetic and Epigenetic Variants

Chemotherapy-related cardiotoxicity (CTRTOX) is a profound and common side effect of cancer-based therapy in a subset of patients. The underlying factors and the associated mechanisms contributing to severe toxicity of the heart among these patients remain unknown. While challenges remain in accessing human subjects and their ventricular cardiomyocytes (CMs), advancements in human induced pluripotent stem cell (hiPSC)-technology-based CM differentiation protocols over the past few decades have paved the path for iPSC-based models of human cardiac diseases. Here, we offer a detailed analysis of the underlying mechanisms of CTRTOX. We also discuss the recent advances in therapeutic strategies in different animal models and clinical trials. Furthermore, we explore the prospects of iPSC-based models for identifying novel functional targets and developing safer chemotherapy regimens for cancer patients that may be beneficial for developing personalized cardioprotectants and their application in clinical practice.

Dissecting cardiovascular disease-associated noncoding genetic variants using human iPSC models

Advancements in genomics have revealed hundreds of loci associated with cardiovascular diseases, highlighting the role genetic variants play in disease pathogenesis. Notably, most variants lie within noncoding genomic regions that modulate transcription factor binding, chromatin accessibility, and thereby the expression levels and cell type specificity of gene transcripts. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a powerful tool to delineate the pathogenicity of such variants and elucidate the underlying transcriptional mechanisms. Our review discusses the basics of noncoding variant-mediated pathogenesis, the methodologies utilized, and how hiPSC-based heart models can be leveraged to dissect the mechanisms of noncoding variants.

Engineering cardiology with miniature hearts

Cardiac organoids offer sophisticated 3D structures that emulate key aspects of human heart development and function. This review traces the evolution of cardiac organoid technology, from early stem cell differentiation protocols to advanced bioengineering approaches. We discuss the methodologies for creating cardiac organoids, including self-organization techniques, biomaterial-based scaffolds, 3D bioprinting, and organ-on-chip platforms, which have significantly enhanced the structural complexity and physiological relevance of in vitro cardiac models. We examine their applications in fundamental research and medical innovations, highlighting their potential to transform our understanding of cardiac biology and pathology. The integration of multiple cell types, vascularization strategies, and maturation protocols has led to more faithful representations of the adult human heart. However, challenges remain in achieving full functional maturity and scalability. We critically assess the current limitations and outline future directions for advancing cardiac organoid technology. By providing a comprehensive analysis of the field, this review aims to catalyze further innovation in cardiac tissue engineering and facilitate its translation to clinical applications.

DNA Damage Response and Repair Genes and Anthracycline-Induced Cardiomyopathy in Childhood Cancer Survivors: A Report From the Children's Oncology Group and the Childhood Cancer Survivor Study

BACKGROUND

Anthracyclines induce cardiotoxicity via DNA double-strand breaks and reactive oxygen species formation, resulting in cardiomyocyte dysfunction. The role of DNA damage response/repair (DDR) genes in anthracycline-induced cardiomyopathy remains unstudied.

METHODS

We conducted a gene-based and pathway-based analysis to examine the main effect and gene-anthracycline interaction effect between DDR genes and anthracycline-induced cardiomyopathy. A discovery analysis performed with a matched case-control set of anthracycline-exposed non-Hispanic White childhood cancer survivors from Children's Oncology Group-ALTE03N1 (113 cases; 226 controls) was replicated using a cohort of anthracycline-exposed non-Hispanic White childhood cancer survivors from the Childhood Cancer Survivor Study cohort (n=1658; 97 cases). Functional analyses were performed by examining the response to doxorubicin of human-induced pluripotent stem cell-derived cardiomyocytes with CRISPR/Cas9-mediated knockout of prioritized genes.

RESULTS

Successfully replicated DDR genes demonstrating main-effect association included FANCC (P=0.037) and XRCC5 (P=0.001) and demonstrated gene-anthracycline interaction included MGMT (P=0.041). Knockouts of FANCC and MGMT in human-induced pluripotent stem cell-derived cardiomyocytes demonstrated significant resistance to doxorubicin, suggesting that these genes play a role in anthracycline-induced cardiotoxicity. Successfully replicated DDR pathways demonstrating main-effect association included base excision repair (P=2.7×10-4); role of BRCA1 in DDR (P=9.2×10-5); p53 signaling (P<1×10-16); role of checkpoint kinases proteins in cell cycle checkpoint control (P<1×10-16); mismatch repair (P<10-16); and double-strand break repair by homologous recombination (P<1×10-16). Successfully replicated DDR pathways demonstrating significant interaction effects included role of BRCA1 in DDR (P=1.4×10-4); p53 signaling (P<1×10-16); the role of checkpoint kinases proteins in cell cycle checkpoint control (P<1×10-16); mismatch repair (P<1×10-16); cell cycle: G2/M DNA damage checkpoint regulation (P=0.002); double-strand break repair by homologous recombination (P=0.009); GADD45 signaling (P=4.8×10-4); and cell cycle control of chromosomal replication (P=4.5×10-4).

CONCLUSIONS

These findings provide evidence for the role of DDR genes and pathways in anthracycline-induced cardiomyopathy and provide a framework for targeted therapeutic interventions.

Mitochondrial Amount Determines Doxorubicin-Induced Cardiotoxicity in Cardiomyocytes

Doxorubicin, an anthracycline commonly used for treating cancer patients, is known for its cardiotoxic side-effects. Although dose-dependent, but susceptibility remains variable among patients, and childhood-exposure-adult-onset remains challenging. Besides topoisomerase toxicity, Doxorubicin is also toxic to the mitochondria yet the underlying late onset mechanism remains elusive. Here, it is observed that the mitochondrial copy number in PBMCs of patients treated with anthracycline chemotherapy is negatively correlated with the change in plasma BNP levels after treatment. Isogenic hiPSC-CMs are generated with high, norm, and low mitochondrial copy numbers using mitochondrial transplantation and the YFP-Parkin system. Remarkably, lower mitochondria copy number translates to lower IC50, suggesting increased susceptibility. Mitochondria supplementation by intramyocardial injection prevents doxorubicin induced heart failure. Mechanistically, doxorubicin treatment leads to mPTP opening and mitochondrial DNA (mtDNA) leakage. This mtDNA leakage event activates the cGAS-STING pathway and drives inflammation and myocardial senescence. Cardiomyocyte-specific knockout of Sting (Myh6-Cre/Stingflox/flox; StingCKO) and over expression of mitochondrial tagged DNase1 in mice partially rescue doxorubicin-induced cardiac dysfunction. In conclusion, the work establishes a negative correlation between cardiomyocyte mitochondrial copy number and doxorubicin toxicity. Molecularly, it is demonstrated that mtDNA leakage activates cGAS-STING pathway and accelerates myocardial dysfunction. These insights offer new co-administration strategies for cancer patients.

Examining patient-specific responses to PARP inhibitors in a novel, human induced pluripotent stem cell-based model of breast cancer

Preclinical models of breast cancer that better predict patient-specific drug responses are critical for expanding the clinical utility of targeted therapies, including for inhibitors of poly(ADP-ribose) polymerase (PARP). Reprogramming primary cancer cells into human induced pluripotent stem cells (hiPSCs) recently emerged as a powerful tool to model drug response phenotypes, but its use to date has been limited to hematopoietic malignancies. We designed an optimized reprogramming methodology to generate breast cancer-derived hiPSCs (BC-hiPSCs) from nine patients representing all major subtypes of breast cancer. BC-hiPSCs retain patient-specific oncogenic variants, including variants unique to individual tumor subclones. Additionally, we developed a protocol to differentiate BC-hiPSCs into mammary epithelial cells and mammary-like organoids for in vitro disease modeling, including drug response phenotyping. Using these tools, we demonstrated that BC-hiPSCs can be used to screen for differential sensitivity to PARP inhibitors and mechanistically investigated the causal genetic variant driving drug sensitivity in one patient.

Genetic and epigenetic bases of long-term adverse effects of childhood cancer therapy

Over the past decade, genome-scale molecular profiling of large childhood cancer survivorship cohorts has led to unprecedented advances in our understanding of the genetic and epigenetic bases of therapy-related adverse health outcomes in this vulnerable population. To facilitate the integration of knowledge generated from these studies into formulating next-generation precision care for survivors of childhood cancer, we summarize key findings of genetic and epigenetic association studies of long-term therapy-related adverse effects including subsequent neoplasms and cardiomyopathies among others. We also discuss therapy-related genotoxicities including clonal haematopoiesis and DNA methylation, which may underlie accelerated molecular ageing. Finally, we highlight enhanced risk prediction models for survivors of childhood cancer that incorporate both genetic factors and treatment exposures, aiming to achieve enhanced accuracy in predicting risks for this population. These new insights will hopefully inspire future studies that harness both expanding omics resources and evolving data science methodology to accelerate the translation of precision medicine for survivors of childhood cancer.

Indole-3-Lactic Acid Inhibits Doxorubicin-Induced Ferroptosis Through Activating Aryl Hydrocarbon Receptor/Nrf2 Signalling Pathway

The clinical application of doxorubicin (DOX) is limited due to its cardiotoxicity, which is primarily attributed to its interaction with iron in mitochondria, leading to lipid peroxidation and myocardial ferroptosis. This study aimed to investigate the role of the gut microbiota-derived metabolite, indole-3-lactic acid (ILA), in mitigating DOX-induced cardiotoxicity (DIC). Cardiac function, pathological changes, and myocardial ferroptosis were assessed in vivo. The cardioprotective effects and mechanisms of ILA were explored using multi-omics approaches, including single-nucleus RNA sequencing (snRNA-seq) and bulk RNA-seq, and were further validated in Nrf2 knockout mice. The findings revealed that DOX treatment disrupted gut microbiota, significantly reducing the levels of the tryptophan metabolite ILA. In DIC models, ILA supplementation markedly improved cardiac function, reduced collagen deposition, and mitigated cardiac atrophy. The bulk and snRNA-seq analyses indicated that myocardial ferroptosis played a crucial role in the cardioprotective effects of ILA. Experimental data demonstrated that ILA decreased DOX-induced ferroptosis in both DIC mice and DOX-treated H9C2 cells, evidenced by restoration of GPX4 and SLC7A11 levels and reduction of ACSL4. Mechanistically, ILA functions as a ligand for the aryl hydrocarbon receptor (AhR), leading to the upregulation of Nrf2 expression. The protective effects of ILA against ferroptosis were abolished by silencing AhR. Moreover, the beneficial effects of ILA on DIC were eliminated in Nrf2-deficient mice. In conclusion, ILA exerts therapeutic effects against DIC by inhibiting ferroptosis through activation of the AhR/Nrf2 signalling pathway. Identifying the cardioprotective role of the microbial metabolite ILA could offer viable therapeutic strategies for DIC.

Straight to the heart: Protecting the patient's heart during chemotherapy

How do we protect the heart during chemotherapy with the anthracycline drug class? Tackling this question, Liu et al. combined pluripotent stem cell models, CRISPR genetic screens, and molecular modeling to identify indisulam as a potential cardioprotective drug in this issue of Cell Stem Cell.

Evolving therapeutics and ensuing cardiotoxicities in triple-negative breast cancer

Defined as scarce expression of hormone receptors and human epidermal growth factor receptor 2, triple-negative breast cancer (TNBC) is labeled as the most heterogeneous subtype of breast cancer with poorest prognosis. Despite rapid advancements in precise subtyping and tailored therapeutics, the ensuing cancer therapy-related cardiovascular toxicity (CTR-CVT) could exert detrimental impacts to TNBC survivors. Nowadays, this interdisciplinary issue is incrementally concerned by cardiologists, oncologists and other pertinent experts, propelling cardio-oncology as a booming field focusing on the whole-course management of cancer patients with potential cardiovascular threats. Here in this review, we initially profile the evolving molecular subtyping and therapeutic landscape of TNBC. Further, we introduce various monitoring approaches of CTR-CVT. In the main body, we elaborate on typical cardiotoxicities ensuing anti-TNBC treatments in detail, ranging from chemotherapy (especially anthracyclines), surgery, anesthetics, radiotherapy to immunotherapy, with future perspectives on promising directions in the era of artificial intelligence and traditional Chinese medicine.

Clinical trials in-a-dish for cardiovascular medicine

Cardiovascular diseases persist as a global health challenge that requires methodological innovation for effective drug development. Conventional pipelines relying on animal models suffer from high failure rates due to significant interspecies variation between humans and animal models. In response, the recently enacted Food and Drug Administration Modernization Act 2.0 encourages alternative approaches including induced pluripotent stem cells (iPSCs). Human iPSCs provide a patient-specific, precise, and screenable platform for drug testing, paving the way for cardiovascular precision medicine. This review discusses milestones in iPSC differentiation and their applications from disease modelling to drug discovery in cardiovascular medicine. It then explores challenges and emerging opportunities for the implementation of 'clinical trials in-a-dish'. Concluding, this review proposes a framework for future clinical trial design with strategic incorporations of iPSC technology, microphysiological systems, clinical pan-omics, and artificial intelligence to improve success rates and advance cardiovascular healthcare.

Genome-wide pan-GPCR cell libraries accelerate drug discovery

G protein-coupled receptors (GPCRs) are pivotal in mediating diverse physiological and pathological processes, rendering them promising targets for drug discovery. GPCRs account for about 40% of FDA-approved drugs, representing the most successful drug targets. However, only approximately 15% of the 800 human GPCRs are targeted by market drugs, leaving numerous opportunities for drug discovery among the remaining receptors. Cell expression systems play crucial roles in the GPCR drug discovery field, including novel target identification, structural and functional characterization, potential ligand screening, signal pathway elucidation, and drug safety evaluation. Here, we discuss the principles, applications, and limitations of widely used cell expression systems in GPCR-targeted drug discovery, GPCR function investigation, signal pathway characterization, and pharmacological property studies. We also propose three strategies for constructing genome-wide pan-GPCR cell libraries, which will provide a powerful platform for GPCR ligand screening, and facilitate the study of GPCR mechanisms and drug safety evaluation, ultimately accelerating the process of GPCR-targeted drug discovery.

The Human OCTN Sub-Family: Gene and Protein Structure, Expression, and Regulation

OCTN1 and OCTN2 are membrane transport proteins encoded by the SLC22A4 and SLC22A5 genes, respectively. Even though several transcripts have been predicted by bioinformatics for both genes, only one functional protein isoform has been described for each of them. Both proteins are ubiquitous, and depending on the physiopathological state of the cell, their expression is regulated by well-known transcription factors, although some aspects have been neglected. A plethora of missense variants with uncertain clinical significance are reported both in the dbSNP and the Catalogue of Somatic Mutations in Cancer (COSMIC) databases for both genes. Due to their involvement in human pathologies, such as inflammatory-based diseases (OCTN1/2), systemic primary carnitine deficiency (OCTN2), and drug disposition, it would be interesting to predict the impact of variants on human health from the perspective of precision medicine. Although the lack of a 3D structure for these two transport proteins hampers any speculation on the consequences of the polymorphisms, the already available 3D structures for other members of the SLC22 family may provide powerful tools to perform structure/function studies on WT and mutant proteins.

Cardiotoxicity and pharmacogenetics of doxorubicin in black Zimbabwean breast cancer patients

AIMS

Doxorubicin-induced cardiotoxicity (DIC) is a significant cause of mortality in cancer care. This study was conducted to establish the frequency of DIC in Zimbabwean breast cancer patients on doxorubicin and to test the DIC predictive power of genetic biomarkers.

METHODS

A cohort of 50 Zimbabwean breast cancer patients treated with doxorubicin were followed up for 12 months with serial echocardiography and genotyped for UGTA1A6*4, SLC28A3 and RARG. Eleven per cent of the patients experienced DIC.

RESULTS

The frequencies of SLC28A3 (rs7853758), UGT1A6*4 (rs17863783) and RARG (rs2229774) were 60.7%, 17.9% and 14.3%, respectively. No association between DIC and the three variants was observed.

CONCLUSIONS

This is the first study on the prevalence of DIC and associated genetic biomarker predictive evaluation in Zimbabwean breast cancer patients. The genetic frequencies observed in our study were different to those reported in other populations. A larger sample size with a longer follow-up time will be necessary in future studies.

Pediatric Cardio-Oncology: Screening, Risk Stratification, and Prevention of Cardiotoxicity Associated with Anthracyclines

Anthracyclines have significantly improved the survival of children with malignant tumors, but the associated cardiotoxicity, an effect now under the purview of pediatric cardio-oncology, due to its cumulative and irreversible effects on the heart, limits their clinical application. A systematic screening and risk stratification approach provides the opportunity for early identification and intervention to mitigate, reverse, or prevent myocardial injury, remodeling, and dysfunction associated with anthracyclines. This review summarizes the risk factors, surveillance indexes, and preventive strategies of anthracycline-related cardiotoxicity to improve the safety and efficacy of anthracyclines.

Predicting oncology drug-induced cardiotoxicity with donor-specific iPSC-CMs-a proof-of-concept study with doxorubicin

Many oncology drugs have been found to induce cardiotoxicity in a subset of patients, which significantly limits their clinical use and impedes the benefit of lifesaving anticancer treatments. Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) carry donor-specific genetic information and have been proposed for exploring the interindividual difference in oncology drug-induced cardiotoxicity. Herein, we evaluated the inter- and intraindividual variability of iPSC-CM-related assays and presented a proof of concept to prospectively predict doxorubicin (DOX)-induced cardiotoxicity (DIC) using donor-specific iPSC-CMs. Our findings demonstrated that donor-specific iPSC-CMs exhibited greater line-to-line variability than the intraindividual variability in impedance cytotoxicity and transcriptome assays. The variable and dose-dependent cytotoxic responses of iPSC-CMs resembled those observed in clinical practice and largely replicated the reported mechanisms. By categorizing iPSC-CMs into resistant and sensitive cell lines based on their time- and concentration-related phenotypic responses to DOX, we found that the sensitivity of donor-specific iPSC-CMs to DOX may predict in vivo DIC risk. Furthermore, we identified a differentially expressed gene, DND microRNA-mediated repression inhibitor 1 (DND1), between the DOX-resistant and DOX-sensitive iPSC-CMs. Our results support the utilization of donor-specific iPSC-CMs in assessing interindividual differences in DIC. Further studies will encompass a large panel of donor-specific iPSC-CMs to identify potential novel molecular and genetic biomarkers for predicting DOX and other oncology drug-induced cardiotoxicity.

An update of the molecular mechanisms underlying anthracycline induced cardiotoxicity

Anthracycline drugs mainly include doxorubicin, epirubicin, pirarubicin, and aclamycin, which are widely used to treat a variety of malignant tumors, such as breast cancer, gastrointestinal tumors, lymphoma, etc. With the accumulation of anthracycline drugs in the body, they can induce serious heart damage, limiting their clinical application. The mechanism by which anthracycline drugs cause cardiotoxicity is not yet clear. This review provides an overview of the different types of cardiac damage induced by anthracycline-class drugs and delves into the molecular mechanisms behind these injuries. Cardiac damage primarily involves alterations in myocardial cell function and pathological cell death, encompassing mitochondrial dysfunction, topoisomerase inhibition, disruptions in iron ion metabolism, myofibril degradation, and oxidative stress. Mechanisms of uptake and transport in anthracycline-induced cardiotoxicity are emphasized, as well as the role and breakthroughs of iPSC in cardiotoxicity studies. Selected novel cardioprotective therapies and mechanisms are updated. Mechanisms and protective strategies associated with anthracycline cardiotoxicity in animal experiments are examined, and the definition of drug damage in humans and animal models is discussed. Understanding these molecular mechanisms is of paramount importance in mitigating anthracycline-induced cardiac toxicity and guiding the development of safer approaches in cancer treatment.

The Role of Pharmacogenomics in Rare Diseases

Rare diseases have become an increasingly important public health priority due to their collective prevalence and often life-threatening nature. Incentive programs, such as the Orphan Drug Act have been introduced to increase the development of rare disease therapeutics. While the approval of these therapeutics requires supportive data from stringent pre-market studies, these data lack the ability to describe the causes of treatment response heterogeneity, leading to medications often being more harmful or less effective than predicted. If a Goal Line were to be used to describe the multifactorial continuum of phenotypic variations occurring in response to a medication, the 'Goal Posts', or the two defining points of this continuum, would be (1) Super-Response, or an extraordinary therapeutic effect; and (2) Serious Harm. Investigation of the pharmacogenomics behind these two extreme phenotypes can potentially lead to the development of new therapeutics, help inform rational use criteria in drug policy, and improve the understanding of underlying disease pathophysiology. In the context of rare diseases where cohort sizes are smaller than ideal, 'small data' and 'big data' approaches to data collection and analysis should be combined to produce the most robust results. This paper presents the importance of studying drug response in parallel to other research initiatives in rare diseases, as well as the need for international collaboration in the area of rare disease pharmacogenomics.

Independent compartmentalization of functional, metabolic, and transcriptional maturation of hiPSC-derived cardiomyocytes

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) recapitulate numerous disease and drug response phenotypes, but cell immaturity may limit their accuracy and fidelity as a model system. Cell culture medium modification is a common method for enhancing maturation, yet prior studies have used complex media with little understanding of individual component contribution, which may compromise long-term hiPSC-CM viability. Here, we developed high-throughput methods to measure hiPSC-CM maturation, determined factors that enhanced viability, and then systematically assessed the contribution of individual maturation medium components. We developed a medium that is compatible with extended culture. We discovered that hiPSC-CM maturation can be sub-specified into electrophysiological/EC coupling, metabolism, and gene expression and that induction of these attributes is largely independent. In this work, we establish a defined baseline for future studies of cardiomyocyte maturation. Furthermore, we provide a selection of medium formulae, optimized for distinct applications and priorities, that promote measurable attributes of maturation.

Precision Cardio-oncology: Update on Omics-Based Diagnostic Methods

OPINION STATEMENT

Cardio-oncology is an emerging interdisciplinary field dedicated to the early detection and treatment of adverse cardiovascular events associated with anticancer treatment, and current clinical management of anticancer-treatment-related cardiovascular toxicity (CTR-CVT) remains limited by a lack of detailed phenotypic data. However, the promise of diagnosing CTR-CVT using deep phenotyping has emerged with the development of precision medicine, particularly the use of omics-based methodologies to discover sensitive biomarkers of the disease. In the future, combining information produced by a variety of omics methodologies could expand the clinical practice of cardio-oncology. In this review, we demonstrate how omics approaches can improve our comprehension of CTR-CVT deep phenotyping, discuss the positive and negative aspects of available omics approaches for CTR-CVT diagnosis, and outline how to integrate multiple sets of omics data into individualized monitoring and treatment. This will offer a reliable technical route for lowering cardiovascular morbidity and mortality in cancer patients and survivors.

Novel molecular mechanisms of doxorubicin cardiotoxicity: latest leading-edge advances and clinical implications

Doxorubicin (Dox) is among the most widely used cancer chemotherapeutic drugs. The clinical use of Dox is, however, limited due to its cardiotoxicity. Studies over the past several decades have suggested various mechanisms of Dox-induced cardiotoxicity (DIC). Among them are oxidative stress, topoisomerase inhibition, and mitochondrial damage. Several novel molecular targets and signaling pathways underlying DIC have emerged over the past few years. The most notable advances include discovery of ferroptosis as a major form of cell death in Dox cytotoxicity, and elucidation of the involvement of cardiogenetics and regulatory RNAs as well as multiple other targets in DIC. In this review, we discuss these advances, focusing on latest cutting-edge research discoveries from mechanistic studies reported in influential journals rather than surveying all research studies available in the literature.

Association Between Cancer and Cardiovascular Toxicity: A Nationwide Cross-Sectional Study on NHANES 1999-2018

There is a dearth of evidence pertaining to the relationship of cardiovascular disease (CVD) and its subtype with adjudicated cancer, thereby limiting our understanding of the heightened risk of CVD resulting from long-term complications of cancer and its therapies. The aim of this study was to quantify the risks of CVD and its subtypes in adult cancer survivors compared with cancer-free controls in a nationwide cross-sectional study on Continuous National Health and Nutrition Examination Survey (NHANES). We included 44,442 participants ranging in age from 20 to 85 years. Cancer and CVD diagnoses were ascertained via the household questionnaires. The association of cancer status with the risk of CVD and CVD subtype was examined using weighted logistic regression. Stratification analyses were also performed by age, sex, race, marital status, income status, educational level, and hyperlipidemia. The Wald test was used to calculate P-value for interaction. A total of 4178 participants have cancer, while 4829 participants had CVD, respectively. In the multivariable-adjusted model, the cancer was consistently linked to an elevated risk of CVD. Stratification analyses showed that stronger association between cancer status and CVD risk was found in younger adults, non-white, and participants living without a spouse or partner, and without hyperlipidemia. Our study confirmed that cancer participants were strongly linked to living with CVD, independent of traditional cardiovascular risk factors, especially in younger adults, non-white, and participants living without a spouse or partner, and without hyperlipidemia. There exists a pressing requirement to establish effective strategies for the prevention of CVD within this population characterized by a heightened risk.

Membrane transporters in drug development and as determinants of precision medicine

The effect of membrane transporters on drug disposition, efficacy and safety is now well recognized. Since the initial publication from the International Transporter Consortium, significant progress has been made in understanding the roles and functions of transporters, as well as in the development of tools and models to assess and predict transporter-mediated activity, toxicity and drug-drug interactions (DDIs). Notable advances include an increased understanding of the effects of intrinsic and extrinsic factors on transporter activity, the application of physiologically based pharmacokinetic modelling in predicting transporter-mediated drug disposition, the identification of endogenous biomarkers to assess transporter-mediated DDIs and the determination of the cryogenic electron microscopy structures of SLC and ABC transporters. This article provides an overview of these key developments, highlighting unanswered questions, regulatory considerations and future directions.

Nilotinib-induced alterations in endothelial cell function recapitulate clinical vascular phenotypes independent of ABL1

Nilotinib is a highly effective treatment for chronic myeloid leukemia but has been consistently associated with the development of nilotinib-induced arterial disease (NAD) in a subset of patients. To date, which cell types mediate this effect and whether NAD results from on-target mechanisms is unknown. We utilized human induced pluripotent stem cells (hiPSCs) to generate endothelial cells and vascular smooth muscle cells for in vitro study of NAD. We found that nilotinib adversely affects endothelial proliferation and migration, in addition to increasing intracellular nitric oxide. Nilotinib did not alter endothelial barrier function or lipid uptake. No effect of nilotinib was observed in vascular smooth muscle cells, suggesting that NAD is primarily mediated through endothelial cells. To evaluate whether NAD results from enhanced inhibition of ABL1, we generated multiple ABL1 knockout lines. The effects of nilotinib remained unchanged in the absence of ABL1, suggesting that NAD results from off- rather than on-target signaling. The model established in the present study can be applied to future mechanistic and patient-specific pharmacogenomic studies.

Application Prospect of Induced Pluripotent Stem Cells in Organoids and Cell Therapy

Since its inception, induced pluripotent stem cell (iPSC) technology has been hailed as a powerful tool for comprehending disease etiology and advancing drug screening across various domains. While earlier iPSC-based disease modeling and drug assessment primarily operated at the cellular level, recent years have witnessed a significant shift towards organoid-based investigations. Organoids derived from iPSCs offer distinct advantages, particularly in enabling the observation of disease progression and drug metabolism in an in vivo-like environment, surpassing the capabilities of iPSC-derived cells. Furthermore, iPSC-based cell therapy has emerged as a focal point of clinical interest. In this review, we provide an extensive overview of non-integrative reprogramming methods that have evolved since the inception of iPSC technology. We also deliver a comprehensive examination of iPSC-derived organoids, spanning the realms of the nervous system, cardiovascular system, and oncology, as well as systematically elucidate recent advancements in iPSC-related cell therapies.

Cardiovascular Biomarkers in Cardio-Oncology: Antineoplastic Drug Cardiotoxicity and Beyond

Serum biomarkers represent a reproducible, sensitive, minimally invasive and inexpensive method to explore possible adverse cardiovascular effects of antineoplastic treatments. They are useful tools in risk stratification, the early detection of cardiotoxicity and the follow-up and prognostic assessment of cancer patients. In this literature review, we aim at describing the current state of knowledge on the meaning and the usefulness of cardiovascular biomarkers in patients with cancer; analyzing the intricate relationship between cancer and cardiovascular disease (especially HF) and how this affects cardiovascular and tumor biomarkers; exploring the role of cardiovascular biomarkers in the risk stratification and in the identification of chemotherapy-induced cardiotoxicity; and providing a summary of the novel potential biomarkers in this clinical setting.

Analysis and Validation of Critical Signatures and Immune Cell Infiltration Characteristics in Doxorubicin-Induced Cardiotoxicity by Integrating Bioinformatics and Machine Learning

Purpose

Doxorubicin-induced cardiotoxicity (DIC) is a severe side reaction in cancer chemotherapy that greatly impacts the well-being of cancer patients. Currently, there is still an insufficiency of effective and reliable biomarkers in the field of clinical practice for the early detection of DIC. This study aimed to determine and validate the potential diagnostic and predictive values of critical signatures in DIC.

Methods

We obtained high-throughput sequencing data from the GEO database and performed data analysis and visualization using R software, GO, KEGG and Cytoscape. Machine learning methods and weighted gene coexpression network (WGCNA) were used to identify key genes for diagnostic model construction. Receiver operating characteristic (ROC) analysis and a nomogram were used to assess their diagnostic values. A multiregulatory network was built to reveal the possible regulatory relationships of critical signatures. Cell-type identification by estimating relative subsets of RNA transcript (CIBERSORT) analysis was used to investigate differential immune cell infiltration. Additionally, a cell and animal model were constructed to investigate the relationship between the identified genes and DIC.

Results

Among the 3713 differentially expressed genes, three key genes (CSGALNACT1, ZNF296 and FANCB) were identified. A nomogram and ROC curves based on three key genes showed excellent diagnostic predictive performance. The regulatory network analysis showed that the TFs CREB1, EP300, FLI1, FOXA1, MAX, and MAZ modulated three key genes. An analysis of immune cell infiltration indicated that many immune cells (activated NK cells, M0 macrophages, activated dendritic cells and neutrophils) might be related to the progression of DIC. Furthermore, there may be various degrees of correlation between the three critical signatures and immune cells. RT‒qPCR demonstrated that the mRNA expression of CSGALNACT1 and ZNF296 was significantly upregulated, while FANCB was significantly downregulated in DOX-treated cardiomyocytes in vitro and in vivo.

Conclusion

Our study suggested that the differential expression of CSGALNACT1, ZNF296 and FANCB is associated with cardiotoxicity and is also involved in immune cell infiltration in DIC. They might be potential biomarkers for the early occurrence of DIC.

Functional Validation of Doxorubicin-Induced Cardiotoxicity-Related Genes

Background

Genome-wide association studies and candidate gene association studies have identified more than 180 genetic variants statistically associated with anthracycline-induced cardiotoxicity (AIC). However, the lack of functional validation has hindered the clinical translation of these findings.

Objectives

The aim of this study was to functionally validate all genes associated with AIC using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Methods

Through a systemic literature search, 80 genes containing variants significantly associated with AIC were identified. Additionally, 3 more genes with potential roles in AIC (GSTM1, CBR1, and ERBB2) were included. Of these, 38 genes exhibited expression in human fetal heart, adult heart, and hiPSC-CMs. Using clustered regularly interspaced short palindromic repeats/Cas9-based genome editing, each of these 38 genes was systematically knocked out in control hiPSC-CMs, and the resulting doxorubicin-induced cardiotoxicity (DIC) phenotype was assessed using hiPSC-CMs. Subsequently, functional assays were conducted for each gene knockout on the basis of hypothesized mechanistic implications in DIC.

Results

Knockout of 26 genes increased the susceptibility of hiPSC-CMs to DIC. Notable genes included efflux transporters (ABCC10, ABCC2, ABCB4, ABCC5, and ABCC9), well-established DIC-associated genes (CBR1, CBR3, and RAC2), and genome-wide association study-discovered genes (RARG and CELF4). Conversely, knockout of ATP2B1, HNMT, POR, CYBA, WDR4, and COL1A2 had no significant effect on the in vitro DIC phenotype of hiPSC-CMs. Furthermore, knockout of the uptake transporters (SLC28A3, SLC22A17, and SLC28A1) demonstrated a protective effect against DIC.

Conclusions

The present findings establish a comprehensive platform for the functional validation of DIC-associated genes, providing insights for future studies in DIC variant associations and potential mechanistic targets for the development of cardioprotective drugs.

Anthracyclines induce cardiotoxicity through a shared gene expression response signature

TOP2 inhibitors (TOP2i) are effective drugs for breast cancer treatment. However, they can cause cardiotoxicity in some women. The most widely used TOP2i include anthracyclines (AC) Doxorubicin (DOX), Daunorubicin (DNR), Epirubicin (EPI), and the anthraquinone Mitoxantrone (MTX). It is unclear whether women would experience the same adverse effects from all drugs in this class, or if specific drugs would be preferable for certain individuals based on their cardiotoxicity risk profile. To investigate this, we studied the effects of treatment of DOX, DNR, EPI, MTX, and an unrelated monoclonal antibody Trastuzumab (TRZ) on iPSC-derived cardiomyocytes (iPSC-CMs) from six healthy females. All TOP2i induce cell death at concentrations observed in cancer patient serum, while TRZ does not. A sub-lethal dose of all TOP2i induces limited cellular stress but affects calcium handling, a function critical for cardiomyocyte contraction. TOP2i induce thousands of gene expression changes over time, giving rise to four distinct gene expression response signatures, denoted as TOP2i early-acute, early-sustained, and late response genes, and non-response genes. There is no drug- or AC-specific signature. TOP2i early response genes are enriched in chromatin regulators, which mediate AC sensitivity across breast cancer patients. However, there is increased transcriptional variability between individuals following AC treatments. To investigate potential genetic effects on response variability, we first identified a reported set of expression quantitative trait loci (eQTLs) uncovered following DOX treatment in iPSC-CMs. Indeed, DOX response eQTLs are enriched in genes that respond to all TOP2i. Next, we identified 38 genes in loci associated with AC toxicity by GWAS or TWAS. Two thirds of the genes that respond to at least one TOP2i, respond to all ACs with the same direction of effect. Our data demonstrate that TOP2i induce thousands of shared gene expression changes in cardiomyocytes, including genes near SNPs associated with inter-individual variation in response to DOX treatment and AC-induced cardiotoxicity.

Association between genetic variants of transmembrane transporters and susceptibility to anthracycline-induced cardiotoxicity: Current understanding and existing evidence

Anthracyclines remain the cornerstone of numerous chemotherapeutic protocols, with beneficial effects against haematological malignancies and solid tumours. Unfortunately, the clinical usefulness of anthracyclines is compromised by the development of cardiotoxic side effects, leading to dose limitations or treatment discontinuation. There is no absolute linear correlation between the incidence of cardiotoxicity and the threshold dose, suggesting that genetic factors may modify the association between anthracyclines and cardiotoxicity risk. And the majority of single nucleotide polymorphisms (SNPs) associated with anthracycline pharmacogenomics were identified in the ATP-binding cassette (ABC) and solute carrier (SLC) transporters, generating increasing interest in the pharmacogenetic implications of their genetic variations for anthracycline-induced cardiotoxicity (AIC). This review focuses on the influence of SLC and ABC polymorphisms on AIC and highlights the prospects and clinical significance of pharmacogenetics for individualised preventive approaches.

Anthracycline Toxicity: Light at the End of the Tunnel?

Anthracycline-induced cardiotoxicity (AIC) is a serious and common side effect of anthracycline therapy. Identification of genes and genetic variants associated with AIC risk has clinical potential as a cardiotoxicity predictive tool and to allow the development of personalized therapies. In this review, we provide an overview of the function of known AIC genes identified by association studies and categorize them based on their mechanistic implication in AIC. We also discuss the importance of functional validation of AIC-associated variants in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to advance the implementation of genetic predictive biomarkers. Finally, we review how patient-specific hiPSC-CMs can be used to identify novel patient-relevant functional targets and for the discovery of cardioprotectant drugs to prevent AIC. Implementation of functional validation and use of hiPSC-CMs for drug discovery will identify the next generation of highly effective and personalized cardioprotectants and accelerate the inclusion of approved AIC biomarkers into clinical practice.

iPSCs as a groundbreaking tool for the study of adverse drug reactions: A new avenue for personalized therapy

Induced pluripotent stem cells (iPSCs), obtained by reprogramming different somatic cell types, represent a promising tool for the study of drug toxicities, especially in the context of personalized medicine. Indeed, these cells retain the same genetic heritage of the donor, allowing the development of personalized models. In addition, they represent a useful tool for the study of adverse drug reactions (ADRs) in special populations, such as pediatric patients, which are often poorly represented in clinical trials due to ethical issues. Particularly, iPSCs can be differentiated into any tissue of the human body, following several protocols which use different stimuli to induce specific differentiation processes. Differentiated cells also maintain the genetic heritage of the donor, and therefore are suitable for personalized pharmacological studies; moreover, iPSC-derived differentiated cells are a valuable tool for the investigation of the mechanisms underlying the physiological differentiation processes. iPSCs-derived organoids represent another important tool for the study of ADRs. Precisely, organoids are in vitro 3D models which better represent the native organ, both from a structural and a functional point of view. Moreover, in the same way as iPSC-derived 2D models, iPSC-derived organoids are appropriate personalized models since they retain the genetic heritage of the donor. In comparison to other in vitro models, iPSC-derived organoids present advantages in terms of versatility, patient-specificity, and ethical issues. This review aims to provide an updated report of the employment of iPSCs, and 2D and 3D models derived from these, for the study of ADRs. This article is categorized under: Cancer > Stem Cells and Development.

Priorities in Cardio-Oncology Basic and Translational Science: GCOS 2023 Symposium Proceedings: JACC: CardioOncology State-of-the-Art Review

Despite improvements in cancer survival, cancer therapy-related cardiovascular toxicity has risen to become a prominent clinical challenge. This has led to the growth of the burgeoning field of cardio-oncology, which aims to advance the cardiovascular health of cancer patients and survivors, through actionable and translatable science. In these Global Cardio-Oncology Symposium 2023 scientific symposium proceedings, we present a focused review on the mechanisms that contribute to common cardiovascular toxicities discussed at this meeting, the ongoing international collaborative efforts to improve patient outcomes, and the bidirectional challenges of translating basic research to clinical care. We acknowledge that there are many additional therapies that are of significance but were not topics of discussion at this symposium. We hope that through this symposium-based review we can highlight the knowledge gaps and clinical priorities to inform the design of future studies that aim to prevent and mitigate cardiovascular disease in cancer patients and survivors.

Recent advances in pluripotent stem cell-derived cardiac organoids and heart-on-chip applications for studying anti-cancer drug-induced cardiotoxicity

Cardiovascular disease (CVD) caused by anti-cancer drug-induced cardiotoxicity is now the second leading cause of mortality among cancer survivors. It is necessary to establish efficient in vitro models for early predicting the potential cardiotoxicity of anti-cancer drugs, as well as for screening drugs that would alleviate cardiotoxicity during and post treatment. Human induced pluripotent stem cells (hiPSCs) have opened up new avenues in cardio-oncology. With the breakthrough of tissue engineering technology, a variety of hiPSC-derived cardiac microtissues or organoids have been recently reported, which have shown enormous potential in studying cardiotoxicity. Moreover, using hiPSC-derived heart-on-chip for studying cardiotoxicity has provided novel insights into the underlying mechanisms. Herein, we summarize different types of anti-cancer drug-induced cardiotoxicities and present an extensive overview on the applications of hiPSC-derived cardiac microtissues, cardiac organoids, and heart-on-chips in cardiotoxicity. Finally, we highlight clinical and translational challenges around hiPSC-derived cardiac microtissues/organoids/heart-on chips and their applications in anti-cancer drug-induced cardiotoxicity. • Anti-cancer drug-induced cardiotoxicities represent pressing challenges for cancer treatments, and cardiovascular disease is the second leading cause of mortality among cancer survivors. • Newly reported in vitro models such as hiPSC-derived cardiac microtissues/organoids/chips show enormous potential for studying cardio-oncology. • Emerging evidence supports that hiPSC-derived cardiac organoids and heart-on-chip are promising in vitro platforms for predicting and minimizing anti-cancer drug-induced cardiotoxicity.

Circulating Biomarkers for Monitoring Chemotherapy-Induced Cardiotoxicity in Children

Most commonly diagnosed cancer pathologies in the pediatric population comprise leukemias and cancers of the nervous system. The percentage of cancer survivors increased from approximatively 50% to 80% thanks to improvements in medical treatments and the introduction of new chemotherapies. However, as a consequence, heart disease has become the main cause of death in the children due to the cardiotoxicity induced by chemotherapy treatments. The use of different cardiovascular biomarkers, complementing data obtained from electrocardiogram, echocardiography cardiac imaging, and evaluation of clinical symptoms, is considered a routine in clinical diagnosis, prognosis, risk stratification, and differential diagnosis. Cardiac troponin and natriuretic peptides are the best-validated biomarkers broadly accepted in clinical practice for the diagnosis of acute coronary syndrome and heart failure, although many other biomarkers are used and several potential markers are currently under study and possibly will play a more prominent role in the future. Several studies have shown how the measurement of cardiac troponin (cTn) can be used for the early detection of heart damage in oncological patients treated with potentially cardiotoxic chemotherapeutic drugs. The advent of high sensitive methods (hs-cTnI or hs-cTnT) further improved the effectiveness of risk stratification and monitoring during treatment cycles.

Shenmai injection ameliorates doxorubicin-induced myocardial injury by suppressing autophagy-apoptosis via miR-30a

CONTEXT

Autophagy-apoptosis is the core mechanism of doxorubicin-induced myocardial injury. miR-30a is a pivotal factor in the regulation of autophagy and apoptosis. It remains unclear whether SMI exerts cardioprotective effect by regulating autophagy and apoptosis via miR-30a.

OBJECTIVE

This study evaluates the effects of SMI on ameliorating doxorubicin-induced myocardial injury.

MATERIALS AND METHODS

The level of LDH and CK, and the expression of miR-30a was detected. mCherry-EGFP-LC3B double fluorescence was used to observe autophagy flow. Apoptosis was detected by Annexin V/PI staining. Western Blot was used to estimate the expression of autophagy related proteins and apoptosis-related proteins.

RESULTS

Compared with the control group, there were evidently decreased cell viability, elevated level of LDH and CK, down-regulated expression of miR-30a in the model group. Data from Western blot and fluorescence indicated that doxorubicin contributed to the elevated autophagy and apoptosis. Compared with the model group, there were increased cell viability, decreased level of LDH and CK, and up-regulated expression of miR-30a in the Shenmai group and the Shenmai + miR-30a inhibitor group. Meanwhile, the results manifested that there were suppressed autophagy flow accompanied by the down-regulated expression of Beclin-1, LC3-II, LC3-II/LC3-I and up-regulated expression of p62 protein, and declined apoptosis rate accompanied by the up-regulated Bcl2 expression and the down-regulated expression of Bax, Cleaved Caspase-9, Cleaved Caspase-9/Caspase-9, Cleaved Caspase-3, Cleaved Caspase-3/Caspase-3 in the Shenmai group and the Shenmai + miR-30a inhibitor group.

DISCUSSION AND CONCLUSION

Shenmai injection inhibited autophagy and apoptosis via miR-30a, thereby alleviating doxorubicin-induced myocardial injury.

Protein-encapsulated doxorubicin reduces cardiotoxicity in hiPSC-cardiomyocytes and cardiac spheroids while maintaining anticancer efficacy

The chemotherapeutic doxorubicin (DOX) detrimentally impacts the heart during cancer treatment. This necessitates development of non-cardiotoxic delivery systems that retain DOX anticancer efficacy. We used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), endothelial cells (hiPSC-ECs), cardiac fibroblasts (hiPSC-CFs), multi-lineage cardiac spheroids (hiPSC-CSs), patient-specific hiPSCs, and multiple human cancer cell lines to compare the anticancer efficacy and reduced cardiotoxicity of single protein encapsulated DOX (SPEDOX-6), to standard unformulated (UF) DOX. Cell viability assays and immunostaining in human cancer cells, hiPSC-ECs, and hiPSC-CFs revealed robust uptake of SPEDOX-6 and efficacy in killing these proliferative cell types. In contrast, hiPSC-CMs and hiPSC-CSs exhibited substantially lower cytotoxicity during SPEDOX-6 treatment compared with UF DOX. SPEDOX-6-treated hiPSC-CMs and hiPSC-CSs maintained their functionality, as indicated by sarcomere contractility assessment, calcium imaging, multielectrode arrays, and RNA sequencing. This study demonstrates the potential of SPEDOX-6 to alleviate cardiotoxic side effects associated with UF DOX, while maintaining its anticancer potency.

Altered Peripheral Blood Gene Expression in Childhood Cancer Survivors With Anthracycline-Induced Cardiomyopathy - A COG-ALTE03N1 Report

Background Anthracycline-induced cardiomyopathy is a leading cause of premature death in childhood cancer survivors, presenting a need to understand the underlying pathogenesis. We sought to examine differential blood-based mRNA expression profiles in anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Methods and Results We designed a matched case-control study (Children's Oncology Group-ALTE03N1) with mRNA sequencing on total RNA from peripheral blood in 40 anthracycline-exposed survivors with cardiomyopathy (cases) and 64 matched survivors without (controls). DESeq2 identified differentially expressed genes. Ingenuity Pathway Analyses (IPA) and Gene Set Enrichment Analyses determined the potential roles of altered genes in biological pathways. Functional validation was performed by gene knockout in human-induced pluripotent stem cell-derived cardiomyocytes using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) technology. Median age at primary cancer diagnosis for cases and controls was 8.2 and 9.7 years, respectively. Thirty-six differentially expressed genes with fold change ≥±2 were identified; 35 were upregulated. IPA identified "hepatic fibrosis" and "iron homeostasis" pathways to be significantly modulated by differentially expressed genes, including toxicology functions of myocardial infarction, cardiac damage, and cardiac dilation. Leading edge analysis from Gene Set Enrichment Analyses identified lactate dehydrogenase A (LDHA) and cluster of differentiation 36 (CD36) genes to be significantly upregulated in cases. Interleukin 1 receptor type 1, 2 (IL1R1, IL1R2), and matrix metalloproteinase 8, 9 (MMP8, MMP9) appeared in multiple canonical pathways. LDHA-knockout human-induced pluripotent stem cell-derived cardiomyocytes showed increased sensitivity to doxorubicin. Conclusions We identified differential mRNA expression profiles in peripheral blood of anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Upregulation of LDHA and CD36 genes suggests metabolic perturbations in a failing heart. Dysregulation of proinflammatory cytokine receptors IL1R1 and IL1R2 and matrix metalloproteinases, MMP8 and MMP9 indicates structural remodeling that accompanies the clinical manifestation of symptomatic cardiotoxicity.

Hyperoside prevents doxorubicin-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway

Clinical application of doxorubicin (Dox) in cancer chemotherapy is limited by its cardiotoxicity. Present study aimed to demonstrate the effect and mechanism of hyperoside in Dox-induced cardiotoxicity. C57BL/6 mice were injected with 12 mg/kg of Dox, and 1 μM Dox was exposed to primary cardiomyocytes. Cardiac function was evaluated by echocardiographic and myocardial enzyme levels. Cardiomyocyts apoptosis was analyzed by TUNEL staining and flow cytometry. Network pharmacology and molecular docking were utilized to explore potential targets of hyperoside. Protein expressions were detected by western blot and enzyme activities were determined by colorimetry. Cardiac dysfunction and cardiomyocyte apoptosis induced by Dox were attenuated by hyperoside. Mechanism of hyperoside was mainly related to "oxidative stress" pathway. Hyperoside exhibited strong binding activities with nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs, the main source of ROS in cardiomyocytes) and cyclooxygenases (COXs). Experiments proved that hyperoside suppressed the ROS generation and the elevated activities of NOXs and COXs induced by Dox. Dox also triggered the activation of NLRP3 inflammasome, which was reversed by hyperoside. Hyperoside bound to NOXs and COXs, which prevents Dox-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway. Hyperoside holds promise as a therapeutic strategy for Dox-induced cardiotoxicity.

Modulation of lncRNA links endothelial glycocalyx to vascular dysfunction of tyrosine kinase inhibitor

AIMS

Novel cancer therapies leading to increased survivorship of cancer patients have been negated by a concomitant rise in cancer therapies-related cardiovascular toxicities. Sunitinib, a first line multi-receptor tyrosine kinase inhibitor, has been reported to cause vascular dysfunction although the initiating mechanisms contributing to this side effect remain unknown. Long non-coding RNAs (lncRNAs) are emerging regulators of biological processes in endothelial cells (ECs); however, their roles in cancer therapies-related vascular toxicities remain underexplored.

METHODS AND RESULTS

We performed lncRNA expression profiling to identify potential lncRNAs that are dysregulated in human-induced pluripotent stem cell-derived ECs (iPSC-ECs) treated with sunitinib. We show that the lncRNA hyaluronan synthase 2 antisense 1 (HAS2-AS1) is significantly diminished in sunitinib-treated iPSC-ECs. Sunitinib was found to down-regulate HAS2-AS1 by an epigenetic mechanism involving hypermethylation. Depletion of HAS2-AS1 recapitulated sunitinib-induced detrimental effects on iPSC-ECs, whereas CRISPR-mediated activation of HAS2-AS1 reversed sunitinib-induced dysfunction. We confirmed that HAS2-AS1 stabilizes the expression of its sense gene HAS2 via an RNA/mRNA heteroduplex formation. Knockdown of HAS2-AS1 led to reduced synthesis of hyaluronic acid (HA) and up-regulation of ADAMTS5, an enzyme involved in extracellular matrix degradation, resulting in disruption of the endothelial glycocalyx which is critical for ECs. In vivo, sunitinib-treated mice showed reduced coronary flow reserve, accompanied by a reduction in Has2os and degradation of the endothelial glycocalyx. Finally, we identified that treatment with high molecular-weight HA can prevent the deleterious effects of sunitinib both in vitro and in vivo by preserving the endothelial glycocalyx.

CONCLUSIONS

Our findings highlight the importance of lncRNA-mediated regulation of the endothelial glycocalyx as an important determinant of sunitinib-induced vascular toxicity and reveal potential novel therapeutic avenues to attenuate sunitinib-induced vascular dysfunction.

Identification of novel hypermethylated or hypomethylated CpG sites and genes associated with anthracycline-induced cardiomyopathy

Anthracycline-induced cardiomyopathy is a leading cause of late morbidity in childhood cancer survivors. Aberrant DNA methylation plays a role in de novo cardiovascular disease. Epigenetic processes could play a role in anthracycline-induced cardiomyopathy but remain unstudied. We sought to examine if genome-wide differential methylation at 'CpG' sites in peripheral blood DNA is associated with anthracycline-induced cardiomyopathy. This report used participants from a matched case-control study; 52 non-Hispanic White, anthracycline-exposed childhood cancer survivors with cardiomyopathy were matched 1:1 with 52 survivors with no cardiomyopathy. Paired ChAMP (Chip Analysis Methylation Pipeline) with integrated reference-based deconvolution of adult peripheral blood DNA methylation was used to analyze data from Illumina HumanMethylation EPIC BeadChip arrays. An epigenome-wide association study (EWAS) was performed, and the model was adjusted for GrimAge, sex, interaction terms of age at enrollment, chest radiation, age at diagnosis squared, and cardiovascular risk factors (CVRFs: diabetes, hypertension, dyslipidemia). Prioritized genes were functionally validated by gene knockout in human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) using CRISPR/Cas9 technology. DNA-methylation EPIC array analyses identified 32 differentially methylated probes (DMP: 15 hyper-methylated and 17 hypo-methylated probes) that overlap with 23 genes and 9 intergenic regions. Three hundred and fifty-four differential methylated regions (DMRs) were also identified. Several of these genes are associated with cardiac dysfunction. Knockout of genes EXO6CB, FCHSD2, NIPAL2, and SYNPO2 in hiPSC-CMs increased sensitivity to doxorubicin. In addition, EWAS analysis identified hypo-methylation of probe 'cg15939386' in gene RORA to be significantly associated with anthracycline-induced cardiomyopathy. In this genome-wide DNA methylation profile study, we observed significant differences in DNA methylation at the CpG level between anthracycline-exposed childhood cancer survivors with and without cardiomyopathy, implicating differential DNA methylation of certain genes could play a role in pathogenesis of anthracycline-induced cardiomyopathy.

Modeling Cardiotoxicity in Pediatric Oncology Patients Using Patient-Specific iPSC-Derived Cardiomyocytes Reveals Downregulation of Cardioprotective microRNAs

Anthracyclines are widely used in the treatment of many solid cancers, but their efficacy is limited by cardiotoxicity. As the number of pediatric cancer survivors continues to rise, there has been a concomitant increase in people living with anthracycline-induced cardiotoxicity. Accordingly, there is an ongoing need for new models to better understand the pathophysiological mechanisms of anthracycline-induced cardiac damage. Here we generated induced pluripotent stem cells (iPSCs) from two pediatric oncology patients with acute cardiotoxicity induced by anthracyclines and differentiated them to ventricular cardiomyocytes (hiPSC-CMs). Comparative analysis of these cells (CTX hiPSC-CMs) and control hiPSC-CMs revealed that the former were significantly more sensitive to cell injury and death from the anthracycline doxorubicin (DOX), as measured by viability analysis, cleaved caspase 3 expression, oxidative stress, genomic and mitochondrial damage and sarcomeric disorganization. The expression of several mRNAs involved in structural integrity and inflammatory response were also differentially affected by DOX. Functionally, optical mapping analysis revealed higher arrythmia complexity after DOX treatment in CTX iPSC-CMs. Finally, using a panel of previously identified microRNAs associated with cardioprotection, we identified lower levels of miR-22-3p, miR-30b-5p, miR-90b-3p and miR-4732-3p in CTX iPSC-CMs under basal conditions. Our study provides valuable phenotype information for cellular models of cardiotoxicity and highlights the significance of using patient-derived cardiomyocytes for studying the associated pathogenic mechanisms.

Human Stem Cells for Cardiac Disease Modeling and Preclinical and Clinical Applications—Are We on the Road to Success?

Cardiovascular diseases (CVDs) are pointed out by the World Health Organization (WHO) as the leading cause of death, contributing to a significant and growing global health and economic burden. Despite advancements in clinical approaches, there is a critical need for innovative cardiovascular treatments to improve patient outcomes. Therapies based on adult stem cells (ASCs) and embryonic stem cells (ESCs) have emerged as promising strategies to regenerate damaged cardiac tissue and restore cardiac function. Moreover, the generation of human induced pluripotent stem cells (iPSCs) from somatic cells has opened new avenues for disease modeling, drug discovery, and regenerative medicine applications, with fewer ethical concerns than those associated with ESCs. Herein, we provide a state-of-the-art review on the application of human pluripotent stem cells in CVD research and clinics. We describe the types and sources of stem cells that have been tested in preclinical and clinical trials for the treatment of CVDs as well as the applications of pluripotent stem-cell-derived in vitro systems to mimic disease phenotypes. How human stem-cell-based in vitro systems can overcome the limitations of current toxicological studies is also discussed. Finally, the current state of clinical trials involving stem-cell-based approaches to treat CVDs are presented, and the strengths and weaknesses are critically discussed to assess whether researchers and clinicians are getting closer to success.

Human Stem Cells for Cardiac Disease Modeling and Preclinical and Clinical Applications-Are We on the Road to Success?

Cardiovascular diseases (CVDs) are pointed out by the World Health Organization (WHO) as the leading cause of death, contributing to a significant and growing global health and economic burden. Despite advancements in clinical approaches, there is a critical need for innovative cardiovascular treatments to improve patient outcomes. Therapies based on adult stem cells (ASCs) and embryonic stem cells (ESCs) have emerged as promising strategies to regenerate damaged cardiac tissue and restore cardiac function. Moreover, the generation of human induced pluripotent stem cells (iPSCs) from somatic cells has opened new avenues for disease modeling, drug discovery, and regenerative medicine applications, with fewer ethical concerns than those associated with ESCs. Herein, we provide a state-of-the-art review on the application of human pluripotent stem cells in CVD research and clinics. We describe the types and sources of stem cells that have been tested in preclinical and clinical trials for the treatment of CVDs as well as the applications of pluripotent stem-cell-derived in vitro systems to mimic disease phenotypes. How human stem-cell-based in vitro systems can overcome the limitations of current toxicological studies is also discussed. Finally, the current state of clinical trials involving stem-cell-based approaches to treat CVDs are presented, and the strengths and weaknesses are critically discussed to assess whether researchers and clinicians are getting closer to success.

RBL2 Regulates Cardiac Sensitivity to Anthracycline Chemotherapy

Background

Anthracycline chemotherapies cause heart failure in a subset of cancer patients. We previously reported that the anthracycline doxorubicin (DOX) induces cardiotoxicity through the activation of cyclin-dependent kinase 2 (CDK2).

Objectives

The aim of this study was to determine whether retinoblastoma-like 2 (RBL2/p130), an emerging CDK2 inhibitor, regulates anthracycline sensitivity in the heart.

Methods

Rbl2-/- mice and Rbl2+/+ littermates received DOX (5 mg/kg/wk for 4 weeks intraperitoneally, 20 mg/kg cumulative). Heart function was monitored with echocardiography. The association of RBL2 genetic variants with anthracycline cardiomyopathy was evaluated in the SJLIFE (St. Jude Lifetime Cohort Study) and CPNDS (Canadian Pharmacogenomics Network for Drug Safety) studies.

Results

The loss of endogenous Rbl2 increased basal CDK2 activity in the mouse heart. Mice lacking Rbl2 were more sensitive to DOX-induced cardiotoxicity, as evidenced by rapid deterioration of heart function and loss of heart mass. The disruption of Rbl2 exacerbated DOX-induced mitochondrial damage and cardiomyocyte apoptosis. Mechanistically, Rbl2 deficiency enhanced CDK2-dependent activation of forkhead box O1 (FOXO1), leading to up-regulation of the proapoptotic protein Bim. The inhibition of CDK2 desensitized Rbl2-depleted cardiomyocytes to DOX. In wild-type cardiomyocytes, DOX exposure induced Rbl2 expression in a FOXO1-dependent manner. Importantly, the rs17800727 G allele of the human RBL2 gene was associated with reduced anthracycline cardiotoxicity in childhood cancer survivors.

Conclusions

Rbl2 is an endogenous CDK2 inhibitor in the heart and represses FOXO1-mediated proapoptotic gene expression. The loss of Rbl2 increases sensitivity to DOX-induced cardiotoxicity. Our findings suggest that RBL2 could be used as a biomarker to predict the risk of cardiotoxicity before the initiation of anthracycline-based chemotherapy.

Haptoglobin Gene Expression and Anthracycline-Related Cardiomyopathy in Childhood Cancer Survivors: A COG-ALTE03N1 Report

Background

Anthracycline-related cardiomyopathy is a leading cause of premature death in childhood cancer survivors. The high interindividual variability in risk suggests the need to understand the underlying pathogenesis.

Objectives

The authors interrogated differentially expressed genes (DEGs) to identify genetic variants serving regulatory functions or genetic variants not easily identified when using genomewide array platforms. Using leads from DEGs, candidate copy number variants (CNVs) and single-nucleotide variants (SNVs) were genotyped.

Methods

Messenger RNA sequencing was performed on total RNA from peripheral blood of 40 survivors with cardiomyopathy (cases) and 64 matched survivors without cardiomyopathy (control subjects). Conditional logistic regression analysis adjusting for sex, age at cancer diagnosis, anthracycline dose, and chest radiation was used to assess the associations between gene expression and cardiomyopathy and between CNVs and SNVs and cardiomyopathy.

Results

Haptoglobin (HP) was identified as the top DEG. Participants with higher HP gene expression had 6-fold greater odds of developing cardiomyopathy (OR: 6.4; 95% CI: 1.4-28.6). The HP2-specific allele among the HP genotypes (HP1-1, HP1-2, and HP2-2) had higher transcript levels, as did the G allele among SNVs previously reported to be associated with HP gene expression (rs35283911 and rs2000999). The HP1-2 and HP2-2 genotypes combined with the G/G genotype for rs35283911 and/or rs2000999 placed the survivors at 4-fold greater risk (OR: 3.9; 95% CI: 1.0-14.5) for developing cardiomyopathy.

Conclusions

These findings provide evidence of a novel association between HP2 allele and cardiomyopathy. HP binds to free hemoglobin to form an HP-hemoglobin complex, thereby preventing oxidative damage from free heme iron, thus providing biological plausibility to the mechanistic basis of the present observation.

Targeting the Na+/K+ ATPase DR-region with DR-Ab improves doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a potent chemotherapeutic drug for various cancers. Yet, the cardiotoxic side effects limit its application in clinical uses, in which ferroptosis serves as a crucial pathological mechanism in DOX-induced cardiotoxicity (DIC). A reduction of Na+/K + ATPase (NKA) activity is closely associated with DIC progression. However, whether abnormal NKA function was involved in DOX-induced cardiotoxicity and ferroptosis remains unknown. Here, we aim to decipher the cellular and molecular mechanisms of dysfunctional NKA in DOX-induced ferroptosis and investigate NKA as a potential therapeutic target for DIC. A decrease activity of NKA further aggravated DOX-triggered cardiac dysfunction and ferroptosis in NKAα1 haploinsufficiency mice. In contrast, antibodies against the DR-region of NKAα-subunit (DR-Ab) attenuated the cardiac dysfunction and ferroptosis induced by DOX. Mechanistically, NKAα1 interacted with SLC7A11 to form a novel protein complex, which was directly implicated in the disease progression of DIC. Furthermore, the therapeutic effect of DR-Ab on DIC was mediated by reducing ferroptosis by promoting the association of NKAα1/SLC7A11 complex and maintaining the stability of SLC7A11 on the cell surface. These results indicate that antibodies targeting the DR-region of NKA may serve as a novel therapeutic strategy to alleviate DOX-induced cardiotoxicity.

The Battlefield of Chemotherapy in Pediatric Cancers

The survival rate for pediatric cancers has remarkably improved in recent years. Conventional chemotherapy plays a crucial role in treating pediatric cancers, especially in low- and middle-income countries where access to advanced treatments may be limited. The Food and Drug Administration (FDA) approved chemotherapy drugs that can be used in children have expanded, but patients still face numerous side effects from the treatment. In addition, multidrug resistance (MDR) continues to pose a major challenge in improving the survival rates for a significant number of patients. This review focuses on the severe side effects of pediatric chemotherapy, including doxorubicin-induced cardiotoxicity (DIC) and vincristine-induced peripheral neuropathy (VIPN). We also delve into the mechanisms of MDR in chemotherapy to the improve survival and reduce the toxicity of treatment. Additionally, the review focuses on various drug transporters found in common types of pediatric tumors, which could offer different therapeutic options.