Antineoplastic Drug-Induced Cardiotoxicity: A Redox Perspective

Nicotinamide mononucleotide attenuates doxorubicin-induced cardiotoxicity by reducing oxidative stress, inflammation and apoptosis in rats

Doxorubicin (DOX) is an effective and widely used antineoplastic drug. However, its clinical application is limited due to its dose-dependent cardiotoxicity. Great efforts have been made to explore the pathological mechanism of DOX-induced cardiotoxicity (DIC), but new drugs and strategies to alleviate cardiac damage are still needed. Here, we aimed to investigate the effect of nicotinamide mononucleotide (NMN) on DIC in rats. The results of the present study showed that DOX treatment significantly induced cardiac dysfunction and cardiac injury, whereas NMN alleviated these changes. In addition, NMN inhibited Dox-induced activation of nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome-mediated inflammation, as evidenced by decreased caspase 1 and IL-1β activity. Moreover, NMN treatment increased glutathione (GSH) levels and superoxide dismutase (SOD) activity and decreased the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) in DOX-treated rats. Furthermore, NMN treatment mitigated DOX-induced cardiomyocyte apoptosis and cardiac fibrosis. In conclusion, the results indicated that NMN protects against DIC in rats by inhibiting NLRP3 inflammasome activation, oxidative stress, and apoptosis.

Advances in Cardiotoxicity Induced by Altered Mitochondrial Dynamics and Mitophagy

Mitochondria are the most abundant organelles in cardiac cells, and are essential to maintain the normal cardiac function, which requires mitochondrial dynamics and mitophagy to ensure the stability of mitochondrial quantity and quality. When mitochondria are affected by continuous injury factors, the balance between mitochondrial dynamics and mitophagy is broken. Aging and damaged mitochondria cannot be completely removed in cardiac cells, resulting in energy supply disorder and accumulation of toxic substances in cardiac cells, resulting in cardiac damage and cardiotoxicity. This paper summarizes the specific underlying mechanisms by which various adverse factors interfere with mitochondrial dynamics and mitophagy to produce cardiotoxicity and emphasizes the crucial role of oxidative stress in mitophagy. This review aims to provide fresh ideas for the prevention and treatment of cardiotoxicity induced by altered mitochondrial dynamics and mitophagy.

Skeletal Muscle Deconditioning in Breast Cancer Patients Undergoing Chemotherapy: Current Knowledge and Insights From Other Cancers

Breast cancer represents the most commonly diagnosed cancer while neoadjuvant and adjuvant chemotherapies are extensively used in order to reduce tumor development and improve disease-free survival. However, chemotherapy also leads to severe off-target side-effects resulting, together with the tumor itself, in major skeletal muscle deconditioning. This review first focuses on recent advances in both macroscopic changes and cellular mechanisms implicated in skeletal muscle deconditioning of breast cancer patients, particularly as a consequence of the chemotherapy treatment. To date, only six clinical studies used muscle biopsies in breast cancer patients and highlighted several important aspects of muscle deconditioning such as a decrease in muscle fibers cross-sectional area, a dysregulation of protein turnover balance and mitochondrial alterations. However, in comparison with the knowledge accumulated through decades of intensive research with many different animal and human models of muscle atrophy, more studies are necessary to obtain a comprehensive understanding of the cellular processes implicated in breast cancer-mediated muscle deconditioning. This understanding is indeed essential to ultimately lead to the implementation of efficient preventive strategies such as exercise, nutrition or pharmacological treatments. We therefore also discuss potential mechanisms implicated in muscle deconditioning by drawing a parallel with other cancer cachexia models of muscle wasting, both at the pre-clinical and clinical levels.

Biological Aspects of Inflamm-Aging in Childhood Cancer Survivors

Anti-cancer treatments improve survival in children with cancer. A total of 80% of children treated for childhood cancer achieve 5-year survival, becoming long-term survivors. However, they undergo several chronic late effects related to treatments. In childhood cancer survivors a chronic low-grade inflammation, known as inflamm-aging, is responsible for frailty, a condition characterized by vital organ failure and by premature aging processes. Inflamm-aging is closely related to chemotherapy and radiotherapy, which induce inflammation, accumulation of senescent cells, DNA mutations, and the production of reactive oxygen species. All these conditions are responsible for the onset of secondary diseases, such as osteoporosis, cardiovascular diseases, obesity, and infertility. Considering that the pathobiology of frailty among childhood cancer survivors is still unknown, investigations are needed to better understand frailty's biological and molecular processes and to identify inflamm-aging key biomarkers in order to facilitate the screening of comorbidities and to clarify whether treatments, normally used to modulate inflamm-aging, may be beneficial. This review offers an overview of the possible biological mechanisms involved in the development of inflamm-aging, focusing our attention on immune system alteration, oxidative stress, cellular senescence, and therapeutic strategies.

Redox interactions-induced cardiac toxicity in cancer therapy

Cancer patients undergoing radiotherapy, chemotherapy, or targeted cancer therapy are exposed to the risk of several side effects because of the heavy production of ROS by ionizing radiation or some chemotherapy drugs. Damages to DNA, mitochondria, membrane and other organelles within normal tissue cells such as cardiomyocytes and endothelial cells lead to the release of some toxins which are associated with triggering inflammatory cells to release several types of cytokines, chemokines, ROS, and RNS. The release of some molecules following radiotherapy or chemotherapy stimulates reduction/oxidation (redox) reactions. Redox reactions cause remarkable changes in the level of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Excessive production of ROS and RNS or suppression of antioxidant defense enzymes leads to damage to critical macromolecules, which may continue for long times. Increased levels of some cytokines and oxidative injury are hallmarks of heart injury following cancer therapy. Redox reactions may be involved in several heart disorders such as fibrosis, cardiomyopathy, and endothelium injury. In the current review, we explain the cellular and molecular mechanisms of redox interactions following radiotherapy, chemotherapy, and targeted cancer therapy. Afterward, we explain the evidence of the involvement of redox reactions in heart diseases.

Updates on Anticancer Therapy-Mediated Vascular Toxicity and New Horizons in Therapeutic Strategies

Vascular toxicity is a frequent adverse effect of current anticancer chemotherapies and often results from endothelial dysfunction. Vascular endothelial growth factor inhibitors (VEGFi), anthracyclines, plant alkaloids, alkylating agents, antimetabolites, and radiation therapy evoke vascular toxicity. These anticancer treatments not only affect tumor vascularization in a beneficial manner, they also damage ECs in the heart. Cardiac ECs have a vital role in cardiovascular functions including hemostasis, inflammatory and coagulation responses, vasculogenesis, and angiogenesis. EC damage can be resulted from capturing angiogenic factors, inhibiting EC proliferation, survival and signal transduction, or altering vascular tone. EC dysfunction accounts for the pathogenesis of myocardial infarction, atherothrombosis, microangiopathies, and hypertension. In this review, we provide a comprehensive overview of the effects of chemotherapeutic agents on vascular toxicity leading to hypertension, microvascular rarefaction thrombosis and atherosclerosis, and affecting drug delivery. We also describe the potential therapeutic approaches such as vascular endothelial growth factor (VEGF)-B and prokineticin receptor-1 agonists to maintain endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor effectiveness.

The Human Fetal and Adult Stem Cell Secretome Can Exert Cardioprotective Paracrine Effects against Cardiotoxicity and Oxidative Stress from Cancer Treatment

Simple Summary

Anthracyclines, such as doxorubicin (Dox), are an important class of chemotherapeutic drugs. However, their use is hampered by the risk of developing heart failure. The aim of this study was to assess and compare the cardioprotective effects exerted by a set of factors, collectively named secretomes, secreted by either adult or fetal human stem cells. Both secretome formulations were effective in counteracting Dox-induced apoptosis and mitochondrial impairment in cardiomyocytes and cardiac fibroblasts. In vivo experiments in a mouse model of Dox-induced cardiomyopathy (DIC) indicated that early administration of both secretomes during Dox treatment exerted beneficial long-term effects, preserving cardiac function and body mass. These findings suggest that the stem cell secretome could represent a feasible option for future paracrine cardioprotective therapy against Dox-related cardiotoxicity during cancer treatment.

Abstract

Cardiovascular side effects are major shortcomings of cancer treatments causing cardiotoxicity and late-onset cardiomyopathy. While doxorubicin (Dox) has been reported as an effective chemotherapy agent, unspecific impairment in cardiomyocyte mitochondria activity has been documented. We demonstrated that the human fetal amniotic fluid-stem cell (hAFS) secretome, namely the secreted paracrine factors within the hAFS-conditioned medium (hAFS-CM), exerts pro-survival effects on Dox-exposed cardiomyocytes. Here, we provide a detailed comparison of the cardioprotective potential of hAFS-CM over the secretome of mesenchymal stromal cells from adipose tissue (hMSC-CM). hAFS and hMSC were preconditioned under hypoxia to enrich their secretome. The cardioprotective effects of hAFS/hMSC-CM were evaluated on murine neonatal ventricular cardiomyocytes (mNVCM) and on their fibroblast counterpart (mNVFib), and their long-term paracrine effects were investigated in a mouse model of Dox-induced cardiomyopathy. Both secretomes significantly contributed to preserving mitochondrial metabolism within Dox-injured cardiac cells. hAFS-CM and hMSC-CM inhibited body weight loss, improved myocardial function, reduced lipid peroxidation and counteracted the impairment of mitochondrial complex I activity, oxygen consumption, and ATP synthesis induced by Dox. The hAFS and hMSC secretomes can be exploited for inhibiting cardiotoxic detrimental side effects of Dox during cancer therapy, thus ensuring cardioprotection via combinatorial paracrine therapy in association with standard oncological treatments.

Loss of TRIM21 alleviates cardiotoxicity by suppressing ferroptosis induced by the chemotherapeutic agent doxorubicin

BACKGROUND

Doxorubicin, an anthracycline chemotherapeutic agent, is widely used in the treatment of many cancers. However, doxorubicin posts a great risk of adverse cardiovascular events, which are thought to be caused by oxidative stress. We recently reported that the ubiquitin E3 ligase TRIM21 interacts and ubiquitylates p62 and negatively regulates the p62-Keap1-Nrf2 antioxidant pathway. Therefore, we sought to determine the role TRIM21 in cardiotoxicity induced by oxidative damage.

METHODS

Using TRIM21 knockout mice, we examined the effects of TRIM21 on cardiotoxicity induced by two oxidative damage models: the doxorubicin treatment model and the Left Anterior Descending (LAD) model. We also explored the underlying mechanism by RNA-sequencing of the heart tissues, and by treating the mouse embryonic fibroblasts (MEFs), immortalized rat cardiomyocyte line H9c2, and immortalized human cardiomyocyte line AC16 with doxorubicin.

FINDINGS

TRIM21 knockout mice are protected from heart failure and fatality in both the doxorubicin and LAD models. Hearts of doxorubicin-treated wild-type mice exhibit deformed mitochondria and elevated level of lipid peroxidation reminiscent of ferroptosis, which is alleviated in TRIM21 knockout hearts. Mechanistically, TRIM21-deficient heart tissues and cultured MEFs and H9c2 cells display enhanced p62 sequestration of Keap1 and are protected from doxorubicin-induced ferroptosis. Reconstitution of wild-type but not the E3 ligase-dead and the p62 binding-deficient TRIM21 mutants impedes the protection from doxorubicin-induced cell death.

INTERPRETATION

Our study demonstrates that TRIM21 ablation protects doxorubicin-induced cardiotoxicity and illustrates a new function of TRIM21 in ferroptosis, and suggests TRIM21 as a therapeutic target for reducing chemotherapy-related cardiotoxicity.

FUNDING

NIH (CA129536; DK108989): data collection, analysis. Shanghai Pujiang Program (19PJ1401900): data collection. National Natural Science Foundation (31971161): data collection. Department of Veteran Affairs (BX004083): data collection. Tianjin Science and Technology Plan Project (17ZXMFSY00020): data collection.

The evaluation of anti-breast cancer activity and safety pharmacology of the ethanol extract of Aralia elata Seem. leaves

Aralia elata Seem. is a traditional folk Chinese medicinal plant and its leaves have been used to treat many diseases. We aimed to evaluate the anti-breast cancer activity and safety pharmacology of the ethanol extract of A. elata Seem. leaves (ELE). Cytotoxicity was evaluated on human tumor cell lines by MTT assay in vitro. A tumor bearing-nude mice model was used to assess antitumor activity in vivo. Cell apoptosis was determined by Hoechst 33258 staining, flow cytometry and TUNEL staining. The protein levels were determined by western-blotting and immunohistochemical staining. In safety evaluation, ICR mice and beagle dogs were orally administered ELE at different doses to determine its adverse effects on the central nervous system and cardiorespiratory system. ELE significantly inhibited tumor growth and induced cell apoptosis in MCF-7 cells in vitro and in vivo. The protein levels including caspase-3, caspase-9, bax, bcl-2, PARP, and cytochrome c were significantly changed. For the central nervous system, no treatment-related changes in behavior, motor activity or coordination were observed in mice. For the cardiorespiratory system, no significant differences in cardiorespiratory parameters including heart rate, PR interval, RR interval, P wave duration, QRS duration, QTcF interval, respiratory frequency, tidal volume, body temperature, and blood pressure were observed in beagle dogs between the ELE treatment and control group. In conclusion, ELE possessed anti-breast cancer activity by activating a mitochondrial-mediated apoptotic pathway with high biological safety in animals, which indicates it could be a potential therapeutic agent for treating human breast cancer in the future.

An update of the molecular mechanisms underlying doxorubicin plus trastuzumab induced cardiotoxicity

Cardiotoxicity is a major side effect of the chemotherapeutic drug doxorubicin (Dox), which is further exacerbated when it is combined with trastuzumab, a standard care approach for Human Epidermal growth factor Receptor-type 2 (HER2) positive cancer patients. However, the molecular mechanisms of the underlying cardiotoxicity of this combination are still mostly elusive. Increased oxidative stress, impaired energetic substrate uses and topoisomerase IIB inhibition are among the biological processes proposed to explain Dox-induced cardiomyocyte dysfunction. Since cardiomyocytes express HER2, trastuzumab can also damage these cells by interfering with neuroregulin-1 signaling and mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/Akt and focal adhesion kinase (FAK)-dependent pathways. Nevertheless, Dox and trastuzumab target other cardiac cell types, such as endothelial cells, fibroblasts, cardiac progenitor cells and leukocytes, which can contribute to the clinical cardiotoxicity observed. This review aims to summarize the current knowledge on the cardiac signaling pathways modulated by these two antineoplastic drugs highly used in the management of breast cancer, not only focusing on cardiomyocytes but also to broaden the knowledge of the potential impact on other cells found in the heart.

A Targeted Metabolomics-Based Assay Using Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Identifies Structural and Functional Cardiotoxicity Potential

Implementing screening assays that identify functional and structural cardiotoxicity earlier in the drug development pipeline has the potential to improve safety and decrease the cost and time required to bring new drugs to market. In this study, a metabolic biomarker-based assay was developed that predicts the cardiotoxicity potential of a drug based on changes in the metabolism and viability of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Assay development and testing was conducted in 2 phases: (1) biomarker identification and (2) targeted assay development. In the first phase, metabolomic data from hiPSC-CM spent media following exposure to 66 drugs were used to identify biomarkers that identified both functional and structural cardiotoxicants. Four metabolites that represent different metabolic pathways (arachidonic acid, lactic acid, 2'-deoxycytidine, and thymidine) were identified as indicators of cardiotoxicity. In phase 2, a targeted, exposure-based biomarker assay was developed that measured these metabolites and hiPSC-CM viability across an 8-point concentration curve. Metabolite-specific predictive thresholds for identifying the cardiotoxicity potential of a drug were established and optimized for balanced accuracy or sensitivity. When predictive thresholds were optimized for balanced accuracy, the assay predicted the cardiotoxicity potential of 81 drugs with 86% balanced accuracy, 83% sensitivity, and 90% specificity. Alternatively, optimizing the thresholds for sensitivity yields a balanced accuracy of 85%, 90% sensitivity, and 79% specificity. This new hiPSC-CM-based assay provides a paradigm that can identify structural and functional cardiotoxic drugs that could be used in conjunction with other endpoints to provide a more comprehensive evaluation of a drug's cardiotoxicity potential.

Cardioprotective Roles of β-Hydroxybutyrate Against Doxorubicin Induced Cardiotoxicity

Background: β-Hydroxybutyrate (BHB) is produced by fatty acid oxidation in the liver under the fasting state and confirmed to play a cardioprotective role in ischemia and hypertensive settings. Doxorubicin (DOX) is an effective chemotherapeutic drug, but limited by serious irreversible cardiotoxicity. However, whether BHB can protect from DOX-induced cardiotoxicity remains unknown.

Methods and Results: C57BL/6 mice were intraperitoneally injected with DOX to induce cardiac toxicity and intragastrically administered into BHB for treatment. They were randomly divided into three groups, namely a sham group (Sham), a doxorubicin group (DOX), and a doxorubicin+β-Hydroxybutyrate group (DOX + BHB). Echocardiography and pathological staining were performed to evaluate cardiac function and fibrosis. H9c2 cardiomyocyte was treated with DOX or BHB for in vitro experiments. Cell apoptosis and ROS were determined by flow cytometry. BHB significantly restored DOX-induced cardiac function decline and partially prevented cardiac reverse remodeling, characterized by increased cell size and decreased fibrosis. In vitro, BHB treatment decreased cellular injury and apoptosis. Also, BHB alleviated oxidative stress level and increased mitochondrial membrane potential.

Conclusion: Our results suggested that BHB could protected from DOX-induced cardiotoxicity by inhibiting cell apoptosis and oxidative stress and maintaining mitochondrial membrane integrity.

Salmon acyl-ghrelin increases food intake and reduces doxorubicin-induced myocardial apoptosis in rats, likely by anti-oxidative activity

We had reported that orally administered ghrelin-containing salmon stomach extract prevents doxorubicin (DOX)-induced cardiotoxicity. In this study, we investigated the binding affinity of salmon ghrelin to rat ghrelin receptor and the cardioprotective effects of subcutaneous (sc) injected synthetic salmon ghrelin in rats with DOX-induced acute heart failure in order to clarify the potential efficacy of salmon ghrelin. Intracellular calcium mobilization assay was performed on rat GHS-R1a-expressing CHO cells to reveal ghrelin activity. Rats were divided into five groups; the normal control (I), and toxic control (II) groups were given saline (sc, twice daily), and the salmon acyl-ghrelin (sAG) (III), salmon unacylated-ghrelin (sUAG) (IV), and rat acyl-ghrelin (rAG) (V) groups were given corresponding synthetic ghrelins (sc, twice daily), respectively. After seven days of treatment, DOX (20 mg/kg BW) or saline was administered to the corresponding groups by intraperitoneal injection. The toxic control group was the negative control group for the DOX-induced cardiotoxicity groups. While sAG displayed similar affinity to rAG upon application to GHS-R1a-expressing cells, and also decreased DOX-induced apoptosis and increased food intake, sUAG did not. Both sAG and rAG improved DOX-induced deterioration, showing anti-oxidative activity. The anti-oxidative activity of sAG might contribute to the protective effects on cardiomyocytes. The results also suggest that, similar to rAG, sAG is a potent protectant against DOX-induced cardiotoxicity and a potential functional component in orally administered ghrelin-containing salmon stomach extract, which prevented DOX-induced cardiotoxicity in our previous study.

Antioxidant Approach as a Cardioprotective Strategy in Chemotherapy-Induced Cardiotoxicity

Significance: Chemotherapy-induced cardiotoxicity (CTX) has been associated with redox signaling imbalance. In fact, redox reactions are crucial for normal heart physiology, whereas excessive oxidative stress can cause cardiomyocyte structural damage. Recent Advances: An antioxidant approach as a cardioprotective strategy in this setting has shown encouraging results in preventing anticancer drug-induced CTX. Critical Issues: In fact, traditional heart failure drugs as well as many other compounds and nonpharmacological strategies, with a partial effect in reducing oxidative stress, have been shown to counterbalance chemotherapy-induced CTX in this setting to some extent. Future Directions: Given the various pathways of toxicity involved in different chemotherapeutic schemes, interactions with redox balance need to be fine-tuned and a personalized cardioprotective approach seems to be required.

Exploring the Potential Role of the Gut Microbiome in Chemotherapy-Induced Neurocognitive Disorders and Cardiovascular Toxicity

Chemotherapy, targeting not only malignant but also healthy cells, causes many undesirable side effects in cancer patients. Due to this fact, long-term cancer survivors often suffer from late effects, including cognitive impairment and cardiovascular toxicity. Chemotherapy damages the intestinal mucosa and heavily disrupts the gut ecosystem, leading to gastrointestinal toxicity. Animal models and clinical studies have revealed the associations between intestinal dysbiosis and depression, anxiety, pain, impaired cognitive functions, and cardiovascular diseases. Recently, a possible link between chemotherapy-induced gut microbiota disruption and late effects in cancer survivors has been proposed. In this review, we summarize the current understanding of preclinical and clinical findings regarding the emerging role of the microbiome and the microbiota-gut-brain axis in chemotherapy-related late effects affecting the central nervous system (CNS) and heart functions. Importantly, we provide an overview of clinical trials evaluating the relationship between the gut microbiome and cancer survivorship. Moreover, the beneficial effects of probiotics in experimental models and non-cancer patients with neurocognitive disorders and cardiovascular diseases as well as several studies on microbiota modulations via probiotics or fecal microbiota transplantation in cancer patients are discussed.

Metabolic Aspects of Anthracycline Cardiotoxicity

OPINION STATEMENT

Heart failure (HF) is increasingly recognized as the major complication of chemotherapy regimens. Despite the development of modern targeted therapies such as monoclonal antibodies, doxorubicin (DOXO), one of the most cardiotoxic anticancer agents, still remains the treatment of choice for several solid and hematological tumors. The insurgence of cardiotoxicity represents the major limitation to the clinical use of this potent anticancer drug. At the molecular level, cardiac side effects of DOXO have been associated to mitochondrial dysfunction, DNA damage, impairment of iron metabolism, apoptosis, and autophagy dysregulation. On these bases, the antioxidant and iron chelator molecule, dexrazoxane, currently represents the unique FDA-approved cardioprotectant for patients treated with anthracyclines.A less explored area of research concerns the impact of DOXO on cardiac metabolism. Recent metabolomic studies highlight the possibility that cardiac metabolic alterations may critically contribute to the development of DOXO cardiotoxicity. Among these, the impairment of oxidative phosphorylation and the persistent activation of glycolysis, which are commonly observed in response to DOXO treatment, may undermine the ability of cardiomyocytes to meet the energy demand, eventually leading to energetic failure. Moreover, increasing evidence links DOXO cardiotoxicity to imbalanced insulin signaling and to cardiac insulin resistance. Although anti-diabetic drugs, such as empagliflozin and metformin, have shown interesting cardioprotective effects in vitro and in vivo in different models of heart failure, their mechanism of action is unclear, and their use for the treatment of DOXO cardiotoxicity is still unexplored.This review article aims at summarizing current evidence of the metabolic derangements induced by DOXO and at providing speculations on how key players of cardiac metabolism could be pharmacologically targeted to prevent or cure DOXO cardiomyopathy.

Cardiotoxicity in HER2-positive breast cancer patients

Due to the recent advances in diagnosis and management of patients with HER2-positive breast cancer, especially through novel HER2-targeted agents, cardiotoxicity becomes an emerging problem. Although chemotherapy significantly increases survival, the risk of cardiovascular disease development is high and still underestimated and could imply treatment discontinuation. Frequently, due to lack of rigorous diagnosis strategies, cardiotoxicity assessment is delayed, and, moreover, the efficacy of current therapy options in restoring heart function is questionable. For a comprehensive risk assessment, it is vital to characterize the clinical spectrum of HER2-targeted agents and anthracyclines, as well as their pathogenic pathways involved in cardiotoxicity. Advanced cardiovascular multimodal imaging and circulating biomarkers plays primary roles in early assessing cardiotoxicity and also in guiding specific preventive measures. Even though the knowledge in this field is rapidly expanding, there are still questions that arise regarding the optimal approach in terms of timing and methods. The aim of the current review aims to providean overview of currently available data.

Dexrazoxane ameliorates radiation-induced heart disease in a rat model

Treatment of thoracic tumors with radiotherapy can lead to severe cardiac injury. We investigated the effects of dexrazoxane, a USFDA-approved cardioprotective drug administered with chemotherapy, on radiation-induced heart disease (RIHD) in a rat model. Male Sprague-Dawley rats were irradiated with a single dose of 20 Gy to the heart and treated with dexrazoxane at the time of irradiation and for 12 subsequent weeks. Dexrazoxane suppressed radiation-induced myocardial apoptosis and significantly reversed changes in serum cardiac troponin I levels and histopathological characteristics six months post-radiation. Treatment with dexrazoxane did not alter the radiosensitivity of thoracic tumors in a tumor formation experiment using male nude Balb/C mice with tumors generated by H292 cells. Dexrazoxane reduced the accumulation of reactive oxygen species in rat cardiac tissues, but not in tumors in nude mice. Transcriptome sequencing showed that IKBKE, MAP3K8, NFKBIA, and TLR5, which are involved in Toll-like receptor signaling, may be associated with the anti-RIHD effects of dexrazoxane. Immunohistochemistry revealed that dexrazoxane significantly decreased NF-κB p65 expression in cardiomyocytes. These findings suggest dexrazoxane may protect against RIHD by suppressing apoptosis and oxidative stress in cardiomyocytes.

Cancer Risk in the Heart Failure Population: Epidemiology, Mechanisms, and Clinical Implications

PURPOSE OF REVIEW

Along with population aging, the incidence of both heart failure (HF) and cancer is increasing. However, little is known about new-onset cancer in HF patients. This review aims at showing recent discoveries concerning this subset of patients.

RECENT FINDINGS

Not only cancer and HF share similar risk factors but also HF itself can stimulate cancer development. Some cytokines produced by the failing heart induce mild inflammation promoting carcinogenesis, as it has been recently suggested by an experimental model of HF in mice. The incidence of new-onset cancer is higher in HF patients compared to the general population, and it significantly worsens their prognosis. Moreover, the management of HF patients developing new-onset cancer is challenging, especially due to the limited therapeutic options for patients affected by both cancer and HF and the higher risk of cardiotoxicity from anticancer drugs.

Is There a Role for Basophils in Cancer?

Basophils were identified in human peripheral blood by Paul Ehrlich over 140 years ago. Human basophils represent <1% of peripheral blood leukocytes. During the last decades, basophils have been described also in mice, guinea pigs, rabbits, and monkeys. There are many similarities, but also several immunological differences between human and mouse basophils. There are currently several strains of mice with profound constitutive or inducible basophil deficiency useful to prove that these cells have specific roles in vivo. However, none of these mice are solely and completely devoid of all basophils. Therefore, the relevance of these findings to humans remains to be established. It has been known for some time that basophils have the propensity to migrate into the site of inflammation. Recent observations indicate that tissue resident basophils contribute to lung development and locally promote M2 polarization of macrophages. Moreover, there is increasing evidence that lung-resident basophils exhibit a specific phenotype, different from circulating basophils. Activated human and mouse basophils synthesize restricted and distinct profiles of cytokines. Human basophils produce several canonical (e.g., VEGFs, angiopoietin 1) and non-canonical (i.e., cysteinyl leukotriene C₄) angiogenic factors. Activated human and mouse basophils release extracellular DNA traps that may have multiple effects in cancer. Hyperresponsiveness of basophils has been demonstrated in patients with JAK2^V617F-positive polycythemia vera. Basophils are present in the immune landscape of human lung adenocarcinoma and pancreatic cancer and can promote inflammation-driven skin tumor growth. The few studies conducted thus far using different models of basophil-deficient mice have provided informative results on the roles of these cells in tumorigenesis. Much more remains to be discovered before we unravel the hitherto mysterious roles of basophils in human and experimental cancers.

Activated ROCK/Akt/eNOS and ET-1/ERK pathways in 5-fluorouracil-induced cardiotoxicity: modulation by simvastatin

5-Fluorouracil (5-FU) is used in the treatment of different solid tumors; however, its use is associated with rare, but serious cardiotoxicity. Nevertheless, the involvement of ROCK/NF-κB, Akt/eNOS and ET-1/ERK1/2 trajectories in the cardiotoxic effect and in the potential cardioprotective upshot of simvastatin has been elusive. Male Wistar rats were allocated into 5-FU (50 mg/kg/week; i.p, 6 weeks), simvastatin (15 mg/kg/day; p.o, 8 weeks) treated groups and simvastatin + 5-FU, besides the normal control group. 5-FU-induced cardiotoxicity boosted the serum level of N-terminal pro-brain (B-type) natriuretic peptide (NT-proBNP), aortic contents of endothelin (ET)-1 and thromboxane (TX) A2, as well as cardiac contents of NADPH oxidases (Nox), cyclooxygenase (COX)-2, malondialdehyde (MDA), phosphorylated Akt (p-Akt), phosphorylated extracellular signal-regulated kinase (p-ERK)1/2 and the protein expressions of rho-kinase (ROCK) and caspase-3. On the other hand, it suppressed cardiac reduced glutathione (GSH) and phosphorylated endothelial nitric oxide synthase (p-eNOS). Contrariwise, co-administration with simvastatin overcame these disturbed events and modulated the ROCK/NF-κB, Akt/eNOS and ET-1/ERK1/2 signaling pathways. This study highlights other mechanisms than coronary artery spasm in the 5-FU cardiotoxicity and reveals that NT-proBNP is a potential early marker in this case. Moreover, the cross-talk between ROCK/ NF-κB, ROS/COX-2/TXA2, Akt/eNOS and ET-1/ERK1/2 pathways contributes via different means to upsetting the vasoconstriction/vasodilatation equilibrium as well as endothelial cell function and finally leads to cardiomyocyte stress and death-the modulation of these trajectories offers simvastatin its potential cardio-protection against 5-FU.

Nuclear cardiology in the context of multimodality imaging to detect cardiac toxicity from cancer therapeutics: Established and emerging methods

The complexity of cancer therapies has vastly expanded in the last decade, along with type and severity of cardiac toxicities associated with these treatments. Prevention of pre-clinical cardiotoxicity may improve cardiovascular outcomes and circumvent the decision to place life-sustaining chemotherapeutic agents on hold, making the early detection of cancer therapeutic related cardiac toxicity with non-invasive imaging essential to the care of these patients. There are several established methods of cardiac imaging in the areas of nuclear cardiology, echocardiography, computed tomography, and cardiac magnetic resonance imaging that are used to assess for cardiovascular toxicity of cancer treatments, with several methods under development. The following review will provide an overview of current and emerging imaging techniques in these areas.

Redox Imbalances in Ageing and Metabolic Alterations: Implications in Cancer and Cardiac Diseases. An Overview from the Working Group of Cardiotoxicity and Cardioprotection of the Italian Society of Cardiology (SIC)

Metabolic syndrome (MetS) is a well established risk factor for cardiovascular (CV) diseases. In addition, several studies indicate that MetS correlates with the increased risk of cancer in adults. The mechanisms linking MetS and cancer are not fully understood. Several risk factors involved in MetS are also cancer risk factors, such as the consumption of high calorie-food or high fat intake, low fibre intake, and sedentary lifestyle. Other common aspects of both cancer and MetS are oxidative stress and inflammation. In addition, some anticancer treatments can induce cardiotoxicity, including, for instance, left ventricular (LV) dysfunction and heart failure (HF), endothelial dysfunction and hypertension. In this review, we analyse several aspects of MetS, cancer and cardiotoxicity from anticancer drugs. In particular, we focus on oxidative stress in ageing, cancer and CV diseases, and we analyse the connections among CV risk factors, cancer and cardiotoxicity from anticancer drugs.

Cardiac dysfunction in cancer patients: beyond direct cardiomyocyte damage of anticancer drugs: novel cardio-oncology insights from the joint 2019 meeting of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart

In western countries, cardiovascular (CV) disease and cancer are the leading causes of death in the ageing population. Recent epidemiological data suggest that cancer is more frequent in patients with prevalent or incident CV disease, in particular, heart failure (HF). Indeed, there is a tight link in terms of shared risk factors and mechanisms between HF and cancer. HF induced by anticancer therapies has been extensively studied, primarily focusing on the toxic effects that anti-tumour treatments exert on cardiomyocytes. In this Cardio-Oncology update, members of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart discuss novel evidence interconnecting cardiac dysfunction and cancer via pathways in which cardiomyocytes may be involved but are not central. In particular, the multiple roles of cardiac stromal cells (endothelial cells and fibroblasts) and inflammatory cells are highlighted. Also, the gut microbiota is depicted as a new player at the crossroads between HF and cancer. Finally, the role of non-coding RNAs in Cardio-Oncology is also addressed. All these insights are expected to fuel additional research efforts in the field of Cardio-Oncology.

Cardiovascular Magnetic Resonance Imaging: Identifying the Effects of Cancer Therapy

The era of modern oncology incorporates an ever-evolving personalized approach to hematological malignancies and solid tumors. As a result, patient survival rates have, in part, substantially improved, depending on the specific type of underlying malignancy. However, systemic therapies may come along with potential cardiotoxic effects resulting in heart failure with increased morbidity and mortality. Ultimately, patients may survive their malignancy but die as a result of cancer treatment. Cardiovascular magnetic resonance imaging has long been in use for the assessment of function and tissue characteristics in patients with various nonischemic cardiac diseases. Besides an introductory overview on the general definition of cardiotoxicity including potential underlying mechanisms, this review provides insight into the application of various cardiovascular magnetic resonance imaging techniques in the setting of cancer therapy-related cardiac and vascular toxicity. Early identification of cardiotoxic effects may allow for on-time therapy adjustment and/or cardioprotective measures to avoid subsequent long-term heart failure with increased mortality.

Identification of novel potent and non-toxic anticancer, anti-angiogenic and antimetastatic rhenium complexes against colorectal carcinoma

Combination therapy targeting both tumor growth and vascularization is considered to be a cornerstone for colorectal carcinomas (CRC) treatment. However, the major obstacles of most clinical anticancer drugs are their weak selective activity towards cancer cells and inherent inner organs toxicity, accompanied with fast drug resistance development. In our effort to discover novel selective and non-toxic agents effective against CRC, we designed, synthesized and characterized a series of rhenium(I) tricarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity in vivo (zebrafish-human HCT-116 xenograft model), being effective at very low doses (1-3 μM). At doses as high as 250 μM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). In vivo assays showed that the two compounds exceed the anti-tumor and anti-angiogenic activity of clinical drugs cisplatin and sunitinib malate, and display a large therapeutic window.

Clerodendrum volubile Ethanol Leaf Extract: A Potential Antidote to Doxorubicin-Induced Cardiotoxicity in Rats

Doxorubicin is widely applied in hematological and solid tumor treatment but limited by its off-target cardiotoxicity. Thus, cardioprotective potential and mechanism(s) of CVE in DOX-induced cardiotoxicity were investigated using cardiac and oxidative stress markers and histopathological endpoints. 50–400 mg/kg/day CVE in 5% DMSO in distilled water were investigated in Wistar rats intraperitoneally injected with 2.5 mg/kg DOX on alternate days for 14 days, using serum troponin I and LDH, complete lipid profile, cardiac tissue oxidative stress marker assays, and histopathological examination of DOX-treated cardiac tissue. Preliminary qualitative and quantitative assays of CVE's secondary metabolites were also conducted. Phytochemical analyses revealed the presence of flavonoids (34.79 ± 0.37 mg/100 mg dry extract), alkaloids (36.73 ± 0.27 mg/100 mg dry extract), reducing sugars (07.78 ± 0.09 mg/100 mg dry extract), and cardiac glycosides (24.55 ± 0.12 mg/100 mg dry extract). 50–400 mg/kg/day CVE significantly attenuated increases in the serum LDH and troponin I levels. Similarly, the CVE dose unrelatedly decreased serum TG and VLDL-c levels without significant alterations in the serum TC, HDL-c, and LDL-c levels. Also, CVE profoundly attenuated alterations in the cardiac tissue oxidative stress markers' activities while improving DOX-associated cardiac histological lesions that were possibly mediated via free radical scavenging and/or antioxidant mechanisms. Overall, CVE may play a significant therapeutic role in the management of DOX-induced cardiotoxicity in humans.

PET Radiopharmaceuticals for Imaging Chemotherapy-Induced Cardiotoxicity

Purpose of Review

Currently, cardiotoxicity is monitored through echocardiography or multigated acquisition scanning and is defined as 10% or higher LVEF reduction. The latter stage may represent irreversible myocardium injury and limits modification of therapeutic paradigms at earliest stages. To stratify patients for anthracycline-related heart failure, highly sensitive and molecularly specific probes capable of interrogating cardiac damage at the subcellular levels have been sought.

Recent Findings

PET tracers may provide noninvasive assessment of earliest changes within myocardium. These tracers are at nascent stages of development and belong primarily to (a) mitochondrial potential-targeted and (b) general ROS (reactive oxygen species)-targeted radiotracers. Given that electrochemical gradient changes at the mitochondrial membrane represent an upstream, and earliest event before triggering the production of the ROS and caspase activity in a biochemical cascade, the former category might offer interrogation of cardiotoxicity at earliest stages exemplified by PET imaging, using ¹⁸F-Mitophos and ⁶⁸Ga-Galmydar in rodent models.

Summary

Both categories of radiotracers may provide tools for monitoring chemotherapy-induced cardiotoxicity and interrogating therapeutic efficacy of cardio-protectants.

Cardiac Damage in Anthracyclines Therapy: Focus on Oxidative Stress and Inflammation

Significance: Despite their serious side effects, anthracyclines (ANTs) are the most prescribed chemotherapeutic drugs because of their strong efficacy in both solid and hematological tumors. A major limitation to ANTs clinical application is the severe cardiotoxicity observed both acutely and chronically. The mechanism underlying cardiac dysfunction under chemotherapy is mainly dependent on the generation of oxidative stress and systemic inflammation, both of which lead to progressive cardiomyopathy and heart failure. Recent Advances: Over the years, the iatrogenic ANTs-induced cardiotoxicity was believed to be simply given by iron metabolism and reactive oxygen species production; however, several experimental data indicate that ANTs may use alternative damaging mechanisms, such as topoisomerase 2β inhibition, inflammation, pyroptosis, immunometabolism, and autophagy. Critical Issues: In this review, we aimed at discussing ANTs-induced cardiac injury from different points of view, updating and focusing on oxidative stress and inflammation, since these pathways are not exclusive or independent from each other but they together importantly contribute to the complexity of ANTs-induced multifactorial cardiotoxicity. Future Directions: A deeper understanding of the mechanistic signaling leading to ANTs side effects could reveal crucial targeting molecules, thus representing strategic knowledge to promote better therapeutic efficacy and lower cardiotoxicity during clinical application.

Signaling Pathways Underlying Anthracycline Cardiotoxicity

Significance: The cardiac side effects of hematological treatments are a major issue of the growing population of cancer survivors, often affecting patient survival even more than the tumor for which the treatment was initially prescribed. Among the most cardiotoxic drugs are anthracyclines (ANTs), highly potent antitumor agents, which still represent a mainstay in the treatment of hematological and solid tumors. Unfortunately, diagnosis, prevention, and treatment of cardiotoxicity are still unmet clinical needs, which call for a better understanding of the molecular mechanism behind the pathology. Recent Advances: This review article will discuss recent findings on the pathomechanisms underlying the cardiotoxicity of ANTs, spanning from DNA and mitochondrial damage to calcium homeostasis, autophagy, and apoptosis. Special emphasis will be given to the role of reactive oxygen species and their interplay with major signaling pathways. Critical Issues: Although new promising therapeutic targets and new drugs have started to be identified, their efficacy has been mainly proven in preclinical studies and requires clinical validation. Future Directions: Future studies are awaited to confirm the relevance of recently uncovered targets, as well as to identify new druggable pathways, in more clinically relevant models, including, for example, human induced pluripotent stem cell-derived cardiomyocytes.

Sex differences in anthracycline-induced cardiotoxicity: the benefits of estrogens

Anthracyclines are the cornerstone for many oncologic treatments, but their cardiotoxicity has been recognized for several decades. Female subjects, especially before puberty and adolescence, or after menopause, seem to be more at increased risk, with the prognostic impact of this sex issue being less consistent compared to other cardiovascular risk factors. Several studies imply that sex differences could depend on the lack of the protective effect of sex hormones against the anthracycline-initiated damage in cardiac cells, or on differential mitochondria-related oxidative gene expression. This is also reflected by the results obtained with different diagnostic methods, such as cardiovascular biomarkers and imaging techniques (echocardiography, magnetic resonance, and nuclear medicine) in the diagnosis and monitoring of cardiotoxicity, confirming that sex differences exist. The same is true about protective strategies from anthracycline cardiotoxicity. Indeed, first studied to withstand oxidative damage in response to ischemia/reperfusion (I/R) injury, cardioprotection has different outcomes in men and women. A number of studies assessed the differences in I/R response between male and female hearts, with oxidative stress and apoptosis being shared mechanisms between the I/R and anthracyclines heart damage. Sex hormones can modulate these mechanisms, thus confirming their importance in the pathophysiology in cardioprotection not only from the ischemia/reperfusion damage, but also from anthracyclines, fueling further cardio-oncologic research on the topic.

The Role of Antioxidants in Ameliorating Cyclophosphamide-Induced Cardiotoxicity

The chemotherapeutic and immunosuppressive agent cyclophosphamide has previously been shown to induce complications within the setting of bone marrow transplantation. More recently, cardiotoxicity has been shown to be a dose-limiting factor during cyclophosphamide therapy, and cardiooncology is getting wider attention. Though mechanism of cyclophosphamide-induced cardiotoxicity is not completely understood, it is thought to encompass oxidative and nitrative stress. As such, this review focuses on antioxidants and their role in preventing or ameliorating cyclophosphamide-induced cardiotoxicity. It will give special emphasis to the cardioprotective effects of natural, plant-derived antioxidants that have garnered significant interest in recent times.

Cardioprotective Effect of Croton macrostachyus Stem Bark Extract and Solvent Fractions on Cyclophosphamide-Induced Cardiotoxicity in Rats

Objective

To evaluate the antioxidant and cardioprotective activities of stem bark extract and solvent fractions of Croton macrostachyus on cyclophosphamide-induced cardiotoxicity in rats. Materials and Methods. DPPH free radical scavenging assay method was used to determine antioxidant activity whereas Sprague-Dawley rats were used to evaluate the cardioprotective activity. Except for the normal control, all groups were subjected to cyclophosphamide (200 mg/kg, i.p.) toxicity on the first day. Enalapril at 10 mg/kg was used as a reference. The hydromethanolic crude extract (100, 200, and 400 mg/kg) and aqueous and ethyl acetate fractions (100 and 200 mg/kg, each) were administered for 10 days. The cardioprotective activities were evaluated using cardiac biomarkers such as Troponin I, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), and histopathological studies of heart tissue.

Results

Crude extract and ethyl acetate and aqueous fractions exhibited free radical scavenging activities at IC₅₀ of 594 μg/mL, 419 μg/mL, and 716 μg/mL, respectively. Crude extract at 400 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.29 ± 0.06 ng/mL, 103.00 ± 7.63 U/L, 99.80 ± 6.18 U/L, and 108.80 ± 8.81 U/L, respectively. In addition, ethyl acetate fraction at 200 mg/kg decreased the levels of troponin, AST, ALT, and ALP to 0.22 ± 0.02 ng/mL, 137.00 ± 14.30 U/L, 90.33 ± 6.13 U/L, and 166.67 ± 13.50 U/L, respectively, compared with the cyclophosphamide control group.

Conclusions

Croton macrostachyus possesses cardioprotective activities and it could be a possible source of treatment for cardiotoxicity induced by cyclophosphamide.

Nanocarriers for the Delivery of Medical, Veterinary, and Agricultural Active Ingredients

Nanocarrier-based delivery systems can be used to increase the safety and efficacy of active ingredients in medical, veterinary, or agricultural applications, particularly when such ingredients are unstable, sparingly soluble, or cause off-target effects. In this review, we highlight the diversity of nanocarrier materials and their key advantages compared to free active ingredients. We discuss current trends based on peer-reviewed research articles, patent applications, clinical trials, and the nanocarrier formulations already approved by regulatory bodies. Although most nanocarriers have been engineered to combat cancer, the number of formulations developed for other purposes is growing rapidly, especially those for the treatment of infectious diseases and parasites affecting humans, livestock, and companion animals. The regulation and prohibition of many pesticides have also fueled research to develop targeted pesticide delivery systems based on nanocarriers, which maximize efficacy while minimizing the environmental impact of agrochemicals.

Natural compounds as potential adjuvants to cancer therapy: Preclinical evidence

Traditional chemotherapy is being considered due to hindrances caused by systemic toxicity. Currently, the administration of multiple chemotherapeutic drugs with different biochemical/molecular targets, known as combination chemotherapy, has attained numerous benefits like efficacy enhancement and amelioration of adverse effects that has been broadly applied to various cancer types. Additionally, seeking natural-based alternatives with less toxicity has become more important. Experimental evidence suggests that herbal extracts such as Solanum nigrum and Claviceps purpurea and isolated herbal compounds (e.g., curcumin, resveratrol, and matairesinol) combined with antitumoral drugs have the potential to attenuate resistance against cancer therapy and to exert chemoprotective actions. Plant products are not free of risks: Herb adverse effects, including herb-drug interactions, should be carefully considered. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

The role of A-kinase anchoring proteins in cardiac oxidative stress

Cardiac stress initiates a pathological remodeling process that is associated with cardiomyocyte loss and fibrosis that ultimately leads to heart failure. In the injured heart, a pathologically elevated synthesis of reactive oxygen species (ROS) is the main driver of oxidative stress and consequent cardiomyocyte dysfunction and death. In this context, the cAMP-dependent protein kinase (PKA) plays a central role in regulating signaling pathways that protect the heart against ROS-induced cardiac damage. In cardiac cells, spatiotemporal regulation of PKA activity is controlled by A-kinase anchoring proteins (AKAPs). This family of scaffolding proteins tether PKA and other transduction enzymes at subcellular microdomains where they can co-ordinate cellular responses regulating oxidative stress. In this review, we will discuss recent literature illustrating the role of PKA and AKAPs in modulating the detrimental impact of ROS production on cardiac function.

Basophils in Tumor Microenvironment and Surroundings

Basophils represent approximately 1% of human peripheral blood leukocytes. Their effector functions were initially appreciated in the 1970s when basophils were shown to express the high-affinity receptor (FcεRI) for IgE and to release proinflammatory mediators (histamine and cysteinyl leukotriene C₄) and immunoregulatory cytokines (i.e., IL-4 and IL-13). Basophils in the mouse were subsequently identified and immunologically characterized. There are many similarities but also several differences between human and mouse basophils. Basophil-deficient mice have enabled to examine the in vivo roles of basophils in several immune disorders and, more recently, in tumor immunity. Activated human basophils release several proangiogenic molecules such as vascular endothelial growth factor-A (VEGF-A), vascular endothelial growth factor-B (VEGF-B), CXCL8, angiopoietin 1 (ANGPT1), and hepatocyte growth factor (HGF). On the other side, basophils can exert anti-tumorigenic effects by releasing granzyme B, TNF-α, and histamine. Circulating basophils have been associated with certain human hematologic (i.e., chronic myeloid leukemia) and solid tumors. Basophils have been found in tumor microenvironment (TME) of human lung adenocarcinoma and pancreatic cancer. Basophils played a role in melanoma rejection in basophil-deficient mouse model. By contrast, basophils appear to play a pro-tumorigenic role in experimental and human pancreatic cancer. In conclusion, the roles of basophils in experimental and human cancers have been little investigated and remain largely unknown. The elucidation of the roles of basophils in tumor immunity will demand studies on increasing complexity beyond those assessing basophil density and their microlocalization in TME. There are several fundamental questions to be addressed in experimental models and clinical studies before we understand whether basophils are an ally, adversary, or even innocent bystanders in cancers.

New insight in endocrine-related adverse events associated to immune checkpoint blockade

Anticancer immunotherapy, in the form of immune checkpoint inhibition, is a paradigm shift that has transformed the care of patients with different types of solid and hematologic cancers. The most notable improvements have been seen in patients with melanoma, non-small-cell lung, bladder, renal, cervical, urotherial, and colorectal cancers, Merkel cell carcinoma, and Hodgkin lymphoma. Monoclonal antibodies (mAbs) targeting immune checkpoints (i.e., anti-CTLA: ipilimumab; anti-PD-1: nivolumab, pembrolizumab; anti-PD-L1: durvalumab, atezolizumab, avelumab) unleash the immune system against tumor cells targeting mainly T cells. Treatment with immune checkpoint inhibitors (ICIs) is associated with a variety of diverse and distinct immune-related adverse events (irAEs), reflecting the mechanistic underpinning of each target (i.e., CTLA-4, and PD-1/PD-L1 network). The most frequent endocrine irAEs associated with anti-PD-1 mAb treatment are thyroid dysfunctions, whereas hypophysitis is mostly linked to anti-CTLA-4 treatment. Type 1 diabetes mellitus and adrenalitis are rare irAEs. Combination therapy (anti-CTLA-4 plus anti-PD-1/PD-L1) can be associated with an increased risk and prevalence of endocrine irAEs. In this paper we discuss the pathophysiological and clinical aspects of irAEs with specific emphasis on endocrine irAEs associated with ICIs. With a growing number of patients treated with ICIs, a tight collaboration among oncologists, endocrinologists and immunologists appears necessary when the circumstances are more challenging and for better management of severe endocrine irAEs. Further investigations are urgently needed to better understand the mechanisms by which different ICIs can induce a variety of endocrine irAEs.

What Is the Cardiac Impact of Chemotherapy and Subsequent Radiotherapy in Lymphoma Patients?

Anthracyclines are widely used in anticancer protocols, but can induce cardiotoxicity by mechanisms that mainly involve oxidative damage and mitochondrial dysfunction. Radiotherapy (RT) can also impair cardiac function by promoting myocardial fibrosis, microvascular damage, and decreased density of myocardial capillaries. Hence, we aim at investigating prospectively whether RT impacts heart function in lymphoma patients who had been already treated with anthracyclines. Twenty-nine consecutive patients with Hodgkin or non-Hodgkin lymphomas underwent echocardiography at baseline (before antineoplastic treatments), and then every 2 months, until 6 months after treatment completion. Echo evaluation included standard two-dimensional and speckle tracking. Twenty-two patients treated with anthracycline-based regimens were eligible. Out of the 22 patients, 8 received chemotherapy (CT) only (subgroup 1), while 14 underwent RT after CT [subgroup 2 (S2)]. At the end of CT, ejection fraction was significantly reduced in the whole population. At 6 months after completion of therapies, E/E' increased and global longitudinal strain was compromised in S2, suggesting additional damage induced by RT after CT. On the basis of the data from our small prospective study, we can hypothesize that in lymphoma patients, anthracyclines can worsen cardiac function, and RT may have an additional unfavorable myocardial impact.

Future Needs in Mast Cell Biology

The pathophysiological roles of mast cells are still not fully understood, over 140 years since their description by Paul Ehrlich in 1878. Initial studies have attempted to identify distinct "subpopulations" of mast cells based on a relatively small number of biochemical characteristics. More recently, "subtypes" of mast cells have been described based on the analysis of transcriptomes of anatomically distinct mouse mast cell populations. Although mast cells can potently alter homeostasis, in certain circumstances, these cells can also contribute to the restoration of homeostasis. Both solid and hematologic tumors are associated with the accumulation of peritumoral and/or intratumoral mast cells, suggesting that these cells can help to promote and/or limit tumorigenesis. We suggest that at least two major subsets of mast cells, MC1 (meaning anti-tumorigenic) and MC2 (meaning pro-tumorigenic), and/or different mast cell mediators derived from otherwise similar cells, could play distinct or even opposite roles in tumorigenesis. Mast cells are also strategically located in the human myocardium, in atherosclerotic plaques, in close proximity to nerves and in the aortic valve. Recent studies have revealed evidence that cardiac mast cells can participate both in physiological and pathological processes in the heart. It seems likely that different subsets of mast cells, like those of cardiac macrophages, can exert distinct, even opposite, effects in different pathophysiological processes in the heart. In this chapter, we have commented on possible future needs of the ongoing efforts to identify the diverse functions of mast cells in health and disease.

Geniposide attenuates cadmium‑induced oxidative stress injury via Nrf2 signaling in osteoblasts

Geniposide, as a type of iridoid glycoside, has antioxidative capacity. However, the mechanism underlying the effect of geniposide in cadmium (Cd)-induced osteoblast injury remains only partly elucidated. In the present study, Cell Counting Kit-8 (CCK-8) was used to determine MC-3T3-E1 cell viability. Flow cytometry was used to determine the rate of apoptosis and levels of reactive oxygen species (ROS). Oxidative stress-related factors were assessed using enzyme-linked immunosorbent method (ELISA). Quantitative real-time polymerase chain reaction (qPCR) and western blotting were used to evaluate apoptosis- and bone formation-related genes and nuclear factor erythroid 2-related factor (Nrf2) signaling. It was demonstrated that geniposide increased the viability of the Cd-treated MC-3T3-E1 cells. Geniposide decreased apoptosis and ROS accumulation compared to these parameters in the Cd group. Geniposide attenuated oxidative stress-related factors, malondialdehyde and lactate dehydrogenase and increased antioxidant key enzyme superoxidase dismutase (SOD). The expression levels of Bax, Bcl-2 and survivin were modulated by geniposide. Additionally, the mRNA and protein expression of the receptor activator of NF-κB ligand (RANKL) and osterix were significantly increased, while osteoprotegerin was decreased by geniposide treatment compared to the Cd groups. Geniposide also enhanced Nrf2, heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1) expression. The present study identified a potential agent for the treatment of Cd-induced osteoblast injury.

Mesenchymal Stem Cell Therapy for Doxorubicin-Induced Cardiomyopathy: Potential Mechanisms, Governing Factors, and Implications of the Heart Stem Cell Debate

Over the past decades, researchers have reported several mechanisms for doxorubicin (DOX)-induced cardiomyopathy, including oxidative stress, inflammation, and apoptosis. Another mechanism that has been suggested is that DOX interferes with the cell cycle and induces oxidative stress in C-kit+ cells (commonly known as cardiac progenitor cells), reducing their regenerative capacity. Cardiac regeneration through enhancing the regenerative capacity of these cells or administration of other stem cells types has been the axis of several studies over the past 20 years. Several experiments revealed that local or systemic injections with mesenchymal stem cells (MSCs) were associated with significantly improved cardiac function, ameliorated inflammatory response, and reduced myocardial fibrosis. They also showed that several factors can affect the outcome of MSC treatment for DOX cardiomyopathy, including the MSC type, dose, route, and timing of administration. However, there is growing evidence that the C-kit+ cells do not have a cardiac regenerative potential in the adult mammalian heart. Similarly, the protective mechanisms of MSCs against DOX-induced cardiomyopathy are not likely to include direct differentiation into cardiomyocytes and probably occur through paracrine secretion, antioxidant and anti-inflammatory effects. Better understanding of the involved mechanisms and the factors governing the outcomes of MSCs therapy are essential before moving to clinical application in patients with DOX-induced cardiomyopathy.

Role of oxidative stress in cardiotoxicity of antineoplastic drugs

Tumors and heart disease are two of the leading causes of human death. With the development of anti-cancer therapy, the survival rate of cancer patients has been significantly improved. But at the same time, the incidence of cardiovascular adverse events caused by cancer treatment has also been considerably increased, such as arrhythmia, left ventricular (LV) systolic and diastolic dysfunction, and even heart failure (HF), etc., which seriously affects the quality of life of cancer patients. More importantly, the occurrence of adverse events may lead to the adjustment or the cessation of anti-cancer treatment, which affects the survival rate of patients. Understanding the mechanism of cardiotoxicity (CTX) induced by antineoplastic drugs is the basis of adequate protection of the heart without impairing the efficacy of antineoplastic therapy. Based on current research, a large amount of evidence has shown that oxidative stress (OS) plays an essential role in CTX induced by antineoplastic drugs and participates in its toxic reaction directly and indirectly. Here, we will review the mechanism of action of OS in cardiac toxicity of antineoplastic drugs, to provide new ideas for researchers, and provide further guidance for clinical prevention and treatment of cardiac toxicity of anti-tumor drugs in the future.

Heart Failure and Cancer: Mechanisms of Old and New Cardiotoxic Drugs in Cancer Patients

Although there have been many improvements in prognosis for patients with cancer, anticancer therapies are burdened by the risk of cardiovascular toxicity. Heart failure is one of the most dramatic clinical expressions of cardiotoxicity, and it may occur acutely or appear years after treatment. This article reviews the main mechanisms and clinical presentations of left ventricular dysfunction induced by some old and new cardiotoxic drugs in cancer patients, referring to the most recent advances in the field. The authors describe the mechanisms of cardiotoxicity induced by anthracyclines, which can lead to cardiovascular problems in up to 48% of patients who take them. The authors also describe mechanisms of cardiotoxicity induced by biological drugs that produce left ventricular dysfunction through secondary mechanisms. They outline the recent advances in immunotherapies, which have revolutionised anticancer therapies.

The Role of Cardiac Magnetic Resonance Imaging to Detect Cardiac Toxicity From Cancer Therapeutics

PURPOSE OF REVIEW

The emerging complexity of cardiac toxicity caused by cancer therapies has created demand for more advanced non-invasive methods to better evaluate cardiac structure, function, and myocardial tissue characteristics. Cardiac magnetic resonance imaging meets these needs without exposure to ionizing radiation, and with superior spatial resolution.

RECENT FINDINGS

Special applications of cardiac magnetic resonance (CMR) to assess for cancer therapy-induced cardiac toxicity include the detection of subclinical LV dysfunction through novel methods of measuring myocardial strain, detection of microcirculatory dysfunction, identification of LV and LA fibrosis, and more sensitive detection of inflammation caused by immune checkpoint inhibitors. CMR plays a significant role in the non-invasive workup of cardiac toxicity from cancer therapies, with recent advancements in the field that have opened avenues for further research and development.

The novel butyrate derivative phenylalanine-butyramide protects from doxorubicin-induced cardiotoxicity

AIMS

Butyric acid (BUT), a short chain fatty acid produced daily by the gut microbiota, has proven beneficial in models of cardiovascular diseases. With advancements in cancer survival, an increasing number of patients are at risk of anticancer drug cardiotoxicity. Here we assess whether the novel BUT derivative phenylalanine-butyramide (FBA) protects from doxorubicin (DOXO) cardiotoxicity, by decreasing oxidative stress and improving mitochondrial function.

METHODS AND RESULTS

In C57BL6 mice, DOXO produced left ventricular dilatation assessed by echocardiography. FBA prevented left ventricular dilatation, fibrosis and cardiomyocyte apoptosis when co-administered with DOXO. DOXO increased atrial natriuretic peptide, brain natriuretic peptide, connective tissue growth factor, and matrix metalloproteinase-2 mRNAs, which were not elevated on co-treatment with FBA. DOXO, but not FBA + DOXO mice, also showed higher nitrotyrosine levels, and increased inducible nitric oxide synthase expression. Accordingly, DOXO hearts showed lower levels of intracellular catalase vs. sham, while pre-treatment with FBA prevented this decrease. We then assessed for reactive oxygen species (ROS) emission: DOXO induced increased activity of mitochondrial superoxide dismutase and higher production of H₂ O₂ , which were blunted by FBA pre-treatment. FBA also ameliorated mitochondrial state 3 and state 4 respiration rates that were compromised by DOXO. Furthermore, in DOXO animals, the mitochondrial degree of coupling was significantly increased vs. sham, while FBA was able to prevent such increase, contributing to limit ROS production, Finally, FBA reduced DOXO damage in human cellular models, and increased the tumour-killing action of DOXO.

CONCLUSIONS

Phenylalanine-butyramide protects against experimental doxorubicin cardiotoxicity. Such protection is accompanied by reduction in oxidative stress and amelioration of mitochondrial function.