Doxorubicin-induced and trastuzumab-induced cardiotoxicity in mice is not prevented by metoprolol

Empagliflozin attenuates trastuzumab-induced cardiotoxicity through suppression of DNA damage and ferroptosis

Trastuzumab (TZM) is commonly used for target therapy in breast cancer patients with high HER2 although the cardiotoxicity restricts its clinical usage. DNA damage and ferroptosis are implicated in anti-tumor drug cardiotoxicity. Given the emerging use of SGLT2 inhibitors in clinical cardiology, this study evaluated the impact of SGLT2 inhibitor Empagliflozin on TZM-induced cardiotoxicity, and mechanism involved with a focus on DNA damage and ferroptosis. Adult C57BL/6 mice were challenged with TZM (10 mg/kg/week, i.p.) or saline for six weeks. A cohort of mice received Empagliflozin (10 mg/kg, i.p.) at the same time. Myocardial function, morphology, ultrastructure, mitochondrial integrity, oxidative stress, DNA damage and various cell death domains were evaluated in TZM-challenged mice with or without Empagliflozin treatment. Our data revealed that TZM challenge overtly increased levels of serum LDH and troponin I, promoted adverse myocardial remodeling (increased heart weight, chamber size, cardiomyocyte area and interstitial fibrosis), contractile dysfunction and intracellular Ca²⁺ mishandling, oxidative stress, lipid peroxidation, mitochondrial ultrastructural damage, DNA damage, apoptosis and ferroptosis, the effects of which were greatly attenuated or mitigated by Empagliflozin with little effects from Empagliflozin itself. In vitro study indicated that induction of DNA damage mimicked TZM-induced lipid peroxidation and cardiomyocyte contractile dysfunction while the ferroptosis inducer erastin mitigated Empagliflozin-offered protection against lipid peroxidation and cardiomyocyte dysfunction (but not DNA damage). Likewise, in vivo and in vitro inhibition of ferroptosis recapitulated Empagliflozin-offered cardioprotection against TZM exposure. Taken together, these data demonstrated that Empagliflozin may be possible candidate drug for TZM cardiotoxicity likely through a DNA damage-ferroptosis-mediated mechanism.

Prevention of Anthracycline-Induced Cardiotoxicity: The Good and Bad of Current and Alternative Therapies

Doxorubicin (Dox)-induced cardiotoxicity (DIC) remains a serious health burden, especially in developing countries. Unfortunately, the high cost of current preventative strategies has marginalized numerous cancer patients because of socio-economic factors. In addition, the efficacy of these strategies, without reducing the chemotherapeutic properties of Dox, is frequently questioned. These limitations have widened the gap and necessity for alternative medicines, like flavonoids, to be investigated. However, new therapeutics may also present their own shortcomings, ruling out the idea of “natural is safe”. The U.S. Food and Drug Administration (FDA) has stipulated that the concept of drug-safety be considered in all pre-clinical and clinical studies, to explore the pharmacokinetics and potential interactions of the drugs being investigated. As such our studies on flavonoids, as cardio-protectants against DIC, have been centered around cardiac and cancer models, to ensure that the efficacy of Dox is preserved. Our findings thus far suggest that flavonoids of Galenia africana could be suitable candidates for the prevention of DIC. However, this still requires further investigation, which would focus on drug-interactions as well as in vivo experimental models to determine the extent of cardioprotection.

Mulberrin Confers Protection against Doxorubicin-Induced Cardiotoxicity via Regulating AKT Signaling Pathways in Mice

Doxorubicin (DOX) is an antitumor anthracycline, but its clinical use was largely limited by its cardiac toxicity. DOX-induced oxidative damage and cardiomyocyte loss have been recognized as the potential causative mechanisms of this cardiac toxicity. Growing interests are raised on mulberrin (Mul) for its wide spectrum of biological activities, including antioxidative and anti-inflammatory properties. The aim of this study was to investigate the effect of Mul on DOX-induced heart injury and to clarify the underlying mechanism. Mice were given daily 60 mg/kg of Mul via gavage for 10 days. Mice received an intraperitoneal injection of DOX to mimic the model of DOX-related acute cardiac injury at the seventh day of Mul treatment. Mul-treated mice had an attenuated cardiac injured response and improved cardiac function after DOX injection. DOX-induced oxidative damage, inflammation accumulation, and myocardial apoptosis were largely attenuated by the treatment of Mul. Activated protein kinase B (AKT) activation was essential for the protective effects of Mul against DOX-induced cardiac toxicity, and AKT inactivation abolished Mul-mediated protective effects against DOX cardiotoxicity. In conclusion, Mul treatment attenuated DOX-induced cardiac toxicity via activation of the AKT signaling pathway. Mul might be a promising therapeutic agent against DOX-induced cardiac toxicity.

Preparation and Evaluation of Animal Models of Cardiotoxicity in Antineoplastic Therapy

The continuous development of antineoplastic therapy has significantly reduced the mortality of patients with malignant tumors, but its induced cardiotoxicity has become the primary cause of long-term death in patients with malignant tumors. However, the pathogenesis of cardiotoxicity of antineoplastic therapy is currently unknown, and practical means of prevention and treatment are lacking in clinical practice. Therefore, how to effectively prevent and treat cardiotoxicity while treating tumors is a major challenge. Animal models are important tools for studying cardiotoxicity in antitumor therapy and are of great importance in elucidating pathophysiological mechanisms and developing and evaluating modality drugs. In this paper, we summarize the existing animal models in antitumor therapeutic cardiotoxicity studies and evaluate the models by observing the macroscopic signs, echocardiography, and pathological morphology of the animals, aiming to provide a reference for subsequent experimental development and clinical application.

Prophylactic Evidence of MSCs-Derived Exosomes in Doxorubicin/Trastuzumab-Induced Cardiotoxicity: Beyond Mechanistic Target of NRG-1/Erb Signaling Pathway

Trastuzumab (Trz) is a humanized monoclonal antibody targeting epidermal growth factor receptor 2 (HER2; ErbB2). The combined administration of Trz and doxorubicin (DOX) has shown potent anti-cancer efficacy; however, this regimen may be accompanied by severe cardiac toxicity. Mesenchymal stem cells (MSCs)-derived exosomes are nanosized vesicles that play a crucial role in cell–cell communication and have shown efficacy in the treatment of various diseases. In this study, we aim to investigate the cardioprotective effects of MSCs-derived exosomes in a DOX/Trz- mediated cardiotoxicity model, and the possible mechanisms underlying these effects are elucidated. Forty-nine male rats were randomly assigned into four groups: Group I (control); Group II (Dox/Trz); Group III (protective group); and Group IV (curative group). Cardiac hemodynamic parameters, serum markers of cardiac injury, oxidative stress indices, and cardiac histopathology were investigated. Further, transcript profile of specific cardiac tissue injury markers, apoptotic markers, and fibrotic markers were analyzed using qRT-PCR, while the protein expressions of pAkt/Akt, pERK/ERK, pJNK/JNK, pJNK/JNK, and pSTAT3/STAT3 were evaluated by ELISA. Additionally, cardiac mirR-21 and miR-26a were assessed. A combined administration of DOX/Trz disrupted redox and Ca²⁺ homeostasis in cardiac tissue induced myocardial fibrosis and myofibril loss and triggered cardiac DNA damage and apoptosis. This cardiotoxicity was accompanied by decreased NRG-1 mRNA expression, HER2 protein expression, and suppressed AKT and ERK phosphorylation, while triggering JNK phosphorylation. Histological and ultra-structural examination of cardiac specimens revealed features typical of cardiac tissue injury. Moreover, a significant decline in cardiac function was observed through biochemical testing of serum cardiac markers and echocardiography. In contrast, the intraperitoneal administration of MSCs-derived exosomes alleviated cardiac injury in both protective and curative protocols; however, superior effects were observed in the protective protocol. The results of the current study indicate the ability of MSCs-derived exosomes to protect from and attenuate DOX/Trz-induced cardiotoxicity. The NRG-1/HER2, MAPK, PI3K/AKT, PJNK/JNK, and PSTAT/STAT signaling pathways play roles in mediating these effects.

Cardiotoxicity of Epidermal Growth Factor Receptor 2-Targeted Drugs for Breast Cancer

Breast cancer is the most common form of cancer in women and its incidence has been increasing over the years. Human epidermal growth factor receptor 2 (HER2 or ErbB2) overexpression is responsible for 20 to 25% of invasive breast cancers, and is associated with poor prognosis. HER2-targeted therapy has significantly improved overall survival rates in patients with HER2-positive breast cancer. However, despite the benefits of this therapy, its cardiotoxicity is a major concern, especially when HER2-targeted therapy is used in conjunction with anthracyclines. At present, the mechanism of this cardiotoxicity is not fully understood. It is thought that HER2-targeting drugs inhibit HER2/NRG 1 dimer formation, causing an increase in ROS in the mitochondria of cardiomyocytes and inhibiting the PI3K/Akt and Ras/MAPK pathways, resulting in cell apoptosis. Antioxidants, ACE inhibitors, angiotensin II receptor blockers, β-blockers, statins and other drugs may have a cardioprotective effect when used with ErbB2-targeting drugs. NT-proBNP can be used to monitor trastuzumab-induced cardiotoxicity during HER2-targeted treatment and may serve as a biological marker for clinical prediction of cardiotoxicity. Measuring NT-proBNP is non-invasive, inexpensive and reproducible, therefore is worthy of the attention of clinicians. The aim of this review is to discuss the potential mechanisms, clinical features, diagnostic strategies, and intervention strategies related to cardiotoxicity of ErbB2-targeting drugs.

The Protective Effects of Coenzyme Q10 and Lisinopril Against Doxorubicin-Induced Cardiotoxicity in Rats: A Stereological and Electrocardiogram Study

Doxorubicin (DOX) is used as an anticancer drug despite its several side effects, especially its irreversible impacts on cardiotoxicity. Coenzyme Q10 (Q10) as a powerful antioxidant and lisinopril (LIS) as an angiotensin-converting enzyme inhibitor seem to provide protection against DOX-induced cardiotoxicity. Therefore, this study aimed to assess the cardioprotective effects of Q10 and LIS against DOX-induced cardiotoxicity in rats. Adult male Sprague-Dawley rats were randomly assigned into the control, LIS, Q10, DOX, DOX + LIS, and DOX + Q10 groups. On day 21, ECG was recorded and the right ventricle was dissected for evaluation of catalase activity and malondialdehyde (MDA) concentration. Additionally, the left ventricle and the sinoatrial (SA) node were dissected to assess the stereological parameters. The results of ECG indicated bradycardia and increase in QRS duration and QT interval in the DOX group compared to the control group. Meanwhile, the total volumes of the left ventricle, myocytes, and microvessels and the number of cardiomyocyte nuclei decreased, whereas the total volume of the connective tissue and the mean volume of cardiomyocytes increased in the DOX group. On the other hand, the SA node and the connective tissue were enlarged, while the volume of the SA node nuclei was reduced in the DOX group. Besides, catalase activity was lower and MDA concentration was higher in the DOX-treated group. Q10 could recover most stereological parameters, catalase activity, and MDA concentration. LIS also prevented some stereological parameters and ECG changes and improved catalase activity and MDA concentration in the DOX group. The findings suggested that Q10 and LIS exerted cardioprotective effects against DOX-induced cardiac toxicity.

Doxorubicin-induced and trastuzumab-induced cardiotoxicity in mice is not prevented by metoprolol

Aims

Our objectives were to validate a murine model of chronic cardiotoxicity induced by Doxorubicin (Dox) and Trastuzumab (Trast) and to test the potential cardio‐protective effect of metoprolol.

Methods and results

Male C57Bl6 mice were intraperitoneally injected during 2 weeks with Dox (24 mg/kg) or saline, and then with Trast (10 mg/kg) or saline for two more weeks. Half of the mice received metoprolol (100 mg/kg). Cardiotoxicity was defined by a decline in left ventricular ejection fraction (LVEF) ≥ 10 points. At Day 42, Dox + Trast‐treated mice exhibited a 13‐points decline in LVEF (74 ± 2.6% vs. 87 ± 0.8% for control mice, P < 0.001) and a severe cardiac atrophy (heart weight: 105 ± 2.7 mg vs. 119 ± 3.9 mg for control mice, P < 0.01). This cardiac atrophy resulted from an excess of cardiac necrosis (assessed by plasma cardiac troponin I level: 3.2 ± 0.4 ng/L vs. 1.3 ± 0.06 ng/L for control mice, P < 0.01), an increase in apoptosis (caspase 3 activity showing a six‐fold increase for Dox + Trast‐treated mice vs. controls, P < 0.001), and cardiomyocyte atrophy (myocyte size: 0.67 ± 0.08 μm² vs. 1.36 ± 0.10 μm² for control mice, P < 0.001). In addition, Dox + Trast‐treated mice were shown to have an increased cardiac oxidative stress (164 ± 14 dihydroethidine‐marked nuclei per area vs. 56 ± 9.5 for control mice, P < 0.01) and increased cardiac fibrosis (the semi‐quantitative fibrosis score was three‐fold higher for Dox + Trast‐treated mice as compared with controls, P < 0.01). Metoprolol was not able to prevent either the decrease in LVEF or the severe cardiac atrophy, the cardiac necrosis, and the cardiac remodelling induced by chemotherapies.

Conclusion

A murine model of chronic cardiotoxicity induced by Dox and Trast was characterized by a decrease in cardiac function, a cardiac apoptosis and necrosis leading to cardiomyocyte atrophy. Metoprolol did not prevent this cardiotoxicity.