Imatinib-induced Cardiotoxicity Research Articles

Imatinib-Induced Cardiotoxicity

INTRODUCTION: The success of tyrosine kinase inhibitors in the treatment of chronic myeloid leukemia (CML) has increased the focus on survivorship and late toxicity in oncological care. Cardiovascular (CV) health has emerged as an important consideration in patients of CML. Some studies have shown an increased incidence of CHF with Imatinib therapy. This study was conducted to assess the cardiac functions in patients of CML on Imatinib therapy. METHODS: Seventy newly diagnosed CML patients started on Imatinib therapy having normal baseline cardiac functions as assessed by two-dimensional echocardiography and multigated acquisition (MUGA) scan were included in the study. Further assessment of cardiac functions at 3, 6, and 12 months was done by MUGA scan. RESULTS: At 3, 6, and 12 months of follow-up, 7.14%, 10%, and 11.43% of patients, respectively, showed evidence of cardiotoxicity in the form of reduced ejection fraction and wall abnormalities on MUGA scan (P = 0.58, 0.013, and 0.006, respectively). CONCLUSION: Cardiac dysfunction was seen in 11.43% of patients on Imatinib therapy for CML, though none of them were symptomatic. CML patients on Imatinib therapy must be monitored for cardiac functions, especially if they have other CV risk factors.

Induction of autophagy has protective roles in imatinib-induced cardiotoxicity.

Cardiotoxicity is one of the severe adverse effects of chemotherapeutic agents. Imatinib was previously reported to induce cardiotoxicity. Autophagy is an intracellular bulk protein and organelle degradation process, but its roles in cardiac diseases are unclear. We examined whether imatinib induces cardiomyocyte autophagy, and the role of autophagy in imatinib-induced cardiotoxicity using in vitro and in vivo experiments. In in vitro experiments, neonatal rat cardiomyocytes were treated with imatinib (1, 5, or 10 μM; 6 h). Myocyte autophagy was assessed by microtubule-associated protein light chain (LC) 3-II, beclin 1, mature cathepsin D, and acridine orange-stained mature autolysosome expression. Imatinib increased their expression, suggesting that it induced autophagy. Consequently, imatinib altered the production of mitochondria-derived reactive oxygen species (ROS) and loss of mitochondrial membrane potential, which were assessed by the fluorescent indicator MitoSOX and JC-1, respectively, leading to cardiomyocyte apoptosis. 3-methyl-adenine (3MA), an autophagic inhibitor, exacerbated imatinib-induced apoptosis by 30 %. In in vivo experiments, C57BL/6 mice were treated with imatinib (50 and 200 mg/kg/day) for 5 weeks in the presence or absence of 3MA. Echocardiographic measurement revealed that imatinib (200 mg) caused dilatation of the left ventricle (LV) and reduced LV fractional shortening. Apoptosis and LC3-II expression in cardiac tissue were increased by imatinib. Co-treatment with 3MA and imatinib further impaired imatinib-induced cardiac apoptosis and LV dysfunction. This study suggests that imatinib induces cardiomyocyte apoptosis, leading to cardiac dysfunction. Imatinib increases cardiomyocyte autophagy as a consequence of apoptosis and autophagy has a pro-survival role in imatinib-induced cardiac impairment.

P6275Role of autophagy in imatinib-induced cardiotoxicity

Abstract Background Cardiotoxicity is one of the severe adverse effects of chemotherapeutic agents. Imatinib, a therapeutic agent for chronic myelogenous leukemia, has been reported to induce cardiotoxicity. Autophagy is an intracellular bulk protein and organelle degradation process, but it is unclear whether autophagy functions as pro-death or pro-survival program during disease conditions. We examined whether imatinib induces myocyte autophagy and the role of autophagy in imatinib-induced cardiotoxicity in in vitro and in vivo experiments. Methods In in vitro experiments, neonatal rat cardiac myocytes were treated with imatinib (1, 5, 10 μM; 1–6 hrs). Inhibition of autophagy was performed using 3-methyl-adenine (3MA), an autophagic inhibitor, and transfection with Atg5-targeted siRNA. Myocyte apoptosis was detected by morphological change in nuclei and caspase 3 activity. Mitochondria-derived reactive oxygen species production was detected using MitoSOX and mitochondrial membrane potential was assessed by TMRM staining. Expressions of cytochrome c in mitochondria and cytosole were examined by Werstern blotting. Myocyte autophagy was assessed by monodansylcadaverine staining and microtubule-associated protein light chain (LC) 3-II expression. In in vivo experiments, C57BL6 mice were treated with imatinib (50 and 200 mg/kg/day) for 5 weeks in the presence or absence of 3MA. Cardiac function was examined by echocardiography. In cardiac tissue, apoptotic myocytes were examined by TUNEL assay and autophagy was examined by LC3-II expression. Results In in vitro experiments, imatinib increased apoptotic nuclei and caspase 3 activity, in a dose-dependent manner. Consequently, imatinib augmented production of mitochondria-derived reactive oxygen species, loss of mitochondrial membrane potential, and the release of cytochrome c from mitochondria to cytosole, suggesting that imatinib induced mitochondrial-apoptotic pathway. On the other hand, imatinib significantly increased monodansylcadaverine stained dots and LC3-II expression, suggesting that imatinib increased autophagy. 3MA and Atg5 siRNA augmented imatinib-induced apoptosis by 60% and 30%, respectively. In in vivo experiments, imatinib (200 mg) exhibited the dilatation of left ventricle by 15% and the depression of left ventricular fractional shortening by 23%. Ratio of apoptotic myocytes was significantly increased and LC3-II expression in cardiac tissue was enhanced by imatinib in a dose-dependent fashion. Co-treatment with 3MA and imatinib further impaired imatinib-induced myocyte apoptosis by 3 fold and LV dysfunction by 20%. Conclusion These results indicate that imatinib induced myocyte apoptosis, leading to cardiac dysfunction. Imatinib enhanced myocyte autophagy as a consequence of apoptosis and autophagy was a beneficial phenomenon in this condition.

Cardiotoxicity in Hematological Diseases: Are the Tyrosine Kinase Inhibitors Imatinib and Nilotinib Safe?

Chemotherapy-induced cardiotoxicity is a growing concern. The cardiotoxic impact of new drugs such as tyrosine kinase inhibitors is unknown, especially the ones used for chronic myeloid leukemia. We aim to evaluate nilotinib- and imatinib-induced cardiotoxicity. Single-center prospective study of consecutive patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors was conducted during 2015. Patients underwent an initial clinical, laboratorial and echocardiographic evaluation, repeated after 1year. Eleven patients were included [60.0 (11) years, 63.6% of males; seven patients treated with imatinib and four with nilotinib]. After 1year of follow-up, all patients remained in functional NYHA class I, with a similar Minnesota quality of life score. Also there was no difference in the biomarkers evaluated (cystatin-C and NT-proBNP). Likewise, no modification in systolic or diastolic function evaluated by echocardiography was observed. All patients presented normal values of longitudinal, circumferential and radial strain in the baseline study, without changes during follow-up. In addition, there were no differences between the two tyrosine kinase inhibitors used, considering all the aforementioned variables. No clinical, laboratory or echocardiographic evidence of nilotinib- and imatinib-induced cardiotoxicity was observed. However, these results should be confirmed in multicenter studies given the low incidence of chronic myeloid leukemia.

Imatinib-Induced Congestive Heart Failure: A Case Report

Imatinib has been approved by the FDA as an oral drug for the treatment of Chronic Myeloid Leukemia (CML), gastrointestinal stromal tumors (GISTs) and hyper eosinophilic syndrome. Although imatinib is well tolerated, the incidence of edema and dyspnea are reported to be as high as 66 and 16%, respectively. Imatinib-induced cardiotoxicity is a very uncommon adverse event <1%. A 53-year-old male with history of Chronic Myeloid Leukemia (CML) on Imatinib for the past 5 years. He presented with symptoms of exertional dyspnea, poor exercise performance, fatigue, and leg swellings. Chest X-ray revealed cardiomegaly, and pulmonary edema. Electrocardiogram showed normal sinus rhythm, no ischemic changes. Cardiac enzymes were normal. 2D Echocardiogram showed ejection fraction EF of 35%, normal pulmonary systolic pressure, no wall motion abnormality, with normal valvular function. In our case report, we discuss the association between Imatinib use and congestive heart failure, which may need discontinuing the medication and prompt treatment of congestive heart failure.

The Myocyte-Damaging Effects of the BCR-ABL1-Targeted Tyrosine Kinase Inhibitors Increase with Potency and Decrease with Specificity.

Five clinically approved BCR-ABL1-targeted tyrosine kinase inhibitors (bosutinib, dasatinib, imatinib, nilotinib, and ponatinib) used for treating chronic myelogenous leukemia have been studied in a neonatal rat myocyte model for their relative ability to induce myocyte damage. This was done in order to determine if kinase inhibitor-induced myocyte damage was a consequence of inhibiting ABL1 (on-target effects), or due to a lack of kinase selectivity (off-target effects) since previous studies have come up with conflicting conclusions about whether imatinib-induced cardiotoxicity results directly from inhibition of ABL1. The most specific and least potent inhibitors, imatinib and nilotinib, induced the least myocyte damage, while the least specific and most potent inhibitors, ponatinib and dasatinib, induced the most damage. Inhibitor-induced myocyte damage also correlated with clinically observed cardiovascular toxicity. Growth inhibition of the erythroleukemic K562 human cell line with a constitutively active BCR-ABL1 kinase was negatively correlated with inhibitor-induced myocyte damage, which suggests that inhibition of ABL1 causes myocyte damage. Myocyte damage was also negatively correlated with inhibitor dissociation binding constants and with inhibition of enzymatic ABL1 kinase activity. Myocyte damage was also positively correlated with two measures of inhibitor selectivity, which suggests that a lack of inhibitor selectivity is responsible for myocyte damage. In conclusion, myocyte damage, and thus the cardiovascular toxicity of the BCR-ABL1-targeted tyrosine kinase inhibitors, is due to direct inhibition of ABL1 and/or their lack of inhibitor selectivity.

Imatinib-induced decompensated heart failure in an elderly patient with chronic myeloid leukemia: case report and literature review

Because it is safe and well tolerated, imatinib is a standard first-line therapy for chronic myeloid leukemia (CML). Although there have been sporadic reports of imatinib-induced cardiotoxicity, including left ventricle (LV) dysfunction and heart failure, the evidence for it is contradictory. Here, we reported a case of an 88-year-old male patient with CML developed decompensated heart failure following imatinib therapy. Four days after the initiation of imatinib, the patient developed orthopnea, edema and a pleural effusion accompanied by abdominal distension, nausea and vomiting. The chest X-ray film showed an enlarged cardiac profile. The echocardiogram demonstrated a decreased LV ejection fraction and enlarged left-side cardiac chambers. B-type natriuretic peptide concentrations were markedly increased. The patient recovered soon after the withdrawal of imatinib and introduction of comprehensive therapy for heart failure. Imatinib-induced cardiotoxicity in elderly patients is a potentially serious complication that merits further evaluation.

BGP-15, a PARP-inhibitor, prevents imatinib-induced cardiotoxicity by activating Akt and suppressing JNK and p38 MAP kinases

In this study, we investigate the cardiotoxic effects of the well-known cytostatic agent imatinib mesylate (Gleevec), and presented evidence for the cardioprotective effect of BGP-15 which is a novel insulin sensitizer. The cardiotoxic effect of imatinib mesylate was assessed in Langendorff rat heart perfusion system. The cardiac high-energy phosphate levels (creatine phosphate (PCr) and ATP) were monitored in situ by (31)P NMR spectroscopy. The protein oxidation, lipid peroxidation, and the activation of signaling pathways were determined from the freeze-clamped hearts. Prolonged treatment of the heart with imatinib mesylate (20 mg/kg) resulted in cardiotoxicity, which were characterized by the depletion of high-energy phosphates (PCr and ATP), and significantly increased protein oxidation and lipid peroxidation. Imatinib mesylate treatment-induced activation of MAP kinases (including ERK1/2, p38, and JNK) and the phosphorylation of Akt and GSK-3beta. BGP-15 (200 μM) prevented the imatinib mesylate-induced oxidative damages, attenuated the depletion of high-energy phosphates, altered the signaling effect of imatinib mesylate by preventing p38 MAP kinase and JNK activation, and induced the phosphorylation of Akt and GSK-3beta. The suppressive effect of BGP-15 on p38 and JNK activation could be significant because these kinases contribute to the cell death and inflammation in the isolated perfused heart.

Imatinib: the controversial discussion on cardiotoxicity induced by endoplasmic reticulum (ER) stress

The safety profile of imatinib, and especially its relevance to cardiotoxicity, has been controversially discussed in recent years (Kerkela et al. 2006; Herman et al. 2011; Wolf et al. 2010; Ribeiro et al. 2008). Therefore, the editors are pleased that Eirini Thanopoulou and Ian Judson from the Royal Marsden NHS foundation Trust in London contributed a comprehensive review on the long-term tolerability of imatinib (Gleevec) (Thanopoulou and Judson 2012). The introduction of imatinib represents one of the most prominent success stories in cancer therapy of the past decade. A reciprocal translocation creating the Philadelphia chromosome is involved in pathogenesis of more than 90% of the cases of chronic myelogenous leukaemia (CML) (Van Etten 2004). This translocation creates the Bcr-Abl fusion protein of the nonreceptor tyrosine kinase c-Abl and the multidomain protein Bcr, leading to a constitutively active cytosolic protein that activates several signalling pathways involved in proliferation and antiapoptosis. Imatinib inhibits the fusion protein, Bcr-Abl resulting in remission in a high fraction of patients with CML. In addition, imatinib is efficient in gastrointestinal stromal tumour (GIST), because—besides its effect on Bcr-Abl—it also inhibits KIT proteins that play a role in progression of GIST and other tumours (Joensuu et al. 2001; Micke et al. 2003, 2004). The success stories of imatinib, and the Her-2-targeting antibody, trastuzumab, led to the novel concept of identifying and targeting the mechanisms responsible of tumour progression, in addition to identifying subtypes of carcinomas with the perspective of a biologically justified therapy (Schmidt et al. 2008, 2010; Hellwig et al. 2010; Cadenas et al. 2010; Lee et al. 2010; Brase et al. 2010; Petry et al. 2010). Previously, Kerkela et al. (2006) reported on the cardiotoxic side effect of imatinib. Individuals without any prior history of heart disease developed heart failure after treatment with imatinib (Kerkela et al. 2006). Interestingly, imatinib also showed toxic effects on cultivated cardiomyocytes, most likely due to an induction of endoplasmic reticulum (ER) stress, leading to decreased translation and a block in protein synthesis (Kerkela et al. 2006). A simultaneous upregulation of stress response genes suggested that the ER stress response is an adequate mechanism to compensate short-term cell stress. However, prolonged activation may induce cell death by pathways, including Jun N-terminal kinases (JNKs), a mechanism shown for imatinib in cardiomyocytes (Kerkela et al. 2006). Since cardiotoxicity is one of the leading topics in toxicology addressed in our journal (Sumi et al. 2011; Vavrova et al. 2011; Lee et al. 2010), we welcome the current review by Thanopoulou and Judson (2012). Overall, imatinib shows an excellent long-term tolerability and the clinical relevance of imatinib-induced cardiotoxicity may have been overestimated. The comprehensive review of Thanopoulou and Judson (2012) comes highly recommended for anyone interested in the safety profile of imatinib.

A Multifaceted Evaluation of Imatinib-induced Cardiotoxicity in the Rat

Cardiotoxicity was an unanticipated side effect elicited by the clinical use of imatinib (Imb). This toxicity has been examined in only a limited number of experimental studies. The present study sought, by a variety of approaches, to identify important characteristics of Imb-induced cardiac alterations. Male spontaneously hypertensive rats (SHRs) received oral doses of 10, 30, or 50 mg/kg Imb or water daily for 10 d. Cardiac lesions, detected at all doses, were characterized by cytoplasmic vacuolization and myofibrillar loss. In a second experiment, cardiac lesions were found in Sprague Dawley (SD) and SHR rats given 50 or 100 mg/kg Imb for 14 d. Mean cardiac lesion scores and serum levels of cardiac troponin I were higher in SHRs than in SD rats. Imb induced myocyte death by necrosis, autophagy, and apoptosis. Dose-related increases in cardiac expression were observed for several genes associated with endoplasmic reticulum stress response, protein folding, and vascular development and remodeling. Imb caused alterations in isolated myocytes (myofibrillar loss, highly disrupted and disorganized sarcomeric α-actinin, apoptosis, and increased lactate dehydrogenase release) at low concentrations (5 mM). The authors conclude that Imb exerts cardiotoxic effects that are manifest through a complex pattern of cellular alterations, the severity of which can be influenced by arterial blood pressure.

Abstract 3584: Comparison of the severity of imatinib-induced cardiotoxicity in normotensive Sprague-Dawley (SD) and spontaneously hypertensive (SHR) rats

Abstract Imatinib (IMNB) is a promising type of chemotherapeutic agent that specifically targets tyrosine kinase pathway-dependent tumors. However, cardiotoxicity has been reported with clinical use of IMNB. The characteristics of IMNB-induced cardiac alterations are not completely defined. The present study sought to examine the influence of a concomitant disease such as hypertension on the cardiotoxic effects of IMNB. Groups of adult male SD or SHR were dosed with 50 (5/group) or 100 mg/kg (10/group) IMNB or water (10/group)(p.o.) daily for 14 days (dose of 50 mg/kg is approximately 2x recommended human dose of 600 mg/m2). Tissues and blood samples were collected 24 hours after the last dosing. The 100 mg/kg dose caused a slight reduction in the rate of body weight gain. Serum levels of glucose were decreased and alanine transaminase (ALT) were increased in both SD and SHR dosed with IMNB. Changes from control were most pronounced in SD given 100mg/kg IMNB (ALT=175% vs 118% and glucose=81% vs 91% compared to SHR). White blood cell counts were depressed in SHR but not in SD rats. Dose-dependent cardiac lesions were noted in the groups of SD and SHR given either dose of IMNB (blinded evaluation). Cardiac lesions were characterized by cytoplasmic vacuolization, myofibrillar loss, interstitial infiltration with chronic inflammatory cells and fibrosis (proliferation of myofibroblasts). Mean lesion scores (based on a scale of 0 to 3) were higher in SHR than in SD (100mg/kg-1.9 vs 1.25 and 50 mg/kg-1.5 vs 1.1, p&amp;lt;0.05)(Tukey-Kramer test). Increased serum levels of cardiac troponin I were detected in all IMNB-treated groups. The overall mean cTnI levels were higher in SHR (31.5, 41.3 and 53.9 pg/ml) compared to SD (6.8, 25 and 30 pg/ml) at the vehicle control, 50 and 100 mg/kg doses, respectively. These results indicate that hypertension as expressed in SHR appears to be a factor that can intensify the cardiotoxic effects of IMNB and that monitoring for cardiac troponin I may provide a sensitive means of detecting IMNB toxicity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3584.

Results of plasma N-terminal pro B-type natriuretic peptide and cardiac troponin monitoring in GIST patients do not support the existence of imatinib-induced cardiotoxicity

BackgroundRecently, case reports of patients treated with imatinib (imatinib mesylate; Gleevec®; Glivec®) indicated that this tyrosine kinase inhibitor may induce cardiomyopathy. Consequently, careful cardiac monitoring was advocated for clinical studies. The purpose of this study was to prospectively evaluate whether imatinib (Gleevec) induces early, subclinical, cardiac toxicity. Patients and methodsHistory and physical examination were carried out with special attention for symptoms of heart failure. Additionally, assessments of serial plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) and serum cardiac troponin T (cTnT) measurement before and 1 and 3 months after the start of imatinib treatment (400–800 mg daily) were done in patients with advanced and/or metastatic gastrointestinal stromal tumours (GIST). ResultsA total of 55 GIST patients were enrolled. Only one patient, with a normal pretreatment NT-proBNP, showed an increase in NT-proBNP to above age-specific normal values during imatinib treatment and developed symptomatic heart failure due to pre-existent cardiac valvular disease. cTnT levels remained stable. ConclusionsIn our study population, imatinib treatment for GIST was not associated with an increase in plasma NT-proBNP levels, indicating that the risk of subclinical cardiac toxicity is limited with the use of this agent. These results do not support the current strategy to standard cardiac monitoring in all patients. This may be restricted to GIST patients with a history of cardiac disease.

In Vitro Cardiotoxicity Potential Comparative Assessments of Chronic Myelogenous Leukemia Tyrosine Kinase Inhibitor Therapies: Dasatinib, Imatinib and Nilotinib.

Tyrosine kinase inhibitors (TKI) selective for Bcr-Abl, such as dasatinib, imatinib, and nilotinib have had remarkable success in the clinic, potentially shifting the prognosis of chronic myelogenous leukemia (CML) to a manageable chronic disease. With the increase in longevity of CML patients, there is rising concern of co-morbidities that may be influenced by chemotherapy (Force et al., Nature Rev. 2007; 7:332–340). Recently, congestive heart failure (CHF) and direct cellular cardiotoxicity have been reported in CML patients on imatinib therapy (Kerkela et al., Nature Medicine 2006; 12:908–916). Ultrastructural mitochondrial abnormalities in cardiomyocytes were observed in CML patients with severe CHF and, interestingly, similar abnormalities were observed in cardiomyocytes of imatinib-treated mice, thus providing a prospective in vivo animal model for imatinib-induced cardiotoxicity. Furthermore, correlative findings of mitochondrial membrane potential loss, decreased cell viability, and increased apoptosis resulted from an array of cell-based assays in imatinib-treated primary rat cardiomyocytes, consequentially affording a supportive, if not predictive, in vitro cardiomyocyte toxicity model. Since imatinib-induced inhibition of the native form of c-Abl kinase was speculated to cause the observed cardiotoxicity and c-Abl is a shared target of dasatinib, imatinib, and nilotinib, the in vitro cardiotoxicity potential of dasatinib and nilotinib at pharmacologically relevant concentrations (0.09 μM and 5 μM, respectively) and up to 10-fold higher concentrations were compared side-by-side with imatinib in primary rat cardiomyocytes. Dasatinib did not significantly affect mitochondrial membrane potential, cell viability, apoptosis, or cellular ultrastructure in vitro, whereas imatinib significantly affected these parameters. Nilotinib at pharmacologically relevant concentration demonstrated decreased cell viability, but differed from imatinib in that mitochondrial membrane potential integrity was not affected under identical experimental conditions. Results suggest that at pharmacologically relevant concentrations, dasatinib does not induce cardiotoxicity, as does imatinib and nilotinib, and the molecular mechanisms of the observed cardiotoxicities may differ between imatinib and nilotinib. Of indirect relation, results from assessing another cardiovascular liability, namely hERG K+ channel blockade, demonstrated that dasatinib, imatinib and nilotinib differentially inhibited the hERG currents in vitro with IC50 of 14.3, 15.6 and 0.66 μM, respectively. These in vitro findings occurred at concentration levels approximately 150, 3 and 0.1-fold the expected human Cmax for the three TKIs, respectively. Thus, although TKI therapies may share similar targeting and clinical indications, differentiating specific toxicity profiles may be predictive of differences in potential clinical adversities.

ER stress response behind imatinib-induced cardiotoxicity

ER stress response behind imatinib-induced cardiotoxicity