Cardiotoxicity Of Sunitinib Research Articles

Autophagic degradation of CCN2 (cellular communication network factor 2) causes cardiotoxicity of sunitinib

ABSTRACT Excessive macroautophagy/autophagy is one of the causes of cardiomyocyte death induced by cardiovascular diseases or cancer therapy, yet the underlying mechanism remains unknown. We and other groups previously reported that autophagy might contribute to cardiomyocyte death caused by sunitinib, a tumor angiogenesis inhibitor that is widely used in clinic, which may help to understand the mechanism of autophagy-induced cardiomyocyte death. Here, we found that sunitinib-induced autophagy leads to apoptosis of cardiomyocyte and cardiac dysfunction as the cardiomyocyte-specific Atg7 −/+ heterozygous mice are resistant to sunitinib. Sunitinib-induced maladaptive autophagy selectively degrades the cardiomyocyte survival mediator CCN2 (cellular communication network factor 2) through the TOLLIP (toll interacting protein)-mediated endosome-related pathway and cardiomyocyte-specific knockdown of Ccn2 through adeno-associated virus serotype 9 (AAV9) mimics sunitinib-induced cardiac dysfunction in vivo, suggesting that the autophagic degradation of CCN2 is one of the causes of sunitinib-induced cardiotoxicity and death of cardiomyocytes. Remarkably, deletion of Hmgb1 (high mobility group box 1) inhibited sunitinib-induced cardiomyocyte autophagy and apoptosis, and the HMGB1-specific inhibitor glycyrrhizic acid (GA) significantly mitigated sunitinib-induced autophagy, cardiomyocyte death and cardiotoxicity. Our study reveals a novel target protein of autophagic degradation in the regulation of cardiomyocyte death and highlights the pharmacological inhibitor of HMGB1 as an attractive approach for improving the safety of sunitinib-based cancer therapy.

Findings of congestive heart failure associated with sunitinib cardiotoxicity in 18F-FDG PET/CT

Findings of congestive heart failure associated with sunitinib cardiotoxicity in 18F-FDG PET/CT

Sunitinib-induced cardiac hypertrophy and the endothelin axis.

Anti-angiogenics drugs in clinical use for cancer treatment induce cardiotoxic side effects. The endothelin axis is involved in hypertension and cardiac remodelling, and addition of an endothelin receptor antagonist to the anti-angiogenic sunitinib was shown to reduce cardiotoxicity of sunitinib in mice. Here, we explored further the antidote effect of the endothelin receptor antagonist macitentan in sunitinib-treated animals on cardiac remodeling.Methods: Tumor-bearing mice treated per os daily by sunitinib or vehicle were imaged before and after 1, 3 and 6 weeks of treatment by positron emission tomography using [18F]fluorodeoxyglucose and by echocardiography. Non-tumor-bearing animals were randomly assigned to be treated per os daily by vehicle or sunitinib or macitentan or sunitinib+macitentan, and imaged by echocardiography after 5 weeks. Hearts were harvested for histology and molecular analysis at the end of in vivo exploration.Results: Sunitinib treatment increases left ventricular mass and ejection fraction and induces cardiac fibrosis. Sunitinib also induces an early increase in cardiac uptake of [18F]fluorodeoxyglucose, which is significantly correlated with increased left ventricular mass at the end of treatment. Co-administration of macitentan prevents sunitinib-induced hypertension, increase in ejection fraction and cardiac fibrosis, but fails to prevent increase of the left ventricular mass.Conclusion: Early metabolic changes predict sunitinib-induced cardiac remodeling. Endothelin blockade can prevent some but not all cardiotoxic side-effects of sunitinib, in particular left ventricle hypertrophy that appears to be induced by sunitinib through an endothelin-independent mechanism.

Heart slice culture system reliably demonstrates clinical drug-related cardiotoxicity

The limited availability of human heart tissue and its complex cell composition are major limiting factors for the reliable testing of drug efficacy and toxicity. Recently, we developed functional human and pig heart slice biomimetic culture systems that preserve the viability and functionality of 300 μm heart slices for up to 6 days. Here, we tested the reliability of this culture system for testing the cardiotoxicity of anti-cancer drugs. We tested three anti-cancer drugs (doxorubicin, trastuzumab, and sunitinib) with known different mechanisms of cardiotoxicity at three concentrations and assessed the effect of these drugs on heart slice viability, structure, function and gene expression. Slices incubated with any of these drugs for 48 h showed diminished in viability as well as loss of cardiomyocyte structure and function. Mechanistically, RNA sequencing of doxorubicin-treated tissues demonstrated a significant downregulation of cardiac genes and upregulation of oxidative stress responses. Trastuzumab treatment downregulated cardiac muscle contraction-related genes consistent with its clinically known effect on cardiomyocytes. Interestingly, sunitinib treatment resulted in significant downregulation of angiogenesis-related genes, in line with its mechanism of action. Similar to hiPS-derived-cardiomyocytes, heart slices recapitulated the expected toxicity of doxorubicin and trastuzumab, however, slices were superior in detecting sunitinib cardiotoxicity and mechanism in the clinically relevant concentration range of 0.1–1 μM. These results indicate that heart slice culture models have the potential to become a reliable platform for testing and elucidating mechanisms of drug cardiotoxicity.

Mitochondrial oxidative stress plays a critical role in the cardiotoxicity of sunitinib: Running title: Sunitinib and oxidative stress in hearts

Sunitinib is cardiotoxic, but the mechanisms are not entirely clear. We aimed to enlarge our knowledge about the role of mitochondria in cardiac toxicity of sunitinib in vitro and in vivo. For this reason, we studied the toxicity of sunitinib on cardiac H9c2 cells exposed for 24 h, permeabilized rat cardiac fibers exposed for 15 min and in mice treated orally with sunitinib for 2 weeks (7.5 mg/kg/day).In H9c2 cells exposed for 24 h, sunitinib was more cytotoxic under galactose (favoring mitochondrial metabolism) compared to glucose conditions (favoring glycolysis). Sunitinib dissipated the mitochondrial membrane potential starting at 10 μM under glucose and at 5 μM under galactose conditions. Sunitinib reduced activities of mitochondrial enzyme complexes of the electron transport chain (ETC), increased mitochondrial ROS accumulation and decreased the cellular GSH pool. Electron microscopy revealed swollen mitochondria with loss of cristae. Accordingly, sunitinib caused caspase 3 activation and DNA fragmentation in H9c2 cells. Co-exposure with mito-TEMPO (mitochondrial-specific ROS scavenger) for 24 h prevented ATP and GSH depletion, as well as the increases in H2O2 and caspase 3/7 activity observed with sunitinib. In mice, treatment with sunitinib for two weeks increased plasma concentrations of troponin I and creatine kinase MB, indicating cardiomyocyte damage. The activity of enzyme complexes of the ETCwas decreased, mitochondrial ROS were increased and cleavage of caspase 3 was increased, suggesting cardiomyocyte apoptosis.In conclusion, mitochondrial damage with ROS accumulation appears to be an important mechanism of cardiotoxicity associated with sunitinib, eventually leading to apoptotic cell death.

Increased Afterload Augments Sunitinib-Induced Cardiotoxicity in an Engineered Cardiac Microtissue Model

Sunitinib, a multitargeted oral tyrosine kinase inhibitor, used widely to treat solid tumors, results in hypertension in up to 47% and left ventricular dysfunction in up to 19% of treated individuals. The relative contribution of afterload toward inducing cardiac dysfunction with sunitinib treatment remains unknown. We created a preclinical model of sunitinib cardiotoxicity using engineered microtissues that exhibited cardiomyocyte death, decreases in force generation, and spontaneous beating at clinically relevant doses. Simulated increases in afterload augmented sunitinib cardiotoxicity in both rat and human microtissues, which suggest that antihypertensive therapy may be a strategy to prevent left ventricular dysfunction in patients treated with sunitinib.

Abstract 225: Assessing Sunitinib Cardiotoxicity Using Engineered Cardiac Microtissues

Introduction: Sunitinib is an oral tyrosine kinase inhibitor that effectively treats a variety of solid tumors but carries a significant risk of hypertension and left ventricular (LV) dysfunction. Although AMP-K inhibition may be central to the development of cardiotoxicity, these mechanisms remain incompletely understood as does the pathogenic role of hypertension in the development of LV dysfunction. We hypothesized that sunitinib results in dose- and duration-dependent changes in cardiac energetics that are worsened by increased afterload. Methods: These studies employed the use of a cardiac microtissue (CMT) model where neonatal rat cardiomyocytes and fibroblasts self-assemble on microfabricated PDMS cantilevers. With these CMTs, afterload can be effectively modified (stiff vs. soft) through variations in the elastic modulus of the cantilevers. Caspase 3/7 activation and ATP levels were determined using luminescence assays. Spontaneous beating rate was assessed by counting the number of beats during a 1 min interval. Mitochondrial membrane potential (MMP) was measured by labeling cells with TMRM and analyzed via flow cytometry. Results: CMTs treated with as little as 1uM sunitinib for 4hrs demonstrated a nearly two-fold increase in activated caspase 3/7 compared to control (DMSO treated) CMTs. Moreover, there was a 2-fold increase in caspase activation when CMTs were cultured on stiff versus soft cantilevers (p=0.01). Dose - dependent decreases in spontaneous beating rate following treatment with 1uM sunitinib (p>0.05) or 10uM sunitinib (p<0.0001) were observed (p-values are compared to control). MMP decreased with 1uM sunitinib treatment after 4hr (28±2.7% vs. 22±2.1% for control, n= 2x10 4 , p<0.05) and 8hr (22±2.2% vs. 27±1.4% for control, n= 2x10 4 , p<0.05). ATP levels after 24hr of 1uM sunitinib treatment were also decreased relative to control (66.2± 2.4 pg vs. 53.4±3 pg; p=0.01). Conclusions: These findings demonstrate that the CMT model is a robust model to study sunitinib cardiotoxicity, and cardiotoxicity is a function of sunitinib dose, duration and afterload. Experiments with CMTs comprised of human iPS derived cardiomyocytes (iPS-CMs) are ongoing to understand the relevance of these findings in human cardiomyocytes.

CARDIOTOXICITY OF CHRONIC SUNITINIB TREATMENT IN NORMOTENSIVE AND SPONTANEOUSLY HYPERTENSIVE RATS

AimsSunitinib is a modern multi-targeted tyrosine kinase inhibitor, which showed great promise in the treatment of human cancer. However, its chronic use may be associated with cardiotoxicity, which is poorly...

Cardioprotection during chemotherapy: A case study to understand intracellular mechanisms to combat the cardiotoxicity of Sunitinib

Cardioprotection during chemotherapy: A case study to understand intracellular mechanisms to combat the cardiotoxicity of Sunitinib

20 Cardioprotection During Chemotherapy: A Case Study to Understand Intracellular Mechanisms to Combat the Cardiotoxicity of Sunitinib

Tyrosine Kinase inhibitor Sunitinib mediates its apoptotic anti-cancer effects by inhibiting intracellular signalling involved in tumour angiogenesis and cell proliferation. Unfortunately Sunitinib has revealed unwanted cardiotoxicity side-effects and investigations into...

Role of Preeclampsia-Related Angiogenic Factors in Sunitinib Cardiotoxicity: Two Cases and Review of the Literature

Sunitinib is a multi-targeted tyrosine kinase inhibitor widely used in clear cell renal carcinoma and in imatinib-resistant gastrointestinal stromal tumors. Sunitinib-associated cardiotoxicity has been recognized and includes hypertension, left ventricular dysfunction and congestive heart failure; nevertheless, few data exist in the literature regarding the role of preeclampsia-related angiogenic factors in sunitinib cardiotoxicity. We report a case of sunitinib-induced severe left ventricular dysfunction that occurred in a hypertensive woman with metastatic renal carcinoma and a history of preeclampsia, and a case of sunitinib-induced preeclampsia-like syndrome in a normotensive patient with an imatinib-resistant gastrointestinal stromal tumor. Our experience confirms that inhibition of angiogenic factors to treat cancer is a novel challenge for the oncologist and requires the cardiologist's support.

Partial Response and Cardiovascular Recovery after Sorafenib Dose Reduction in a Multinodular HCC Patient

In the past, heart failure has been a major adverse event induced by some conventional chemotherapeutic agents [1]. The introduction of the new agents targeting angiogenesis, if on one hand has offered new therapeutic strategies to orphan drug tumors, has on the other hand also enhanced the risk of heart muscle injuries on account of their inhibition of vascular endothelial growth factor (VEGF) and plateletderived grow factor (PDGF) which are fundamental factors for heart cell survival [2]. Several reports have recently raised the concern of potential cardiotoxicity of sunitinib [3]. The multikinase inhibitor sorafenib is the first targeted agent able to extend survival after many trials on the medical treatment of advanced stages of renal cell carcinoma [4] and hepatocellular carcinoma (HCC) [5, 6]. Even if in clinical trials the reduction of ejection fraction (left ventricular failure, LVEF) rarely turned out related to sorafenib [3–6], a monitoring of cardiac adverse events is advocated with more approved antiangiogenic inhibitors [7, 8], and regulatory recommendations have suggested sorafenib discontinuation in case of onset of signs of cardiotoxicity [9, 10]. Few data have been reported regarding the possibility to restart the drug after interruption due to cardiotoxicity [11] and no information is available regarding the efficacy of the drug after a dose reduction. Here we report the case of an HCC patient who restarted sorafenib after a significant drop of LVEF. The lower dose employed at the restart drove to tumor reduction with cardiac heart failure (CHF) recovery.

Use of human stem cell derived cardiomyocytes to examine sunitinib mediated cardiotoxicity and electrophysiological alterations

Sunitinib, an oral tyrosine kinase inhibitor approved to treat advanced renal cell carcinoma and gastrointestinal stroma tumor, is associated with clinical cardiac toxicity. Although the precise mechanism of sunitinib cardiotoxicity is not known, both the key metabolic energy regulator, AMP-activated protein kinase (AMPK), and ribosomal S 6 kinase (RSK) have been hypothesized as causative, albeit based on rodent models. To study the mechanism of sunitinib-mediated cardiotoxicity in a human model, induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) having electrophysiological and contractile properties of native cardiac tissue were investigated. Sunitinib was cardiotoxic in a dose-dependent manner with an IC 50 in the low micromolar range, observed by a loss of cellular ATP, an increase in oxidized glutathione, and induction of apoptosis in iPSC-CMs. Pretreatment of iPSC-CMs with AMPK activators AICAR or metformin, increased the phosphorylation of pAMPK-T172 and pACC-S79, but only marginally attenuated sunitinib mediated cell death. Furthermore, additional inhibitors of AMPK were not directly cytotoxic to iPSC-CMs up to 250 μM concentrations. Inhibition of RSK with a highly specific, irreversible, small molecule inhibitor (RSK-FMK-MEA) did not induce cytotoxicity in iPSC-CMs below 250 μM. Extensive electrophysiological analysis of sunitinib and RSK-FMK-MEA mediated conduction effects were performed. Taken together, these findings suggest that inhibition of AMPK and RSK are not a major component of sunitinib-induced cardiotoxicity. Although the exact mechanism of cardiotoxicity of sunitinib is not known, it is likely due to inhibition of multiple kinases simultaneously. These data highlight the utility of human iPSC-CMs in investigating the potential molecular mechanisms underlying drug-induced cardiotoxicity.

Autophagy plays an important role in Sunitinib-mediated cell death in H9c2 cardiac muscle cells

Sunitinib, which is a multitargeted tyrosine-kinase inhibitor, exhibits antiangiogenic and antitumor activity, and extends survival of patients with metastatic renal-cell carcinoma (mRCC) and gastrointestinal stromal tumors (GIST). This molecule has also been reported to be associated with cardiotoxicity at a high frequency, but the mechanism is still unknown. In the present study, we observed that Sunitinib showed high anti-proliferative effect on H9c2 cardiac muscle cells measured by PI staining and the MTT assay. But apoptotic markers (PARP cleavage, caspase 3 cleavage and chromatin condensation) were uniformly negative in H9c2 cells after Sunitinib treatment for 48 h, indicating that another cell death pathway may be involved in Sunitinib-induced cardiotoxicity. Here we found Sunitinib dramatically increased autophagic flux in H9c2 cells. Acidic vesicle fluorescence and high expression of LC3-II in H9c2 cells identified autophagy as a Sunitinib-induced process that might be associated with cytotoxicity. Furthermore, knocking down Beclin 1 by RNA-interference to block autophagy in H9c2 cells revealed that the death rate was decreased when treated with Sunitinib in comparison to control cells. These results confirmed that autophagy plays an important role in Sunitinib-mediated H9c2 cells cytotoxicity. Taken together, the data presented here strongly suggest that autophagy is associated with Sunitinib-induced cardiotoxicity, and that inhibition of autophagy constitutes a viable strategy for reducing Sunitinib-induced cardiomyocyte death thereby alleviating Sunitinib cardiotoxicity.

High-resolution electrocardiography (HRECG) in detection of preclinical cardiotoxicity of sunitinib and sorafenib in renal cell carcinoma (RCC) patients

16097 Background: Tyrosine-kinase inhibitors (TKI), have significant clinical activity in patients (pts) with RCC. Cardiotoxicity is relatively common toxicity of these molecules. Schmidinger et al (ASCO, 2007) have detected preclinical and clinical stage of myocardial damage in more than 20% of patients treated with TKIs. ECG-changes and biochemical markers are the most important indicators of this damage. HRECG is promising method for early identification of patients at risk of anthracycline cardiotoxicity. The aim of this prospective observational study was to investigate the value of HRECG in combination with biochemical markers in identification myocardial damage in preclinical stage in pts undergoing TKI-treatment for RCC. Methods: Eighteen consecutive patients (5F/13M; median age 63, range 47–75) intended for TKI treatment were analyzed for medical history of coronary artery disease (CAD) and risk-factors. Time- and frequency-domain analyses of HRECG, biochemical markers of cardiac damage (cardiac troponin T -cTNT, pro brain natriuretic peptide- proBNP-) and echocardiography were performed before and 12 weeks after begining of treatment. Results: Twelve patients were treated with sunitinib and 6 patients with sorafenib. All patients had normal pro-BNP and TNT at baseline. Median follow-up was 6 months (range: 3–8 months). During this period, we didn´t observed clinical or laboratory signs of myocardial damage. Mean values of proBNP and cTNT were 401 pg/ mL and 0.01 ng/mL before therapy and 406 pg/mL and 0.01 ng/mL after 12 weeks of therapy (p = 0.96). The HRECG had not shown any signs of myocardial damage. Conclusions: In presented study the number of events of myocardial damage was lower than was expected. However, based on our results, it seems that normal HRECG before and after 12 weeks of therapy could be a usefull marker for selection of patients with low risk of cardiotoxicity induced by sunitinib and sorafenib. Longer follow-up is needed. Updated clinical results will be presented. No significant financial relationships to disclose.

Abstract 1505: Sunitinib-Induced Cardiotoxicity is Mediated in Part via Direct Effects on Cardiac Myocytes and Smooth Muscle Cells

Tyrosine kinase inhibitors (TKI) have revolutionized cancer therapy, spawning over 500 clinical trials, yet cardiotoxicities are emerging. Sunitinib, a multi-targeted TKI, prolongs life in renal cell and gastrointestinal cancer patients, but hypertension and heart failure have required treatment adjustments. Objective: Sunitinib cardiotoxicity may be due, in part, to direct effects on smooth muscle and cardiac myocytes. Methods: We used C57Bl/6J mice, rat neonatal cardiomyocytes (NCM), and human coronary artery smooth muscle cells (SMC) treated with Sunitinib to measure drug-induced cardiovascular toxicity. Structural (transmission electron microscopy, immunohistochemistry (IHC)/confocal microscopy) and functional [apoptosis/survival, nitric oxide synthesis (intracellular and extracellular), signaling] effects were assessed [real-time PCR, Western blotting, receptor phosphorylation (immunoprecipitation/Western blotting)]. Results: We show mitochondrial injury in hearts from Sunitinib treated mice which persisted off of the drug. In vitro , Sunitinib accumulated in myocytes, caused myofibrillar disorganization, mitochondrial injury, and localized to the lysosomes. Sunitinib caused reductions in akt, MAPK, and AMPK signaling, and activated pro-apoptotic caspase-9 in NCM and SMC with similar effects in large and small vessel endothelial cells. In hearts of Sunitinib-treated mice, we found similar changes in signaling pathways. Conclusion: Sunitinib causes direct cardiac myocyte and smooth muscle cell toxicities, which may contribute to the cardiovascular side effects seen in patients. Further understanding of these mechanisms will guide monitoring, intervention and future rational drug design.