Anthracycline cardiotoxicity: prevalence, pathogenesis and treatment

Mechanisms of Cardiotoxicity and the Development of Heart Failure

Cardiotoxicity is a broad term that refers to the negative effects of toxic substances on the heart. Cancer drugs can cause cardiotoxicity by effects on heart cells, thromboembolic events, and/or hypertension that can lead to heart failure. Rheumatoid arthritis biologics may interfere with ischemic preconditioning and cause/worsen heart failure. Long-term and heavy alcohol use can result in oxidative stress, apoptosis, and decreased contractile protein function. Cocaine use results in sympathetic nervous system stimulation of heart and smooth muscle cells and leads to cardiotoxicity and evolution of heart failure. The definition of cardiotoxicity is likely to evolve along with knowledge about detecting subclinical myocardial injury.

Subcellular localization of anthracyclines in cultured rat cardiomyoblasts as possible predictors of cardiotoxicity

In this study, we compared the cellular uptake, intracellular localization and cytotoxicity of two groups of anthracycline derivatives in cultured H9c2(2-1) rat cardiomyoblasts. The first group consisted of doxorubicin (DOX) and two of its derivatives containing a formamidino group (–N = CH–N<) at the C-3′ position with a morpholine (DOXM) or a hexamethyleneimine (DOXH) ring. The second group consisted of daunorubicin (DRB) and its derivatives containing a morpholine (DRBM) or a hexamethyleneimine (DRBH) ring. DOXH and DRBH were taken up by cardiomyoblasts more efficiently than estimated for other tested anthracyclines. The cellular uptakes of DOXM and DRBM were reduced compared to those of the parent compounds. Applied structural modifications of DOX and DRB influenced the subcellular localization of the tested derivatives. DOX and DOXH were localized primarily in nuclei, whereas the other anthracyclines were found in the nuclei and cytoplasm. The percentages of the compounds that accumulated in the nuclei were 80.2 and 54.2 % for DOX and DOXH, respectively. The lowest nuclear accumulation values were observed for DRBM (19.9 %), DRBH (21.9 %) and DOXM (23.7 %). The ability of anthracyclines to accumulate in the nuclei correlated with their DNA binding constants (r = 0.858, P = 0.029). A correlation was found between the accumulation of the tested anthracyclines in the nuclei of cardiomyoblasts and their cardiotoxicity in vivo, which was observed in our previous study. We suggest that cytotoxicity and the anthracycline accumulation level in the nuclei of cultured cardiomyoblasts could be used for early prediction of their cardiotoxicity.

[Analysis of proteomic profile changes of zebrafish embryos during exposure to doxorubicin, built-in the phospholipid transport nanosystem]

The proteome profile of Danio rerio embryos grown in the medium containing doxorubicin, included in the phospholipid transport nanosystem (doxolip) has been investigated using combination of 1D-electrophoresis with subsequent MALDI-TOF-PMF mass spectrometry. Cultivation of growing of D. rerio embryos in the medium with doxolip caused a substantial increase in expression of the cytoskeletal proteins, a decrease in the number of nuclear proteins involved in DNA and RNA synthesis and disappearance of vitellogenin 2 in comparison with control (the cultivation medium containing the phospholipid transport nanosystem). Analysis of the proteomic profiles of doxolip-treated embryos suggests lower toxicity of doxorubicin incorporated in the phospholipid nanosystem.

Mesenchymal stem cell therapy for doxorubicin cardiomyopathy: hopes and fears

Chemotherapy has made an essential contribution to cancer treatment in recent decades despite its adverse effects. As cancer survivors have increased, concern about ex-patient lifespan has become more important too. Doxorubicin is an effective anti-neoplastic drug that produces a cardiotoxic effect. Cancer survivors who received doxorubicin became more vulnerable to cardiac disease than the normal population did. Many efforts have been made to prevent cardiac toxicity in patients with cancer. However, current therapies cannot guarantee permanent cardiac protection. One of their main limitations is that they do not promote myocardium regeneration. In this review, we summarize and discuss the promising use of mesenchymal stem cells for cardio-protection or cardio-regeneration therapies and consider their regenerative potential without leaving aside their controversial effects on tumor progression.

Targeted Inhibition of Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Sensitizes Pancreatic Cancer Cells to Doxorubicin without Exacerbating Cardiac Toxicity

Pancreatic cancer has the lowest 5-year survival rate of all major cancers despite decades of effort to design and implement novel, more effective treatment options. In this study, we tested whether the dual phosphoinositide 3-kinase/mechanistic target of rapamycin inhibitor BEZ235 (BEZ) potentiates the antitumor effects of doxorubicin (DOX) against pancreatic cancer. Cotreatment of BEZ235 with DOX resulted in dose-dependent inhibition of the phosphoinositide 3-kinase/mechanistic target of rapamycin survival pathway, which corresponded with an increase in poly ADP ribose polymerase cleavage. Moreover, BEZ cotreatment significantly improved the effects of DOX toward both cell viability and cell death in part through reduced Bcl-2 expression and increased expression of the shorter, more cytotoxic forms of BIM. BEZ also facilitated intracellular accumulation of DOX, which led to enhanced DNA damage and reactive oxygen species generation. Furthermore, BEZ in combination with gemcitabine reduced MiaPaca2 cell proliferation but failed to increase reactive oxygen species generation or BIM expression, resulting in reduced necrosis and apoptosis. Treatment with BEZ and DOX in mice bearing tumor xenographs significantly repressed tumor growth as compared with BEZ, DOX, or gemcitabine. Additionally, in contrast to the enhanced expression seen in MiaPaca2 cells, BEZ and DOX cotreatment reduced BIM expression in H9C2 cardiomyocytes. Also, the Bcl-2/Bax ratio was increased, which was associated with a reduction in cell death. In vivo echocardiography showed decreased cardiac function with DOX treatment, which was not improved by combination treatment with BEZ. Thus, we propose that combining BEZ with DOX would be a better option for patients than current standard of care by providing a more effective tumor response without the associated increase in toxicity.

High Throughput Screening Identifies a Novel Compound Protecting Cardiomyocytes from Doxorubicin-Induced Damage

Antracyclines are effective antitumor agents. One of the most commonly used antracyclines is doxorubicin, which can be successfully used to treat a diverse spectrum of tumors. Application of these drugs is limited by their cardiotoxic effect, which is determined by a lifetime cumulative dose. We set out to identify by high throughput screening cardioprotective compounds protecting cardiomyocytes from doxorubicin-induced injury. Ten thousand compounds of ChemBridge's DIVERSet compound library were screened to identify compounds that can protect H9C2 rat cardiomyocytes against doxorubicin-induced cell death. The most effective compound proved protective in doxorubicin-treated primary rat cardiomyocytes and was further characterized to demonstrate that it significantly decreased doxorubicin-induced apoptotic and necrotic cell death and inhibited doxorubicin-induced activation of JNK MAP kinase without having considerable radical scavenging effect or interfering with the antitumor effect of doxorubicin. In fact the compound identified as 3-[2-(4-ethylphenyl)-2-oxoethyl]-1,2-dimethyl-1H-3,1-benzimidazol-3-ium bromide was toxic to all tumor cell lines tested even without doxorubicine treatment. This benzimidazole compound may lead, through further optimalization, to the development of a drug candidate protecting the heart from doxorubicin-induced injury.

Structural and functional screening in human induced-pluripotent stem cell-derived cardiomyocytes accurately identifies cardiotoxicity of multiple drug types

Safety pharmacology studies that evaluate new drug entities for potential cardiac liability remain a critical component of drug development. Current studies have shown that in vitro tests utilizing human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) may be beneficial for preclinical risk evaluation. We recently demonstrated that an in vitro multi-parameter test panel assessing overall cardiac health and function could accurately reflect the associated clinical cardiotoxicity of 4 FDA-approved targeted oncology agents using hiPS-CM. The present studies expand upon this initial observation to assess whether this in vitro screen could detect cardiotoxicity across multiple drug classes with known clinical cardiac risks. Thus, 24 drugs were examined for their effect on both structural (viability, reactive oxygen species generation, lipid formation, troponin secretion) and functional (beating activity) endpoints in hiPS-CM. Using this screen, the cardiac-safe drugs showed no effects on any of the tests in our panel. However, 16 of 18 compounds with known clinical cardiac risk showed drug-induced changes in hiPS-CM by at least one method. Moreover, when taking into account the Cmax values, these 16 compounds could be further classified depending on whether the effects were structural, functional, or both. Overall, the most sensitive test assessed cardiac beating using the xCELLigence platform (88.9%) while the structural endpoints provided additional insight into the mechanism of cardiotoxicity for several drugs. These studies show that a multi-parameter approach examining both cardiac cell health and function in hiPS-CM provides a comprehensive and robust assessment that can aid in the determination of potential cardiac liability.

Strain echocardiography combined with pharmacological stress test for early detection of anthracycline induced cardiomyopathy

INTRODUCTION

Advances in echocardiography, including 2-D speckle tracking to quantitate myocardial strain and strain rate, have improved myocardial functional and mechanical evaluation and may provide a more sensitive assessment of cardiac functional and mechanical changes. Additionally, evaluating myocardial performance induced by a pharmacologic stress test (dobutamine infusion) may further improve the evaluation of potential changes in cardiac function. This study evaluates the use of 2-D speckle tracking strain echocardiography (2DSE) combined with a dobutamine stress test to detect doxorubicin induced cardiomyopathy in the rat.

METHODS

Rats were dosed once per week with 2 mg/kg doxorubicin for 6 weeks. Echocardiography was performed weekly at rest and during dobutamine infusion (20 mcg/kg/min IV).

RESULTS

Throughout the study there were no differences between control and doxorubicin treated groups at rest for radial strain, circumferential strain, fractional shortening (FS), or heart rate (HR). During dobutamine infusion, radial strain, circumferential strain, FS, and HR similarly increased significantly in both the control and doxorubicin treated groups at weeks 0, 1, and 2. At week 3 there was a significant attenuation of the increase in radial strain in the doxorubicin treated group, and at weeks 4 and 6 there was significant attenuation in radial strain and circumferential strain. No significant differences were detected in FS or HR between the two groups at any time points. Histology of the left ventricle at week 7 showed mild changes (mild cardiomyocyte vacuolation with minimal inflammation and no fibrosis) in the doxorubicin treated animals as compared to the control animals, which were consistent with mild doxorubicin induced injury.

DISCUSSION

These data suggest that 2 D speckle tracking strain echocardiography combined with dobutamine stress test can detect early changes in myocardial function and may be useful tools in early detection of drug-induced cardiac dysfunction.

Cardiotoxicity of antineoplastic agents: what is the present and future role for imaging?

As antineoplastic treatment options expand at an increasing rate, both traditional and novel agents continue to be limited by their cardiotoxic effects. While functional decline becomes clinically apparent at late states of toxicity, little is known about early stages during which treatment or prevention may still be an option. Several imaging modalities,including echocardiography, multiple gated acquisition, and cardiac magnetic resonance imaging have the ability to identify cardiac effects before they produce clinical symptoms.Here we discuss the current and future role of cardiac imaging in the assessment of cardiotoxicity of antineoplastic agents. effects on cardiac tissue, resulting in myocardial cellular damage,and ultimately lead to a wide range of effects including electrophysiological abnormalities, symptomatic heart failure(HF), and even death. This represents a limiting factor in the therapy of several otherwise treatable neoplasms [2].The cardiotoxicity of antineoplastic agents raises several important questions regarding the actual prevalence of cardiac toxicity, the ability to effectively treat or prevent such effects with pharmaceutical interventions, and the availability of a means for early diagnosis. Here, we focus on the latter, specifically examining current and potential future imaging strategies to detect the cardiac effects of chemotherapeutic agents.

Effects of histidine and N-acetylcysteine on doxorubicin-induced cardiomyopathy in rats

The amino acids histidine and n-acetylcysteine have many biological activities such as antioxidant effect. The present study investigated the effects of histidine and n-acetylcysteine on the heart lesions induced by doxorubicin (DOX) in rats. Forty-eight male Wistar rats were divided into two major groups treated intraperitoneally (i.p.) with normal saline and 4 mg/kg of DOX, respectively. Each group was further divided into four subgroups that were treated with separate and combined i.p. injections of histidine and n-acetylcysteine (NAC) at a same dose of 40 mg/kg. Electrocardiography (ECG) was recorded using lead II. The heart lesions were evaluated by light microscopy. Serum levels of creatine phosphokinase and lactate dehydrogenase and heart tissue malondialdehyde levels were measured. Histidine and especially NAC at a same dose of 40 mg/kg recovered ECG changes, improved heart lesions and prevented biochemical changes induced by DOX. Co-administration of histidine and NAC showed better responses when compared with them used alone. The results of the present study showed protective effects for histidine and NAC on the heart. Reduction in free radical-induced toxic effects may be involved in cardioprotective properties of histidine and NAC.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

Myopericarditis in a pregnant woman with acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a form of acute leukemia with a characteristic translocation, t(15;17), and is considered a hematologic emergency, typically treated with all-trans retinoic acid and an anthracycline. We present the case of a young, gravid woman who was diagnosed with APL in the third trimester, initiated typical treatment, and suffered uncommon cardiac complications. .

A single-institution analysis of the utility of pre-induction ejection fraction measurement in patients newly diagnosed with acute myeloid leukemia

Anthracyclines, a standard component of induction therapy for acute myeloid leukemia (AML) are known to be cardiotoxic. Existing evidence supporting routine baseline pre-induction cardiac function testing is limited. We conducted a retrospective analysis of 119 consecutive patients diagnosed with AML at our center from 2009 to 2012. In the 76 patients for whom induction chemotherapy was planned, baseline ejection fraction measurements were rarely abnormal (four cases), and in none of these abnormal cases did the result change management decisions. Awaiting LVEF evaluation results led to a delay in chemotherapy administration by a mean of approximately 2 days at significant additional costs to the healthcare system. Routine baseline ejection fraction measurement should be abandoned as it does not change management, results in treatment delay and unnecessary healthcare expenditures. More selective baseline testing, preferentially in patients in whom there is a clinical reason of cardiac disease, should be pursued.

P53 inhibition exacerbates late-stage anthracycline cardiotoxicity

AIMS

Doxorubicin (DOX) is an effective anti-cancer therapeutic, but is associated with both acute and late-stage cardiotoxicity. Children are particularly sensitive to DOX-induced heart failure. Here, the impact of p53 inhibition on acute vs. late-stage DOX cardiotoxicity was examined in a juvenile model.

METHODS AND RESULTS

Two-week-old MHC-CB7 mice (which express dominant-interfering p53 in cardiomyocytes) and their non-transgenic (NON-TXG) littermates received weekly DOX injections for 5 weeks (25 mg/kg cumulative dose). One week after the last DOX treatment (acute stage), MHC-CB7 mice exhibited improved cardiac function and lower levels of cardiomyocyte apoptosis when compared with the NON-TXG mice. Surprisingly, by 13 weeks following the last DOX treatment (late stage), MHC-CB7 exhibited a progressive decrease in cardiac function and higher rates of cardiomyocyte apoptosis when compared with NON-TXG mice. p53 inhibition blocked transient DOX-induced STAT3 activation in MHC-CB7 mice, which was associated with enhanced induction of the DNA repair proteins Ku70 and Ku80. Mice with cardiomyocyte-restricted deletion of STAT3 exhibited worse cardiac function, higher levels of cardiomyocyte apoptosis, and a greater induction of Ku70 and Ku80 in response to DOX treatment during the acute stage when compared with control animals.

CONCLUSION

These data support a model wherein a p53-dependent cardioprotective pathway, mediated via STAT3 activation, mitigates DOX-induced myocardial stress during drug delivery. Furthermore, these data suggest an explanation as to how p53 inhibition can result in cardioprotection during drug treatment and, paradoxically, enhanced cardiotoxicity long after the cessation of drug treatment.

Nrf2 deficiency exaggerates doxorubicin-induced cardiotoxicity and cardiac dysfunction

The anticancer therapy of doxorubicin (Dox) has been limited by its acute and chronic cardiotoxicity. In addition to a causative role of oxidative stress, autophagy appears to play an important role in the regulation of Dox-induced cardiotoxicity. However, the underlying mechanisms remain unclear. Accordingly, we explored a role of nuclear factor erythroid-2 related factor 2 (Nrf2) in Dox-induced cardiomyopathy with a focus on myocardial oxidative stress and autophagic activity. In wild type (WT) mice, a single intraperitoneal injection of 25 mg/kg Dox rapidly induced cardiomyocyte necrosis and cardiac dysfunction, which were associated with oxidative stress, impaired autophagy, and accumulated polyubiquitinated protein aggregates. However, these Dox-induced adverse effects were exaggerated in Nrf2 knockout (Nrf2(-/-)) mice. In cultured cardiomyocytes, overexpression of Nrf2 increased the steady levels of LC3-II, ameliorated Dox-induced impairment of autophagic flux and accumulation of ubiquitinated protein aggregates, and suppressed Dox-induced cytotoxicity, whereas knockdown of Nrf2 exerted opposite effects. Moreover, the exaggerated adverse effects in Dox-intoxicated Nrf2 depleted cardiomyocytes were dramatically attenuated by forced activation of autophagy via overexpression of autophagy related gene 5 (Atg5). Thus, these results suggest that Nrf2 is likely an endogenous suppressor of Dox-induced cardiotoxicity by controlling both oxidative stress and autophagy in the heart.

Systemic treatment of soft-tissue sarcoma-gold standard and novel therapies

Soft-tissue sarcoma (STS) is a rare and heterogeneous group of tumours that comprise approximately 1% of all adult cancers, and encompass over 50 different subtypes. These tumours exhibit a wide range of differing behaviours and underlying molecular pathologies, and can arise anywhere in the body. Surgical resection is critical to the management of locoregional disease. In the locally advanced or metastatic disease settings, systemic therapy has an important role in the multidisciplinary management of sarcoma. Cytotoxic therapy that usually consists of doxorubicin and ifosfamide has been the mainstay of treatment for many years. However recent advances in molecular pathogenesis, the development of novel targeted therapies, changes in clinical trial design and increased international collaboration have led to the development of histology-driven therapy. Furthermore, genomic profiling has highlighted that some STS are driven by translocation, mutation or amplification and others have more complex and chaotic karyotypes. In this Review, we aim to describe the current gold standard treatment for specific STS subtypes as well as outline future promising therapies in the pipeline.

High-throughput screening identifies idarubicin as a preferential inhibitor of smooth muscle versus endothelial cell proliferation

Intimal hyperplasia is the cause of the recurrent occlusive vascular disease (restenosis). Drugs currently used to treat restenosis effectively inhibit smooth muscle cell (SMC) proliferation, but also inhibit the growth of the protective luminal endothelial cell (EC) lining, leading to thrombosis. To identify compounds that selectively inhibit SMC versus EC proliferation, we have developed a high-throughput screening (HTS) format using human cells and have employed this to screen a multiple compound collection (NIH Clinical Collection). We developed an automated, accurate proliferation assay in 96-well plates using human aortic SMCs and ECs. Using this HTS format we screened a 447-drug NIH Clinical Library. We identified 11 compounds that inhibited SMC proliferation greater than 50%, among which idarubicin exhibited a unique feature of preferentially inhibiting SMC versus EC proliferation. Concentration-response analysis revealed this differential effect most evident over an ∼10 nM-5 µM window. In vivo testing of idarubicin in a rat carotid injury model at 14 days revealed an 80% reduction of intimal hyperplasia and a 45% increase of lumen size with no significant effect on re-endothelialization. Taken together, we have established a HTS assay of human vascular cell proliferation, and identified idarubicin as a selective inhibitor of SMC versus EC proliferation both in vitro and in vivo. Screening of larger and more diverse compound libraries may lead to the discovery of next-generation therapeutics that can inhibit intima hyperplasia without impairing re-endothelialization.

Cisplatin-induced bradycardia and the importance of the QT interval

Cisplatin is a very common chemotherapeutic agent used in the treatment of gynecologic malignancies, including cervical, ovarian, and endometrial cancers. Bradycardia is a rare, though potentially severe, side effect of this medication. Here we present the case of a young woman with ovarian cancer who demonstrated significant short-lived cardiotoxicity associated with cisplatin treatment.

Targeted delivery system of nanobiomaterials in anticancer therapy: from cells to clinics

Targeted delivery systems of nanobiomaterials are necessary to be developed for the diagnosis and treatment of cancer. Nanobiomaterials can be engineered to recognize cancer-specific receptors at the cellular levels and to deliver anticancer drugs into the diseased sites. In particular, nanobiomaterial-based nanocarriers, so-called nanoplatforms, are the design of the targeted delivery systems such as liposomes, polymeric nanoparticles/micelles, nanoconjugates, norganic materials, carbon-based nanobiomaterials, and bioinspired phage system, which are based on the nanosize of 1-100 nm in diameter. In this review, the design and the application of these nanoplatforms are discussed at the cellular levels as well as in the clinics. We believe that this review can offer recent advances in the targeted delivery systems of nanobiomaterials regarding in vitro and in vivo applications and the translation of nanobiomaterials to nanomedicine in anticancer therapy.

Tunable visible and near-IR photoactivation of light-responsive compounds by using fluorophores as light-capturing antennas

Although the corrin ring of vitamin B12 is unable to efficiently absorb light beyond 550 nm, it is shown that commercially available fluorophores can be used as antennas to capture long-wavelength light to promote scission of the Co-C bond at wavelengths up to 800 nm. The ability to control the molecular properties of bioactive species with long visible and near-IR light has implications for drug delivery, nanotechnology, and the spatiotemporal control of cellular behavior.

Protective effect of saffron extract against doxorubicin cardiotoxicity in isolated rabbit heart

CONTEXT

Anticancer treatments such as anthracyclines are effective; however, they induce cardiotoxicity by releasing radical oxygen species (ROS). Saffron (Crocus sativus; Iridaceae) is a widely used spice with antioxidant properties and numerous health benefits that may provide cardioprotection.

OBJECTIVE

To assess the effect of saffron against acute myocardium damage by anthracyclines compared with electrolysis as a free radical generating system.

MATERIALS AND METHODS

According to the Langendorff method, we used the model of an isolated rabbit heart perfused in retrograde. In one set of experiments, ROS was generated by electrolysis of the perfused heart solution (3 mA for 30 min) in the presence and absence of saffron extracts at the optimal dose (10 μg/ml). In another set, we perfused the heart with anthracycline, i.e. 30 μM doxorubicin (Doxo) in the presence and absence of 10 μg/ml saffron extracts. We evaluated cardiodynamics, as well as biochemical and pathological parameters, to emphasize the effectiveness of the treatment with saffron extract using the optimal dose of catalase (150 IU) as a positive control.

RESULTS

ROS generated, respectively, by electrolysis and by Doxo significantly (p < 0.05) affects cardiovascular function; it decreased ventricular pressure (45.02 and 40.41%), heart rate (36.31 and 22.39%) and coronary flow (50.98 and 36.67%). Increased lipid peroxidation of the myocardium was also observed (118.22 and 56.58%), while superoxide dismutase activity decreased (48.33 and 38.70%). The myocardial architecture was altered and the intercellular spaces increased.

CONCLUSION

Saffron perfused during electrolysis helps trap ROS and significantly improves myocardial function; however, saffron was less effective against Doxo, thus suggesting that mechanisms other than oxidative stress underlie Doxo cardiotoxicity.

Cell surface receptor targeted biomimetic apatite nanocrystals for cancer therapy

Nanosized drug carriers functionalized with moieties specifically targeting tumor cells are promising tools in cancer therapy, due to their ability to circulate in the bloodstream for longer periods and their selectivity for tumor cells, enabling the sparing of healthy tissues. Because of its biocompatibility, high bioresorbability, and responsiveness to pH changes, synthetic biomimetic nanocrystalline apatites are used as nanocarriers to produce multifunctional nanoparticles, by coupling them with the chemotherapeutic drug doxorubicin (DOXO) and the DO-24 monoclonal antibody (mAb) directed against the Met/Hepatocyte Growth Factor receptor (Met/HGFR), which is over-expressed on different types of carcinomas and thus represents a useful tumor target. The chemical-physical features of the nanoparticles are fully investigated and their interaction with cells expressing (GTL-16 gastric carcinoma line) or not expressing (NIH-3T3 fibroblasts) the Met/HGFR is analyzed. Functionalized nanoparticles specifically bind to and are internalized in cells expressing the receptor (GTL-16) but not in the ones that do not express it (NIH-3T3). Moreover they discharge DOXO in the targeted GTL-16 cells that reach the nucleus and display cytotoxicity as assessed in an MTT assay. Two different types of ternary nanoparticles are prepared, differing for the sequence of the functionalization steps (adsorption of DOXO first and then mAb or vice versa), and it is found that the ones in which mAb is adsorbed first are more efficient under all the examined aspects (binding, internalization, cytotoxicity), possibly because of a better mAb orientation on the nanoparticle surface. These multifunctional nanoparticles could thus be useful instruments for targeted local or systemic drug delivery, allowing a reduction in the therapeutic dose of the drug and thus adverse side effects. Moreover, this work opens new perspectives in the use of nanocrystalline apatites as a new platform for theranostic applications in nanomedicine.

Cardiovascular disease among breast cancer survivors: the call for a clinical vascular health toolbox

With better detection and treatment, breast cancer is less likely to be the primary cause of death in the majority of breast cancer survivors; mortality due to cardiovascular disease (CVD) is now more common. Given the long latency periods between cancer treatment completion and potential symptomatic CVD, there is a need to detect vascular changes before symptoms appear. This short review provides an overview of non-invasive, widely available, and relatively inexpensive techniques for assessing endothelial function, central and regional arterial stiffness, central blood pressures, and intima-media thickness. These tools exhibit acceptable reliability and validity, and are relatively practical. Clinical assessment recommendations are also provided. There is sufficient evidence to encourage the use of these techniques as a component of routine serial assessments, and to help guide appropriate treatment strategies.

IMD-0354 targets breast cancer stem cells: a novel approach for an adjuvant to chemotherapy to prevent multidrug resistance in a murine model

Although early detection of breast cancer improved in recent years, prognosis of patients with late stage breast cancer remains poor, mostly due to development of multidrug resistance (MDR) followed by tumor recurrence. Cancer stem cells (CSCs), with higher drug efflux capability and other stem cell-like properties, are concentrated in a side population (SP) of cells, which were proposed to be responsible for MDR and tumor repopulation that cause patients to succumb to breast cancer. Therefore, targeting of CSCs as an adjuvant to chemotherapy should be able to provide a more effective treatment of this disease. Here, we used IMD-0354, an inhibitor of NF-κB, identified for targeting CSCs, in a combination therapy with doxorubicin encapsulated in targeted nanoparticles. IMD-0354 did target CSCs, evidenced by a decrease in the SP, demonstrated by the inhibition of the following: dye/drug efflux, reduction in ABC transporters as well as in colony formation in soft agar and low attachment plates. Decrease of stem-like gene expression of Oct4, Nanog and Sox2, and apoptosis resistance related to the Survivin gene also was observed after treatment with this compound. In addition, IMD-0354 targeted non-CSCs as indicated by reducing viability and increasing apoptosis. Targeted drug delivery, achieved with a legumain inhibitor, proved to enhance drug delivery under hypoxia, a hallmark of the tumor microenvironment, but not under normoxia. Together, this allowed a safe, non-toxic delivery of both anticancer agents to the tumor microenvironment of mice bearing syngeneic metastatic breast cancer. Targeting both bulk tumor cells with a chemotherapeutic agent and CSCs with IMD-0354 should be able to reduce MDR. This could eventually result in decreasing tumor recurrences and/or improve the outcome of metastatic disease.

High-throughput screen identifies disulfiram as a potential therapeutic for triple-negative breast cancer cells: interaction with IQ motif-containing factors

Triple-negative breast cancer (TNBC) represents an aggressive subtype, for which radiation and chemotherapy are the only options. Here we describe the identification of disulfiram, an FDA-approved drug used to treat alcoholism, as well as the related compound thiram, as the most potent growth inhibitors following high-throughput screens of 3185 compounds against multiple TNBC cell lines. The average IC₅₀ for disulfiram was ~300 nM. Drug affinity responsive target stability (DARTS) analysis identified IQ motif-containing factors IQGAP1 and MYH9 as direct binding targets of disulfiram. Indeed, knockdown of these factors reduced, though did not completely abolish, cell growth. Combination treatment with 4 different drugs commonly used to treat TNBC revealed that disulfiram synergizes most effectively with doxorubicin to inhibit cell growth of TNBC cells. Disulfiram and doxorubicin cooperated to induce cell death as well as cellular senescence, and targeted the ESA⁺/CD24^-/low/CD44⁺ cancer stem cell population. Our results suggest that disulfiram may be repurposed to treat TNBC in combination with doxorubicin.

Non-invasive assessment of cardiac hemodynamics in patients with advanced cancer and with chronic heart failure: a pilot feasibility study

INTRODUCTION

Relationships between cardiac pressure and volume have been suggested as markers of cardiac contractility; parameters include stroke work and the maximal rate of pressure rise during isovolumic contraction (dP/dtmax). Patients with cancer often display dyspnea and fatigue. These are also frequent symptoms in patients with chronic heart failure (HF). The reasons for similar symptoms in cancer patients are unknown. Using the novel Nexfin Finapres technique, we sought to assess measures of cardiac performance in patients with cancer and compare these values with those from control subjects and patients with chronic HF.

MATERIAL AND METHODS

We prospectively studied 98 patients (control n = 18, chronic HF n = 37, advanced pancreatic or colorectal cancer n = 43) and assessed blood pressure (BP), stroke volume (SV), cardiac output (CO), and dP/dtmax at rest.

RESULTS

All parameters of interest could be assessed using the Nexfin Finapres technique with SV and CO being significantly higher in patients with cancer than in controls (both p < 0.05). The SV was significantly higher in patients with chronic HF than in controls (p < 0.05). In patients with cancer, SV correlated with age (r = -0.45, p < 0.01) and body weight (r = +0.55, p = 0.0001). In chronic HF, SV declined with increasing age (r = -0.49, p < 0.01); in control subjects, SV increased with increasing body weight (r = +0.57, p = 0.01).

CONCLUSIONS

Patients with cancer tended to display elevated BP, CO, SV, and dP/dtmax as compared to control subjects and patients with HF. These findings may reveal an elevated risk for cardiovascular diseases in this group.

The force of the spontaneously contracting zebrafish heart, in the assessment of cardiovascular toxicity: application on adriamycin

The heart of the zebrafish has been used extensively to assess the cardiotoxic effect of compounds, using the frequency of heart contractions as the main index of cardiac response to drugs. In this study, the force and the frequency generated by the spontaneously contracting zebrafish heart, isolated in saline, were found to be 0.87 ± 0.05 mN and 1.54 ± 0.03 Hz (n=6) respectively within the first hour of recording. Both values of force and frequency remained constant for over 8h. The advantage of prolonged vitality in the assessment of cardiovascular toxicity was shown using the well-known anticancer drug adriamycin, which has severe cardiotoxic side effects. At 10.0 μM there was a 21.05 ± 4.42% (p=0.02, n=4) decrease in the force of contraction, while the frequency was not affected after 3h treatment (p>0.05). At 50.0 and 100.0 μM there was a 33.24 ± 3.0 and 46.6 ± 4.80% irreversible decrease in force (p<0.05, n=4), while a 18.02 ± 4.07% and 16.16 ± 4.07% reversible increase was observed in the frequency (p=0.02, n=4). These contradictory positive chronotropic and negative inotropic responses indicate the strong inhibitory effect of adriamycin on ventricular cardiomyocytes and its excitatory effects on auto-rhythmical pacemaker cells. If heart frequency was the only parameter used to assess the cardiotoxic effect of adriamycin, at the above range of concentrations, this compound would have been classified as non-cardiotoxic.

Lifestyle interventions for cardiovascular risk reduction in women with breast cancer

PURPOSE

The purpose of this paper is to identify risk factors for cardiovascular disease in women with breast cancer and review healthy lifestyle behaviors as essential risk reduction strategies.

FINDINGS

Women with breast cancer account for 22% of the 12 million cancer survivors. Women diagnosed with breast cancer often present with modifiable and non-modifiable cardiovascular risk factors and/or pre-existing co-morbid illness. Any one or a combination of these factors may increase the risk of cardiovascular disease. There is strong evidence that healthy eating and routine physical activity can reduce cardiovascular disease. Exercise improves cardiovascular fitness, body composition and quality of life in breast cancer survivors and observational studies suggest a survival benefit.

CLINICAL IMPLICATIONS

Lifestyle interventions including a healthy diet, regular physical activity, weight management and smoking cessation should be integrated into a survivorship care plan to reduce cardiovascular disease risk and promote better health for women with breast cancer.