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1 August 2023

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Cardiotoxicity News

PubMed articles on: Cardio-Oncology

Role of the mechanisms for antibody repertoire diversification in monoclonal light chain deposition disorders: when a friend becomes foe

Front Immunol. 2023 Jul 13;14:1203425. doi: 10.3389/fimmu.2023.1203425. eCollection 2023.

ABSTRACT

The adaptive immune system of jawed vertebrates generates a highly diverse repertoire of antibodies to meet the antigenic challenges of a constantly evolving biological ecosystem. Most of the diversity is generated by two mechanisms: V(D)J gene recombination and somatic hypermutation (SHM). SHM introduces changes in the variable domain of antibodies, mostly in the regions that form the paratope, yielding antibodies with higher antigen binding affinity. However, antigen recognition is only possible if the antibody folds into a stable functional conformation. Therefore, a key force determining the survival of B cell clones undergoing somatic hypermutation is the ability of the mutated heavy and light chains to efficiently fold and assemble into a functional antibody. The antibody is the structural context where the selection of the somatic mutations occurs, and where both the heavy and light chains benefit from protective mechanisms that counteract the potentially deleterious impact of the changes. However, in patients with monoclonal gammopathies, the proliferating plasma cell clone may overproduce the light chain, which is then secreted into the bloodstream. This places the light chain out of the protective context provided by the quaternary structure of the antibody, increasing the risk of misfolding and aggregation due to destabilizing somatic mutations. Light chain-derived (AL) amyloidosis, light chain deposition disease (LCDD), Fanconi syndrome, and myeloma (cast) nephropathy are a diverse group of diseases derived from the pathologic aggregation of light chains, in which somatic mutations are recognized to play a role. In this review, we address the mechanisms by which somatic mutations promote the misfolding and pathological aggregation of the light chains, with an emphasis on AL amyloidosis. We also analyze the contribution of the variable domain (VL) gene segments and somatic mutations on light chain cytotoxicity, organ tropism, and structure of the AL fibrils. Finally, we analyze the most recent advances in the development of computational algorithms to predict the role of somatic mutations in the cardiotoxicity of amyloidogenic light chains and discuss the challenges and perspectives that this approach faces.

PMID:37520549 | PMC:PMC10374031 | DOI:10.3389/fimmu.2023.1203425

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PubMed articles on: Cardio-Oncology

Reduction of Doxorubicin-Induced Cardiotoxicity by Co-Administration of Smart Liposomal Doxorubicin and Free Quercetin: In Vitro and In Vivo Studies

Pharmaceutics. 2023 Jul 11;15(7):1920. doi: 10.3390/pharmaceutics15071920.

ABSTRACT

Doxorubicin is one of the most effective chemotherapeutic agents; however, it has various side effects, such as cardiotoxicity. Therefore, novel methods are needed to reduce its adverse effects. Quercetin is a natural flavonoid with many biological activities. Liposomes are lipid-based carriers widely used in medicine for drug delivery. In this study, liposomal doxorubicin with favorable characteristics was designed and synthesized by the thin-film method, and its physicochemical properties were investigated by different laboratory techniques. Then, the impact of the carrier, empty liposomes, free doxorubicin, liposomal doxorubicin, and quercetin were analyzed in animal models. To evaluate the interventions, measurements of cardiac enzymes, oxidative stress and antioxidant markers, and protein expression were performed, as well as histopathological studies. Additionally, cytotoxicity assay and cellular uptake were carried out on H9c2 cells. The mean size of the designed liposomes was 98.8 nm, and the encapsulation efficiency (EE%) was about 85%. The designed liposomes were anionic and pH-sensitive and had a controlled release pattern with excellent stability. Co-administration of liposomal doxorubicin with free quercetin to rats led to decreased weight loss, creatine kinase (CK-MB), lactate dehydrogenase (LDH), and malondialdehyde (MDA), while it increased the activity of glutathione peroxidase, catalase, and superoxide dismutase enzymes in their left ventricles. Additionally, it changed the expression of NOX1, Rac1, Rac1-GTP, SIRT3, and Bcl-2 proteins, and caused tissue injury and cell cytotoxicity. Our data showed that interventions can increase antioxidant capacity, reduce oxidative stress and apoptosis in heart tissue, and lead to fewer complications. Overall, the use of liposomal doxorubicin alone or the co-administration of free doxorubicin with free quercetin showed promising results.

PMID:37514106 | PMC:PMC10385381 | DOI:10.3390/pharmaceutics15071920

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PubMed articles on: Cardio-Oncology

Cardioprotective Agents for the Primary Prevention of Trastuzumab-Associated Cardiotoxicity: A Systematic Review and Meta-Analysis

Pharmaceuticals (Basel). 2023 Jul 9;16(7):983. doi: 10.3390/ph16070983.

ABSTRACT

There are significant considerations about the prevention of cardiotoxicity caused by trastuzumab therapy in patients with breast cancer, leading to discontinuation. Recently, randomized controlled trials (RCTs) have evaluated the effects of early commitment of beta-blockers (BBs), angiotensin receptor blockers (ARBs) and angiotensin converting enzyme inhibitors (ACEIs) during trastuzumab chemotherapy in order to prevent the related cardiotoxicity. The present systematic review and meta-analysis of six RCTs included patients who have predominantly non-metastatic, HER2-positive, breast cancer and received trastuzumab as primary or adjuvant therapy. Those patients did not have any obvious cardiac dysfunction or any previous therapy with cardioprotective agent. We evaluated the efficacy of the aforementioned medications for primary prevention of cardiotoxicity, using random effects models. Any preventive treatment did not reduce cardiotoxicity occurrence compared to controls (Odds ratios (OR) = 0.92, 95% CI 0.54-1.56, p= 0.75). Results were similar for ACEIs/ARBs and beta-blockers. Treatment with ACEIs/ARBs led to a slight, but significant, increase in LVEF in patients compared to the placebo group. Only two studies reported less likelihood of discontinuation of trastuzumab treatment. More adequately powered RCTs are needed to determine the efficacy of routine prophylactic therapy.

PMID:37513895 | PMC:PMC10383255 | DOI:10.3390/ph16070983

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PubMed articles on: Cardio-Oncology

A Novel Bromophenol Compound from Leathesia nana Inhibits Breast Cancer in a Direct Tumor Killing and Immunotherapy Manner

Molecules. 2023 Jul 12;28(14):5349. doi: 10.3390/molecules28145349.

ABSTRACT

Considering the resistance and toxicity of traditional chemotherapeutic drugs, seeking potential candidate for treating breast cancer effectively is a clinical problem that should be solved urgently. Natural products have attracted extensive attention, owing to their multi-target advantages and low toxicity. In the current study, the effects of XK-81, a novel bromophenol compound extracted from Leathesia nana, on breast cancer, and its underlying mechanisms, were explored. Firstly, data from in vitro experiments indicated that 4T-1, one of common mouse breast cancer cell lines, was a XK-81-susceptible cell line, and ferroptosis was the major death manner in response to XK-81 treatment, which was evidenced by increasing intracellular Fe2+ and ROS level with condensed mitochondrial membrane densities, as well as decreasing the protein expressions of SLC7A11 and GPX4. In vivo, XK-81 suppressed the growth of 4T-1 breast-tumor in both BALB/C mice and zebrafish. Obviously, XK-81 decreased the protein expression of SLC7A11 and GPX4 in tumor tissues, hinting at the occurrence of ferroptosis. Moreover, XK-81 increased CD8+ T cells and NK cells numbers and regulated M1/M2 macrophage ratio in tumor tissues, indicating XK-81's immunotherapeutic effect. Additionally, the secretions of immune-related cytokines, including TNF-α, IL-1β, and IL-12, were elevated with XK-81 stimulation in RAW 264.7 cells. Intriguingly, compared with doxorubicin-induced heart damage, XK-81 demonstrated the therapeutic advantage of little cardiotoxicity on the heart. XK-81 demonstrated potential antitumor advantage by both directly inducing ferroptosis-mediated death of tumor cells and immunization.

PMID:37513222 | PMC:PMC10385854 | DOI:10.3390/molecules28145349

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PubMed articles on: Cardio-Oncology

Current Cardioprotective Strategies for the Prevention of Radiation-Induced Cardiotoxicity in Left-Sided Breast Cancer Patients

J Pers Med. 2023 Jun 24;13(7):1038. doi: 10.3390/jpm13071038.