Neutrophil Extracellular Traps Are Increased in Chronic Myeloid Leukemia and Are Differentially Affected by Tyrosine Kinase Inhibitors

Cardiovascular complications are increasingly reported with the use of certain tyrosine kinase inhibitors (TKIs) to treat chronic myeloid leukemia (CML). We studied neutrophil extracellular trap (NET) formation in CML and evaluated the effect of TKIs on NET formation. Neutrophils isolated from treatment-naïve patients with CML showed a significant increase in NET formation compared to matched controls at baseline and after stimulation with ionomycin (IO) and phorbol 12-myristate 13-acetate (PMA). Expression of citrullinated histone H3 (H3cit), peptidyl arginine deiminase 4 (PAD4) and reactive oxygen species (ROS) was significantly higher in CML samples compared to controls. Pre-treatment of neutrophils with TKIs was associated with a differential effect on NET formation, and ponatinib significantly augmented NET-associated elastase and ROS levels as compared to controls and other TKIs. BCR-ABL1 retroviral transduced HoxB8-immortalized mouse hematopoietic progenitors, which differentiate into neutrophils in-vitro, demonstrated increased H3cit & myeloperoxidase (MPO) expression consistent with excess NET formation. This was inhibited by Cl-amidine, a PAD4 inhibitor, but not by the NADPH inhibitor diphenyleneiodonium (DPI). Ponatinib pre-exposure significantly increased H3cit expression in HoxB8-BCR-ABL1 cells after stimulation with IO. In summary, CML is associated with increased NET formation, which is augmented by ponatinib, suggesting a possible role for NETs in promoting vascular toxicity in CML.

Real World Experience of the BTK Inhibitors. Comparing Cardiac, Vascular and Infectious Toxicities

Background: Cardiac and vascular toxicities are known complications on Bruton Tyrosine kinase inhibitor (BTKi)drugs. Ibrutinib, acalibrutinib and zanubrutinib are all approved BTKi drugs. We did a retrospective analysis on adverse effects (AE) of BTKi's that has been made available to public by the FDA. Methods: The FDA has made the data on AEs of various treatments available to general public through the FDA Adverse Events Reports System (FAERS) public dashboard. We investigated the infectious, cardiac and vascular AEs of various BTKi for the years 2019-2021. Results: The percentage of cardiac AE compared to total AEs reported for ibrutinib, acalibrutinib and zanubrutinib were 12%, 7.3% and 6.2% respectively. The most common cardiac toxicity was atrial fibrillation. The percentage of vascular AE compared to total AEs reported for ibrutinib, acalibrutinib and zanubrutinib were 8.2 %, 5.2 % and 3.9 % respectively. The most common vascular toxicity was hemorrhage. The percentage of infectious AE compared to total AEs reported for ibrutinib, acalibrutinib and zanubrutinib were 18.3%, 13.6% and 35.5% respectively. The most common vascular toxicity was pneumonia. Conclusions: Out of the reported cases of AEs to BTKis approved, ibrutinib have most and acalibrutinib have least cardiac AEs. Zanubrutinib has least vascular AEs. Out of the reported cases of AEs to BTKis approved, zanubrutinib have most infectious AEs. Disclosures Master: Blue Bird Bio: Current holder of individual stocks in a privately-held company.

Cisplatin, environmental metals, and cardiovascular disease: an urgent need to understand underlying mechanisms

Significantly increased risks of cardiovascular disease occur in testicular cancer survivors given cisplatin-based chemotherapy. The postulated mechanism of platinum-based chemotherapy’s vascular toxicity has been thought secondary to its different early- and late- effects on vascular injury, endothelial dysfunction, and induction of a hypercoagulable state. We highlight for the first time the similarities between platinum-associated vascular adverse events and the vascular toxicity associated with other xenobiotic-metal contaminants. The vascular toxicity seen in large epidemiologic studies of testicular cancer survivors may in part be similar and mechanistically linked to the risk seen in environmental heavy metal contaminants linked to cardiovascular disease. Future research should be directed to better understand the magnitude of the adverse cardiovascular effects of platinum and to elucidate the underlying mechanisms of action.

Breast cancer chemotherapy vascular toxicity: A review of mediating mechanisms and exercise as a potential therapeutic

Breast cancer chemotherapy, although very potent against tumour tissue, results in significant cardiovascular toxicity. The focus of research in this area has been predominantly towards cardiotoxicity. There is limited evidence detailing the impact of such treatment on the vasculature despite its central importance within the cardiovascular system and resultant detrimental effects of damage and dysfunction. This review highlights the impact of chemotherapy for breast cancer on the vascular endothelium. We consider the most likely mechanisms of endothelial toxicity to be through direct damage and dysfunction of the endothelium. There are sharp consequences of these detrimental effects as they can lead to cardiovascular disease. However, there is potential for exercise to alleviate some of the vascular toxicity of chemotherapy, and the evidence for this is provided. The potential role of exercise in protecting against vascular toxicity is explained, highlighting the recent in-human and animal model exercise interventions. Lastly, the mediating mechanisms of exercise protection of endothelial health is discussed, focusing on the importance of exercise for endothelial health, function, repair, inflammation and hyperlipidaemia, angiogenesis, and vascular remodelling. These are all important counteracting measures against chemotherapy-induced toxicity and are discussed in detail.

G-CSF and G-CSF-related vasculitis: a systematic review of the literature and intriguing future research perspectives

Background: There are several case reports suggesting that G-CSFs may, in rare conditions, produce serious side effects, such as vasculitis. Materials & methods: A systematic search was conducted in Medline via PubMed, Embase and Cochrane Library to describe this unusual side effect to raise awareness among clinicians for early recognition and treatment. Results: Fifty-seven patients were analyzed. The most prevalent cancer type was breast cancer (47%). Long-acting G-CSF was used in 38 patients (67%). Only 47% of patients were treated with steroids. Conclusion: Although the benefit of G-CSF treatment outweighs the potential damage, oncologists should consider the possibility of triggering a vascular toxicity and try to identify patients at increased risk for this side effect.

Updates on Anticancer Therapy-Mediated Vascular Toxicity and New Horizons in Therapeutic Strategies

Vascular toxicity is a frequent adverse effect of current anticancer chemotherapies and often results from endothelial dysfunction. Vascular endothelial growth factor inhibitors (VEGFi), anthracyclines, plant alkaloids, alkylating agents, antimetabolites, and radiation therapy evoke vascular toxicity. These anticancer treatments not only affect tumor vascularization in a beneficial manner, they also damage ECs in the heart. Cardiac ECs have a vital role in cardiovascular functions including hemostasis, inflammatory and coagulation responses, vasculogenesis, and angiogenesis. EC damage can be resulted from capturing angiogenic factors, inhibiting EC proliferation, survival and signal transduction, or altering vascular tone. EC dysfunction accounts for the pathogenesis of myocardial infarction, atherothrombosis, microangiopathies, and hypertension. In this review, we provide a comprehensive overview of the effects of chemotherapeutic agents on vascular toxicity leading to hypertension, microvascular rarefaction thrombosis and atherosclerosis, and affecting drug delivery. We also describe the potential therapeutic approaches such as vascular endothelial growth factor (VEGF)-B and prokineticin receptor-1 agonists to maintain endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor effectiveness.

Ameliorative Effects of Quercetin in Cyclophosphamide-Induced Vascular Toxicity in Rats

Cyclophosphamide (CYP) causes vascular toxicity and endothelial damage. In this study aimed the determination of the protective effects of Quercetin (Q) in the CYP-induced vascular toxicity in rats. The rats were randomly divided into the following five groups: Control, CYP, Q50+CYP, Q100+CYP and Q100. The control group was given intragastric (i.g.) corn oil for seven days. The CYP group received i.g. corn oil for seven days and a single dose (200 mg/kg) of CYP via intraperitoneal (i.p.) injection on the seventh day. The rats in the three Q-treated groups received Q for seven days. On the seventh day after the Q treatment, the Q50+CYP, and Q100+CYP groups were injected to single dose (200 mg/kg, i.p.) of CYP. The CYP-treatment both worsen the Phenylephrine (PE)-induced contractions and acetylcholine (ACh)-induced relaxation responses in isolated thoracic aorta of rats, and the application of Q corrected these responses. The malondialdehyde (MDA) levels were significantly higher in the CYP-treated groups. The both dose of Q decreased the MDA level. Superoxide dismutase (SOD) and glutathione (GSH) activities were significantly decreased in the CYP group, whereas the high dose of Q increased SOD and GSH activities. Q treatment attenuated CYP-induced pathologies, and endothelial damage. According to results, Q has protective effects against CYP-induced vascular toxicity in rats.